Organic light emitting display device and driving method thereof
Claim Score by NHIP
Abstract
The present invention has been made in an effort to provide an organic light emitting display device comprising a panel; a power supply supplying power to the panel; a current detection unit detecting a current flowing through power line wiring of the panel and outputting the detected current; and a power controller comparing the detected current with a current value configured internally and outputting a shutdown signal which turns off the power supply if the detected current exceeds the predetermined current value.

Term
6.3 yearsto projected expiry
Projected expiry 11 January 2033, counted from filing; an application has no term until it is granted.
- Priority and filed
- Published
- Today
- Projected expiry
20 claims: 4 independent, 16 dependent
- 1Broadest claimClaim Score 74, broad(NHIP)An organic light emitting display device, comprising:a panel;a driving unit driving the panel;a timing controller controlling the driving unit;a power supply supplying power to the panel;a current detection unit detecting a current flowing through power line wiring of the panel and outputting the detected currents;and An a power controller comparing the detected current with a current value configured internally and outputting a shutdown signal which turns off the power supply if the detected current exceeds the predetermined current value.
- 7An organic light emitting display device, comprising:a panel including power line wiring wired up for individual blocks;a driving unit driving the panel;a timing controller controlling the driving unit;a power supply supplying power to the panel;a current detection unit detecting a current flowing through the power line wiring of each block and outputting the detected current of the block;and a power controller comparing detected currents of the individual blocks with each other and outputting a shutdown signal which turns off the power supply if a current higher or lower than the currents of the other blocks is detected.
- 13An organic light emitting display device, comprising:a panel;a driving unit driving the panel;a power supply supplying power to the panel;a compensation voltage supply supplying a compensation voltage to the panel;a voltage sensing unit sensing the compensation voltage output from the compensation voltage supply and comparing the compensation voltage with an internally set threshold voltage and outputting a result value;and a timing controller controlling the driving unit and outputting a shutdown signal for turning off the power supply based on the result value.
- 18An organic light emitting display device, comprising:a panel including power line wiring wired up for individual blocks;a driving unit driving the panel;a power supply supplying power through the power line wiring wired up for individual blocks;a current sensing unit sensing a current flowing through the power line wiring wired up for individual blocks and amplifying the sensed currents of the individual blocks into the corresponding analog voltages and outputs the analog voltages;an analog-to-digital converter converting the analog voltage of each block provided from the current sensing unit into the corresponding digital voltage and outputting the digital voltage;and a timing controller controlling the driving unit and determining occurrence of an overcurrent by using the digital voltage of each block provided from the analog-to-digital converter and outputting a shutdown signal for turning off the power supply in the event of the overcurrent.
Independent claims4
201 paragraphs in 4 sections, as filed
0001This application claims the benefit of Korean Patent Application No. 10-2012-0106563 filed on Sep. 25, 2012 and 10-2012-0106565 filed on Sep. 25, 2012. The contents of all of these applications are hereby incorporated by reference.
BACKGROUND
00021. Field
0003This document relates to an organic light emitting display device and a driving method of the device.
00042. Related Art
0005An organic light emitting element used for an organic light emitting display device refers to a self-light emitting element in which a light emitting layer is formed between two electrodes on the substrate of the device. Organic light emitting display devices are classified into top-emission type, bottom-emission type, dual-emission type, and so on according to a direction along which light is emitted. Alternatively, organic light emitting devices can be divided into passive matrix type and active matrix type according to a driving method employed.
0006A sub-pixel disposed in an organic light emitting display panel comprises a transistor unit including a switching transistor, a driving transistor, and a capacitor; and an organic light emitting diode including a lower electrode connected to the driving transistor included in the transistor unit, an organic light emitting layer; and an organic light emitting diode including a upper electrode.
0007An organic light emitting display panel exhibits light intensity varying in proportion to the amounts of a current flowing through the organic light emitting diode. Since organic light emitting display panels require a large amount of current compared with liquid crystal display panels, in the event of short circuit at power terminals, an excessive amount of current flows into the elements of the respective sub-pixels. Various factors cause short circuit at power terminals, which include not only internal, structural factors such as particles introduced into the organic light emitting display panel during a manufacturing process (or a module process), cracks, misalignment of pad units, and narrow wiring layout but also external factors such as static electricity.
0008If an excessive current flows into a sub-pixel due to short circuit at power terminals, elements of the corresponding sub-pixel are burnt out. Burning out in a small region may not be perceived at its early stage but neighboring sub-pixels are gradually burnt out as the organic light emitting display panel continues to operate.
0009In this respect, there are high chances short circuit at power terminals burns out sub-pixels of an organic light emitting display panel and subsequently leads to a fire; therefore, a means for preventing short circuit has to be provided.
SUMMARY
0010The present invention has been made in an effort to provide an organic light emitting display device comprising a panel; a driving unit driving the panel; a timing controller controlling the driving unit; a power supply supplying power to the panel; a current detection unit detecting a current flowing through power line wiring of the panel and outputting the detected current; and a power controller comparing the detected current with a current value configured internally and outputting a shutdown signal which turns off the power supply if the detected current exceeds the predetermined current value.
0011Another aspect of the present invention provides an organic light emitting display device comprising a panel including power line wiring wired up for individual blocks; a driving unit driving the panel; a timing controller controlling the driving unit; a power supply supplying power to the panel; a current detection unit detecting a current flowing through the power line wiring of each block and outputting the detected current of the block; and a power controller comparing detected currents of the individual blocks with each other and outputting a shutdown signal which turns off the power supply if a current higher or lower than the currents of the other blocks is detected.
BRIEF DESCRIPTION OF THE DRAWINGS
0012The accompany drawings, which are included to provide a further understanding of the invention and are incorporated on and constitute a part of this specification illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
0013<figref idref="DRAWINGS">FIG. 1</figref> is a block diagram of an organic light emitting display device according to the present invention;
0014<figref idref="DRAWINGS">FIG. 2</figref> is a circuit diagram of a sub-pixel;
0015<figref idref="DRAWINGS">FIG. 3</figref> is a block diagram of a power supply controller according to a first embodiment of the present invention;
0016<figref idref="DRAWINGS">FIG. 4</figref> is a first circuit diagram illustrating a power controller;
0017<figref idref="DRAWINGS">FIG. 5</figref> is a second circuit diagram illustrating a power controller;
0018<figref idref="DRAWINGS">FIG. 6</figref> is a waveform diagram illustrating operation of a power controller and a power supply in response to a blank interval;
0019<figref idref="DRAWINGS">FIG. 7</figref> is a waveform diagram illustrating operation of a power controller and a power supply in response to an interval for which sensing data are provided;
0020<figref idref="DRAWINGS">FIG. 8</figref> illustrates output states of a power supply according to a comparison result between a detected current value and a configured current value;
0021<figref idref="DRAWINGS">FIG. 9</figref> is a block diagram of a power supply controller according to a modified example of a first embodiment;
0022<figref idref="DRAWINGS">FIG. 10</figref> illustrates an organic light emitting display device implemented according to a first embodiment of the present invention;
0023<figref idref="DRAWINGS">FIG. 11</figref> is a flow diagram illustrating a method for operating an organic light emitting display device according to a first embodiment of the present invention;
0024<figref idref="DRAWINGS">FIG. 12</figref> is a block diagram of a power supply controller according to a second embodiment;
0025<figref idref="DRAWINGS">FIG. 13</figref> illustrates output states of a power supply according to a comparison result between detected currents of individual blocks;
0026<figref idref="DRAWINGS">FIG. 14</figref> illustrates an organic light emitting display device implemented according to a second embodiment of the present invention;
0027<figref idref="DRAWINGS">FIG. 15</figref> is a flow diagram illustrating a method for operating an organic light emitting display device according to a second embodiment of the present invention;
0028<figref idref="DRAWINGS">FIG. 16</figref> is a block diagram of an organic light emitting display device according to a third embodiment of the present invention;
0029<figref idref="DRAWINGS">FIG. 17</figref> is a first example of a compensation voltage supply;
0030<figref idref="DRAWINGS">FIG. 18</figref> is a second example of a compensation voltage supply;
0031<figref idref="DRAWINGS">FIG. 19</figref> is a circuit diagram of a sub-pixel;
0032<figref idref="DRAWINGS">FIG. 20</figref> is an example of a compensation circuit of <figref idref="DRAWINGS">FIG. 19</figref>;
0033<figref idref="DRAWINGS">FIG. 21</figref> is a driving waveform diagram of a sub-pixel of <figref idref="DRAWINGS">FIG. 20</figref>;
0034<figref idref="DRAWINGS">FIG. 22</figref> is a block diagram implementing a circuit according to a third embodiment of the present invention;
0035<figref idref="DRAWINGS">FIG. 23</figref> is a circuit diagram of a compensation voltage supply and a voltage sensing unit of <figref idref="DRAWINGS">FIG. 22</figref>;
0036<figref idref="DRAWINGS">FIG. 24</figref> illustrates an organic light emitting display device implemented by using constituting elements according to a third embodiment of the present invention;
0037<figref idref="DRAWINGS">FIG. 25</figref> illustrates a maximum and a minimum level of a reference voltage;
0038<figref idref="DRAWINGS">FIG. 26</figref> illustrates an allowable range of a reference voltage;
0039<figref idref="DRAWINGS">FIG. 27</figref> illustrates output states of a power supply according to a shutdown signal;
0040<figref idref="DRAWINGS">FIG. 28</figref> is a flow diagram illustrating a method for operating an organic light emitting display device according to a third embodiment of the present invention;
0041<figref idref="DRAWINGS">FIG. 29</figref> is a block diagram of an organic light emitting display device according to a fourth embodiment of the present invention;
0042<figref idref="DRAWINGS">FIG. 30</figref> illustrates a current sensing unit and an analog-to-digital converter of <figref idref="DRAWINGS">FIG. 29</figref>;
0043<figref idref="DRAWINGS">FIG. 31</figref> is a circuit diagram of a current sensing unit of a first block of <figref idref="DRAWINGS">FIG. 30</figref>;
0044<figref idref="DRAWINGS">FIG. 32</figref> is a block diagram of an analog-to-digital converter, a timing controller, and a power supply;
0045<figref idref="DRAWINGS">FIG. 33</figref> is a waveform diagram illustrating operation of an analog-to-digital converter in response to a blank interval;
0046<figref idref="DRAWINGS">FIGS. 34 and 35</figref> illustrate output states of a power supply according to a decision of a timing controller; and
0047<figref idref="DRAWINGS">FIG. 36</figref> is a flow diagram illustrating a method for operating an organic light emitting display device according to a fourth embodiment of the present invention.
DETAIL DESCRIPTION OF THE INVENTION
0048Reference will now be made in detail embodiments of the invention examples of which are illustrated in the accompanying drawings.
