Display apparatus

Display device

This creation is related to a display device that uses thin film transistors to drive electroluminescence (hereinafter referred to as EL) display elements and other electroluminescent elements. In particular, it refers to a display device driven by a thin film transistor that can suppress long-term deterioration.

After a thorough investigation of the organic EL display element driven by thin film transistors, the author knows the following: (1) In the organic EL display element driven by thin film transistors, since the organic EL display element is a direct current element Therefore, the thin-film transistors inserted in series for its control will also flow direct current; (2) The thin-film transistor system is divided into two types: n-channel type and p-channel type. Both n-channel type and p-channel type are durable. The situation of deterioration is very different.

Therefore, the purpose of this creation is to suppress the long-term deterioration of the thin film transistor in the current light emitting device driven by the thin film transistor.

(1) The purpose of this creation is to provide an organic electroluminescence display device formed with a plurality of scan lines and a plurality of data lines, and corresponding to the intersections of the scan lines and the data lines, formed with thin film transistors and electroluminescent elements , It is characterized in that: among the thin film transistors, at least one of them is a p-channel type thin film transistor.

According to the creation described in (1), it can suppress the long-term deterioration of thin film transistors.

(2) This creation is formed when a plurality of scanning lines, a plurality of data lines, a common electrode and a counter electrode are formed, and corresponding to the intersections of the scanning lines and the data lines, the first thin film transistor and the second thin film transistor are formed. Crystals, retention capacitors, pixels, electrodes, and current-emitting elements. The first thin film transistor controls the conduction between the data line and the retention capacitor based on the potential of the scan line. The second thin film transistor described above is based on the retention capacitor. Potential to control the conduction between the common electrode and the pixel electrode, thereby controlling the current flowing in the current light-emitting element between the pixel electrode and the counter electrode, in an organic electroluminescence display device, characterized in that the first 2 Thin film transistors are p-channel type transistors.

(3) This creation is in the organic electroluminescent display device described in (1) or (2), and it is characterized in that in addition to a plurality of scanning lines, a plurality of data lines, thin film transistors, and luminescence on the substrate In addition to the elements, a driving circuit for driving the light-emitting element is formed at the same time, and the p-channel type thin film transistor is formed by the same step as the thin film transistor in the driving circuit.

(4) In the organic electroluminescence display device of any one of items (1) to (3), the feature is that the thin film transistor is formed of a polycrystalline silicon thin film transistor.

(5) The feature of this creation is composed of the organic electroluminescence display device described in (3); and the above-mentioned driving circuit is composed of complementary thin-film transistors; the above-mentioned first thin-film transistor and the above-mentioned driving circuit N-channel type The thin film transistor is formed by the same step; and the second thin film transistor and the p-channel type thin film transistor in the driving circuit are formed by the same step.

According to item (5), a current-driven light-emitting display device can be provided, which does not increase the manufacturing steps and has high performance without long-term degradation.

The overall structure of the organic EL display device.

Hereinafter, the preferred implementation mode of this creation will be described with reference to the drawings.

As shown in Fig. 1, the central part on the substrate 1 serves as a display part. In the peripheral portion of the transparent substrate 1, to the upper side of the figure is a data-side drive circuit 3 configured to output image signals to the data line 112, and to the left of the figure is a data-side drive circuit 3 configured to output scanning signals to the scanning line 111 Scan side driving circuit 4. These driving circuits 3 and 4 are composed of N-type thin-film transistors and P-type thin-film transistors as complementary thin-film transistors. In the complementary thin-film transistors, a shift register circuit, a level shift circuit, and Analog switch circuit, etc.

The transparent substrate 1 is provided with a plurality of scan lines 111 and a plurality of data lines 112 arranged in a crossing direction with the extending direction of the scan lines 111. The intersection of these data lines 112 and the scan lines 111 forms a matrix-like figure Vegetarian 7.

In these pixels 7, a first thin film transistor (hereinafter referred to as a switching thin film transistor) 121 that supplies a scanning signal to its gate (first gate) via a scanning line 111 is constituted. One end of the source and drain regions of the switching thin film transistor 121 is electrically connected to the data line 112, and the other end of the source and drain regions is It is electrically connected to the potential holding electrode 113. In addition, the common line 114 is arranged side by side with the scanning line 111, and a storage capacitor 123 is formed between the common line 114 and the potential holding electrode 113. The common line 114 is maintained at a constant potential. Therefore, when the switching thin film transistor 121 selected according to the scanning signal is turned on, the image signal from the data line 112 is stored in the holding capacitor 123 via the switching thin film transistor 121.

