Keyboard apparatus

Keyboard device

KEYBOARD APPARATUS

The present invention relates to a keyboard device, and more particularly to a keyboard device having an anti-ghost function.

In order to avoid the use of excessive wiring to increase manufacturing costs, and based on convenience considerations during assembly, etc., many keyboards currently employ a keyboard matrix architecture. Such a keyboard may have a Ghost Key phenomenon.

Please refer to the 1A~1D diagram, which shows a schematic diagram of the occurrence of ghost keys. The button matrix here sets four button units KU(1,1), KU(1,2), KU(2,1), KU(2,2) on two line signal lines C(1), C. (2) Four intersections formed by the two column signal lines R(1) and R(2). The button unit KU(1,1) is located in the first row of the first row, the button unit KU(1,2) is located in the second row of the first row, the button unit KU(2,1) is located in the first column of the second row, and the button unit KU(2,2) is located in the second column of the second row. Wherein, the circle drawn by the bottom of the net represents the pressed button unit, and the circle drawn by the white background represents the button unit that has not been pressed. When any one of the button units is pressed, the row signal line and the column signal line connected to the button unit will be electrically connected to each other. For example, if the button unit KU(1, 1) is pressed, the row signal line C(1) and the column signal line R(1) are turned on each other.

The keyboard controller will continuously scan the voltage on each line of the signal line and detect it. The level of each column signal line. Therefore, if the keyboard controller sends a scan signal to the row signal line C(1) and the button unit KU(1,1) is pressed, the keyboard controller can confirm the button through the high level of the column signal line R(1). The unit KU (1, 1) is pressed.

In the first picture, it is assumed that the button unit KU(1,1) is not pressed, but the button units KU(1,2), KU(2,1), KU(2,2) are pressed. under. In this case, the scan voltage sent by the keyboard controller from the line signal line C(1) may be made through the button units KU(1, 2), KU(2, 2), KU(2, 1). The signal line R(1) is at a high level. In conjunction, the keyboard controller determines that the button unit KU(1,1) is turned on because the column signal line R(1) is at a high level.

Therefore, the result judged by the keyboard controller for any of the pressing conditions of the 1A to 1D drawings may be mistaken for the button that has not been pressed (that is, the button unit KU (1, 1) of the 1A map is misjudged, The button unit KU (1, 2) of Fig. 1B, the button unit KU (2, 1) of Fig. 1C, and the button unit KU (2, 2) of Fig. 1D are pressed, causing a misjudgment. It is a ghost key phenomenon.

According to the above, the ghost key phenomenon means that the keyboard controller may mistakenly press the button unit that is not pressed as being pressed when a plurality of button units around a button unit that is not pressed are simultaneously pressed. Case. How to solve the above-mentioned ghost key phenomenon is one of the topics that the industry is working on.

The present invention relates to a keyboard device having an anti-ghost function.

According to an aspect of the invention, a keyboard device is provided, comprising: M driving circuits DC(1)~DC(M); N transition circuits TC(1)~TC(N), wherein M and N are positive integers a control module having N input ports and M output ports, wherein the N input ports are electrically coupled to the N transition circuits, respectively TC(1)~TC(N), and the M output turns are electrically coupled to the M drive circuits DC(1)~DC(M), respectively; M line signal lines C(1)~C(M) And electrically coupled to the M driving circuits DC(1)~DC(M); N column signal lines R(1)~R(N), respectively electrically coupled to the N transition circuits TC ( 1)~TC(N), wherein the N column signal lines R(1)~R(N) form MxN intersections with the M row signal lines C(1)~C(M); and MxN buttons Units KU(1,1)~KU(M,N) are respectively set at the MxN intersections, and one of the MxN button units KU(1,1)~KU(M,N) is KU(i , j) includes a switch sw(i,j), where i is a positive integer less than or equal to M, and j is a positive integer less than or equal to N, and the two ends of the switch sw(i, j) are respectively electrically Coupling to a row of signal lines C(i) and a column of signal lines R(j), wherein when the button unit KU(i,j) is pressed, the switch sw(i,j) causes the row of signal lines C(i) And the column signal line R(j) is electrically connected; wherein the control module is respectively for the M row signal lines C(1)~C in the M scan periods scan(1)~scan(M) (M) scanning, the scanning of the M line signal lines C(1)~C(M) includes: (a) setting one a starting value of the number k, the starting value of the variable k is a positive integer less than or equal to M; (b) in a scan period scan(k): (b1) the control module via the M outputs That is, a scan voltage is supplied to the kth row signal line C(k) to scan the row signal line C(k), and an unscanned voltage is supplied to the other row signal lines C(1) to C ( K-1) and C(k+1)~C(M), wherein the level of the unscanned voltage is lower than the level of the scanning voltage; (b2) using the N transition circuits TC(1)~ TC(N) detects N button units KU(k, 1)~KU electrically coupled to a row of signal lines C(k) in the MxN button units KU(1,1)~KU(M,N) (k, N) conduction state, where (1) the N button lists In the element KU(k,1)~KU(k,N), when a button unit KU(k, at the intersection of the kth row signal line C(k) and a xth column signal line R(x) is present, x) When pressed, one of the switches sw(k, x) included in the button unit KU(k, x) transmits the scan voltage on the row signal line C(k) to a column of signal lines R(x) The scan voltage turns on a transition circuit TC(x) connected to the column signal line R(x), and the output voltage Rout(x) generated by the transition circuit TC(x) is a first voltage value. Where x is a positive integer less than or equal to N; (2) in the MxN button units KU(1,1)~KU(M,N), when a signal line C(m) is located in a mth row When a button unit KU(m, x) at the intersection of the xth column signal line R(x) is pressed, one of the switches sw(m, x) included in the button unit KU(m, x) The unscanned voltage on the row signal line C(m) is transmitted to a column of signal lines R(x), where m is a positive integer less than or equal to M, and m is not equal to the variable k; (3) when the transition state When the circuit TC(x) is turned on, the control module determines that the button unit KU(k, x) is pressed; and (4) when the transition circuit TC(x) is not turned on, the control module determines the button unit KU(k,x) Pressed; and (c) update the variable k, the updated variable k corresponds to the line signal line that has not been scanned, and the steps (b1), (b2) and (c) are repeatedly performed according to the updated k value. Until all the line signal lines have been scanned.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