0049In what follows, preferred embodiments of the present invention will be described in detail with reference to appended drawings.
First Embodiment
0050As shown in <figref idref="DRAWINGS">FIGS. 1 and 2</figref>, an organic light emitting display device comprises an image processing unit <b>120</b>, a power supply <b>125</b>, a timing controller <b>130</b>, a data driving unit <b>150</b>, a scan driving unit <b>140</b>, a panel <b>160</b>, a current detection unit <b>170</b>, and a power controller <b>180</b>.
0051An image processing unit <b>120</b> provides a timing controller <b>130</b> with a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable signal (DE), a clock signal (CLK), and a data signal (DATA). The image processing unit <b>120</b> is formed in a system board <b>110</b>.
0052The timing controller <b>130</b> controls an operation timing of the data driving unit <b>150</b> and the scan driving unit <b>140</b> by using timing signals such as the vertical synchronization signal (Vsync), the horizontal synchronization signal (Hsync), the data enable signal (DE), and the clock signal (CLK). Since the timing controller <b>130</b> is capable of determining a frame interval by counting the data enable signal (DE) during one horizontal interval, the vertical synchronization signal (Vsync) and the horizontal synchronization signal (Hsync) provided from the outside can be omitted. Control signals generated at the timing controller <b>130</b> include a gate timing control signal (GDC) for controlling the operational timing of the scan driving unit <b>140</b> and a data timing control signal (DDC) for controlling the operational timing of the data driving unit <b>150</b>. The gate timing control signal (GDC) includes a gate start pulse, a gate shift clock, and a gate output enable signal. The data timing control signal (DDC) includes a source start pulse, a source sampling clock, and a source output enable signal.
0053The scan driving unit <b>140</b> shifts the level of a gate driving voltage in response to the gate timing control signal (GDC) provided from the timing controller <b>130</b> and generates a scan signal in a sequential manner. The scan driving unit <b>140</b> provides a scan signal through scan lines (SL) connected to sub-pixels (SPs) included in the panel <b>160</b>.
0054The data driving unit <b>150</b> performs sampling of the data signal (DATA) provided from the timing controller <b>130</b> in response to the data timing control signal (DDC) provided from the timing controller <b>130</b> and latches on the sampled data signal and transforms the latched, sampled data signal into the data of a parallel data system. The data driving unit <b>150</b> transforms the data signal (DATA) into a gamma reference voltage. The data driving unit <b>150</b> provides the data signal (DATA) through the data lines (DLs) connected to sub-pixels (SPs) included in the panel <b>160</b>.
0055The panel <b>160</b> comprises sub-pixels disposed in the form of a matrix. Sub-pixels consist of red, green, and blue sub-pixels; in some cases, white sub-pixels are included. A panel <b>160</b> incorporating white sub-pixels can emit white light even if light emitting layers of individual sub-pixels do not emit red, green, and blue light. In this case, the white light is converted into red, green, and blue light by an RGB color filter.
0056Meanwhile, sub-pixels included in the panel <b>160</b> may be comprised as shown in <figref idref="DRAWINGS">FIG. 2</figref>. One sub-pixel comprises a switching transistor SW, a driving transistor DR, a capacitor Cst, a compensation circuit CC, and an organic light emitting diode D. The switching transistor (SW) performs a switching operation in such a way that a data signal provided through a first data line DL<b>1</b> in response to a scan signal provided through a first scan line SL<b>1</b> is stored in the capacitor as a data voltage. The driving transistor DR operates to have a driving current flow between a first power line wiring VDD and the ground GND. The compensation circuit CC compensates for a threshold voltage of the driving transistor DR. The compensation circuit CC comprises one or more transistor and capacitor. The compensation circuit CC can be implemented in various ways; specific descriptions and examples of the compensation circuit are not provided furthermore. The organic light emitting diode D operates to emit light according to a driving current developed by the driving transistor DR.
0057One sub-pixel is formed to have a 2T (Transistor) 1C (Capacitor) structure comprising a switching transistor SW, a driving transistor DR, a capacitor Cst, and an organic light emitting diode D. In case a compensation circuit CC is further incorporated, the sub-pixel may form a 3T1C, 4T2C, or 5T2C structure. A sub-pixel having the structure above can form a top-emission type, bottom-emission type, or dual-emission type depending on a structure employed.
0058The power supply <b>125</b> converts an external voltage supplied from the outside into a first voltage (for example, 20 V level), a second voltage (for example, 3.3V level), and a low voltage (for example, 0 V level), and so on. The first voltage, being supplied to a first power line wiring VDD, is a drain level voltage; the second voltage, being supplied to a second power line wiring VCC, is a collector level voltage; and the low level voltage is supplied to the ground GND and is a base level voltage. The power supply <b>125</b> is formed in the system board <b>110</b> together with the image processing unit <b>120</b>. The output voltage of the power supply <b>125</b> is used for the image processing unit <b>120</b>, the timing controller <b>130</b>, the data driving unit <b>150</b>, the scan driving unit <b>140</b>, and the panel <b>160</b>.
0059The current detection unit <b>170</b> detects a current flowing into the panel <b>160</b> through the first power line wiring VDD and outputs the detected current. The current detection unit <b>170</b> detects a current flowing into the panel <b>160</b> through the first power line wiring VDD and provides the detected current to the power controller <b>180</b>. The current detection unit <b>170</b> can be realized with conventional OP amps and the detected current may be an analog value but the present invention is not limited to the above.
0060The power controller <b>180</b> generates a shutdown signal SDS according to a current detected by the current detection unit <b>170</b>. The power controller <b>180</b> outputs the shutdown signal SDS when the detected current reaches an overcurrent, thereby turning off the power supply <b>125</b>. In other words, the whole output of the power supply <b>125</b> is shut down.
0061The current detection unit <b>170</b> and the power controller <b>180</b> described earlier comprise a short detection circuit which detects occurrence of short circuit at the power supply and in the event of short circuit, turns off the power supply <b>125</b>. Various factors cause short circuit at power terminals, which include not only internal, structural factors such as particles introduced into the panel <b>160</b> during manufacturing process (or module process), cracks, misalignment of pad units, and narrow wiring layout; but also external factors such as static electricity.
0062If an excessive current flows into a sub-pixel due to short circuit at power terminals, elements of the corresponding sub-pixel are burnt out. Burning out in a small region may not be perceived at its early stage but neighboring sub-pixels are gradually burnt out as the panel <b>160</b> continues to operate. To prevent the above problem, the short detection circuit controls the power supply <b>125</b> in such a way to remove the possibility of generating a fire at the panel <b>160</b>, where specific descriptions thereof are given below.
0063In this respect, there are high chances short circuit at power terminals burns out sub-pixels of an organic light emitting display panel and subsequently leads to a fire; therefore, a means for preventing the short circuit has to be provided.
0064In what follows, an organic light emitting display device according to the present invention will be described in more detail.
First Embodiment
0065As shown in <figref idref="DRAWINGS">FIG. 3</figref>, the circuit for controlling the power supply <b>125</b> comprises a timing controller <b>130</b>, a current detection unit <b>170</b>, and a power controller <b>180</b>.
0066The current detection unit <b>170</b> detects a current flowing through a first power line wiring VDD and supplies the detected current to the power controller <b>180</b>. The current detection unit <b>170</b> detects a current flowing through the first power line wiring VDD periodically or aperiodically. If the current detection unit <b>170</b> detects a current flowing through the first power line wiring VDD regularly and it is not controlled by a particular device, it can be implemented by using OP amps. On the other hand, if the current detection unit <b>170</b> detects a current flowing aperiodically through the first power line wiring VDD and it is controlled by a particular device, it can be implemented by using OP amps and switches. In this case, a switch detects a current in accordance with a control signal. Meanwhile, the current detection unit <b>170</b> may further comprise an analog-to-digital converter according to the structure of the power controller. At this time, the analog-to-digital converter converts an analog current value to a digital current value and displays the converted current.
0067The timing controller <b>130</b> provides a sensing signal SS to the power controller <b>180</b>. The timing controller <b>130</b> can not only provide a panel with sensing data through a data driving unit periodically but also provide the power controller <b>180</b> with the sensing signal SS in order for the power controller <b>180</b> to operate in synchronization with a timing at which the sensing data is displayed. On the other hand, the timing controller <b>130</b> can provide the sensing signal SS to the power controller <b>180</b> in order for the power controller <b>180</b> to operate for blank intervals excluding an image display interval of the panel.
0068The power controller <b>180</b> receives a detected current from the current detection unit <b>170</b> and compares the detected current with an internally set current value. If the detected current exceeds the specified current value, a shutdown signal SDS is output and turns off the power supply <b>125</b>.
0069Meanwhile, if a physical distance between the power supply <b>125</b> and the power controller <b>180</b> is rather long (in other words, in case a transmission path is long or a transmission method is different), the strength of the shutdown signal SDS output from the power controller <b>180</b> may be weakened. Similarly, due to a difference between the circuit of the power controller <b>180</b> and that of the power supply <b>125</b>, logic level of the shutdown signal SDS may be changed. To compensate for this change, the power controller <b>180</b> may be comprised as described below.
0070As shown in <figref idref="DRAWINGS">FIGS. 4 and 5</figref>, the power controller comprises an analysis unit <b>181</b> and a shutdown signal generation unit <b>185</b>. At this time, the analysis unit <b>181</b> and the shutdown signal generation unit <b>185</b> can be formed in the same board together with the timing controller. Similarly, the analysis unit <b>181</b> may be formed in the same board together with the timing controller while the shutdown signal generation unit <b>185</b> may be formed in the same board together with the power supply <b>125</b>.
0071The analysis unit <b>181</b> receives a detected current value from the current detection unit <b>170</b> and compares the detected current value with an internally set current value and outputs a digital pulse if the values are different from each other. The shutdown signal generation unit <b>185</b> generates a shutdown signal SDS by using a digital pulse output from the analysis unit <b>181</b>.
0072As an example, the shutdown generation unit <b>185</b> comprises a resistor Rs and a transistor TFT as shown in <figref idref="DRAWINGS">FIG. 4</figref>. One end of the resistor Rs is connected to a second power line wiring VCC (which can be connected to the first power line wiring VDD, too) and the other end is connected to a first electrode (for example, a drain) of the transistor TFT. The gate electrode of the transistor TFT is connected to a digital pulse output port of the analysis unit <b>181</b>; the first electrode is connected to the other end of the resistor Rs and a signal input port of the power supply <b>125</b>; and a second electrode (for example, a source) is connected to the ground wiring GND.