The potential holding electrode 113 is electrically connected to the gate of the second thin film transistor (hereinafter referred to as current thin film transistor) 122, and one end of the source and drain regions of the current thin film transistor 122 is electrically connected to the common line 114 , The other end of the source and drain regions is electrically connected to an electrode 115 of the light-emitting element 131. When the current thin film transistor 122 is turned on, the current of the common line 114 flows through the current thin film transistor 122 to the light emitting element 131 such as an organic EL display element, and the light emitting element 131 emits light. Furthermore, in this configuration, one electrode of the holding capacitor 123 is connected to the common line 114, but it may not be connected to the common line 114, and a capacitor line may be separately provided and connected to the structure of the capacitor line. In addition, one electrode of the holding capacitor may be connected to the structure of the adjacent gate line.

Example 1

Figure 2 is an equivalent circuit diagram of the organic EL display device with thin film transistors of the creative embodiment 1, and Figure 3 is a driving voltage diagram of the organic EL display device with thin film transistors of the creative embodiment 1, and fourth The figure is a current-voltage characteristic diagram of the current thin film transistor of the creative embodiment 1, and Figure 5 is a current-voltage characteristic diagram of the organic EL display device of the creative embodiment 1.

In Figure 2, 111 is a scan line, 112 is a data line, 113 is a sustain electrode, 114 is a common line, 115 is a pixel electrode formed of aluminum, and 116 is formed of indium oxide/tin oxide (hereinafter referred to as ITO) The counter electrode 121 is a switching thin film transistor, 122 is an n-channel current thin film transistor, 123 is a holding capacitor, and 131 is an organic EL display element that emits light by the current flowing from the power supply line 116 to the pixel electrode 115, (Hereinafter referred to as an upright organic EL display element), 141 is the current direction of the organic EL display element.

In Figure 3, 211 is a scanning potential, 212 is a signal potential, 213 is a holding potential, 214 is a common potential, 215 is a pixel potential, and 216 is an opposing potential. In addition, in Fig. 3, only a part of each potential is described in order to explain the relationship between the voltages. The potential of the scan line 111 is the scan potential 211, the potential of the data line 112 is the signal potential 212, the potential of the sustain electrode 113 is the sustain potential 213, the potential of the common line 114 is the common potential 214, the potential of the pixel electrode 115 formed of aluminum This is the pixel potential 215, and the potential of the counter electrode 116 formed of ITO is the counter potential 216. In addition, Fig. 3 shows a part of each signal potential in a pattern.

During the period when the 221 series pixels are in the display state, current flows through the upright organic EL display element 131 and emits light. During the period when the 222 series pixels are in the non-display state, the current does not flow to the upright organic EL display element 131 and therefore does not emit light.

In Figure 4, 31 is the current-voltage characteristic of the n-channel current thin film transistor 122 when the drain voltage is 4V, and 32 is the current-voltage characteristic of the n-channel current thin film transistor 122 when the drain electrode is 8V. It can be seen from the figure that no matter which drain voltage is at which gate voltage is low, the n-channel current thin film transistor 122 is in the on-off state, a small drain current flows, and the resistance between the source and the drain becomes high resistance. When the gate voltage is high, the n-channel current thin film transistor 122 is turned on and a large drain current flows. The resistance between the source and drain will become low resistance.

In FIG. 5, 4 is the current-voltage characteristic of the upright organic EL display element 131. Here, it is assumed that the voltage represents the counter voltage 216 with respect to the pixel potential 215, and the current represents the current flowing from the counter electrode 116 to the pixel electrode 115. When the upright organic EL display element 131 is below a certain threshold voltage, it becomes an on-off state, has a high resistance, does not flow current, and does not emit light. When the threshold voltage is higher than the threshold voltage, it becomes the ON state, the resistance is low, current flows, and light is emitted. Here, the threshold voltage is approximately 2V.

Hereinafter, the operation of the organic EL display device with the thin film transistor of this embodiment will be described with reference to the second, third, fourth, and fifth figures.

