TWI612443B - Keyboard apparatus - Google Patents

Abstract

The invention is a keyboard device, which includes M driving circuits DC (1) ~ DC (M); N transition circuits TC (1) ~ TC (N); a control module; M row signal lines C (1 ) ~ C (M); N column signal lines R (1) ~ R (N); and MxN key units KU (1,1) ~ KU (M, N). The control module scans the M line signal lines C (1) ~ C (M) in M scanning cycles scan (1) ~ scan (M), respectively. In the N key units KU (k, 1) ~ KU (k, N), when the key unit KU (k) at the intersection of the k-th row signal line C (k) and the x-th column signal line R (x) k, x) When pressed, the switch sw (k, x) included in the key unit KU (k, x) transmits the scanning voltage on the row signal line C (k) to the column signal line R (x). The transition circuit TC (x) connected to the column signal line R (x) changes the output voltage Rout (x) generated according to whether it is turned on. Thereafter, the control module determines whether the key unit KU (k, x) is pressed according to the level of the output voltage Rout (x).

Description

Keyboard device

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

In order to avoid using too many wires to increase manufacturing costs, and based on convenience considerations during assembly, many keyboards currently use a keyboard matrix architecture. Ghost keys may exist on this type of keyboard.

Please refer to Figures 1A ~ 1D, which are schematic diagrams showing the occurrence of ghost keys. The key matrix here sets the four key units KU (1,1), KU (1,2), KU (2,1), and KU (2,2) on two line signal lines C (1), C (2) Four intersections formed by two column signal lines R (1), R (2). The button unit KU (1,1) is located in the first row and first column, the button unit KU (1,2) is located in the first row and second column, the button unit KU (2,1) is located in the second row and first column, and the button unit KU (2,2) is in the second row and second column. Among them, a circle drawn on the screen represents the pressed key unit, and a circle drawn on the white background represents the unpressed key unit. When any one of the key units is pressed, the row signal line and the column signal line connected to the key unit will be conducted to each other. For example, if the key unit KU (1,1) is pressed, the row signal line C (1) and the column signal line R (1) are electrically connected to each other.

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

It is assumed that in Figure 1A, the key unit KU (1,1) is not pressed, but the key units KU (1,2), KU (2,1), and KU (2,2) are all pressed. under. In this case, the scanning voltage sent by the keyboard controller from the row signal line C (1) may cause the column to pass through the key units KU (1,2), KU (2,2), and KU (2,1). The signal line R (1) is biased at a high level. Together, the keyboard controller determines that the key unit KU (1,1) is on because the column signal line R (1) is biased at a high level.

Therefore, the results determined by the keyboard controller for any of the pressing conditions in Figs. 1A to 1D may mistakenly think that the key has not been pressed (that is, the key unit KU (1, 1) in Fig. 1A, The key unit KU (1,2) in FIG. 1B, the key unit KU (2, 1) in FIG. 1C, and the key unit KU (2, 2) in FIG. 1D) were pressed, causing misjudgment. That is the ghost key phenomenon.

According to the above, the ghost key phenomenon refers to the fact that the keyboard controller may misjudge that the unpressed key unit is pressed when multiple key units around a key unit that is not pressed are pressed at the same time. Case. How to solve the above-mentioned ghost bond phenomenon is one of the topics devoted to the industry.

The invention relates to a keyboard device with an anti-ghost key function.

According to an aspect of the present invention, a keyboard device is provided, including: M driving circuits DC (1) ~ DC (M): N transition circuits TC (1) ~ TC (N), where M and N are positive integers ; A control module with N input ports and M output ports, wherein the N input ports are respectively electrically coupled to the N transition circuits TC (1) ~ TC (N), and the M output ports are electrically coupled to the M driving circuits DC (1) ~ DC (M) respectively; M row signal lines C (1) ~ C (M ) Are electrically coupled to the M driving circuits DC (1) ~ DC (M), respectively; N column signal lines R (1) ~ R (N) are respectively electrically coupled to the N transition circuits TC ( 1) ~ TC (N), where the N column signal lines R (1) ~ R (N) and the M row signal lines C (1) ~ C (M) form MxN intersections; and MxN keys The units KU (1,1) ~ KU (M, N) are respectively arranged at the MxN intersections, and one of the MxN key units KU (1,1) ~ KU (M, N) is a key unit 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. The two ends of the switch sw (i, j) are electrically Coupled to one row of signal lines C (i) and one row of signal lines R (j), wherein when the key unit KU (i, j) is pressed, the switch sw (i, j) causes the row of signal lines C (i ) And the column signal lines R (j) are electrically connected; among them, the control module is respectively for the M row signal lines C (1) ~ C in M scan periods scan (1) ~ scan (M). (M) Scanning, scanning the M line signal lines C (1) ~ C (M) includes: (a) setting a 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 passes the M outputs Port, providing a scanning voltage to the kth row signal line C (k) to scan the row signal line C (k), and providing an unscanned voltage to the other row signal lines C (1) ~ C ( k-1) and C (k + 1) ~ C (M), where the level of the unscanned voltage is lower than the level of the scanned voltage; (b2) using the N transition circuits TC (1) ~ TC (N) detects the N key units KU (k, 1) ~ KU that are electrically coupled to a row of signal lines C (k) among the MxN key units KU (1,1) ~ KU (M, N) (k, N) on state, where (1) is on the N key sheets Among the elements KU (k, 1) ~ KU (k, N), when a key unit KU (k, at the intersection of the kth row signal line C (k) and an xth column signal line R (x) x) When pressed, a switch sw (k, x) included in the key unit KU (k, x) transmits the scanning voltage on the row of signal lines 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 an 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) Among the MxN key units KU (1,1) ~ KU (M, N), when a signal line C (m) is located in an m-th row When a button unit KU (m, x) at the intersection with the x-th column signal line R (x) is pressed, a switch 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 When the circuit TC (x) is on, the control module determines that the key unit KU (k, x) is pressed; and (4) When the transition circuit TC (x) is not on, the control module determines the key unit KU (k, x) Being pressed; and (c) updating the variable k, the updated variable k corresponds to the signal line of the row that has not yet been scanned, and repeats steps (b1), (b2), and (c) according to the updated k value Until all the line signal lines have been scanned.