0073As can be shown from <figref idref="DRAWINGS">FIG. 4</figref>, since the transistor TFT maintains a turn-off state when the digital pulse output from the analysis unit <b>181</b> is a logic low level, a shutdown signal SDS corresponding to the level of a second voltage provided to the second power line wiring VCC is output. Meanwhile, if the digital pulse output from the analysis unit <b>181</b> is a logic high level, the transistor TFT maintains a turn-on state and a shutdown signal SDS corresponding to the level of a low voltage provided to the ground wiring GND is output.
0074For example, if the power supply <b>125</b> is turned off by the shutdown signal SDS corresponding to the logic low level, the power supply <b>125</b> is turned off even if the digital pulse output from the analysis unit <b>181</b> becomes the logic high level. Different from the above example, if the power supply <b>125</b> is turned off by the shutdown signal SDS corresponding to the logic high level, the power supply is turned off even if the digital pulse output from the analysis unit <b>181</b> becomes the logic low level. At this time, it should be noted that even if level of the digital pulse output from the analysis unit <b>181</b> changes, it is compensated by the transistor TFT constituting the shutdown signal generation unit <b>185</b> and a power supply connected to the transistor TFT.
0075As another example, the shutdown signal generation unit <b>185</b> comprises a NAND gate (or an inverter), a resistor Rs, and a transistor TFT, as shown in <figref idref="DRAWINGS">FIG. 5</figref>. Two input ports of the NAND gate are connected to a digital pulse output port of the analysis unit <b>181</b> and the output of the NAND gate is connected to the gate electrode of the transistor TFT. One end of the resistor Rs is connected to a second power line wiring VCC (which can be connected to the first power line wiring VDD, too) and the other end is connected to a first electrode (for example, the drain) of the transistor TFT. The gate electrode of the transistor TFT is connected to the output port of the NAND gate; the first electrode is connected to the other end of the resistor Ts and a signal input port of the power supply <b>125</b>; and the second electrode (for example, the source) is connected to the ground wiring GND.
0076As can be shown from <figref idref="DRAWINGS">FIG. 5</figref>, since the transistor TFT maintains a turn-off state when the digital pulse output from the analysis unit <b>181</b> is a logic high level, a shutdown signal SDS corresponding to the level of a second voltage provided to the second power line wiring VCC is generated. Meanwhile, if the digital pulse output from the analysis unit <b>181</b> is a logic low level, the transistor TFT maintains a turn-on state and a shutdown signal SDS corresponding to the level of a low voltage provided to the ground wiring GND is generated.
0077For example, if the power supply <b>125</b> is turned off by the shutdown signal SDS corresponding to the logic low level, the power supply <b>125</b> is turned off even if the digital pulse output from the analysis unit <b>181</b> becomes the logic low level. Different from the above example, if the power supply <b>125</b> is turned off by the shutdown signal SDS corresponding to the logic high level, the power supply is turned off even if the digital pulse output from the analysis unit <b>181</b> becomes the logic high level. At this time, it should be noted that even if level of the digital pulse output from the analysis unit <b>181</b> changes, it is compensated by the transistor TFT constituting the shutdown signal generation unit <b>185</b> and a power supply connected to the transistor TFT.
0078The configurations shown in <figref idref="DRAWINGS">FIGS. 4 and 5</figref> described above are valid when the transmission path (in other words, an interface) between the analysis unit <b>181</b> and shutdown signal generation unit <b>185</b> employs the miniLVDS interface.
0079In what follows, operation states of the power controller <b>180</b> and the power supply <b>125</b> according to control of the timing controller will be described.
0080As shown in <figref idref="DRAWINGS">FIGS. 1 to 8</figref>, the timing controller <b>130</b> provides a sensing signal SS to the power controller <b>180</b> in order for the power controller <b>180</b> to operate in the blank intervals VB excluding the image display interval (1 frame) of the panel <b>160</b>. The blank interval VB refers to a vertical blank formed between vertical synchronization signals Vsync identifying frames. The “DE” not explained refers to a data enable signal and “DATA” refers to a data signal output from the timing controller <b>130</b>.
0081While maintaining the sensing signal SS at logic low during the image display interval (1 frame), the timing controller <b>130</b> converts the sensing signal SS to logic high H during the blank interval VB. The power controller <b>180</b> can determine whether the current detection unit <b>170</b> detects an overcurrent in response to the sensing signal SS of logic high H. At this time, a criterion for determining the occurrence of an overcurrent, as described earlier, employs a method of comparing a detected current with an internally set current value.
0082If a detected current value corresponds to “Ab(A)” which is larger than a predetermined current value “N(A)”, it indicates an abnormal state where an overcurrent is detected and the power controller <b>180</b> outputs a shutdown signal SDS. Since the power supply <b>125</b> is turned off in response to the shutdown signal SDS, an output voltage of the output port Vout of the power supply is cut off. On the other hand, if a detected current value is similar to or the same as the predetermined current value “N(A)”, it indicates a normal state where an overcurrent is not detected and the power supply <b>125</b> outputs an output voltage through the output port Vout.
0083Meanwhile, in case the current detection unit <b>170</b> consists only of passive elements, the current detection unit <b>170</b> continuously detects and outputs a current flowing through the power line wiring VDD, independently of the sensing signal SS driving the power controller <b>180</b>. However, in case the current detection unit <b>170</b> comprises active and passive elements at the same time, the current detection unit <b>170</b>, in the same manner as the power controller <b>180</b>, detects and outputs a current flowing through the power line wiring VDD for a blank interval excluding the image display interval (1 frame) of the panel.
0084As described above, in case the timing controller <b>130</b> outputs a sensing signal SS driving the power controller <b>180</b> only for the blank interval VB, a current value detection time is very short compared with “T2” as can be seen from the period of “T1”. Therefore, instead of generating a one-off sensing signal SS driving the power controller <b>180</b>, the timing controller <b>130</b> may generate continuously N (where N is an integer two or more) sensing signals SS<b>1</b>, SS<b>2</b> driving the power controller <b>180</b> for each blank interval VB.
0085The timing controller <b>130</b> not only periodically provides the panel <b>160</b> through the data driving unit <b>150</b> with sensing data stored internally but also provides a sensing signal SS to the power controller <b>180</b> in order for the power controller <b>180</b> to operate in synchronization with a timing at which the sensing data is displayed. Sensing data has been described with reference to black data representing a black color but is not limited to the above, which may comprise data requiring a small amount of data for image display. For example, sensing data can be displayed when a screen protector is used, a screen protector is displayed on the panel <b>160</b>, or the whole image displayed on the panel <b>160</b> is converted into another image but the present invention is not limited to the above examples.
0086The timing controller <b>130</b> maintains the sensing signal SS at logic low L during an image display interval (1 frame) but converts the sensing signal SS to logic high H during which the sensing data such as black data is displayed. The power controller <b>180</b> can detect whether a current value corresponding to an overcurrent has occurred from the current detection unit <b>170</b> in response to the sensing signal SS of logic high H. At this time, a criterion for determining the occurrence of an overcurrent, as described earlier, employs a method of comparing a detected current with an internally set current value.
0087If a detected current value corresponds to “Ab(A)” which is larger than a predetermined current value “N(A)”, it indicates an abnormal state where an overcurrent is detected and the power controller <b>180</b> outputs a shutdown signal SDS. Since the power supply <b>125</b> is turned off in response to the shutdown signal SDS, an output voltage of the output port Vout of the power supply is cut off. On the other hand, if a detected current value is similar to or the same as the predetermined current value “N(A)”, it indicates a normal state where an overcurrent is not detected and the power supply <b>125</b> outputs an output voltage through the output port Vout.
0088Meanwhile, in case the current detection unit <b>170</b> consists only of passive elements, the current detection unit <b>170</b> continuously detects and outputs a current flowing through the power line wiring VDD, independently of the sensing signal SS driving the power controller <b>180</b>. However, in case the current detection unit <b>170</b> comprises active and passive elements at the same time, the current detection unit <b>170</b>, in the same manner as the power controller <b>180</b>, detects and outputs a current flowing through the power line wiring VDD for an interval during which sensing data such as black data is displayed on the panel <b>160</b>.
0089As described above, in case the timing controller <b>130</b> outputs a sensing data and a sensing signal SS operating the power controller <b>180</b> in synchronization with a timing at which the sensing data is displayed, as can be noticed from the period of “T2”, an advantageous effect is obtained that a current value detection time becomes long compared with “T1”.
0090As shown in <figref idref="DRAWINGS">FIG. 9</figref>, a circuit controlling the power supply <b>125</b> comprises a timing controller <b>130</b>, a current detection unit <b>170</b>, and a power controller <b>180</b>. A power controller <b>180</b> according to a modified example includes an inverter INV between the timing controller <b>130</b> and the power controller <b>180</b>.
0091Although the structure of <figref idref="DRAWINGS">FIG. 3</figref> assumes that the timing controller <b>130</b> generates a separate sensing signal SS, the structure of <figref idref="DRAWINGS">FIG. 9</figref> can be used when the timing controller <b>130</b> is equipped with a port generating a vertical synchronization signal Vsync. The inverter INV inverts the vertical synchronization signal Vsync and outputs a logic high level during the “VB” interval of <figref idref="DRAWINGS">FIG. 6</figref>. Therefore, the structure of <figref idref="DRAWINGS">FIG. 9</figref>, by employing the inverter NV, can control the power controller <b>180</b> and the power supply <b>125</b> as shown in <figref idref="DRAWINGS">FIG. 6</figref>.
0092Meanwhile, the method as shown in <figref idref="DRAWINGS">FIG. 9</figref> controls the power controller <b>180</b> and the power supply <b>125</b> during the “VB” interval. When the timing controller <b>130</b> does not have an output port for the vertical synchronization signal Vsync, a data enable signal DE output from the timing controller <b>130</b> may be utilized. To this purpose, a counter circuit may be installed between the timing controller <b>130</b> and the power controller <b>180</b> instead of the inverter INV; the enable signal DE is counted by using the counter circuit; and the “VB” interval is detected and used as the sensing signal SS.
0093The first embodiment described above can be applied to the structure where the first power line wiring VDD in the panel <b>160</b> is connected to each other. The first embodiment can be implemented by employing an organic light emitting display device as described below.
0094As shown in <figref idref="DRAWINGS">FIG. 10</figref>, a plurality of scan driving units <b>140</b> are formed in a non-display area NA located at the outer periphery of a display area AA of the panel <b>160</b>. The scan driving unit <b>140</b> is formed in the panel <b>160</b> in the form of a gate-in panel along with a transistor process for sub-pixels. The data driving unit <b>150</b> is implemented in the form of a plurality (for example, four) of integrated circuits (ICs) and installed on a plurality (for example, four) of flexible printed circuit boards <b>155</b>; one end of the data driving unit <b>150</b> is attached to a pad unit of the panel <b>160</b> by employing the FOG method and the other end is attached to a plurality (for example, two) of source circuit boards <b>157</b>.