The switching thin film transistor 121 controls the conduction between the data line 112 and the sustain electrode 113 according to the potential of the scan line 111. That is, the conduction between the signal potential 212 and the holding potential 213 is controlled by the scanning potential 211. In addition, the switching thin film transistor 121 here uses an n-channel type thin film transistor, but a p-channel type transistor may also be used.

In the period 221 in which the pixel is in the display state, the signal potential 212 becomes a high potential, and the high potential is maintained at the holding potential 113. In the period 222 in which the pixel is in the non-display state, the signal potential 212 becomes a low potential, and the holding potential 213 maintains its low potential.

The n-channel current thin film transistor 122 has the characteristics shown in Fig. 4, therefore, the conduction between the common line 114 and the pixel electrode 115 can be controlled according to the potential of the holding voltage 113, that is, the holding potential 213 controls the common potential 214 Conduction with the pixel potential 215. Is the period during which the pixels are displayed 221. The holding voltage 213 is at a high potential. Therefore, the common line 114 is connected to the pixel electrode 115 during the period 222 when the pixel becomes non-display. The holding potential 213 is at a low potential. The element electrodes 115 are cut off.

The organic EL display element 131 has the characteristics shown in FIG. 5, in that a current flows between the pixel electrode 115 and the counter electrode 116 during the period 221 when the pixel is in the display state, and the organic EL display element 131 emits light. In the period 222 when the pixels are not displayed, no current flows and no light is emitted.

Figure 6(a) is a cross-sectional view of the thin-film transistor organic EL display element (1 pixel) of this creative embodiment. Figure 6(b) is a plan view of the thin-film transistor organic EL display element (1 pixel) of this creative embodiment. Section A-A' in Fig. 6(a) corresponds to section A-A' in Fig. 6(b).

In Figure 6, 132 is a hole injection layer, 133 is an organic EL layer, and 151 is a resist.

Also, in this example, the structure and processing of the switching thin film transistor 121 and the n-channel current thin film transistor 122 are used in the thin film transistor liquid crystal display element. The structure and processing of the low temperature polycrystalline thin film transistor Steps, that is, the top gate structure and the processing of the maximum temperature below 600 degrees. However, other structures and processing methods can also be used.

The pixel electrode 115 formed of aluminum and the counter electrode 116 formed of ITO, the hole injection layer 132, and the organic EL display element 131 are formed as an upright organic EL display element 131. In the upright organic EL display element 131, the current direction 141 of the organic EL display element can be set to be opposite to the one formed by ITO. The electrode 116 faces the direction of the pixel electrode 115 formed of aluminum. Regarding the organic EL display element, the structure used here may not be used, as long as the current direction of the organic EL display element can be changed from the counter electrode to the pixel electrode, other structures are acceptable.

In addition, here, the hole injection layer 132 and the organic EL layer 133 are formed by the inkjet printing method using the resist 151 as the separation structure between the pixels, and the counter electrode 116 formed by ITO is formed by sputtering. It is formed by shooting, but other methods are also possible.

In this embodiment, the common potential 214 is a lower potential than the opposite potential 216. Moreover, the current thin film transistor is an n-channel type current thin film transistor 122.

In the period 221 in which the pixel is in the display state, the n-channel current thin film transistor 122 is in the on state. The current flowing through the upright organic EL display element 131, that is, the on-current of the n-channel current thin film transistor 122 is as shown in FIG. 3 and depends on the gate voltage. Here, the gate voltage is the potential difference between the holding potential 213 and the lower one of the common potential 214 and the pixel potential 215. According to this embodiment, the common potential 214 is lower than the pixel potential 215. Therefore, the gate voltage is the potential difference between the holding potential 213 and the common potential 214. This potential difference can be very large, and thus a sufficiently large conduction current can be obtained. In addition, although the on-current of the n-channel current thin film transistor 122 also depends on the drain voltage, the conclusion here remains unchanged.

On the contrary, in order to obtain the required conduction current, it is also possible to maintain the potential 213 is a lower potential, which can reduce the amplitude of the signal potential 212, thereby reducing the amplitude of the scanning potential 211. That is, in the switching thin film transistor 121 or the n-channel current thin film transistor 122, the driving voltage can be reduced without causing deterioration of image quality, or abnormal operation, and reduction of the operable frequency.

In addition, in this embodiment, the signal potential 212 for bringing the pixel into the display state is a potential lower than the counter potential 216.