In order to have a better understanding of the above and other aspects of the present invention, preferred embodiments are described below in detail with the accompanying drawings, as follows:

111a‧‧‧M input ports

111b‧‧‧N output ports

C (1), C (k), C (M), C (2), C (3), C (4) line

R (1), R (x), R (N), R (2), R (3), R (4) ‧‧‧ column signal line

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

10, 60‧‧‧ keyboard device

11‧‧‧Computer Motherboard

113, 913‧‧‧Drive Module

DC (1), DC (k), DC (M) ‧‧‧Drive circuit

111、911‧‧‧Control Module

115, 915‧‧‧Reading module

TC (1), TC (x), TC (N), TC (2), TC (3), TC (4)

117a, 117b‧‧‧first connector

133a, 133b‧‧‧Second connector

13‧‧‧Keyboard Module

131, 931‧‧‧ Key Matrix

Cin (1), Cin (k), Cin (M), Cin (2) ‧‧‧ line input lines

Rout (1), Rout (x), Rout (N), Rout (2), Rout (3), Rout (4) ‧‧‧ Output voltage

BJT (x) ‧‧‧Transistor

S41, S43, S431, S433, S433a, S433b, S433c, S45, S47, S51, S52, S53, S54, S55, S56, S57

431‧‧‧Divided voltage circuit

433‧‧‧pull-up circuit

435‧‧‧Switch circuit

N _{Rout (x)} , N _{Rout (1)} , N _{Rout (2)} , N _{Rout (3)} , N _{Rout (4)} ‧‧‧ column read nodes

N _{R (x)} , N _{R (1)} , N _{R (2)} , N _{R (3)} , N _{R (4)} ‧‧‧ column signal nodes

N _{b (x)} , N _{b (1)} , N _{b (2)} , N _{b (3)} , N _{b (4)} ‧‧‧Compare node

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

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), tb1 (1), rb2 (1), rb1 (2), rb2 (2), rb1 (3), rb2 (3), rb1 (4), rb2 (4), r _‧ ‧‧‧ resistance

scan (1), scan (2), scan (3), scan (4) ‧‧‧scan period

V _scan ‧‧‧scan voltage

V _un-scan ‧‧‧

V _{RoutH ‧‧‧High} level

V _Rout L‧‧‧ Low

Vth‧‧‧Threshold voltage

V1on, V2on, V4on‧‧‧Voltage

t0, t1, t2, t3, t4, t5

T1, T2, T3, T4, T5

82, 84‧‧‧ equivalent circuit

821, 8411, ‧‧ upper part

823, 843‧‧‧ lower part

843a, 843b ‧‧‧ subsection

9130‧‧‧Boost circuit

MCUout‧‧‧controller output line

MCUin‧‧‧controller input line

Csel (1), Csel (2), Csel (Q) ‧‧‧ Controller line selection line

Rsel (1), Rsel (2), Rsel (P) ‧‧‧Controller column selection line

9111d‧‧‧controller input port

9111c‧‧‧P column selection port

9115‧‧‧ Multiplexer

9115c‧‧‧Multiplex output port

9115a‧‧‧P column setting port

9115b‧‧‧N transition input ports

9111a‧‧‧controller output port

9111b‧‧‧Q row selection port

9113‧‧‧Demultiplexer

9113c‧‧‧Demultiplexed input port

9113a‧‧‧Q line setting port

9113b‧‧‧M driver output ports

Figures 1A ~ 1D are schematic diagrams showing the occurrence of ghost keys.

FIG. 2 is a schematic diagram of a keyboard device according to an embodiment of the disclosure.

FIG. 3 is a flowchart of performing a continuous scan according to a keyboard device according to an embodiment of the present disclosure.

FIG. 4 is a diagram illustrating a 4x4 key matrix as an example to explain a pressing condition of the keyboard device according to the embodiment of the present disclosure.

FIG. 5 is a schematic diagram of a key unit KU (k, x) used with a transition circuit TC (x).

FIG. 6 is a waveform diagram of a pressing condition of the keyboard device corresponding to FIG. 4.

FIG. 7 is a schematic diagram of the key units and transition circuits in the second and fourth rows of the keyboard device of FIG. 4 during a scan period scan (1).

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

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

FIG. 9 is a schematic diagram of using the keyboard device with a boost circuit, a demultiplexer, and a multiplexer according to the embodiment of the present invention.

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

As shown in FIG. 2, the first connectors 117a, 117b, M driving circuits DC (1) to DC (M), 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 row signal lines C (1) to C (M), N column signal lines R (1) ~ R (N), and MxN key unit KU (1,1) ~ KU (M, N) is disposed on the keyboard module 13. The first connectors 117a, 117b may be combined into one body or separately provided, and the second connectors 133a, 133b are also the same. When the keyboard module 13 is assembled on the computer motherboard 11, the first connectors 117a, 117b are connected to the second connectors 133a, 133b, and the M driving circuits DC (1) ~ DC (M) are electrically coupled to The M row signal lines C (1) ~ C (M) and the N transition circuits TC (1) ~ TC (N) are electrically coupled to the 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) ~ DC (M) and the driving circuits DC (1) ~ DC (M) of the driving module 113 through M row input lines Cin (1) ~ Cin (M). M) is further electrically coupled to the key matrix 131 through M row signal lines C (1) ~ C (M). The control module 111 is electrically coupled to the N transition circuits TC (1) ~ TC (N) in the reading module 115 through the N column read lines. The transition circuits TC (1) ~ TC (N) are electrically coupled to the key matrix 131 through N column signal lines R (1) ~ R (N). The key matrix 131 contains MxN key units, and the MxN key units are dispersedly arranged on the MxN formed by the row signal lines C (1) ~ C (M) and the column signal lines R (1) ~ R (N). One of these interchanges. More specific operation of the key matrix and the transition circuit will be further explained in conjunction with FIG. 4 below.