0095The timing controller <b>130</b>, the current detection unit <b>170</b>, and the power controller <b>180</b> are formed on the control circuit board <b>134</b>. The source circuit board <b>157</b> and the control circuit board <b>134</b> are connected to each other by a flexible printed circuit board <b>137</b>.
0096In case an organic light emitting display device is implemented as described above, a first voltage output from the power supply <b>125</b> is provided through all the first power line wiring CDD covering from the control circuit board <b>134</b> to the panel <b>160</b>.
0097In this case, since the first power line wiring VDD is connected together with each other from the control circuit board <b>134</b> to the panel <b>160</b>, it suffices to connect one current detection unit <b>170</b> to an arbitrary point of the first power line wiring VDD. As described earlier, this structure generates a shutdown signal SDS in the event of overcurrent and turns off the power supply <b>125</b> formed in the system board.
0098In what follows, a method for operating an organic light emitting display device according to the first embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 1 to 10</figref>; however, the operation method of <figref idref="DRAWINGS">FIG. 11</figref> only represents methods utilizing one or more configurations described earlier but is not limited to the description.
0099First, the panel <b>160</b> displays an image S<b>110</b>. Next, a sensing signal SS is provided to the power controller <b>180</b>, S<b>120</b>. Then a current is detected by using the current detection unit <b>170</b> connected to the first power line wiring VDD, S<b>130</b>. Next, a detected current value is compared with a current value predetermined internally for the power controller <b>180</b>, <b>5140</b>. Next, it is determined whether the detected current value is larger than the predetermined current value S<b>150</b>; if the detected current value is smaller than the predetermined current value N, it is determined to be operating in a normal manner S<b>160</b>. On the other hand, if the detected current value exceeds the predetermined current value Y, it is determined to be operating in an abnormal manner S<b>170</b>. And a shutdown signal SDS for turning off the power supply <b>125</b> is output S<b>180</b>. The above process is repeated continuously or carried out at a predetermined time period.
Second Embodiment
0100As shown in <figref idref="DRAWINGS">FIGS. 1 and 12</figref>, a circuit controlling the power supply <b>125</b> comprises a timing controller <b>130</b>, a current detection unit <b>170</b>, and a power controller <b>180</b>. A control block according to a second embodiment is applied to the case where the panel <b>160</b> uses first power line wiring VDD wired up for individual blocks.
0101The current detection unit <b>170</b> detects a current flowing through a first power line wiring VDD wired up for individual blocks and provides the power controller <b>180</b> with the detected current values for the individual blocks. To this purpose, M (where M is an integer two or more) current detection units <b>170</b> are incorporated. For example, in case the first power line wiring VDD is divided into four blocks, the current detection unit <b>170</b> comprises a first current detection unit <b>170</b><i>a </i>detecting a current of a power line wiring <b>1</b><i>a </i>VDDa to a fourth current detection unit <b>170</b><i>d </i>detecting a current of a power line wiring <b>1</b><i>d </i>VDDd.
0102The current detection unit <b>170</b> detects a current flowing through the first power line wiring VDD periodically or aperiodically. If the current detection unit <b>170</b> detects a current flowing through the first power line wiring VDD regularly and it is controlled by a particular device, it can be implemented by using OP amps. On the other hand, if the current detection unit <b>170</b> detects a current flowing aperiodically through the first power line wiring VDD while being controlled by a particular device, it can be implemented by using conventional OP amps and switches. In this case, a switch detects a current in accordance with a control signal.
0103The timing controller <b>130</b> provides a sensing signal SS to the power controller <b>180</b>. The timing controller <b>130</b> can not only provide a panel with sensing data through a data driving unit periodically but also provide the power controller <b>180</b> with the sensing signal SS in order for the power controller <b>180</b> to operate in synchronization with a timing at which the sensing data is displayed. On the other hand, the timing controller <b>130</b> can provide the sensing signal SS to the power controller <b>180</b> in order for the power controller <b>180</b> to operate for blank intervals excluding an image display interval of the panel.
0104The power controller <b>180</b> receives detected current values of individual blocks from the current detection unit <b>170</b> and compares the detected current values of the individual blocks with each other. A shutdown signal SDS is generated and turns off the power supply <b>125</b> if a current higher or lower than the currents of the other blocks is detected.
0105Meanwhile, if a physical distance between the power supply <b>125</b> and the power controller <b>180</b> is rather long (in other words, in case a transmission path is long or a transmission method is different), the strength of the shutdown signal SDS output from the power controller <b>180</b> may be weakened. Similarly, due to a difference between the circuit of the power controller <b>180</b> and the circuit of the power supply <b>125</b>, logic level of the shutdown signal SDS may be changed. To compensate for this change, the power controller <b>180</b> may be implemented as shown in <figref idref="DRAWINGS">FIG. 4</figref> or <b>5</b>.
0106In the second embodiment, a criterion based on which an overcurrent has occurred employs a method of comparing detected current values of individual blocks with each other.
0107As shown in <figref idref="DRAWINGS">FIG. 13</figref>, if a current value of a third block among detected current values of blocks (BL<b>1</b>˜BL<b>4</b>) corresponds to “Ab(A)” which is larger than the current values “N(A)” of the 1, 2, and 4 block (BL<b>1</b>, BL<b>2</b>, and BL<b>4</b>), it indicates an abnormal state where an overcurrent is detected and the power controller <b>180</b> outputs a shutdown signal SDS. Since the power supply <b>125</b> is turned off in response to the shutdown signal SDS, an output voltage of the output port Vout of the power supply is cut off. On the other hand, if detected current values of individual blocks are similar to or the same as each other, it indicates a normal state where an overcurrent is not detected and the power supply <b>125</b> outputs an output voltage through the output port Vout.
0108Meanwhile, the amount of current consumption for each block of the first power line wiring may differ from each other according to the image displayed on the panel <b>160</b>. Therefore, in this situation, it may be advantageous to set up a permissible error range. Therefore, the power controller <b>180</b> may be designed in such a way that if detected current values of individual blocks fall within the error range, the shutdown signal SDS is not generated whereas a detected current value of a block gets out of the error range, the shutdown signal SDS is generated.
0109As shown in <figref idref="DRAWINGS">FIG. 14</figref>, a first power line wiring VDD is disposed in such a way that wiring is distinguished for each individual block of the panel <b>160</b>. For example, the first power line wiring is disposed to form four blocks of <b>1</b><i>a </i>to <b>1</b><i>b </i>power line wiring VDDa VDDd for each individual region of the panel <b>160</b>.
0110A plurality of scan driving units <b>140</b> are formed in a non-display area NA located at the outer periphery of a display area AA of the panel <b>160</b>. The scan driving unit <b>140</b> is formed in the panel <b>160</b> in the form of a gate-in panel along with a transistor process for sub-pixels. The data driving unit <b>150</b> is implemented in the form of a plurality (for example, four) of integrated circuits (ICs) and installed on a plurality (for example, four) of flexible printed circuit boards <b>155</b>; one end of the data driving unit <b>150</b> is attached to a pad unit of the panel <b>160</b> by employing the FOG method and the other end is attached to a plurality (for example, two) of source circuit boards <b>157</b>.
0111The timing controller <b>130</b>, the current detection unit <b>170</b>, and the power controller <b>180</b> are formed on the control circuit board <b>134</b>. The source circuit board <b>157</b> and the control circuit board <b>134</b> are connected to each other by a flexible printed circuit board <b>137</b>.
0112In case an organic light emitting display device is implemented as described above, a first voltage output from the power supply <b>125</b> is first provided through the first power line wiring VDD and then provided through four branches of power line wiring <b>1</b><i>a </i>to <b>1</b><i>d </i>(VDDa VDDd) after the source circuit board <b>157</b>.
0113In this case, since the power line wiring branches into four sub-divisions, it suffices to connect the first to the fourth current detection unit <b>170</b><i>a</i>˜<b>170</b><i>d </i>for each branch point. As described earlier, this structure outputs a shutdown signal SDS in the event of overcurrent and turns off the power supply <b>125</b> formed in the system board.
0114In what follows, a method for operating an organic light emitting display device according to the second embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 1</figref>, <b>12</b>, and <b>15</b>; however, the operation method of <figref idref="DRAWINGS">FIG. 15</figref> only represents methods utilizing one or more configurations described earlier but is not limited to the description.
0115First, the panel <b>160</b> displays an image S<b>210</b>. Next, sensing data (for example, black data) is provided to the panel <b>160</b>, S<b>220</b>. Next, currents are detected by using the first to the fourth current detection unit <b>170</b><i>a</i>˜<b>170</b><i>d </i>connected to the power line wiring for individual groups <b>1</b><i>a </i>to <b>1</b><i>d </i>(VDDa VDDd) S<b>230</b>. Then, detected current values of individual blocks from the first to the fourth current detection unit <b>170</b><i>a</i>˜<b>170</b><i>d </i>are compared with each other S<b>240</b>. Next, it is determined whether the detected current values of individual blocks are identical to (or similar to) or within a permissible error range S<b>250</b>. If the detected current values of individual blocks are identical (or similar) to or within a permissible error range Y, it is determined to be operating in a normal manner S<b>260</b>. On the other hand, if a detected current value is higher or lower than the other current values N, it is determined to be operating in an abnormal manner S<b>270</b>. And a shutdown signal SDS for turning off the power supply <b>125</b> is output S<b>280</b>. The above process is repeated continuously or carried out at a predetermined time period.
0116Meanwhile, the present invention assumes that a current flowing through a first power line wiring is detected to solve a short circuit problem between power terminals. However, in the event of short circuit between the first power line wiring and the ground wiring, currents are made to flow between the first power line and the ground wiring; therefore, it may be still acceptable to have current detection units at the ground wiring rather than the first power line wiring. Also, since various voltages (in addition to VCC, VDD shown in <figref idref="DRAWINGS">FIG. 1</figref>) are employed in case of an organic light emitting display device, power line wiring is not limited only to the first power line wiring described above.
0117Moreover, the power controller described in <figref idref="DRAWINGS">FIGS. 3</figref>, <b>4</b>, <b>5</b>, <b>9</b>, <b>10</b>, and <b>14</b> of the present invention can be incorporated into the timing controller. In this case, the current detection unit further incorporates an analog-to-digital converter which converts a detected analog current value to a digital current value. Accordingly, the power controller included in the timing controller according to the first embodiment can determine based on the digital current value obtained from the analog-to-digital converter whether a detected current value gets out of a range set internally. Meanwhile, the power controller included in the timing controller according to the second embodiment can determine based on the digital current value obtained from the analog-to-digital converter whether a detected current value from a particular block is higher or lower than the current values of the other blocks.