<p>111aM inputsport</p><p>111bN outputport</p><p>C(1), C(k), C(M), C(2), C(3), C(4) lines of signal lines</p><p>R(1), R(x), R(N), R(2), R(3), R(4) column signal lines</p><p>KU(1,1), KU(1,2), KU(2,1), KU(2,2), KU(k,1), KU(M,1), KU(1,x), KU (k, x), KU (M, x), KU (1, N), KU (k, N), KU (M, N), KU (3, 1), KU (4, 1), KU ( 3, 2), KU (4, 2), KU (1, 3), KU (2, 3), KU (3, 3), KU (4, 3), KU (1, 4), KU (2 , 4), KU (3, 4), KU (4, 4) button unit</p><p>10, 60 keyboard device</p><p>11Computer motherboard</p><p>113, 913 drive module</p><p>DC (1), DC (k), DC (M) drive circuit</p><p>111, 911 control module</p><p>115, 915 reading module</p><p>TC(1), TC(x), TC(N), TC(2), TC(3), TC(4)</p><p>117a, 117b first connector</p><p>133a, 133b second connector</p><p>13 keyboard module</p><p>131, 931Key Matrix</p><p>Cin(1), Cin(k), Cin(M), Cin(2) input lines</p><p>Rout(1), Rout(x), Rout(N), Rout(2), Rout(3), Rout(4) output voltage</p><p>BJT (x)O crystal</p><p>Steps S41, S43, S431, S433, S433a, S433b, S433c, S45, S47, S51, S52, S53, S54, S55, S56, S57</p><p>431voltage circuit</p><p>433 Pull-up circuit</p><p>435Switch circuit</p><p>N_Rout(x), N_Rout(1), N_Rout(2), N_Rout(3), N_Rout(4) column read node</p><p>N_R(x), N_R(1), N_R(2), N_R(3), N_R(4) column signal nodes</p><p>N_b(x), N_b(1), N_b(2), N_b(3), N_b(4)Comparative node</p><p>Sw(k,x), sw(1,1), sw(1,2), sw(1,3), sw(1,4), sw(2,1), sw(2,2),sw (2,3), sw(2,4), sw(3,1), sw(3,2), sw(3,3), sw(3,4), sw(4,1), sw( 4, 2), sw (4, 3), sw (4, 4) switch</p><p>r(k,x), r(1,1), r(1,2), r(1,3), r(1,4), r(2,1), r(2,2),r (2,3), r(2,4), r(3,1), r(3,2), r(3,3), r(3,4), r(4,1),r( 4,2), r(4,3), r(4,4), rc(1), rc(2), rc(3), rc(4), rb1(1), rb2(1), rb1 (2), rb2(2), rb1(3), rb2(3), rb1(4), rb2(4), r_<i>∥</i>resistance</p><p>Scan(1), scan(2), scan(3), scan(4) scan cycle</p><p>V_ScanScan voltage</p><p>V_Un-scanUnscanned voltage</p><p>V_RoutHHigh standard</p><p>V_RoutLlow standard</p><p>Vth threshold voltage</p><p>V1on, V2on, V4on voltage</p><p>T0, t1, t2, t3, t4, t5</p><p>T1, T2, T3, T4, T5 time zone</p><p>82, 84 equivalent circuit</p><p>821, 841 upper part</p><p>823, 843 below</p><p>Subsection 843a, 843b</p><p>9130Boost circuit</p><p>MCUout controller output line</p><p>MCUinController input line</p><p>Csel (1), Csel (2), Csel (Q) controller line selection line</p><p>Rsel (1), Rsel (2), Rsel (P) controller column selection line</p><p>9111dController Inputport</p><p>9111cP column selectionport</p><p>9115Multiplexer</p><p>9115cMultiple output</p><p>9115aP column settingsport</p><p>9115bN transitional inputsport</p><p>9111aController outputport</p><p>9111bQ line selectionport</p><p>9113 multiplexer</p><p>9113cSolving multiplex inputport</p><p>9113aQ line settingsport</p><p>9113bM drive outputsport</p>

Figure 1A~1D, which shows a schematic diagram of the occurrence of ghost keys.

Figure 2 is a schematic illustration of one embodiment of a keyboard device disclosed herein.

Fig. 3 is a flow chart showing a continuation of scanning according to the keyboard apparatus of the embodiment of the present disclosure.

FIG. 4 is a schematic diagram showing a pressing condition of a keyboard device for determining an embodiment of the present disclosure, taking a 4×4 button matrix as an example.

Fig. 5 is a schematic diagram showing the use of the button unit KU(k, x) in conjunction with the transition circuit TC(x).

Fig. 6 is a waveform diagram showing the pressing state of the keyboard device corresponding to Fig. 4.

Figure 7 is a schematic diagram of the key unit and the transition circuit of the second column and the fourth column during the scanning period scan(1) of the keyboard device of Figure 4.

FIG. 8A is a schematic diagram showing an equivalent circuit formed by the button units KU(1, 2) to KU(4, 2) of the second column during the scan period scan(1) of the keyboard device of FIG. 4.