As mentioned above, during the period 221 when the pixel is in the display state, the on-current of the n-channel current thin film transistor 122 depends on the potential difference between the holding potential 213 and the common potential 214, and does not directly depend on the holding potential 213 and the opposite. Set the potential difference of the potential 216. Therefore, in the n-channel current thin film transistor 122, the holding voltage 213 can be maintained while still ensuring a sufficiently large conduction current, that is, the signal potential 212 that makes the pixel into the display state can be set as compared with the opposite potential 216 Low potential. Furthermore, the amplitude of the signal voltage 212 or the amplitude of the scanning potential 211 can be reduced. That is, in the switching thin film transistor 121 or the n-channel current thin film transistor 122, the driving voltage can be reduced without causing deterioration of image quality or abnormal operation, and reduction of the operable frequency.

In addition, in this embodiment, the signal voltage 212 when the pixel is brought into the non-display state is one that is higher than the common potential 214.

In the period 222 in which the pixel is in the non-display state, when the signal potential 211 is set to a slightly higher potential than the common potential 214, the n-channel current thin film transistor 122 does not completely enter the off state. However, the n-channel current film The resistance between the source and drain of 122 becomes a relatively high resistance as shown in Fig. 3. Therefore, between the common potential 214 and the opposing potential 216, the pixel potential 215 determined by the resistance value of the n-channel current thin film transistor 122 and the resistance value of the upright organic EL display element 131 will become A potential close to the opposite potential 216.

Although the voltage applied to the upright organic EL display element 131 is the potential difference between the pixel potential 215 and the opposing potential 216, as shown in Figure 5, when the voltage is below a certain threshold value, it is in the on-off state and does not Flow current without emitting light. That is, when the threshold voltage of the upright organic EL display element 131 is used to make the signal potential 212 slightly higher than the common potential 214, although the n-channel current thin film transistor 122 cannot be fully turned on, it can still be upright The organic EL display element 131 does not emit light.

Here, by setting the signal potential 212 to bring the pixel into the display state to a higher potential than the common potential 214, the amplitude of the signal potential 212 can be reduced, and the amplitude of the scanning potential 211 can be reduced. That is, in the switching thin film transistor 121 or the n-channel current thin film transistor 122, the driving voltage can be reduced without causing deterioration of pixel quality, or abnormal operation, and reduction of the operable frequency.

In addition, the operation of the organic EL display device with thin film transistors of this embodiment is not as simple as the above, but operates under a more complicated relationship between voltage and current, but approximately and qualitatively, the above description is Can be established.

Example 2

Figure 7 is the organic EL display with thin film transistors in Example 2 of this creation. The equivalent circuit diagram of the device is shown. Figure 8 is the driving voltage diagram of the organic EL display device with thin film transistor of the creative embodiment 2 and Figure 9 is the current-voltage characteristic diagram of the current thin film transistor of the creative embodiment 2 , Figure 10 is a graph showing the current and voltage characteristics of the organic EL display device of Example 2 of the present creation.

In Figure 7, 615 is a pixel electrode formed of ITO, 616 is a counter electrode formed of aluminum, 622 is a p-channel current thin film transistor, and 631 is based on the flow from the pixel electrode 615 to the power supply line 616 An organic EL display element (hereinafter referred to as an inverted organic EL display element) that emits light with a high current. 64 is the direction of the current of the inverted organic EL display element 631, and its direction is opposite to that of FIG. 2. The rest is the same as in the first and second embodiments described above.

In Figure 8, the levels of each potential are different from those in Figure 3, and the others are the same as those in Figure 3.

In Figure 9,<img file="TWM249169U_D0001.tif" />Is the current and voltage characteristics of the p-channel current thin film transistor 622 when the drain voltage is 4V,<img file="TWM249169U_D0002.tif" />It is the current-voltage characteristic of the p-channel current thin film transistor 622 when the drain voltage is 8V.

In Figure 10,<img file="TWM249169U_D0003.tif" />It is the current-voltage characteristic of the inverted organic EL display element 631.

The operation of the organic EL display device with thin film transistors of this embodiment is that since the current thin film transistor is a p-channel type transistor 622, the potential relationship related to the current thin film transistor becomes inverted, and Example 1 is the same.