0118As described above, the present invention can provide an organic light emitting display device and a method for operating the device, capable of preventing a local burning out from being spread to the whole system (burning out the sub-pixel and its adjacent sub-pixels) as excessive currents flow into the elements included in sub-pixels due to the occurrence of short circuit between power terminals and thus removing a possibility of being led to a fire. Also, the present invention can provide an organic light emitting display device and a method for operating the device, capable of controlling the power supply by using a short-circuit detection circuit which can be modified into various forms and cope with various cases according to configurations of the device.
Third Embodiment
0119As shown in <figref idref="DRAWINGS">FIG. 31</figref>, an organic light emitting display device according to a third embodiment of the present invention comprises an image processing unit <b>120</b>, a power supply <b>125</b>, a timing controller <b>130</b>, a data driving unit <b>150</b>, a scan driving unit <b>140</b>, a panel <b>160</b>, a compensation voltage supply <b>170</b>, and a voltage sensing unit <b>180</b>.
0120An image processing unit <b>120</b> provides a timing controller <b>130</b> with a vertical synchronization signal (Vsync), a horizontal synchronization signal (Hsync), a data enable signal (DE), a clock signal (CLK), and a data signal (DATA). The image processing unit <b>120</b> is formed in a system board <b>110</b>.
0121The timing controller <b>130</b> controls an operation timing of the data driving unit <b>150</b> and the scan driving unit <b>140</b> by using timing signals such as the vertical synchronization signal (Vsync), the horizontal synchronization signal (Hsync), the data enable signal (DE), and the clock signal (CLK). Since the timing controller <b>130</b> is capable of determining a frame interval by counting the data enable signal (DE) during one horizontal interval, the vertical synchronization signal (Vsync) and the horizontal synchronization signal (Hsync) provided from the outside can be omitted. Control signals generated at the timing controller <b>130</b> include a gate timing control signal (GDC) for controlling the operational timing of the scan driving unit <b>140</b> and a data timing control signal (DDC) for controlling the operational timing of the data driving unit <b>150</b>. The gate timing control signal (GDC) includes a gate start pulse, a gate shift clock, and a gate output enable signal. The data timing control signal (DDC) includes a source start pulse, a source sampling clock, and a source output enable signal.
0122The scan driving unit <b>140</b> shifts the level of a gate driving voltage in response to the gate timing control signal (GDC) provided from the timing controller <b>130</b> and generates a scan signal in a sequential manner. The scan driving unit <b>140</b> provides a scan signal through scan lines (SL<b>1</b>˜SLm) connected to sub-pixels (SPs) included in the panel <b>160</b>.
0123The data driving unit <b>150</b> performs sampling of the data signal (DATA) provided from the timing controller <b>130</b> in response to the data timing control signal (DDC) provided from the timing controller <b>130</b> and latches on the sampled data signal and transforms the latched, sampled data signal into the data of a parallel data system. The data driving unit <b>150</b> transforms the data signal (DATA) into a gamma reference voltage. The data driving unit <b>150</b> provides the data signal (DATA) through the data lines (DL<b>1</b>˜DLn) connected to sub-pixels (SPs) included in the panel <b>160</b>.
0124The power supply <b>125</b> converts an external voltage supplied from the outside into a first voltage (for example, 20 V level), a second voltage (for example, 3.3V level), and a low voltage (for example, 0 V level), and so on. The first voltage, being supplied to a first power line wiring EVDD, is a drain level voltage; the second voltage, being supplied to a second power line wiring VCC, is a collector level voltage; and the low level voltage is supplied to the ground EVSS, GND and is a base level voltage. The power supply <b>125</b> is formed in the system board <b>110</b> together with the image processing unit <b>120</b>. The output voltage of the power supply <b>125</b> is used for the image processing unit <b>120</b>, the timing controller <b>130</b>, the data driving unit <b>150</b>, the scan driving unit <b>140</b>, the panel <b>160</b>, and the compensation voltage supply <b>170</b>.
0125The compensation voltage supply <b>170</b> outputs a compensation voltage Vinit, Vref. The compensation voltage Vinit, Vref includes an initialization voltage Vinit and a reference voltage Vref. The initialization voltage Vinit and the reference voltage Vref may be identical to each other or may have different levels from each other. The initialization voltage Vinit and the reference voltage Vref output from the compensation voltage supply <b>170</b> are provided to compensation circuits included in sub-pixels (SPs) of the panel <b>160</b>. As shown in <figref idref="DRAWINGS">FIG. 32(</figref><i>a</i>), the compensation voltage supply <b>170</b> can output the initialization voltage Vinit and the reference voltage Vref by using a voltage output from the power supply <b>125</b>. As shown in <figref idref="DRAWINGS">FIG. 32(</figref><i>b</i>), the compensation voltage supply <b>170</b> can be divided into a first compensation voltage supply <b>170</b><i>a </i>generating the initialization voltage Vinit and a second compensation voltage supply <b>170</b><i>b </i>generating the reference voltage Vref by using a voltage output from the power supply <b>125</b>. Different from the above, as shown in <figref idref="DRAWINGS">FIG. 33</figref>, the compensation voltage supply <b>170</b> can generate the initialization voltage Vinit and the reference voltage Vref by using a voltage output from the inside of the data driving unit <b>150</b>.
0126The voltage sensing unit <b>180</b> senses a compensation voltage Vinit, Vref output from the compensation voltage supply <b>170</b> and outputs the sensed voltage. The voltage sensing unit <b>180</b> separately senses the initialization voltage Vinit and the reference voltage Vref output from the compensation voltage supply <b>170</b>. The compensation voltage Vinit, Vref sensed by the voltage sensing unit <b>180</b> is used as a criterion based on which the timing controller <b>130</b> generates a shutdown signal SDS for turning off the power supply <b>125</b>.
0127The panel <b>160</b> comprises sub-pixels disposed in the form of a matrix. Sub-pixels consist of red, green, and blue sub-pixels; in some cases, white sub-pixels are included. A panel <b>160</b> incorporating white sub-pixels can emit white light even if light emitting layers of individual sub-pixels do not emit red, green, and blue light. In this case, the white light is converted into red, green, and blue light by an RGB color filter.
0128Meanwhile, sub-pixels included in the panel <b>160</b> may be comprised as follows.
0129As shown in <figref idref="DRAWINGS">FIG. 34</figref>, one sub-pixel comprises a switching transistor SW, a driving transistor DR, a capacitor Cst, a compensation circuit CC, and an organic light emitting diode D. In case a compensation circuit CC is included, one scan line SL<b>1</b> comprises a first scan line EM, a second scan line INIT, and a third scan line SCAN.
0130The compensation circuit CC compensates for a threshold voltage of a driving transistor and the like by using the initialization voltage Vinit and the reference voltage Vref. A sub-pixel incorporating the compensation circuit CC detects a threshold voltage of the driving transistor DT by using a diode connection method, a source-following method, and so on. Since there are a large volume of reference documents for the diode connection method, further description thereof will not be given in this document; instead, the source-following method will be described as follows.
0131The source-following method inserts a compensation capacitor between the gate-source electrode of the driving transistor DT and in the event of detecting a threshold voltage, makes the source voltage of the driving transistor DT follow the gate voltage. Moreover, since the drain voltage of the driving transistor DT is separated from the gate electrode and receives a power voltage from a first power line wiring EVDD, the source-following method is enabled to detect a negative-valued threshold voltage as well as a positive-valued threshold voltage.
0132Moreover, the source-following method makes the gate electrode of the driving transistor float in the event of sensing a threshold voltage of the driving transistor DT and improves compensation capability of a threshold voltage by using a compensation capacitor installed between the gate-source electrode of the driving transistor DT and a parasitic capacitor of the driving transistor DT.
0133The compensation circuit CC comprises one or more transistors and capacitors; in the following, circuit configuration of a sub-pixel in <figref idref="DRAWINGS">FIG. 34</figref> will be described more specifically by using one example of compensation circuit for which the source-following method has been applied described above.
0134As shown in <figref idref="DRAWINGS">FIG. 35</figref>, the compensation circuit CC comprises a first transistor ST<b>1</b>, a second transistor ST<b>2</b>, a third transistor ST<b>3</b>, and a compensation capacitor Cgs. In what follows, the compensation circuit CC is introduced for the convenience of description only; the third embodiment of the present invention is not limited to the descriptions below but can be used for all the structure for compensating for a threshold voltage of the driving transistor DT by using the reference voltage Vref.
0135A first transistor ST<b>1</b> provides a data voltage stored in a node A to a node B in response to a light emission control signal (em) provided through a first scan line EM. The gate electrode of the first transistor ST<b>1</b> is connected to the first scan line EM; a first electrode is connected to the node A while a second electrode is connected to the node B. The first transistor ST<b>1</b> is a node voltage switching transistor.
0136A second transistor ST<b>2</b> provides an initialization voltage Vinit to a node C in response to an initialization signal (init) provided through a second scan line INIT. The gate electrode of the second transistor ST<b>2</b> is connected to the second scan line INIT; a first electrode is connected to the node C while a second electrode is connected to an initialization voltage terminal VINIT. The second transistor ST<b>2</b> is an initialization voltage supply transistor.
0137A third transistor ST<b>3</b> provides a reference voltage Vref to a node B in response to an initialization signal (init) provided through a second scan line INIT. The gate electrode of the third transistor ST<b>3</b> is connected to the second scan line INIT; a first electrode is connected to the node B while a second electrode is connected to a reference voltage terminal VREF. The third transistor ST<b>3</b> is a reference voltage supply transistor.
0138The compensation capacitor Cgs renders the source-following method applicable in the event of detecting a threshold voltage of the driving transistor DT and contributes to improving the capability of compensating for the threshold voltage. The gate electrode of the driving transistor DT is connected to one end of the compensation capacity Cgs and the node C is connected to the other end thereof.
0139As the compensation circuit CC is configured as described above, the switching transistor SW provides a data voltage Vdata to the node A in response to a switching signal (scan) provided through the third scan line SCAN. The gate electrode of the switching transistor SW is connected to the third scan line SCAN; the first electrode is connected to the node A while the second voltage is connected to a first data line DL<b>1</b>. One end of a storage capacitor Cst is connected to the node A while the other end of the storage capacitor Cst is connected to the node C. The gate electrode of the driving transistor DT is connected to the node B; the first electode is connected to the node C while the second voltage is connected to a first power line wiring EVDD. The anode of an organic light emitting diode (OLED) is connected to the node C while the cathode of the OLED is connected to the ground wiring EVSS. In the description above, it was assumed that the source electrode of transistors is selected as the first electrode, while the drain electrode thereof as the second electrode; however, the present invention is not limited to the assumption above.