FIG. 8B is a schematic diagram showing an equivalent circuit formed by the button units KU(1, 4) to KU(4, 4) of the fourth column during the scan period scan(1) of the keyboard device of FIG. 4.

Figure 9 is a schematic diagram of the keyboard device of the embodiment of the present invention in combination with a booster circuit, a demultiplexer, and a multiplexer.

Please refer to FIG. 2 and FIG. 4, FIG. 2 is a block diagram of an embodiment of the keyboard device for avoiding ghost key phenomenon, and FIG. 4 is an example of a button matrix of 4 (row) x 4 (column). An example of a detailed circuit diagram of the key matrix and the transition circuit of Fig. 2 will be described. Because the component mounting area of the membrane flexible circuit board is limited, the main circuit components, such as the driving module 113, the control module 111, and the reading module 115 are all disposed on the computer motherboard 11 of FIG. on. The keyboard module 13 at the lower left of FIG. 2 mainly includes a button matrix 131 composed of M (row) x N (column) button units KU (1, 1) ~ KU (M, N), and this M (row) x N (column) buttons The cells KU(1,1)~KU(M,N) are disposed on the thin film flexible circuit board.

As shown in FIG. 2, the first connectors 117a, 117b, the M drive circuits DC(1) to DC(M), the N transition circuits TC(1) to TC(N), and the control module 111 are all provided. On the computer motherboard 11 . Second connectors 133a, 133b, M line signal lines C(1) to C(M), N column signal lines R(1) to R(N), and MxN button units KU(1, 1)~KU (M, N) is disposed on the keyboard module 13. The first connectors 117a, 117b may be integrally or separately disposed, as are the second connectors 133a, 133b. When the keyboard module 13 is assembled to the computer motherboard 11, the first connectors 117a, 117b are connected to the second connectors 133a, 133b, thereby electrically coupling the M driving circuits DC(1)~DC(M) to M row signal lines C(1)~C(M), and electrically coupling N transition circuits TC(1)~TC(N) to N column signal lines R(1)~R(N).

The control module 111 has N input ports 111b and M output ports 111a. The output port 111a is electrically coupled to the M driving circuits DC(1) to DC(M) of the driving module 113 through the M row input lines Cin(1) to Cin(M), and the driving circuit DC(1)~DC( M) is further electrically coupled to the key matrix 131 through the M line signal lines C(1) to C(M). The control module 111 is electrically coupled to the N transition circuits TC(1) to TC(N) in the read module 115 through the N column read lines. The transition circuits TC(1) to TC(N) are electrically coupled to the key matrix 131 through the N column signal lines R(1) to R(N). The button matrix 131 includes MxN button units, and the MxN button units are respectively dispersedly arranged in the MxN formed by the row signal lines C(1) to C(M) and the column signal lines R(1) to R(N). One of the rendezvous. More specific operation of the key matrix and the transition circuit will be further explained below in conjunction with FIG.

Through the row input lines Cin(1) to Cin(M), the control module 111 transmits the M row output signals to the drive circuits DC(1) to DC(M), respectively. Drive circuit DC (1) ~ DC (M) and then through Corresponding to the parallel connected row signal lines C(1)~C(M), the scanning voltage V will be_Scan(example: 5V) or unscanned voltage V_Un-scan(for example: 0V) is transferred to all button units located on the same line. For example, (1) when the control module 111 outputs a row output signal representing a high level to the driving circuit DC(1) through the row input line Cin(1), the driving circuit DC(1) transmits the first row signal. Line C(1) will scan voltage V_ScanOutput to all button units KU(1,1), KU(1,x)...KU(1,N) connected to the first line signal line C(1); (2) Conversely, when the control module 111 transmits When the row input line Cin(1) outputs a low-level row output signal to the driving circuit DC(1), the driving circuit DC(1) transmits the unscanned voltage V through the first row signal line C(1)._Un-scanOutput to all button units KU(1,1), KU(1,x)...KU(1,N) connected to the first line signal line C(1).

When the control module 111 wants to perform the kth scan period scan(k), that is, all the button units KU(k, 1), KU(k, x) connected to the kth line signal line C(k) are scanned... In the case of KU(k, N), the control module 111 simultaneously (1) outputs the scanning voltage V having a high level to the kth row driving circuit DC(k) currently selected for scanning._Scan(2) output the remaining unscanned voltage V of the other row driving circuits DC(1)~DC(k-1), DC(k+1)~DC(M) which are not currently being scanned._Un-scan. Where k is an integer value between 1 and M. The transition circuits TC(1) to TC(N) receive the voltages of the column signal lines R(1) to R(N), and then read the lines in accordance with the voltages of the column signal lines R(1) to R(N). Different output voltages Rout(1)~Rout(N) are generated. On the other hand, the control module 111 determines the button matrix 131 by the output voltages Rout(1) to Rout(N) generated by the transition circuits TC(1) to TC(N) of the read module 115 in the column read lines. Whether the button unit inside is turned on or not.

For example, after the transition circuit TC(x) is turned on or off according to the voltage of the column signal line R(x), and then the output voltage Rout(x) is changed, the control module 111 is further converted according to the input. The output voltage Rout(x) judges that the button unit KU(k, x) located at the intersection of the kth row and the xth column is in an on state or an off state. How the control module 111 is matched with the transition circuit TC(x) located in the xth column to determine whether the button unit KU(k, x) is in an on state or an off state will be described in detail below with reference to FIG.