Figure 11(a) The organic EL display with thin film transistors of the creative embodiment 2 A cross-sectional view of the device (1 pixel) is shown, and Figure 11(b) is a plan view of the organic EL display device (1 pixel) with thin film transistors according to Example 2 of the present creation. Section A-A' in Figure 11(a) corresponds to Section A-A' in Figure 11(b).

In Fig. 11, 632 is a positive hole injection layer, and 633 is an organic EL layer. Others are the same as in Figure 6.

The pixel electrode 615 formed of ITO, the counter electrode 616 formed of aluminum, the hole injection layer 632, and the organic EL layer 633 are formed as an inverted organic display element 631. In this inverted organic EL display element 631. The current direction 641 of the organic EL display element can be a direction from the pixel electrode 615 formed of ITO to the counter electrode 616 formed of aluminum.

In this embodiment, the common potential 714 is a higher potential than the opposite potential 716. Moreover, the current thin film transistor is a p-channel type current thin film transistor 622.

In addition, in this embodiment, the signal potential 712 for bringing the pixel into the display state is a higher potential than the counter potential 716.

In addition, in this embodiment, the signal potential 712 that causes the pixel to be in the non-display state is a potential lower than the common potential 714.

All the effects of the organic EL display device with thin film transistors of this embodiment are also due to the fact that the current thin film transistor is a p-channel thin film transistor 622. Therefore, except that the potential relationship related to the current thin film transistor is inverted, they are all Same as Example 1.

The current thin film transistor 622 of this embodiment is a p-channel type thin film transistor. Due to this configuration, the current thin film transistor 622 can be significantly reduced Deteriorate for a long time. When the p-channel type polycrystalline silicon thin film transistor is formed, the long-term deterioration of the current thin film transistor 622 can be further reduced.

FIG. 14 is a manufacturing step diagram of the current-driven light-emitting display device with thin film transistors according to the above-mentioned creative embodiment.

First, as shown in Figure 14(a), an amorphous silicon layer of 2000 to 600 angstroms is formed on the entire surface of the substrate 1 on the substrate 1.<img file="TWM249169U_D0004.tif" />), applying toughening such as a laser to polycrystallize the amorphous silicon to form a polycrystalline silicon layer. Then, the polycrystalline silicon layer is patterned to form the silicon film 421 in the area of the source drain channel of the switching thin film transistor 121, the first electrode 423 of the capacitor 123, and the source of the current thin film transistor 122 The silicon film 422 in the area of the drain and channel. Next, on the silicon thin films 421, 422, and the first electrode 423, an insulating film 424 constituting a gate insulating film is formed. Next, phosphorus (P) ions are selectively injected into the first electrode 423 to lower the resistance. Next, as shown in FIG. 14(b), gate electrodes 111 and 111' made of tantalum nitride (TaN) are formed on the silicon thin films 421 and 422 via a gate insulating film. Next, a resist mask 42 is formed on the silicon layer 422 that constitutes the current thin film transistor, and the gate is used as the mask film, and phosphorus (P) ions are injected in alignment with each other to form an n-type source on the silicon layer 421. , Drain region. Next, as shown in Figure 14(c), a resist mask 412' is formed on the first silicon layer 421 and the first electrode 423, and on the silicon layer 422, the gate 111' is used as a mask to align itself Boron (B) ions are injected into the ground to form p-type source and drain regions in the silicon layer 422. In this way, 411 is doped with n-channel type impurities to form a switching thin film transistor 621<img file="TWM249169U_D0005.tif" />. At this time, the current thin film transistor 622 is protected by the anti-corrosion mask 42 and is not subject to n-channel type impurity doping. Miscellaneous 411. Next, p-channel type impurities are doped 412 to form a current thin film transistor 622.

Also, although not shown in the figure, when the shift register, sample-and-hold circuit and other thin film transistors constituting the driving circuit part of the driving switching transistor 621 are formed on the same substrate, it can also be the same as the above process. Miscellaneous procedures are formed at the same time.

In addition, the second electrode 425 of the capacitor may be formed of the same material as the gate electrodes 111 and 111' at the same time, or may be formed of other materials.

Next, as shown in FIG. 14(d), after the interlayer insulating film 43 is formed, contact holes are formed, and then electrode layers 426, 427, 428, and 429 made of aluminum or ITO are formed.