0140As shown in <figref idref="DRAWINGS">FIG. 21</figref>, an image display interval of a sub-pixel incorporating a compensation circuit CC is divided into an initialization interval Ti during which the node A, B, and C are initialized into a particular voltage, a sensing interval Ts during which a threshold voltage of the driving transistor DT is detected and stored, a programming interval Tp during which a data voltage Vdata is applied, and a light emission interval Te during which a driving current applied to an organic light emitting diode (OLED) is compensated independently of a threshold voltage by using the threshold voltage and the data voltage Vdata. Here, the light emission interval Te is further divided into a first Te<b>1</b> and a second light emission interval Te<b>2</b>. More detailed description related to the compensation circuit CC refers to Korean patent application no. 10-2012-0095604.
0141Sub-pixels incorporating a compensation circuit CC as described above employs a compensation voltage Vinit, Vref for compensating for a threshold voltage of the driving transistor DT as well as a conventional type of power source such as a first power line wiring EVDD and ground wiring EVSS.
0142Since organic light emitting display panels require a large amount of currents compared with the liquid crystal display panels, in case of short circuit at power terminals, an excessive amount of currents flows into the elements of the respective sub-pixels. Various factors cause short circuit at power terminals, which include not only internal, structural factors such as particles introduced into the organic light emitting display panel during manufacturing process (or module process), cracks, misalignment of pad units, and narrow wiring layout; but also external factors such as static electricity.
0143If short circuit occurs at power terminals, a change occurs subsequently in the compensation voltage Vinit, Vref. According to a third embodiment of the present invention, the compensation voltage Vinit, Vref influenced by short circuit at power sources is sensed and occurrence of short circuit is checked and accordingly, power source of the power supply is cut off, which will be described in more detail below.
0144As shown in <figref idref="DRAWINGS">FIG. 22</figref>, the compensation voltage supply <b>170</b> generates a compensation voltage Vinit, Vref including the initialization voltage Vinit and the reference voltage Vref. The compensation voltage supply <b>170</b> is realized by one of the examples shown in <figref idref="DRAWINGS">FIGS. 32 and 33</figref>.
0145The voltage sensing unit <b>180</b> comprises a first voltage sensing unit <b>181</b> sensing the initialization voltage Vinit and a second voltage sensing unit <b>182</b> sensing the reference voltage Vref. The first and the second voltage sensing unit <b>181</b>, <b>182</b> compares the sensed compensated voltage Vinit, Vref with an internally set threshold voltage and outputs the comparison result.
0146The timing controller <b>130</b> includes a short-circuit detection unit <b>135</b>. The short-circuit detection unit <b>135</b> generates a shutdown signal SDS for turning off the power supply <b>125</b> based on the results obtained from the first <b>181</b> and the second voltage sensing unit <b>182</b>.
0147The first <b>181</b> and the second voltage sensing unit <b>182</b> differ in the voltages provided to a first and a second threshold voltage terminal but have structures which are the same as or similar to each other. Therefore, in what follows, descriptions of the present invention will be given with reference to the second voltage sensing unit <b>182</b> as a representative example.
0148As shown in <figref idref="DRAWINGS">FIG. 23</figref>, the compensation voltage supply <b>170</b> amplifies an external voltage source Vin and outputs a reference voltage Vref. It is assumed that the compensation voltage supply <b>170</b> comprises an amplifier OPV and resistors R<b>1</b>, R<b>2</b>, R<b>3</b>. A first resistor R<b>1</b> has it one end connected to the external voltage source Vin and the other end of the first resistor R<b>1</b> is connected to a first terminal (−) of the amplifier OPV. One end of a second resistor R<b>2</b> is connected to a second terminal (+) of the amplifier while the other end of the second resistor R<b>2</b> is connected to a third terminal (O) of the amplifier OPV. One end of a third resistor R<b>3</b> is connected to a third terminal of the amplifier OPV while the other end of the third resistor R<b>3</b> is connected to an output terminal of the amplifier OPV.
0149The second voltage sensing unit <b>182</b> senses the reference voltage Vref. The second voltage sensing unit <b>182</b> comprises a first comparator Comp<b>1</b> sensing the minimum level of the reference voltage Vref and a second comparator Comp<b>2</b> sensing the maximum level of the reference voltage Vref. A first terminal (−) of the first comparator is connected to a first threshold voltage terminal (−V<b>1</b>) and a second terminal (+) of the first comparator is connected to an output terminal of the compensation voltage supply <b>170</b> and an output terminal (O) of the first comparator is connected to the short-circuit detection unit <b>135</b>. A first terminal (−) of the second comparator is connected to an output terminal of the compensation voltage supply <b>170</b> and a second terminal (+) of the second comparator is connected to the second threshold voltage terminal (-V<b>2</b>) and an output terminal of the second comparator is connected to the short-circuit detection unit. A negative voltage is employed for the voltage provided to the first (−V<b>1</b>) and the second threshold voltage terminal (−V<b>2</b>).
0150The first Comp<b>1</b> and the second comparator Comp<b>2</b> compare a sensed reference voltage with the first and the second threshold voltage internally set; and determine whether the minimum and the maximum level of the reference voltage gets out of a permissible range specified; and output the result.
0151As shown in <figref idref="DRAWINGS">FIG. 10</figref>, a plurality of scan driving units <b>140</b> are formed in a non-display area NA located at the outer periphery of a display area AA of the panel <b>160</b>. The scan driving unit <b>140</b> is formed in the panel <b>160</b> in the form of a gate-in panel along with a transistor process for sub-pixels. The data driving unit <b>150</b> is implemented in the form of a plurality (for example, four) of integrated circuits (ICs) and installed on a plurality (for example, four) of first flexible printed circuit boards <b>155</b>; one end of the data driving unit <b>150</b> is attached to a pad unit of the panel <b>160</b> by employing the FOG method and the other end is attached to a plurality (for example, two) of source circuit boards <b>157</b>.
0152The timing controller <b>130</b>, the compensation voltage supply <b>170</b>, and the voltage sensing unit <b>180</b> are formed on the control circuit board <b>134</b>. The source circuit board <b>157</b> and the control circuit board <b>134</b> are connected to each other by a second flexible printed circuit board <b>137</b>. The image processing unit <b>120</b> and the power supply <b>125</b> are formed on the system board <b>110</b>. The control circuit board <b>134</b> and the system board <b>110</b> are connected to each other by a third flexible printed circuit board <b>115</b>.
0153In case an organic light emitting display device is implemented as described above, a compensation voltage generated at the compensation voltage supply <b>170</b> is provided through the wiring which passes through the control circuit board <b>134</b> and reaches up to the panel <b>160</b>.
0154Meanwhile, the description above assumed that the compensation voltage supply <b>170</b> and the voltage sensing unit <b>180</b> are formed on the control circuit board <b>134</b>. However, it should be noted that the voltage sensing unit <b>180</b> may be formed at various positions including the source circuit board <b>157</b>.
0155In the following, output of a shutdown signal and output states of the power supply will be described with one example illustrating a case where a reference voltage gets out of a permissible range along with indication of a minimum and a maximum level of the reference voltage.
0156As shown in <figref idref="DRAWINGS">FIG. 25</figref>, the reference voltage Vref is output being fixed at a particular voltage or output being varied within a particular voltage range. In what follows, it is assumed that the reference voltage Vref is output being fixed at a voltage level of −2.2V while a permissible range of the minimum level is set at a voltage level of −1V and a permissible range of the maximum level is set at a voltage level of −4V.
0157In this case, the permissible range for the reference voltage Vref as shown in <figref idref="DRAWINGS">FIG. 26</figref> becomes Δ3V level. Thus the first threshold voltage of <figref idref="DRAWINGS">FIG. 23</figref> provided to the first threshold voltage terminal (−V<b>1</b>) becomes −1V while the second threshold voltage of <figref idref="DRAWINGS">FIG. 23</figref> provided to the second threshold voltage terminal (−V<b>2</b>) becomes −4V.
0000<The case where the minimum and the maximum level of a reference voltage ranges between −1V and −4V>
0158The minimum level of reference voltage sensed by a first comparator Comp<b>1</b> and the maximum level of reference voltage sensed by a second comparator Comp<b>2</b> ranges between −1V and −4V. In this case, the short-circuit detection unit <b>135</b> regards the power source of the panel as normal as shown in <figref idref="DRAWINGS">FIG. 26</figref> and generates a shutdown signal SDS of logic low (L) as shown for a first interval T<b>1</b> of <figref idref="DRAWINGS">FIG. 27</figref> (or it may generate no signal). At this time, the power supply <b>125</b> maintains output of the output terminal Vout.
0000<The case where the minimum and the maximum level of a reference voltage gets out of a range between −1V and −4V>
0159The minimum level of reference voltage sensed by a first comparator Comp<b>1</b> and the maximum level of reference voltage sensed by a second comparator Comp<b>2</b> get out of a range between −1V and −4V. In this case, the short-circuit detection unit <b>135</b> regards the power source of the panel as abnormal as shown in <figref idref="DRAWINGS">FIG. 26</figref> and generates a shutdown signal SDS of logic high (H) as shown for a second interval T<b>2</b> of <figref idref="DRAWINGS">FIG. 27</figref>. At this time, the power supply <b>125</b> stops providing an output through the output terminal Vout and is turned off
0160Meanwhile, the example above assumed that the power supply <b>125</b> is turned off only if a shutdown signal SDS of logic high (H) is generated. However, the power supply <b>125</b> can be so designed to be turned off if a shutdown signal SDS of logic low (L) is generated.
0161In what follows, a method for operating an organic light emitting display device according to the third embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 1 to 28</figref>; however, the operation method of <figref idref="DRAWINGS">FIG. 28</figref> only represents methods utilizing one or more configurations described earlier but is not limited to the description.
0162First, the panel <b>160</b> displays an image S<b>110</b>. Next, a compensation voltage Vinit, Vref provided to the panel <b>160</b> is sensed S<b>120</b>. Then the compensation voltage Vinit, Vref is compared with a threshold voltage −V<b>1</b>, −V<b>2</b>, S<b>130</b>. Next, if the reference voltage Vinit, Vref falls within a permissible range without getting out of the threshold voltage −V<b>1</b>, −V<b>2</b> (N), it is regarded as normal S<b>150</b>; and does not generate a shutdown signal SDS for turning off the power supply <b>125</b> which provides power to the panel <b>160</b>. Afterwards, the panel <b>160</b> continues to display images.
0163Different from the above, if the compensation voltage Vinit, Vref exceeds the threshold voltage −V<b>1</b>, −V<b>2</b>, escaping the permissible range for the reference voltage, it is regarded as abnormal S<b>160</b> and generates a shutdown signal SDS for turning off the power supply <b>125</b> which provides power to the panel <b>160</b>, S<b>170</b>. Afterwards, the panel <b>160</b> does not display images.