Please refer to FIG. 3, which is a flow chart of performing a round-trip scanning according to the keyboard device of the embodiment of the present disclosure. The control module 111 performs M scanning periods scan(1) to scan(M) for the M row signal lines C(1) to C(M) through the driving modules DC(1) to DC(M). The following is a variable k representing the number of rows selected for scanning. The following describes the process steps:

Step S41: Set the starting value of the variable k (for example, 1). Wherein, the starting value of the variable k is a positive integer less than or equal to M.

Step S43: Enter the scan period scan(k). The control module 111 scans all of the button units KU(k, 1) to KU(1, N) connected to the k-th line signal line C(k) in this scanning period scan(k).

Step S431: The control module 111 controls the driving modules DC(1) to DC(M) via the output port 111a, and (1) causes the kth output to provide the scanning voltage V._ScanTo the kth row signal line C(k); and at the same time (2) to make the 1~(k-1), (k+1)~M output ports provide the unscanned voltage V_Un-scanThe line signal lines C(1)~C(k-1) and C(k+1)~C(M). Where the unscanned voltage V_Un-scanThe level is lower than the scan voltage V_ScanThe level of the.

Step S433: Through the N transition circuits TC(1) to TC(N), the control module 111 detects N button units KU(k, 1)~KU (which are electrically coupled to the row signal line C(k). The conduction state of k, N). For example, after the output circuits Rout(1), Rout(x), and Rout(N) are generated by the column read lines TC(1), TC(x), and TC(N), the control module 111 outputs according to the output. Voltage Rout(1), Rout(x), The level of Rout(N) determines whether or not the button unit KU(k, 1), KU(k, x), KU(k, N) is pressed (steps S433a, S433b, and S433c). The manner in which the transition circuits TC(1) to TC(N) generate the output voltages Rout(1) to Rout(N) in the column read lines will be described later in conjunction with FIGS. 4 to 6.

Step S45: After the scan period scan(k) ends, it is judged whether the variable k is smaller than M. If so, the variable k is updated with (k+1) (step S47), and steps S431 and S433 are repeatedly executed based on the updated variable k. If not, the representative line signal lines C(1)~C(M) have been scanned in turn, and the process ends.

In other applications, the variable k may be updated in other ways as long as the updated variable k corresponds to a row signal line that has not been scanned. Steps S431 and S433 are also repeatedly executed in accordance with the value of the updated variable k until all the line signal lines C(1) to C(M) have been scanned.

See Figure 4. For convenience of explanation, Figure 4 assumes that the button units on different columns have different pressing conditions. Wherein, it is assumed that the button units KU(1,1)~KU(4,1) located in the first column are not pressed; assuming that the button unit KU(1,2) on the second column is pressed, the button unit KU(2) , 2) ~ KU (4, 2) is not pressed; assume that the button units KU (1, 3), KU (2, 3) on the third column are pressed, the button unit KU (3, 3), KU (4 3) is not pressed; and, assuming that the button units KU(1, 4)~KU(4, 4) on the fourth column are all pressed.

According to the concept of the present disclosure, the control module 111 will independently determine the pressing state for each of the button units KU(1,1)~KU(M,N). Figure 5 is one of the plurality of button units shown in Figures 2 and 4, for example, the button unit KU(k, x), displayed in the button matrix, in the kth row and the xth column The button unit KU(k, x) and its corresponding transition circuit TC(x).

Please refer to FIG. 5, which is a schematic diagram of the use of the button unit KU(k, x) with the transition circuit TC(x). The following also explains how the output voltage Rout(x) generated by the transition circuit TC(x) changes depending on whether the button unit KU(k, x) is pressed or not. The button unit KU(k, x) contains the switch sw(k, x) and the resistance r(k, x). The two ends of the switch sw(k, x) are electrically coupled to one end of the row signal line C(k) and the resistor r(k, x), respectively, and the other end of the resistor is electrically coupled to the column signal line R(x). The voltage received by the row signal line C(k) may be the scan voltage V._ScanOr unscanned voltage V_Un-scan. When the button unit KU(k, x) is pressed, the switch sw(k, x) electrically connects the row signal line C(k) and the column signal line R(x).

According to the concept of the present disclosure, the transition circuit TC(x) includes a voltage dividing circuit 431, a switching circuit 435, and a pull-up circuit 433. The pull-up circuit 433 is configured to transfer the logic high power supply (Vdd) to the column read node N._Rout(x). The voltage dividing circuit 431 is electrically coupled to the column signal line R(x), and generates a comparison node N according to the voltage of the column signal line R(x)_b(x)Voltage. Compare node N_b(x)The voltage will be further used to determine if the switching circuit 435 is conducting.

The switch circuit 435 may include an NPN type bipolar junction transistor (BJT) BJT (x). The transistor BJT(x) has a base B(x) electrically coupled to the column signal line R(x), an emitter E(x) electrically coupled to the ground voltage (Gnd), and a kth input portCollector C(x) electrically coupled to a logic high supply. When the transistor BJT(x) is turned on, the transition circuit TC(x) produces a low level output voltage Rout(x). When the transistor BJT(x) is non-conducting, the transition circuit TC(x) produces a high level of output voltage Rout(x).

The transition circuit according to the present disclosure is not limited to the practice of FIG. For example, the switch circuit 435 can be replaced by a metal-oxide semiconductor (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET for short), reverse logic gate, and the like. that is, Any component having a similar transition function can be used as the switch circuit 435. Furthermore, the voltage level and current flow direction used by the switch circuit 435 can be changed depending on the components used. For example, driving with a reverse level is used for driving and reading.