Through the row input lines Cin (1) ~ Cin (M), the control module 111 transmits M row output signals to the driving circuits DC (1) ~ DC (M), respectively. The driving circuits DC (1) ~ DC (M) pass through the corresponding row signal lines C (1) ~ C (M) to scan voltage V _scan (for example: 5V) or unscan voltage V _un-scan. (Example: 0V) to all key units on the same line. For example, (1) When the control module 111 outputs a high-level line output signal to the drive circuit DC (1) through the line input line Cin (1), the drive circuit DC (1) will pass the first line signal Line C (1) outputs the scan voltage V _scan to all the key 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 outputs the low level line output signal to the driving circuit DC (1) through the line input line Cin (1), the driving circuit DC (1) will pass through the first line signal line C (1) Output the _unscanned voltage V _un-scan to all the key units KU (1,1), KU (1, x) ... KU (1, N) connected to the first line signal line C (1).

When the control module 111 intends to perform the kth scan period scan (k), that is, all the key units KU (k, 1), KU (k, x) connected to the k-th signal line C (k) are scanned. When KU (k, N), the control module 111 simultaneously (1) causes the k-th row driving circuit DC (k) currently selected to be scanned to output a high-level scanning voltage V _scan ; (2) causes the remaining current The other row driving circuits DC (1) ~ DC (k-1), DC (k + 1) ~ DC (M) which do not perform scanning output the low-level unscanned voltage V _un-scan . Among them, k is an integer value between 1 and M. The transition circuits TC (1) ~ TC (N) receive the voltage of the column signal lines R (1) ~ R (N), and read the lines in the column according to the voltage of the column signal lines R (1) ~ R (N). Generate different output voltages Rout (1) ~ Rout (N). On the other hand, the control module 111 determines the key matrix 131 through the output voltages Rout (1) to Rout (N) generated by the transition circuits TC (1) to TC (N) of the read module 115 on the column read lines. Whether the key unit is turned on or not.

For example, 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 output voltage Rout (x) determines whether the key unit KU (k, x) located at the intersection of the k-th row and the x-th 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 x-th column to determine whether the key unit KU (k, x) is on or off will be described in detail below with reference to FIG. 5.

Please refer to FIG. 3, which is a flowchart of performing a continuous scan of a keyboard device according to an embodiment of the present disclosure. The control module 111 performs M scanning cycles scan (1) ~ scan (M) on the M row signal lines C (1) ~ C (M) through the driving modules DC (1) ~ DC (M). In the following, the variable k represents the number of lines selected for scanning. Here are the process steps:

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

Step S43: The scan cycle (k) is entered. The control module 111 will scan all the key units KU (k, 1) to KU (1, N) connected to the k-th signal line C (k) in this scan period scan (k).

Step S431: the control module 111 controls the drive modules DC (1) ~ DC (M) via the output port 111a, (1) so that the k-th output port provides a scan voltage V _scan to the k-th row signal line C ( k); and (2) at the same time, make the first to (k-1), (k + 1) to M output ports provide unscanned voltage V _un-scan to the line signal line C (1) ~ C (k-1 ) And C (k + 1) ~ C (M). The level of the _unscanned voltage V _un-scan is lower than the level of the scan voltage V _scan .

Step S433: Through the N transition circuits TC (1) ~ TC (N), the control module 111 detects the N key units KU (k, 1) ~ KU () which are electrically coupled to the row signal line C (k). k, N). For example: After the transition circuits TC (1), TC (x), and TC (N) generate output voltages Rout (1), Rout (x), and Rout (N) on the column read lines, respectively, the control module 111 controls Voltage Rout (1), Rout (x), The level of Rout (N) determines whether the key units KU (k, 1), KU (k, x), and KU (k, N) are pressed (steps S433a, S433b, S433c). The manner in which the transition circuits TC (1) to TC (N) generate the output voltages Rout (1) to Rout (N) on the column read lines will be described below with reference to FIGS. 4 to 6.

Step S45: After the scan period scan (k) ends, determine whether the variable k is less than M. If yes, update the variable k with (k + 1) (step S47), and repeat steps S431 and S433 according to the updated variable k. If not, the 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 line signal line that has not been scanned. Similarly, steps S431 and S433 are repeatedly performed according to the updated variable k, until all the row signal lines C (1) to C (M) are scanned.

See Figure 4. For convenience of explanation, FIG. 4 assumes that the key units on different columns have different pressing conditions. Among them, it is assumed that the key units KU (1,1) to KU (4,1) in the first column are not pressed; it is assumed that the key units KU (1,2) in the second column are pressed, and the key unit KU (2 , 2) ~ KU (4,2) are not pressed; assuming that the button units KU (1,3) and KU (2,3) on the third column are pressed, the button units KU (3,3) and KU (4 3) is not pressed; and it is assumed that the key units KU (1,4) to 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 of each key unit KU (1,1) ~ KU (M, N). Figure 5 shows one of the multiple key units shown in Figures 2 and 4, such as the key unit KU (k, x), which is displayed in the key matrix and is located in the k-th and x-th columns. Key unit KU (k, x) and its corresponding transition circuit TC (x).