0164As described above, the third embodiment of the present invention provides an organic light emitting display device and a method for operating the device, capable of controlling the power supply in the event of short circuit at the power source or in the case of an overcurrent by sensing a compensation voltage provided when sub-pixels incorporate a compensation circuit.
Fourth Embodiment
0165As shown in <figref idref="DRAWINGS">FIG. 29</figref>, an organic light emitting display device according to a fourth embodiment of the present invention comprises an image processing unit <b>120</b>, a power supply <b>125</b>, a timing controller <b>130</b>, a data driving unit <b>150</b>, a scan driving unit <b>140</b>, a panel <b>160</b>, a current sensing unit <b>190</b>, and an analog-to-digital converter <b>200</b>.
0166In case of the fourth embodiment, sub-pixels (SPs) included in the panel <b>160</b> may assume a structure incorporating a compensation circuit as described in the third embodiment or a conventional structure not incorporating the compensation circuit. However, for the current embodiment, a first power line wiring EVDD in the panel <b>160</b> is wired up separately for individual blocks. Since the image processing unit <b>120</b>, the power supply <b>125</b>, the data driving unit <b>150</b>, and the scan driving unit <b>140</b> are configured to operate in the same way as the third embodiment, further description thereof will not be provided.
0167The current sensing unit <b>190</b> senses a current flowing through the first power line wiring EVDD wired up for individual blocks and amplifies the sensed currents of the individual blocks into the corresponding analog voltages and outputs the analog voltages.
0168The analog-to-digital converter <b>200</b> converts an analog voltage of each block provided from the current sensing unit <b>190</b> into the corresponding digital voltage and outputs the digital voltage.
0169The timing controller <b>130</b> receives a digital voltage of each block through communication with the analog-to-digital converter <b>200</b> and determines occurrence of a short-circuit or an overcurrent in the panel <b>160</b> by using the digital voltage of each block and in the event of a short-circuit or an overcurrent, generates an shutdown signal SDS for turning off the power supply <b>125</b>. In what follows, it is assumed that a communication interface between the timing controller <b>130</b> and the analog-to-digital converter <b>200</b> employs SPI (Serial Peripheral Interface), which is a serial communication method.
0170Different from the third embodiment, the first power line wiring EVDD formed in the panel <b>160</b> of the fourth embodiment is wired up separately for individual blocks. And the timing controller <b>130</b> determines the occurrence of an overcurrent in the panel <b>160</b> through the current sensing unit <b>190</b> and the analog-to-digital converter <b>200</b> and in the event of an overcurrent, turns off the power supply <b>125</b>.
0171As shown in <figref idref="DRAWINGS">FIG. 30</figref>, the data driving unit <b>150</b> is implemented in the form of a plurality (for example, three) of integrated circuits (ICs) and installed on a plurality (for example, three) of first flexible printed circuit boards <b>155</b>; the data driving unit <b>150</b> is attached to a pad unit of the panel <b>160</b> by employing the FOG method. Although not shown in the figure, the other end of the first flexible printed circuit board <b>155</b> is attached to a source circuit board.
0172The first power line wiring EVDD is split into a plurality of wiring (for example, three wirings) before it passes through the first flexible printed circuit board <b>155</b>. Accordingly, the first power line wiring EVDD formed on the panel <b>160</b> is wired up separately for individual blocks. In what follows, it is assumed that the first power line wiring EVDD formed on the panel <b>160</b> is divided into a first to a third block power line wiring EVDD<b>1</b>˜EVDD<b>3</b>.
0173The current sensing unit <b>190</b> comprises a first block current sensing unit <b>190</b><i>a </i>to a third block current sensing unit <b>190</b><i>c</i>. The first block current sensing unit <b>190</b><i>a </i>senses a first block current (i<b>1</b>) flowing through the first block power line wiring EVDD<b>1</b> and amplifies the sensed current into a first block analog voltage SV<b>1</b> and outputs the first block analog voltage SV<b>1</b>. The second block current sensing unit <b>190</b><i>b </i>senses a second block current (i<b>2</b>) flowing through the second block power line wiring EVDD<b>2</b> and amplifies the sensed current into a second block analog voltage SV<b>2</b> and outputs the second block analog voltage SV<b>2</b>. The third block current sensing unit <b>190</b><i>c </i>senses a third block current (i<b>3</b>) flowing through the third block power line wiring EVDD<b>3</b> and amplifies the sensed current into a third block analog voltage SV<b>3</b> and outputs the third block analog voltage SV<b>3</b>.
0174The first to the third block analog voltage SV<b>1</b>˜SV<b>3</b> sensed by the first block current sensing unit <b>190</b><i>a </i>to the third block current sensing unit <b>190</b><i>c </i>are provided to the analog-to-digital converter <b>200</b>. The analog-to-digital converter <b>200</b> converts the first to the third block analog voltage SV<b>1</b>˜SV<b>3</b> into a first to a third block digital voltage. Here, the first to the third block digital voltage are provided to the timing controller <b>130</b> through a communication line (SPI) connecting the analog-to-digital converter <b>200</b> and the timing controller <b>130</b>.
0175The first <b>190</b><i>a </i>to the third block current sensing unit <b>190</b><i>c </i>differ only in their sensing positions but have the same structure with each other. Therefore, in what follows, descriptions of the present invention will be provided by using the first block current sensing unit <b>190</b><i>a </i>as a representative of the three block current sensing units.
0176As shown in <figref idref="DRAWINGS">FIG. 31</figref>, the first block current sensing unit <b>190</b><i>a </i>comprises an amplifier OPR and resistors R<b>1</b>˜R<b>6</b>. The first block current sensing unit <b>190</b><i>a</i>, being installed between the first power line wiring EVDD and the first block power line wiring EVDD<b>1</b>, senses a first block current (i<b>1</b>) flowing through the first block power line wiring EVDD<b>1</b> and converts the sensed first block current (i<b>1</b>) into a first block analog voltage SV<b>1</b> and outputs the first block analog voltage SV<b>1</b>.
0177When converting a current into the corresponding voltage, the first block current sensing unit <b>190</b><i>a </i>makes use of the voltages provided to a positive voltage terminal V+ and a negative voltage terminal V−. At this time, although a scan high voltage generated by the scan driving unit may be used as the voltage applied to the positive voltage terminal V+, the present invention is not limited to the above example.
0178Meanwhile, the embodiment in the figure assumed that the first block current sensing unit <b>190</b><i>a </i>consists only of an amplifier OPR and resistors R<b>1</b>˜R<b>6</b>, capacitors or other passive elements may be further incorporated into the first block current sensing unit <b>190</b><i>a. </i>
0179One ends of the first and the second resistor R<b>1</b>, R<b>2</b> are connected to the first power line wiring EVDD and the other ends are connected to the first block power line wiring EVDD<b>1</b>. The third resistor R<b>3</b> is connected between one ends of the first and the second resistor R<b>1</b>, R<b>2</b> and a third terminal <b>3</b> of the amplifier OPR. The fourth resistor R<b>4</b> is connected between one ends of the first and the second resistor R<b>1</b>, R<b>2</b> and a first terminal <b>1</b> of the amplifier OPR. The fifth resistor R<b>5</b> is connected between a second <b>2</b> and a third terminal <b>3</b> of the amplifier OPR and the ground wiring. The sixth resistor R<b>6</b> is connected between the first <b>1</b> and a fourth terminal <b>4</b> of the amplifier OPR and the ground wiring. The second terminal <b>2</b> is connected to the negative voltage terminal V− of the amplifier OPR and the fifth terminal <b>5</b> is connected to the positive voltage terminal V+ of the amplifier OPR and a first block analog voltage SV<b>1</b> is generated through the first terminal <b>1</b>.
0180In the following, a process of outputting a shutdown signal will be described in conjunction with the analog-to-digital converter, the timing controller, and the power supply.
0181As shown in <figref idref="DRAWINGS">FIGS. 32 to 35</figref>, the analog-to-digital converter <b>200</b> and the timing controller <b>130</b> communicates commands through bus lines SD<b>1</b>, SCLK, SDO, CS included in the communication interface SPI. At this time, the timing controller <b>130</b> is selected as a master unit and the analog-to-digital converter is selected as a slave unit.
0182The timing controller <b>130</b> receives a first to an n-th block digital voltage SV<b>1</b>˜SVn from the analog-to-digital converter <b>200</b> during a blank interval VB. The timing controller <b>130</b> receives digital voltages of individual blocks during at least two times of blank intervals and based on a difference value between the digital voltages, determines occurrence of a short-circuit or an overcurrent. To this purpose, the timing controller <b>130</b> comprises a determination unit <b>131</b> receiving digital voltages of individual blocks during at least two times of blank intervals VB and determines the difference between the digital voltages; and a shutdown signal generation unit <b>136</b> generating a shutdown signal SDS according to a result of the determination unit <b>131</b>.
0183To be more specific, the determination unit <b>131</b> receives first digital voltages of individual blocks about the first to the n-th block digital voltage SV<b>1</b>˜SVn from the analog-to-digital converter <b>200</b> during a first blank interval VB of “T1”. Next, the determination unit <b>131</b> receives second digital voltages of individual blocks about the first to the n-th block digital voltage SV<b>1</b>˜SVn from the analog-to-digital converter <b>200</b> during a second blank interval VB of “T2”.
0184The determination unit <b>131</b> compares the first block digital voltage with the second block digital voltage and if a difference between the two voltages is zero, it is determined to be operating in normal conditions revealing no short-circuit or overcurrent. At this time, the determination unit <b>131</b> provides the shutdown signal generation unit <b>136</b> with either a signal of logic low or no signal at all. Therefore, the output terminal Vout of the power supply maintains its output.
0185On the other hand, if a difference between the first and the second block digital voltage shows non-zero value and exceeds a permissible range, the determination unit <b>131</b> determines that an abnormal state has occurred, revealing a short-circuit or an overcurrent in the panel. At this time, the determination unit <b>131</b> provides the shutdown signal generation unit <b>136</b> with a signal of logic high. Subsequently, the power supply stops its output terminal Vout and is turned off.
0186As a specific example, <figref idref="DRAWINGS">FIG. 35</figref> illustrates a case where the first block digital voltage SV<b>1</b> sensed during the second blank interval VB is larger than the first block digital voltage SV<b>1</b> sensed during the first blank interval VB, exceeding a permissible range by a voltage value “Ab(V)”.
0187Since the first block digital voltage SV<b>1</b> sensed during the second blank interval VB exceeds the permissible range by the amount of voltage “Ab(V)”, the shutdown signal generation unit <b>136</b> generates a shutdown signal SDS of logic high (H) instead of logic low (L). Subsequently, the power supply <b>125</b> stops the output terminal Vout and is turned off.