Please refer to Fig. 6, which is a waveform diagram of the pressing condition of the keyboard device corresponding to Fig. 4. This figure is the voltage change of the row signal lines C(1)~C(4) from top to bottom; the comparison node N corresponding to the transition circuit TC(1)_b(1)Voltage, output voltage Rout(1); comparison node N corresponding to the transition circuit TC(2)_b(2)Voltage, output voltage Rout(2); comparison node N corresponding to the transition circuit TC(3)_b(3)Voltage, output voltage Rout(3); comparison node N corresponding to the transition circuit TC(4)_b(4)Voltage, output voltage Rout (4).

Here, the time point t0 and the time point t1 are defined as the time zone T1; the time point t1 and the time point t2 are defined as the time zone T2, and the like. Wherein, the length of each time segment is equivalent to the length of one scanning cycle. The control module 111 scans the row signal lines C(1) to C(4) by the drive circuits DC(1) to DC(4) in the scan periods scan(1) to scan(4), respectively. After the scan period scan(1)~scan(4) ends, the control module 111 will resume execution from the scan period scan(1). Therefore, both the time zone T1 and the time zone T5 correspond to the scan period scan(1). The scanning cycle scan(1)~scan(2) is taken as an example to illustrate how the transition circuit TC(1)~TC(4) of Fig. 4 generates the output voltage Rout(1) according to the pressing of the button unit. Rout (4).

First, the change of each signal in the scan period scan(1) will be described. In the scan period scan(1), the row signal line C(1) is the scan voltage V._Scan(Example: 5V), the line signal C(2)~C(4) is the unscanned voltage V_Un-scan(Example: 0V). The row signal line C(1) will scan the voltage V during the scan period scan(1)_ScanAfter being transmitted to the button unit KU(1,1)~KU(1,4) of the first row, the control module 111 reads the output voltage Rout(1)~Rout from the transition circuits TC(1)~TC(4). (4) After, used to judge the location The respective pressing states of the button units KU(1,1)~KU(1,4) of one row.

Since the button unit KU(1,1) is off, the scanning voltage V of the line signal line C(1)_ScanIt will not be transferred to the transition circuit TC(1). Therefore, compare node N_b(1)It is in a floating state and the transistor BJT(1) is not turned on. In conjunction with the transistor BJT (1) is not turned on, the output voltage Rout (1) is high level V_RoutH. Since the button unit KU(1, 2) is turned on, the scanning voltage V of the row signal line C(1)_ScanWill be transmitted to the comparison node N via the switch sw(1, 2), the resistor r(1, 2), and the voltage dividing circuit._b(2); therefore compare node N_b(2)The voltage is higher than the threshold voltage Vth of the transistor BJT(2), causing the transistor BJT(2) to be turned on, thereby making the output voltage Rout(2) low._RoutL. Since the button unit KU(1, 3) is turned on, the scanning voltage V of the row signal line C(1)_ScanWill be transmitted to the comparison node N via the switch sw(1,3), the resistor r(1,3), and the voltage dividing circuit._b(3); therefore compare node N_b(3)The voltage is higher than the threshold voltage Vth of the transistor BJT(3), causing the transistor BJT(3) to be turned on, thereby making the output voltage Rout(3) low._RoutL. Similarly, since the button unit KU(1, 4) is turned on, the scanning voltage V of the row signal line C(1) is turned on._ScanWill be transmitted to the comparison node N via the switch sw(1,4), the resistor r(1,4), and the voltage dividing circuit._b(4); therefore compare node N_b(4)The voltage is higher than the threshold voltage Vth of the transistor BJT(4), turning on the transistor BJT(4), thereby making the output voltage Rout(4) low._RoutL。

As shown in Fig. 4, among the button units KU(1,1)~KU(1,4) located in the first row, only the button unit KU(1,1) is off, and the button unit KU(1,2) ) ~ KU (1, 4) are all conductive. Therefore, only the output voltage Rout(1) generated by the transition circuit TC(1) is a high level V._RoutH, and the output voltages Rout(2)~Rout(4) generated by the transition circuit TC(2)~TC(4) are all low level V_RoutL. Accordingly, the control module 111 can determine whether the button unit KU(1,1)~KU(1,4) is pressed according to the output voltage Rout(1)~Rout(4) at the level of the scan period scan(1). .

Incidentally, although in the scan period scan(1), compare node N_b(2), N_b(3), N_b(4)The voltage is greater than the threshold voltage Vth, but it can be seen that the comparison node N_b(2), N_b(3), N_b(4)The voltage is still somewhat different. Wherein, the comparison node N_b(2)Voltage V1on is the highest, compare node N_b(3)Voltage V2on second, compare node N_b(4)The voltage V4on is the lowest. About comparing node N_b(2), N_b(3), N_b(4)The reason for the difference in voltage will be explained in Figures 7, 8A and 8B.

Next, the change of each signal in the scan period scan(2) will be described. In the scan period scan(2), the row signal line C(2) is the scan voltage V._Scan(Example: 5V), the line signal lines C(1), C(3), C(4) are unscanned voltages V_Un-scan(Example: 0V). The row signal line C(2) will match the reading result of the transition circuit TC(1)~TC(4) in the scan period scan(2), and judge the button unit KU(2,1)~KU located in the second row ( 2, 4) respective pressing states.