Please refer to FIG. 5, which is a schematic diagram of a key unit KU (k, x) used with a transition circuit TC (x). The following will also explain how the output voltage Rout (x) generated by the transition circuit TC (x) changes according to whether the key unit KU (k, x) is pressed or not. The key unit KU (k, x) includes a switch sw (k, x) and a resistor r (k, x). Both 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 bias voltage applied to the row signal line C (k) may be the scan voltage V _scan or the _unscan voltage V _un-scan . When the key 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 used to transmit the logic high power (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 voltage of the comparison node N _{b (x)} according to the voltage of the column signal line R (x). The voltage of the comparison node N _{b (x)} will be further used to determine whether the switching circuit 435 is turned on.

The switching 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 a column signal line R (x), an emitter E (x) electrically coupled to a ground voltage (Gnd), and a k-th input port. A collector C (x) electrically coupled to a logic high power supply. When the transistor BJT (x) is on, the output voltage Rout (x) generated by the transition circuit TC (x) is at a low level (ie, the first voltage value). When the transistor BJT (x) is non-conducting, the output voltage Rout (x) generated by the transition circuit TC (x) is at a high level (ie, the second voltage value).

The transition circuit according to the present disclosure is not limited to the method in FIG. 5. For example, the switching circuit 435 may be a metal-Oxide-Semiconductor Field-Effect Transistor (referred to as MOSFET), reverse logic gate and other components. That is, any element having a similar transition function can be used as the switching circuit 435. Furthermore, the voltage level and current flow direction used by the switching circuit 435 can be changed according to different components. For example, driving and reading are performed using a voltage of a reverse level.

Please refer to FIG. 6, which is a waveform diagram of the pressing condition of the keyboard device corresponding to FIG. 4. From the top to the bottom of this diagram, the voltage changes of the row signal lines C (1) to C (4); the voltage of the comparison node N _{b (1)} and the output voltage Rout ( 1); the voltage of the comparison node N _b (2) corresponding to the transition circuit TC (2) and the output voltage Rout (2); the voltage of the comparison node N _{b (3)} corresponding to the transition circuit TC (3), output voltage Rout (3); and transient circuit TC (4) corresponding to the comparison node N _{b (4)} a voltage, the output voltage Rout (4).

Here, the period between time point t0 and time point t1 is defined as time zone T1; the period between time point t1 and time point t2 is defined as time zone T2, and so on. The length of each time segment is equivalent to the length of one scanning period. The control module 111 scans the row signal lines C (1) ~ C (4) using the driving circuits DC (1) ~ DC (4) in the scanning cycles scan (1) ~ scan (4), respectively. After the scan cycles scan (1) ~ scan (4) are completed, the control module 111 will restart execution from the scan cycle scan (1). Therefore, both the time period T1 and the time period T5 correspond to the scan period scan (1). The following uses the scan cycle scan (1) ~ scan (2) as an example to explain how the transition circuits TC (1) ~ TC (4) in Fig. 4 generate the output voltage Rout (1) ~ Rout (4).

First, the change of each signal in the scan period scan (1) will be described. In the scan period scan (1), the bias voltage applied to the row signal line C (1) is the scan voltage V _scan (for example: 5V), and the bias voltage applied to the row signals C (2) to C (4) is not Scan voltage V _un-scan (for example: 0V). After the row signal line C (1) transmits the scan voltage V _scan to the key units KU (1,1) to KU (1,4) in the first row in the scan cycle scan (1), the control module 111 switches from the transition circuit After TC (1) ~ TC (4) read the output voltages Rout (1) ~ Rout (4), it is used to judge the respective one of the key units KU (1,1) ~ KU (1,4) located in the first row. Pressed.

Since the key unit KU (1,1) is turned off, the scan voltage V _scan on the row signal line C (1) is not transmitted to the transition circuit TC (1). Therefore, the comparison node N _{b (1)} is in a floating state, and the transistor BJT (1) is not turned on. Incidentally, because the transistor BJT (1) is not turned on, the output voltage Rout (1) is at a high level V _RoutH . Since the key unit KU (1,2) is on, the scanning voltage V _scan on the row signal line C (1) is transmitted to the comparison via the switch sw (1,2), the resistor r (1,2), and the voltage dividing circuit. Node N _{b (2)} ; therefore _, the voltage at node N _{b (2)} is higher than the threshold voltage Vth of transistor BJT (2), so that transistor BJT (2) is turned on, and the output voltage Rout (2) is low. _Near V _RoutL . Since the key unit KU (1,3) is on, the upper scanning voltage V _{scan of the} row signal line C (1) is transmitted to the comparison via the switch sw (1,3), the resistor r (1,3), and the voltage dividing circuit. Node N _{b (3)} ; therefore _, the voltage at node N _{b (3)} is higher than the threshold voltage Vth of transistor BJT (3), so that transistor BJT (3) is turned on, and the output voltage Rout (3) is low. _Near V _RoutL . Similarly, since the key unit KU (1,4) is on, the scanning voltage V _scan on the row signal line C (1) will pass through the switch sw (1,4), the resistor r (1,4), and the voltage dividing circuit. Transmitted to the comparison node N _{b (4)} ; therefore _, the voltage of the comparison node N _{b (4)} is higher than the threshold voltage Vth of the transistor BJT (4), so that the transistor BJT (4) is turned on, and the output voltage Rout (4 ) Is the low level V _RoutL .

As shown in FIG. 4, among the key units KU (1,1) to KU (1,4) located in the first row, only the key unit KU (1,1) is off, and the key unit KU (1,2, ) ~ KU (1,4) are all on. 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 circuits TC (2) ~ TC (4) _Both are low-level V _RoutL . According to this, the control module 111 can determine whether the key units KU (1,1) ~ KU (1,4) are pressed according to the level of the output voltages Rout (1) ~ Rout (4) in the scan period scan (1). .