Next, an interlayer insulating film 44 is formed, and after planarization, a contact hole is formed. The ITO45 is used to form 1000 to 2000 angstroms, preferably about 1600 angstroms, so that it can be connected to one end electrode of the current thin film transistor. Next, in the area surrounded by the combined layers 46 and 47, an organic EL layer 48 is formed by an inkjet method or the like. After the organic EL layer 48 is formed, 6000 to 8000 angstroms of aluminum/lithium is formed on the organic EL layer as the counter electrode 49. Between the organic EL layer 48 and the counter electrode 49, it can also be set up as shown in Figure 5. Hole injection layer.

Through the above process, a high-performance thin-film transistor-driven organic EL display element can be formed, and the carrier mobility of polycrystalline silicon is exceptionally greater than that of amorphous silicon, so it can operate at high speed.

Especially in this embodiment, when the P-type current thin film transistor 622 and the n-type switching thin film transistor 621 are formed, the driving circuit can be changed. The p-type and n-type thin-film transistors of complementary thin-film transistors such as bit registers, sample-and-hold circuits, etc., are formed at the same time using the above-mentioned embodiments. With this configuration, it is possible to achieve a configuration that reduces the long-term deterioration of the current-reducing thin film transistor 122 without increasing the manufacturing process.

In the above embodiment 1, the current thin film transistor is of the n-channel type, and in the second embodiment, the structure of the current thin film transistor of the p-channel type has been described. The long-term deterioration of the type thin film transistor is reviewed.

Figures 12 and 13 are graphs showing the long-term deterioration of n-channel and p-channel thin film transistors under the same applied voltage conditions, especially polycrystalline thin film transistors. 511 and 512 in Figure 12 are the transfer characteristics of the n-channel thin-film transistor when Vd (drain voltage) = 4V and Vd = 8V before the voltage is applied. In addition, 521 and 522 are the transfer characteristics of the n-channel thin film transistor when Vg (gate voltage) = 0V, Vd = 15V, and a voltage of about 1000 seconds is applied when Vd = 4V and Vd = 8V. 811 and 812 in Figure 13 are the transfer characteristics of the p-channel thin-film transistor when Vd=4V and Vd=8V before applying voltage. In addition, 821 and 822 are the transfer characteristics of p-channel thin film transistors when Vd=4V, Vd=8V after applying voltages of Vg=0V, Vd=15V, and 1000 seconds. Obviously, it can be seen that the p-channel thin film transistor has a small decrease in the on-current and increase in the on-off current.

Taking into account the difference in the long-term degradation characteristics of the p-type and n-type thin film transistors shown in Figures 12 and 13, and at least one of the switching thin film transistors and the current thin film transistors, the p-channel Thin film transistor The body, especially made of p-type polycrystalline silicon thin film transistors, can suppress its long-term deterioration. In addition, not only the current thin film transistors, but also the switching thin film transistors are composed of p-type thin film transistors, so that the characteristics of the display device can be maintained.

In addition, the light-emitting element of the above-mentioned embodiment is an organic EL display element as an example. Of course, it is not limited to an organic EL display element, and is applicable to inorganic EL elements or other current-driven light-emitting elements.

In addition, the display device created by this invention can be used in various current-driven light-emitting elements such as organic EL display elements and inorganic EL display elements, and display devices having switching elements such as thin film transistors that drive these elements.

[The effect of creation]

The display device of this invention has the effect of reducing the driving voltage and restraining long-term deterioration. It can be used in various current-driven light-emitting elements such as organic EL display elements and inorganic EL elements, and display devices with switching elements such as thin film transistors that drive these elements.