0188Meanwhile, the determination unit <b>131</b> and the shutdown signal generation unit <b>136</b> have been functionally separated in the above description for the convenience of understanding; therefore, the two units can be combined into a single unit in a different implementation. In addition, although the present invention assumes that the determination unit <b>131</b> and the shutdown signal generation unit <b>136</b> are incorporated into the timing controller <b>130</b>, the two units can be implemented separately from the timing controller <b>130</b>. Moreover, the permissible range introduced above can be configured differently according to the conditions of the panel, output voltage, and so on.
0189Meanwhile, constituting elements according to the fourth embodiment can be used to implement an organic light emitting display device as in the third embodiment of <figref idref="DRAWINGS">FIG. 24</figref>. At this time, the current sensing unit <b>190</b> and the analog-to-digital converter <b>200</b> can be formed all in the control circuit board <b>134</b> or formed separately in the source circuit board <b>157</b> and the control circuit board <b>134</b>.
0190In what follows, a method for operating an organic light emitting display device according to the fourth embodiment of the present invention will be described with reference to <figref idref="DRAWINGS">FIGS. 29 to 36</figref>; however, the operation method of <figref idref="DRAWINGS">FIG. 36</figref> only represents methods utilizing one or more configurations described earlier but is not limited to the description.
0191First, the panel <b>160</b> displays an image S<b>210</b>. Next, a first block digital voltage is sensed through a first to a third block power line wiring EVDD<b>1</b>˜EVDD<b>3</b> wired up for individual blocks in the panel <b>160</b>, S<b>220</b>. Next, a second block digital voltage is sensed through the first to the third block power line wiring EVDD<b>1</b>˜EVDD<b>3</b> wired up for individual blocks in the panel <b>160</b>, S<b>230</b>. Then, the first block digital voltage is compared with the second block digital voltage S<b>240</b>. Next, it is determined whether a difference between the first and the second block digital voltage exceeds a permissible range S<b>250</b>. Next, if the difference between the first and the second block digital voltage falls within the permissible range Y, it is determined to be operating in a normal manner S<b>260</b> and a shutdown signal SDS for turning off the power supply <b>125</b> which provides power to the panel <b>160</b> is not generated. Afterwards, the panel <b>160</b> continues to display images.
0192Different from the above, if a difference between the first and the second block digital voltage exceeds a permissible range N, it is determined to be operating in an abnormal manner S<b>270</b> and a shutdown signal SDS for turning off the power supply <b>125</b> which provides power to the panel <b>160</b> is generated S<b>280</b>. Afterwards, the panel <b>160</b> stops displaying images.
0193As described above, the fourth embodiment of the present invention provides an organic light emitting display device and a method for operating the device, capable of sensing a current flowing through a first power line wiring wired up for individual blocks on the panel at least two times and comparing the sensed values with each other and controlling the power supply in the event of a short-circuit or an overcurrent at power terminals.
0194As described above, the present invention can provide an organic light emitting display device and a method for operating the device, capable of removing a possibility for a local burning out of an element to be spread to the whole system and to lead to a fire by using a circuit detecting short circuit or an overcurrent at power terminals.
Contents4
25 sheets
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| US2021248940A1 | Cited by | United States of America | Search report |
| US2019318705A1 | Cited by | United States of America | Search report |
| US2014167503A1 | Cited by | United States of America | Pre-grant |
| US9397520B2 | Cited by | United States of America | Search report |
| US11030927B2 | Cited by | United States of America | Search report |
| US10636784B2 | Cited by | United States of America | Search report |
| US2014028658A1 | Cited by | United States of America | Pre-grant |
| US11049459B2 | Cited by | United States of America | Applicant |
| US2023081260A1 | Cited by | United States of America | Search report |
| US2015364105A1 | Cited by | United States of America | Pre-grant |
| US2014184481A1 | Cited by | United States of America | Pre-grant |
| US2016240130A1 | Cited by | United States of America | Pre-grant |
| JP2022537519A | Cited by | Japan | Search report |
| US12536940B2 | Cited by | United States of America | Search report |
| US9966005B2 | Cited by | United States of America | Search report |
| US2014362124A1 | Cited by | United States of America | Pre-grant |
| KR20190119243A | Cited by | Republic of Korea | Search report |
| US10580354B2 | Cited by | United States of America | Search report |
| US2014354618A1 | Cited by | United States of America | Pre-grant |
| US11189236B2 | Cited by | United States of America | Search report |
| US11087694B2 | Cited by | United States of America | Search report |
| US2017372663A1 | Cited by | United States of America | Pre-grant |
| US2015262541A1 | Cited by | United States of America | Pre-grant |
| US2018233085A1 | Cited by | United States of America | Search report |
| US11574566B2 | Cited by | United States of America | Search report |
| US12293693B2 | Cited by | United States of America | Search report |
| CN114283722A | Cited by | China | Search report |
| KR20220047562A | Cited by | Republic of Korea | Search report |
| CN105741777A | Cited by | China | Search report |
| US9779663B2 | Cited by | United States of America | Search report |
| US2017213490A1 | Cited by | United States of America | Search report |
| US9626907B2 | Cited by | United States of America | Search report |
| US10762842B2 | Cited by | United States of America | Search report |
| US2016253966A1 | Cited by | United States of America | Pre-grant |
| US2016027381A1 | Cited by | United States of America | Pre-grant |
| US2016012778A1 | Cited by | United States of America | Pre-grant |
| US2010073275A1 | Cites | United States of America | Pre-grant |
| US2012146520A1 | Cites | United States of America | Pre-grant |
12 members in 4 offices; this record represents the family
Members12
| Document | Office | Kind | |
|---|---|---|---|
| CN103680392A | China | A | |
| DE102012112817A1 | Germany | A1 | |
| US2014084792A1 | United States of America | A1 | |
| KR20140039828A | Republic of Korea | A | |
| KR20140041968A | Republic of Korea | A | |
| US8946994B2 | United States of America | B2 | |
| KR101492693B1 | Republic of Korea | B1 | |
| KR101492694B1 | Republic of Korea | B1 | |
| US2015115799A1 | United States of America | A1 | |
| CN103680392B | China | B | |
| US9378673B2 | United States of America | B2 | |
| DE102012112817B4 | Germany | B4 |
49 transactions on the USPTO file
Allowed without a rejection on record.
- Non-final rejections
- 0
- Final rejections
- 0
- RCEs
- 0
- Appeals
- 0
Over time
Point at a mark for the transactionTransactions
| Event | Code | |
|---|---|---|
| Payment of Maintenance Fee, 8th Year, Large EntityM1552 | M1552 | |
| Payment of Maintenance Fee, 4th Year, Large EntityM1551 | M1551 | |
| Recordation of Patent Grant MailedPGM/ | PGM/ | |
| Patent Issue Date Used in PTA CalculationAllowedPTAC | PTAC | |
| Email NotificationEML_NTR | EML_NTR | |
| Issue Notification MailedAllowedWPIR | WPIR | |
| Dispatch to FDCD1935 | D1935 | |
| Application Is Considered Ready for IssuePILS | PILS | |
| Issue Fee Payment VerifiedN084 | N084 | |
| Issue Fee Payment ReceivedIFEE | IFEE | |
| Correspondence Address ChangeC.ADB | C.ADB | |
| Electronic ReviewELC_RVW | ELC_RVW | |
| Email NotificationEML_NTF | EML_NTF | |
| Mail Notice of AllowanceAllowedMN/=. | MN/=. | |
| Notice of Allowance Data Verification CompletedAllowedN/=. | N/=. | |
| Reasons for AllowanceEX.R | EX.R | |
| Examiner's Amendment CommunicationEX.A | EX.A | |
| Information Disclosure Statement consideredIDSC | IDSC | |
| Information Disclosure Statement consideredIDSC | IDSC | |
| Reference capture on IDSRCAP | RCAP | |
| Information Disclosure Statement (IDS) FiledM844 | M844 | |
| Information Disclosure Statement (IDS) FiledWIDS | WIDS | |
| Date Forwarded to ExaminerFWDX | FWDX | |
| Response to Election / Restriction FiledELC. | ELC. | |
| Priority document has successfully retrieved via PDX/DASPD.RECVD | PD.RECVD | |
| Electronic ReviewELC_RVW | ELC_RVW | |
| Email NotificationEML_NTF | EML_NTF | |
| Mail Restriction RequirementMCTRS | MCTRS | |
| Restriction/Election RequirementCTRS | CTRS | |
| Email NotificationEML_NTR | EML_NTR | |
| PG-Pub Issue NotificationPG-ISSUE | PG-ISSUE | |
| Final PDX/DAS request for priority document has failedPD.FAIL | PD.FAIL | |
| Final PDX/DAS request for priority document has failedPD.FAIL | PD.FAIL | |
| Case Docketed to Examiner in GAUDOCK | DOCK | |
| Case Docketed to Examiner in GAUDOCK | DOCK | |
| Reference capture on IDSRCAP | RCAP | |
| Information Disclosure Statement (IDS) FiledM844 | M844 | |
| Information Disclosure Statement (IDS) FiledWIDS | WIDS | |
| Application Dispatched from OIPEOIPE | OIPE | |
| Application Is Now CompleteCOMP | COMP | |
| Email NotificationEML_NTR | EML_NTR | |
| Email NotificationEML_NTR | EML_NTR | |
| Change in Power of Attorney (May Include Associate POA)PA.. | PA.. | |
| Filing ReceiptFLRCPT.O | FLRCPT.O | |
| Sent to Classification ContractorPGPC | PGPC | |
| Cleared by OIPE CSRL194 | L194 | |
| Request from applicant for the USPTO to retrieve the Priority DocumentPDREQUST | PDREQUST | |
| IFW Scan & PACR Auto Security ReviewSCAN | SCAN | |
| Initial Exam Team nnIEXX | IEXX |
6 legal events, as the office reported them to INPADOC
Over the term
Point at a mark for the eventEvents
| Event | Code | |
|---|---|---|
| Maintenance fee paymentMAFP | MAFP | |
| Maintenance fee paymentMAFP | MAFP | |
| Maintenance fee paymentMAFP | MAFP | |
| Information on status: patent grantGrantedPATENTED CASESTCF | STCF | |
| Fee payment procedurePAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITYFEPP | FEPP | |
| AssignmentAS | AS |
Numbers
- Publication
- 20140084792
- Application
- 13718739
Titles
- English
- ORGANIC LIGHT EMITTING DISPLAY DEVICE AND DRIVING METHOD THEREOF
Patent term adjustment
- A delay
- +48 daysthe office missed an examination deadline
- Applicant delay
- −24 days
- Net adjustment
- 24 days
Classification
- CPC, 8
- H05B37/02
- H05B47/10
- G09G3/006
- G09G2330/028
- G09G2330/10
- G09G2330/12
- G09G3/3208
- Y02B20/40
- IPC, 1
- H05B37 02
- USPC, 1
- 315120000