Incidentally, although in the scan period scan (1), the voltages of the comparison nodes N _{b (2)} , N _{b (3)} , and N _{b (4)} are all greater than the threshold voltage Vth, it can be seen that the comparison node N The voltages of _{b (2)} , Nb ₍₃₎ , and Nb ₍₄₎ are still slightly different. Among them, the voltage V1on of the comparison node Nb _{(2) is} the highest, the voltage V2on of the comparison node Nb _{(3) is} the second, and the voltage V4on of the comparison node Nb _{(4) is} the lowest. The reason why the voltages at the comparison nodes N _{b (2)} , N _{b (3)} , and N _{b (4)} are different will be described in FIGS. 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 bias voltage applied to the row signal line C (2) is the scan voltage V _scan (for example: 5V), and is applied to the row signal line C (1), C (3), C (4). ) Is the unscan voltage V _un-scan (for example: 0V). The row signal line C (2) will be matched with the reading results of the transition circuits TC (1) ~ TC (4) during the scan period scan (2) to determine the key units KU (2,1) ~ KU (2) located in the second row. 2,4).

Since the key unit KU (2,1) is turned off, the scan voltage V _scan on the row signal line C (2) is not transmitted to the transition circuit TC (1). Therefore, the comparison node N _{b (1)} is in a floating state, and the transistor BJT (1) is not turned on. Incidentally, because the transistor BJT (1) is not turned on, the output voltage Rout (1) is at a high level V _RoutH . Since the key unit KU (2, 2) is turned off, the scan voltage V _scan on the row signal line C (2) is not transmitted to the transition circuit TC (2). Therefore, the comparison node N _{b (2)} is in a floating state, and the transistor BJT (2) is not turned on. Incidentally, because the transistor BJT (2) is not turned on, the output voltage Rout (2) is at a high level V _RoutH . Since the key unit KU (2,3) is on, the scan voltage V _scan on the row signal line C (2) is transmitted to the comparison node N _{b (3} ) via the switch sw (2,3) and the resistor r (2,3). ₎ . Therefore, the voltage of the comparison node N _{b (3)} is higher than the threshold voltage Vth. Incidentally, because the transistor BJT (3) is turned on, the output voltage Rout (3) is at a low level V _RoutL . Since the key unit KU (2,4) is on, the scanning voltage V _scan on the row signal line C (2) is transmitted to the comparison node N _{b (4} ) via the switch sw (2,4) and the resistor r (2,4). ₎ . Therefore, the voltage of the comparison node N _{b (4)} is higher than the threshold voltage Vth. As a result, the transistor BJT (4) will be turned on and the output voltage Rout (4) will be at a low level V _RoutL .

Similarly, in the scan period scan (3), the bias voltage applied to the row signal line C (3) is the scan voltage _Vscan , and the bias voltage applied to the row signal line C (1), C (2), C (4) is The bias voltage is an unscanned voltage V _un-scan . At this time, the results read by the transition circuits TC (1) ~ TC (4) will correspond to the respective pressed states of the key units KU (3,1) ~ KU (3,4) also located in the third row. In the scan period scan (4), the bias voltage applied to the row signal line C (4) is the scan voltage V _scan , and the bias voltage applied to the row signal lines C (1) to C (3) is the non-scan. Voltage V _un-scan . At this time, the results read by the transition circuits TC (1) ~ TC (4) will correspond to the respective pressed states of the key units KU (4,1) ~ KU (4,4) also located in the fourth row.

In FIG. 4, the key units KU (1,2), KU (2,2), KU (1,3), and KU (2,3) correspond to the pressing situation in FIG. 1C. Figure 6 represents the signals of the transition circuits TC (2) and TC (3) with thick black dashed boxes. How to use the key units KU (1,2), KU (2,2), KU (1,3), Pressing KU (2,3) changes the level. According to the waveforms in FIG. 6, it can be known that the control module 111 can judge the keys according to the _{levels of the} output voltages Rout (2) and Rout (3) during the scan period scan (1) (both are low _levels V _RoutL ). The units KU (1,2) and KU (1,3) are both on. In addition, the control module 111 can determine the key unit KU (based on the levels of the output voltages Rout (2) and Rout (3) during the scan period scan (2) (the former is the high level V _RoutH and the latter is the low level V _RoutL ) 2,2) is off, and the key unit KU (2,3) is on.

In FIG. 4, when the row signal line C (2) is biased to the scan voltage V _scan (for example: 5V), the current flowing from the row signal line C (2) flows through the key unit KU (2, 3) After KU (1,3), it will flow to the row signal line C (1) which is biased to the unscan voltage V _un-scan (for example: 0V). Because the row signal line C (1) has a lower _unscanned voltage V _un-scan , the current derived from the scan voltage V _scan will be directed to the unscanned voltage source of the row signal line C (1) and will not It then flows from the key unit KU (1,2) to the column signal line R (2) to affect the voltage of the comparison node Nb ₍₂₎ . Therefore, comparing the voltage of the node N _{b (2)} does not make the transistor BJT (2) of the transition circuit TC (2) conductive. According to this, the control module 111 can correctly determine whether the key unit KU (2, 2) is in an unpressed state according to the conduction of the transition circuit TC (2) or not, as shown in FIG. 1C. Ground, the key unit KU (2, 2) is mistakenly judged as being pressed and a ghost key phenomenon occurs. Therefore, according to the concept of the present disclosure, when a plurality of key units are simultaneously pressed, the phenomenon of ghost keys can be effectively avoided.

Please refer to FIG. 7, which is a schematic diagram of the key units and transition circuits in the second and fourth rows of the keyboard device of FIG. 4 during a scan cycle scan (1). The upper part of FIG. 7 corresponds to the key units KU (1,2) to KU (4,2) in the second column and the transition circuit TC (2). The lower part of FIG. 7 corresponds to the key units KU (1,4) to KU (4,4) in the fourth column, and the transition circuit TC (4). Here, the switches and resistors in each key unit are drawn to help explain the current flow.