<p>1. . . Substrate</p><p>3. . . Data side drive circuit</p><p>4. . . Scan side drive circuit</p><p>7. . . Pixel</p><p>111. . . Scan line</p><p>112. . . Data line</p><p>113. . . Shared line</p><p>114. . . Holding electrode</p><p>115. . . Pixel electrode formed of aluminum</p><p>116. . . Counter electrode made of ITO</p><p>121. . . Switching thin film transistor</p><p>122. . . n-channel current thin film transistor</p><p>123. . . Hold capacitor</p><p>131. . . Upright organic EL display element</p><p>132. . . Hole injection layer</p><p>133. . . Organic EL layer</p><p>141. . . Current direction of current light emitting element</p><p>151. . . Resist</p><p>211. . . Sweep potential</p><p>212. . . Signal potential</p><p>213. . . Hold potential</p><p>214. . . Common potential</p><p>215. . . Pixel potential</p><p>216. . . Opposite potential</p><p>221. . . The period during which the pixel becomes the display state</p><p>222. . . The period during which the pixel is in the non-display state</p><p><img file="TWM249169U_D0006.tif" />. . . When the drain voltage is 4V, the current and voltage characteristics of the n-channel current thin film transistor</p><p><img file="TWM249169U_D0007.tif" />. . . When the drain voltage is 8V, the current and voltage characteristics of the n-channel current thin film transistor</p><p><img file="TWM249169U_D0008.tif" />. . . Current and voltage characteristics of upright organic EL display elements</p><p>611. . . Scan line</p><p>612. . . Data line</p><p>613. . . Shared line</p><p>614. . . Holding electrode</p><p>615. . . Pixel electrode formed with ITO</p><p>616. . . Counter electrode made of aluminum</p><p>621. . . Switching thin film transistor</p><p>622. . . p-channel current thin film transistor</p><p>623. . . Hold capacitor</p><p>631. . . Inverted organic EL display element</p><p>632. . . Hole injection layer</p><p>633. . . Organic EL layer</p><p>641. . . Current direction of current light emitting element</p><p>651. . . Resist</p><p>711. . . Sweep potential</p><p>712. . . Signal potential</p><p>713. . . Hold potential</p><p>714. . . Common potential</p><p>715. . . Pixel potential</p><p>716. . . Opposite potential</p><p>721. . . The period during which the pixel becomes the display state</p><p>722. . . The period during which the pixel is in the non-display state</p><p><img file="TWM249169U_D0009.tif" />. . . When the drain voltage is 4V, the current and voltage characteristics of the p-channel current thin film transistor</p><p><img file="TWM249169U_D0010.tif" />. . . When the drain voltage is 8V, the current and voltage characteristics of the p-channel current thin film transistor</p><p><img file="TWM249169U_D0011.tif" />. . . Current and voltage characteristics of inverted organic EL display elements</p><p>511. . . Transfer characteristics of n-channel thin film transistors when Vd=4V before voltage is applied</p><p>512. . . Transfer characteristics of n-channel thin-film transistors when Vd=8V before voltage is applied</p><p>521. . . Transfer characteristics of n-channel thin-film transistors when Vd=4V after applying voltage</p><p>522. . . Transfer characteristics of n-channel thin-film transistors when Vd=8V after applying voltage</p><p>811. . . Transfer characteristics of p-channel membrane transistors when Vd=4V before voltage is applied</p><p>812. . . One of the p-channel thin film transistors when Vd=8V before voltage is applied Transfer characteristics</p><p>821. . . Transfer characteristics of p-channel thin-film transistors when Vd=4V after applying voltage</p><p>822. . . Transfer characteristics of p-channel thin-film transistors when Vd=8V after applying voltage</p>

Figure 1: Block diagram of the basic structure of the display device using this creation.

Figure 2: The equivalent circuit diagram of the display element with thin film transistors of the creative embodiment 1.

Figure 3: The driving voltage diagram of the display device with thin film transistors of the first embodiment of the invention.

Figure 4: The current-voltage characteristic diagram of the current thin-film transistor of Example 1 of the present creation.

Fig. 5: The current-voltage characteristic diagram of the organic EL display device of Example 1 of the present creation.

Figure 6(a): A cross-sectional view of the organic EL device with thin film transistors in Example 1 of the present creation.

Fig. 6(b): A plan view of the organic EL device with thin film transistors in Example 1 of the present creation.

Fig. 7: The equivalent circuit diagram of the organic EL display device with thin film transistors in Example 2 of the present creation.

Fig. 8: The driving voltage diagram of the organic EL display device with thin film transistors according to Example 2 of the present creation.

Figure 9: The current-voltage characteristic diagram of the current thin-film transistor of Example 2 of the present creation.

Fig. 10: The current-voltage characteristic diagram of the organic EL display device of Example 2 of the present creation.

Figure 11(a): A cross-sectional view of the organic EL display device with thin film transistors in Example 2 of the present creation.

Figure 11(b): A plan view of the organic EL display device with thin film transistors according to Example 2 of the present creation.

Figure 12: Long-term deterioration of n-channel thin film transistors.

Figure 13: Long-term deterioration of p-channel thin film transistors.

Figure 14: The manufacturing engineering drawing of the organic EL display device driven by thin film transistors created by this creation.