Since the button unit KU(2, 1) is off, the scanning voltage V of the line signal line C(2)_ScanIt will not be transferred to the transition circuit TC(1). Therefore, compare node N_b(1)It is in a floating state and the transistor BJT(1) is not turned on. In conjunction with the transistor BJT (1) is not turned on, the output voltage Rout (1) is high level V_RoutH. Since the button unit KU(2, 2) is off, the scanning voltage V of the line signal line C(2)_ScanIt will not be transferred to the transition circuit TC(2). Therefore, compare node N_b(2)It is in a floating state and the transistor BJT(2) is not turned on. In connection with the transistor BJT (2) is not turned on, the output voltage Rout (2) is high level V_RoutH. Since the button unit KU(2, 3) is turned on, the scanning voltage V of the row signal line C(2)_ScanWill be transmitted to the comparison node N via the switch sw(2,3) and the resistor r(2,3)_b(3). Therefore, compare node N_b(3)The voltage is higher than the threshold voltage Vth. Associated, because the transistor BJT (3) is turned on, the output voltage Rout (3) is low level V_RoutL. Since the button unit KU(2, 4) is turned on, the scanning voltage V of the row signal line C(2)_ScanWill be transmitted to the comparison node N via the switch sw(2,4) and the resistor r(2,4)_b(4). Therefore, compare node N_b(4)The voltage is higher than the threshold voltage Vth. In conjunction, the transistor BJT(4) will be turned on and the output voltage Rout(4) will be low._RoutL。

Similarly, in the scan period scan(3), the row signal line C(3) is the scan voltage V._Scan, the line signal lines C(1), C(2), C(4) are unscanned voltages V_Un-scan. At this time, the result of reading by the transition circuits TC(1) to TC(4) will correspond to the respective pressed states of the button units KU(3, 1) to KU(3, 4) which are also located in the third row. Furthermore, in the scan period scan(4), the row signal line C(4) is the scan voltage V._Scan, the line signal line C(1)~C(3) is the unscanned voltage V_Un-scan. At this time, the result of reading by the transition circuits TC(1) to TC(4) will correspond to the respective pressed states of the button units KU(4, 1) to KU(4, 4) which are also located in the fourth row.

In Fig. 4, the button units KU (1, 2), KU (2, 2), KU (1, 3), and KU (2, 3) correspond to the pressing condition of the first C-picture. Figure 6 shows the signals of the transition circuits TC(2) and TC(3) in bold black dotted boxes. How to use the button units KU(1,2), KU(2,2), KU(1,3), The KU (2, 3) is pressed to change the level. According to the waveform of FIG. 6, the control module 111 can be in the level of the scan period scan(1) according to the output voltages Rout(2) and Rout(3) (both are low level V)._RoutL), it is judged that the button units KU (1, 2) and KU (1, 3) are all turned on. In addition, the control module 111 can be in the level of the scan period scan(2) according to the output voltages Rout(2) and Rout(3) (the former is a high level V)._RoutHThe latter is a low level V_RoutL), it is judged that the button unit KU (2, 2) is off, and the button unit KU (2, 3) is turned on.

In FIG. 4, when the row signal line C(2) receives the scan voltage V_Scan(for example, 5V), the current flowing from the line signal line C(2) flows to the unscanned voltage V after flowing through the button units KU(2, 3) and KU(1, 3)._Un-scanLine signal line C(1) (for example: 0V). Because the row signal line C(1) has a lower unscanned voltage V_Un-scanTherefore, the scanning voltage V_ScanThe derived current will be directed to the unscanned voltage source of row signal line C(1) and will no longer flow from button unit KU(1,2) to column signal line R(2) to affect comparison node N._b(2)Voltage. Therefore comparing node N_b(2)The voltage does not The transistor BJT(2) of the transition circuit TC(2) is turned on. Accordingly, the control module 111 can correctly determine that the button unit KU(2, 2) is not pressed according to the conduction state of the transition circuit TC(2), and does not show the state as shown in FIG. 1C. In the ground, the button unit KU (2, 2) is erroneously determined to be in a pressed state and a ghost key phenomenon is generated. Therefore, according to the concept of the present disclosure, in the case where a plurality of key units are simultaneously pressed, the ghost key phenomenon can be effectively avoided.

Please refer to FIG. 7 , which is a schematic diagram of the button unit and the transition circuit of the second column and the fourth column during the scanning period scan(1) of the keyboard device of FIG. 4 . The upper part of Fig. 7 corresponds to the button unit KU(1, 2)~KU(4, 2) of the second column, and the transition circuit TC(2). The lower part of Fig. 7 corresponds to the button unit KU(1, 4)~KU(4, 4) of the fourth column, and the transition circuit TC(4). Here, the switches and resistors in each button unit are drawn to illustrate the flow of current.

During the scan period scan(1), the current starts from the high level line signal line C(1), flows through the switch sw(1, 2) of the button unit KU(1, 2) and the resistor r(1, 2) to Column signal node N_R(2). After that, the current is again from the column signal node N_R(2)Resistance rb1(2) flowing through the transition circuit TC(2), comparison node N_b(2), resistance rb2 (2). Wherein, since the switches sw(2, 2), sw(3, 2), and sw(4, 2) are not turned on, during the scan period scan(1), the row signal lines C(2) to C(4) Low level (unscanned voltage V_Un-scan) does not affect the level of the column signal line R(2).

During the scan period scan(1), the current starts from the high level line signal line C(1), and flows through the switch sw(1, 4) of the button unit KU(1, 4) and the resistor r(1, 4) to Column signal node N_R(4). After that, the current will branch into four sub-currents. One of the sub-currents will be from the column signal node N_R(4)After flowing through the transition circuit TC(4), it flows to the ground terminal; the remaining three sub-currents flow to the row signal line C(2)~C(4) via the button units KU(2,4)~KU(4,4). ).

As the voltage of the line signal lines C(1) to C(4) changes depending on the scanning period For the sake of the same, the pressed button units KU(1,4)~KU(4,4) also have different effects on the voltage of the column signal line R(4). During the scan period scan(1), when the button unit KU(1, 4) is pressed, the switch sw(1, 4) will scan the voltage V_ScanIt is transmitted to the column signal line R(4), and the voltage of the column signal line R(4) is raised. On the other hand, although the button units KU(2,4)~KU(4,4) are also pressed, during the scan period scan(1), the switches sw(2,4)~sw(4,4) are Unscanned voltage V on row signal lines C(2)~C(4)_Un-scanIt is transmitted to the column signal line R(4), and the voltage of the column signal line R(4) is lowered.