During the scan period scan (1), the current starts from the high-level row signal line C (1) and flows through the switch sw (1,2) and the resistor r (1,2) of the key unit KU (1,2) to Column signal node N _{R (2)} . Thereafter, the column signal from the current node and then N _{R (2)} flows through the transient circuit TC (2) resistance rb1 (2), comparing the node N _{b (2),} resistance rb2 (2). Among them, because the switches sw (2,2), sw (3,2), and sw (4,2) are not turned on, during the scan period scan (1), the line signal lines C (2) ~ C (4) The low level (unscan 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 row signal line C (1) and flows through the switch sw (1,4) and the resistor r (1,4) to the switch unit KU (1,4) to Column signal node N _{R (4)} . After that, the current will branch into four sub-currents. One of the sub-currents flows from the column signal node N _{R (4)} through the transition circuit TC (4) to the ground terminal; the remaining three sub-currents pass through the key unit KU (2,4) ~ KU (4,4 ) To the line signal lines C (2) ~ C (4).

As the voltage of the row signal lines C (1) ~ C (4) changes due to different scanning periods, it also belongs to the pressed key units KU (1,4) ~ KU (4,4). For column signal lines The effect of R (4) voltage is also different. During the scan period scan (1), when the key unit KU (1,4) is pressed, the switch sw (1,4) transmits the scan voltage V _scan to the column signal line R (4) and makes the column signal The voltage of line R (4) rises. On the other hand, although the key 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 The _unscanned voltage V _un-scan on the row signal lines C (2) to C (4) is transmitted to the column signal line R (4), and the voltage of the column signal line R (4) is decreased.

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

In FIG. 8A, the equivalent circuit 82 can be divided into two parts by the column signal node N _{R (2)} , the upper part 821 is a resistor r (1,2), and the lower part 823 is a resistor rb1 (2), rb2 (2 ). According to this, the voltage of the column signal node NR ₍₂₎ can be obtained through the voltage division relationship of the resistor, as shown in formula (1).

Further, the voltage at the comparison node N _{b (2)} can be calculated according to the divided voltage of the resistor, as shown in formula (2).

Please refer to FIG. 8B, which is a schematic diagram of the equivalent circuit formed by the key unit in the fourth column during the scan period scan (1) of the keyboard device of FIG. 4. This diagram corresponds to the current loop corresponding to the key unit located in the fourth column of FIG. 4 as shown in FIG. 8. In FIG. 8B, the equivalent circuit 84 can be divided into two parts by the column signal node N _{R (4)} . The upper part 841 is a resistor r (1,4), and the lower part 843 is a resistor r (2,4), r. (3,4), r (4,4), rb1 (4), rb2 (4). The lower part 843 can be further divided into two sub-parts 843a and 843b. Sub-section 843a corresponds to resistors r (2,4), r (3,4), r (4,4) located in the key matrix; sub-section 843b corresponds to resistor rb1 (4) located in the transition circuit , Rb2 (4).

For convenience of explanation, the resistance rb (4) is defined here as the series of resistances rb1 (4) and rb2 (4) (ie, rb (4) = rb1 (4) + rb2 (4)), and the parallel resistance r _∥ corresponds to the parallel result of the resistors r (2,4), r (3,4), r (4,4) in the _unscanned row, and the resistor rb (4) connected to the base. That is, the parallel resistance r _∥ can be expressed as Equation (3).

According to this, the voltage of the column signal node NR ₍₄₎ can be obtained through the voltage division relationship between the resistor r (1,4) and the parallel resistor _r∥ . The voltage of the column signal node N _{R (4)} is shown in Equation (4).

Similarly, the voltage at the comparison node N _{b (4)} can be calculated according to the voltage division relationship of the resistor, as shown in equation (5).

Please also refer to the description of Figures 8A and 8B. Generally speaking, rb1 (2) = rb1 (4) and rb2 (2) = rb2 (4). Because transient circuit TC (4) determines whether the system is turned on, thereby changing the output voltage Rout (4) according to the voltage comparison node N _{b (4)} a. Thereafter, the control module 111 can determine whether the key unit KU (1,4) is pressed according to the output voltage Rout (4); therefore, when the key unit KU (1,4) is pressed, the key unit KU (2,4) is not affected. ) ~ KU (4,4) are also pressed at the same time to turn on one, two or three, all need to ensure that the voltage of the column signal node N _{R (4)} is high enough (for example: higher than the transistor BJT (4) (Threshold voltage 0.7V), so that the subsequent transition circuit TC (4) can make a correct comparison and judgment result. In addition, it can be seen from the comparison of equations (1) and (4) that the coefficient multiplied by the scan voltage V _scan will affect the voltages of the column signal nodes N _{R (2)} and N _{R (4)} . Because the parallel resistance r _∥ is a parallel result of multiple resistances, its resistance value must be smaller than the resistance rb (2) = rb1 (2) + rb2 (2). Based on this, it can be determined that the voltage of the column signal node N _{R (4)} in Equation ₍₄₎ must be lower than the voltage of the column signal node N _{R (2)} in Equation (1), and the comparison node N _{b ( 4)} Must be smaller than the comparison node N _{b (2) of} equation (2).

Comparing Figures 8A and 8B, it can be known that when more than one key unit is pressed at the same time in the same row (for example, column x), the number of parallel resistors increases, and the comparison will cause the comparison. The voltage at the node N _{b (x)} decreases. Therefore, in the waveform of FIG. 6, during the scan period scan (1), the voltage V1on of the comparison node N _{b (2) is} the largest, the voltage V2on of the comparison node N _{b (3) is} the second, and the comparison node N _{b (4 )} V4on minimum voltage. This is because in the fourth figure, only one key unit KU (1,2) is pressed in the second column; two key units KU (1,3) and KU (2,3) are pressed in the third column; A total of four key units KU (1,4) to KU (4,4) are pressed in the fourth column.

When the number of simultaneously pressed key units in the same row increases, the voltage of the comparison node N _b may be too low, and even the transistor BJT may be turned off. If the transistor BJT should be turned on originally, but the base voltage is not enough to turn on because of too many parallel resistances, the voltage level of the node N _Rout output from the column reading will also be affected. That is, the level that should have been output as V _RoutL has become the high level V _RoutH because the transistor BJT is turned off.

In order to prevent the transistor BJT from being accidentally turned off and affecting the level of the output voltages Rout (1) ~ Rout (N), it must be ensured that even if there are multiple switches in the same column but different rows are pressed simultaneously, the node N _{b ( 1)} The voltage of ~ N _{b (N} ) is still higher than the threshold voltage of the transistor BJT, and the transistor BJT can be kept on (for example, greater than 0.7V).

For this reason, when the number of rows of the keyboard matrix increases, the present disclosure can also use a boost circuit to provide a larger scanning voltage V _scan to the driving circuits DC (1) ~ DC (M). That is, the driving circuits DC (1) to DC (M) receive the boosted voltage Vup provided by the boosting circuit, and accordingly generate the scanning voltage _Vscan with a higher level. When the scanning at a higher voltage V _scan, comparing the weight of the node N _R points out the higher voltage, can be ensured BJT transistors will not be turned off voltage is too low. For example, if the number of rows of the key unit is 8, it is necessary to boost the scan voltage V _scan to 15V by using a booster circuit to ensure that the transistor can be turned on. The use of a booster circuit can avoid the situation where the voltage output at the comparison nodes N _{b (1) ~} N _{b (N)} is insufficient to promote the transistors BJT (1) ~ BJT (N) due to the increase in the number of parallel resistors.

Assume that the key matrix contains a total of 144 groups of key units. The arrangement of the key units may adopt different arrangements such as 8 (rows) x 18 (columns), 12 (rows) x 12 (columns), and 18 (rows) x 8 (columns). The boost voltage Vup provided by the boost circuit is determined according to the number of rows of the key matrix. Because the greater the number of rows, the greater the number of key units that may be pressed simultaneously in the same column. Associated The more the number of key units in the same row can be simultaneously pressed, according to this, the smaller the equivalent resistance after the overall parallel connection is, the more likely it is. Therefore, as the number of rows increases, the voltage value that the booster circuit needs to pull up is also higher.

For example: if the key matrix is arranged in 8 (row) x 18 (column) mode, a total of 8 switches and resistors are connected in parallel on a single column, the boost circuit must provide a 15V boost voltage Vup; In the row) x 8 (column) arrangement, 18 switches will be connected in parallel on a single column, and the boost circuit must provide a boost voltage Vup of 24V. Both the type of booster circuit and the boosted voltage Vup provided by the booster circuit can be arbitrarily selected according to different applications.

Please refer to FIG. 9, which is a schematic diagram of the keyboard device used in the embodiment of the present invention with a boost circuit, and the control module includes a demultiplexer and a multiplexer. The button matrix 931, the reading module 915, and the driving circuits DC (1) to DC (M) in this figure are similar to those in FIG. 2. Compared with FIG. 2, this figure further includes a boosting circuit 913 in the driving module 913 to provide a higher-level boosting voltage Vup to the driving circuits DC (1) ~ DC (M). In addition, the demultiplexer and / or multiplexer may be provided inside the control module 911 in this figure.

When the control module 911 is provided with a demultiplexer 9113, the controller 9111 includes a controller output port 9111a and Q row selection ports 9111b, and the controller 9111 sequentially transmits the scan voltage V _scan through the controller output port 9111a. When the control module 911 is provided with a multiplexer 9115, the controller 9111 includes a controller input port 9111d and P column selection ports 9111c, and the controller 9111 sequentially receives the output voltage Rout (1) through the controller input port 9111d ~ Rout (N). Among them, Q is a positive integer less than M, and P is a positive integer less than N.

The demultiplexer 9113 includes a demultiplexing input port 9113c, Q line setting ports 9113a, and M drive output ports 9113b. Demultiplexer input port 9113c of the demultiplexer 9113 The MCUout line through the controller output line is electrically coupled to the controller output port 9111a of the controller 9111; the Q line setting ports 9113a of the demultiplexer 9113 are electrically connected through the controller line selection lines Csel (1) ~ Csel (Q), respectively. The Q row selection ports 9111b coupled to the controller 9111, and the M drive output ports 9113b of the demultiplexer 9113 are electrically coupled to the M drive circuits DC (1) ~ DC (M), respectively. Using the demultiplexer 9113 can reduce the number of pins of the controller 9111. In practical applications, the number of output ports of the demultiplexer 9113 may be greater than or equal to the number of the driving circuits DC (1) ~ DC (M). In addition, the choice of the demultiplexer 9113 may vary according to the number of rows of the key unit.

The multiplexer 9115 includes a multiplex output port 9115c, P column setting ports 9115a, and N transition input ports 9115b. The multiplexer output port 9115c of the multiplexer 9115 is electrically coupled to the controller input port 9111d of the controller 9111 through the controller input line MCUin; the P column setting port 9115a of the multiplexer 9115 is selected by the controller column selection line Rsel (1 ) ~ Rsel (P) is electrically coupled to the P column selection ports 9111c of the controller 9111, and the N transition input ports 9115b of the multiplexer 9115 are electrically coupled to the N transition circuits TC (1) ~ TC (N). Using the multiplexer 9115 can reduce the number of pins of the controller 9111. In practical applications, the number of input ports of the multiplexer 9115 may be greater than or equal to the number of the transition circuits TC (1) ~ TC (N). In addition, the selection of the multiplexer 9115 may vary according to the number of columns of the key unit.