Please refer to FIG. 8A, which is a schematic diagram of the equivalent circuit formed by the second column button unit during the scan period scan(1) of the keyboard device of FIG. 4. This figure corresponds to the current loop corresponding to the button unit in the second column of Fig. 4, as shown in Fig. 7.

In FIG. 8A, the equivalent circuit 82 can be a column signal node N._R(2)Divided into two parts, the upper part 821 is the resistance r (1, 2), and the lower part 823 is the resistance rb1 (2), rb2 (2). According to this, the column signal node N_R(2)The voltage can be obtained by the voltage division relationship of the resistor, as shown in equation (1).

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Further, the comparison node N can be calculated according to the partial pressure of the resistor_b(2)The voltage is as shown in equation (2).

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Please refer to FIG. 8B , which is a schematic diagram of the equivalent circuit formed by the button unit of the fourth column during the scanning period scan(1) of the keyboard device of FIG. 4 . This pattern corresponds to the 8th As shown in the figure, the current loop corresponding to the button unit in the fourth column of Fig. 4 is shown. In FIG. 8B, the equivalent circuit 84 can be made up of the column signal node N._R(4)Divided into two parts, the upper part 841 is the resistance r (1, 4), and the lower part 843 is the resistance r (2, 4), r (3, 4), r (4, 4), rb1 (4), rb2 (4). The lower portion 843 can be further divided into two sub-portions 843a, 843b. The sub-portion 843a corresponds to the resistances r(2, 4), r(3, 4), r(4, 4) of the key matrix; the sub-portion 843b corresponds to the resistance rb1(4) of the bit-state circuit. , rb2 (4).

For convenience of explanation, the resistor rb(4) is defined here as a series connection of resistors rb1(4), rb2(4) (ie, rb(4)=rb1(4)+rb2(4)), and a parallel resistance r is defined._<i>∥</i>This is equivalent to the parallel result of the resistors r(2,4), r(3,4), r(4,4) located in the unscanned row, and the resistor rb(4) connected to the base. That is, the parallel resistance r_<i>∥</i>It can be expressed as equation (3).

<maths><img id="" he="515" wi="1967" file="TW201719337A_D0003.tif" alt="" img-content="drawing" img-format="tif" orientation="portrait" inline="no" /></maths>

According to this, the column signal node N_R(4)Voltage, through resistor r (1, 4), and shunt resistor r_<i>∥</i>The partial pressure relationship is derived. Column signal node N_R(4)The voltage is as shown in equation (4).

<maths><img id="" he="154" wi="1941" file="TW201719337A_D0004.tif" alt="" img-content="drawing" img-format="tif" orientation="portrait" inline="no" /></maths>

Similarly, according to the voltage division relationship of the resistor, the comparison node N is calculated._b(4)The voltage is as shown in equation (5).

<maths><img id="" he="167" wi="1949" file="TW201719337A_D0005.tif" alt="" img-content="drawing" img-format="tif" orientation="portrait" inline="no" /></maths>

Please also refer to the description of Figures 8A and 8B. In general, rb1(2)=rb1(4), rb2(2)=rb2(4). Because the transition circuit TC(4) is based on the comparison node N_b(4)Voltage determines whether or not Pass, and then change the output voltage Rout (4). Thereafter, the control module 111 can determine whether the button unit KU (1, 4) is pressed according to the output voltage Rout (4); therefore, when the button unit KU (1, 4) is pressed, regardless of the button unit KU (2, 4) )~KU(4,4) is also pressed at the same time to turn on one, two or three, all need to ensure the column signal node N_R(4)The voltage is high enough (for example, 0.7V above the threshold voltage of the transistor BJT (4)), so that the subsequent transition circuit TC (4) can make a correct comparison judgment result. Also, according to the comparison of the formula (1) and the formula (4), it can be seen that the scan voltage V_ScanThe multiplied coefficient size will affect the column signal node N_R(2), N_R(4)Voltage. Due to the parallel resistance r_<i>∥</i>For the parallel connection of multiple resistors, the resistance value must be smaller than the resistance rb(2)=rb1(2)+rb2(2). According to this, the column signal node N of the equation (4) can be judged._R(4)The voltage must be compared to the column signal node N of equation (1)_R(2)The voltage is small, and the comparison node N of equation (5)_b(4)Certain comparison node N of equation (2)_b(2)small.

Comparing Figures 8A and 8B, it can be seen that when more than one button unit is pressed at the same time in the button unit of the same column (for example, the xth column), the number of resistors formed in parallel increases , and the comparison will be compared. Node N_b(x)The voltage is reduced. Therefore, in the waveform of Fig. 6, in the scan period scan(1), the comparison node N is compared._b(2)Voltage V1on is the largest, compare node N_b(3)Voltage V2on second, compare node N_b(4)The voltage V4on is minimal. This is because in FIG. 4, only one button unit KU(1, 2) is pressed in the second column; in the third column, two button units KU(1, 3) and KU(2, 3) are pressed; In the fourth column, there are four button units KU(1,4)~KU(4,4) pressed.

When the number of button units in the same column is simultaneously pressed, the comparison node N may be caused._bThe voltage is too low and even causes the transistor BJT to be turned off. If the transistor BJT should be turned on, but the voltage of the base is not enough to be turned on because there is too much parallel resistance, the node N is read from the column._RoutThe voltage level of the output is also affected. That is, it should be output as V_RoutLThe level is changed to a high level V because the transistor BJT is turned off._RoutH。

In order to prevent the transistor BJT from being accidentally turned off and affecting the level of the output voltage Rout(1)~Rout(N), it is necessary to ensure that the node N is compared even if there are multiple switches of the same column but different rows are simultaneously pressed._b(1)~N_b(NThe voltage is still higher than the threshold voltage of the transistor BJT and can be maintained to turn on the transistor BJT (eg, greater than 0.7V).

Therefore, when the number of rows of the keyboard matrix is increased, the present disclosure can further provide a larger scanning voltage V to the driving circuits DC(1)~DC(M) by using the boosting circuit._Scan. That is, after the drive circuit DC(1)~DC(M) receives the boosted voltage Vup supplied from the booster circuit, a scan voltage V having a higher level is generated accordingly._Scan. When scanning voltage V_ScanThe higher the comparison node N_RThe voltage obtained by the partial pressure is also higher, thereby ensuring that the transistor BJT is not broken due to the voltage being too low. For example, if the number of rows of the button unit is 8, it is necessary to use the boost circuit to scan the voltage V._ScanBoost to 15V to ensure that the transistor can turn on. The use of the boost circuit can avoid the increase in the number of resistors in parallel, resulting in the comparison node N_b(1)~N_b(N)The voltage output is not sufficient to drive the transistor BJT(1)~BJT(N).

Assuming that the button matrix contains a total of 144 groups of button units, the arrangement of the button units may be 8 (row) x 18 (column), 12 (row) x 12 (column), 18 (row) x 8 (column) and other different methods. The boost voltage Vup provided by the boost circuit is determined according to the number of rows of the button matrix. Because the more rows, the more the number of button units that may be pressed simultaneously in the same column. The more the number of button units in the same column that can be simultaneously pressed, the greater the possibility that the equivalent resistance after the entire parallel connection is smaller. Therefore, as the number of rows increases, the voltage value that the booster circuit needs to pull higher is also higher.

For example, if the button matrix uses 8 (row) x 18 (column) arrangement, 8 switches and resistors are connected in parallel on a single column, then the boost circuit must provide 15V boost voltage Vup; When the key matrix is arranged in 18 (row) x 8 (column), 18 switches will be connected in parallel in a single column, and the boost circuit must provide a boost voltage Vup of 24V. The type of booster circuit that can be used in the present disclosure and the boosted voltage Vup provided by the booster circuit can be arbitrarily selected depending on the application.

Referring to FIG. 9, the keyboard device of the embodiment of the present invention is used with a booster circuit, and the control module includes a schematic diagram of the demultiplexer and the multiplexer. The key matrix 931, the reading module 915, the driving circuits DC(1) to DC(M), and the like of this figure are similar to those of the second drawing. Compared with FIG. 2, this figure further provides a booster circuit 913 for the drive module 913 for providing a higher level boost voltage Vup to the drive circuits DC(1)~DC(M). In addition, a demultiplexer and/or a multiplexer may be disposed inside the control module 911 in this figure.

When the control module 911 is provided with the demultiplexer 9113, the controller 9111 includes a controller output port9111a and Q row selections 9111b, and the controller 9111 sequentially transmits the scan voltage V through the controller output port9111a._Scan. When the control module 911 is provided with the multiplexer 9115, the controller 9111 includes the controller input port9111d and the P column selections 9111c, and the controller 9111 receives the output voltage Rout(1) through the controller input port9111d. Rout(N). Where Q is a positive integer less than M and P is a positive integer less than N.

The demultiplexer 9113 includes a demultiplexing input 9113c, Q row settings 9113a, and M driving outputs 9113b. The demultiplexing input port9113c of the multiplexer 9113 is electrically coupled to the controller output port9111a of the controller 9111 via the controller output line MCUout; the Q rows of the multiplexer 9113 are set to port9113a through the controller row selection line Csel(1)~Csel(Q) are electrically coupled to the Q row selects 9111b of the controller 9111, respectively, and the M drive outputs port9113b of the demultiplexer 9113 are electrically coupled to the M drive circuits DC, respectively. 1)~DC(M). The number of pins of the controller 9111 can be reduced by using the demultiplexer 9113. Decomposition multiplexer in practical application The number of output turns of 9113 may be greater than or equal to the number of drive circuits DC(1)~DC(M). In addition, the selection of the multiplexer 9113 can vary depending on the number of rows of the button unit.

The multiplexer 9115 includes a multiplex output port9115c, P column settings port9115a, and N transition inputs port9115b. The multiplexer output 9115c of the multiplexer 9115 is electrically coupled to the controller input port9111d of the controller 9111 through the controller input line MCUin; the P columns of the multiplexer 9115 are set to port9115a through the controller column selection line Rsel (1 )~Rsel(P) is electrically coupled to the P column selections 9111c of the controller 9111, respectively, and the N transition inputs port9115b of the multiplexer 9115 are electrically coupled to the N transition circuits TC(1), respectively. TC(N). The number of pins of the controller 9111 can be reduced by using the multiplexer 9115. In practical applications, the number of input turns of the multiplexer 9115 may be greater than or equal to the number of transition circuits TC(1)~TC(N). In addition, the selection of the multiplexer 9115 may vary depending on the number of columns of the button unit.

According to the foregoing description, the keyboard device of the present disclosure can accurately determine the pressing state of the button unit located in the same row in each scanning cycle, and can effectively prevent the generation of the ghost key phenomenon, and improve the pressing of the determining button unit. The accuracy of the state and increase the market competitiveness of the keyboard device. In addition, the disclosed state of the transition circuit uses the BJT method, and compared with the other methods of using a comparator to compare the voltage magnitude, the present disclosure can greatly save costs.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.