According to the foregoing description, it can be known that the keyboard device of the present disclosure can accurately determine the pressing state of the key units located in the same row in each scanning cycle, and can effectively avoid the occurrence of ghost keys, and improve the pressing of the key units. The accuracy of the state and increase the market competitiveness of the keyboard device. In addition, the transition circuit of the present disclosure uses the method of BJT. Compared with the method of comparing the voltages by using a comparator in other methods, the present disclosure can greatly save costs.

In summary, although the present invention has been disclosed as above with preferred embodiments, However, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.

10‧‧‧ keyboard device

11‧‧‧Computer Motherboard

113‧‧‧Driver Module

DC (1), DC (k), DC (M) ‧‧‧Drive circuit

111‧‧‧control module

115‧‧‧Read Module

TC (1), TC (x), TC (N) ‧‧‧Transition circuit

117a, 117b‧‧‧first connector

133a, 133b‧‧‧Second connector

13‧‧‧Keyboard Module

131‧‧‧Key Matrix

KU (1,1), KU (k, 1), KU (M, 1), KU (1, x), KU (k, x), KU (M, x), KU (1, N), KU (k, N), KU (M, N) ‧‧‧button unit

C (1), C (k), C (M) ‧‧‧ line signal line

R (1), R (x), R (N) ‧‧‧column signal lines

Cin (1), Cin (k), Cin (M) ‧‧‧line input lines

Rout (1), Rout (x), Rout (N) ‧‧‧ Output voltage

111a‧‧‧Output port

111b‧‧‧input port

Claims (8)

A keyboard device includes: M driving circuits DC (1) ~ DC (M); N transition circuits TC (1) ~ TC (N), where M and N are positive integers; a control module having N Input ports and M output ports, wherein the N input ports are respectively electrically coupled to the N transition circuits TC (1) ~ TC (N), and the M output ports are respectively electrically coupled to the M driving circuits DC (1) ~ DC (M); M row signal lines C (1) ~ C (M) are electrically coupled to the M driving circuits DC (1) ~ DC (M), respectively; N The column signal lines R (1) ~ R (N) are electrically coupled to the N transition circuits TC (1) ~ TC (N), respectively, where the N column signal lines R (1) ~ R (N ) And the M row signal lines C (1) ~ C (M) form MxN intersections; and MxN key units KU (1,1) ~ KU (M, N) are respectively disposed at the MxN intersections A key unit KU (i, j) among the MxN key units KU (1,1) ~ KU (M, N) includes a switch sw (i, j), where i is less than or equal to M positive An integer, and j is a positive integer less than or equal to N. The two ends of the switch sw (i, j) are electrically coupled to a row of signal lines C (i) and a row of signal lines R (j), respectively. When KU (i, j) is pressed, the switch sw (i, j) makes the line signal C (i) and the column signal line R (j) are electrically connected; wherein, the control module is connected to the M row signal lines C (1) in M scan periods scan (1) ~ scan (M), respectively. ) ~ C (M) scans the M messages The scanning operations of the lines C (1) ~ C (M) include: (a) setting a starting value of a variable 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 supplies a scan voltage to a k-th row of signal lines C (k) via the M output ports to the k-th row of signal lines C (k) Scan and provide an unscanned voltage to other row signal lines C (1) ~ C (k-1) and C (k + 1) ~ C (M), where the level of the unscanned voltage Is lower than the scanning voltage level; (b2) using the N transition circuits TC (1) ~ TC (N) to detect the MxN key units KU (1,1) ~ KU (M, N) , The conducting state of the N key units KU (k, 1) ~ KU (k, N) electrically coupled to the row of signal lines C (k), where (1) is the N key units KU (k, 1) ) ~ KU (k, N), when a key unit KU (k, x) located at the intersection of the signal line C (k) in the row and the signal line R (x) in the xth column is pressed, the A switch sw (k, x) included in the key unit KU (k, x) transmits the scanning voltage on the row of signal lines C (k) to the column signal line R (x). The scanning voltage makes the connection A state transition to the column signal line R (x) TC (x) is turned on, and an 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 key units KU (1,1) ~ KU (M, N), When a key unit KU (m, x) located at the intersection of a signal line C (m) and a column signal line R (x) in an m-th row is pressed, the key unit KU (m, x) contains One of the switches sw (m, x) transmits the unscanned voltage on the row of signal lines C (m) to the column of signal lines R (x), where m is a positive integer less than or equal to M, and m Not equal to the variable k; (3) when the transition circuit TC (x) is on, the control module determines that the key unit KU (k, x) is pressed; and (4) when the transition circuit TC (x) ) When it is not conducting, the control module determines that the key unit KU (k, x) is not pressed; and (c) updates the variable k, and the updated variable k corresponds to the signal line of the row that has not been scanned, and Repeat steps (b1) and (b2) according to the updated k value until all the line signal lines have been scanned. The keyboard device described in item 1 of the scope of patent application, wherein the initial value is 1, and step (c) includes: when the variable k is less than M, adding 1 to the variable k to update the variable k, Then repeat steps (b1) and (b2) until all the line signal lines have been scanned. The keyboard device according to item 1 of the scope of the patent application, wherein the transition circuit TC (x) comprises an NPN type bipolar junction transistor (BJT) BJT (x), and the The NPN type bipolar junction transistor BJT (x) has a base B (x) which is electrically coupled to the column signal line R (x) and a ground An emitter electrode E (x) electrically coupled to voltage, and a collector electrode C (x) electrically coupled to a k-th input port and a logic high power source, wherein when the NPN type bipolar junction interface transistor When BJT (x) is on within the scan period scan (k), the output voltage Rout (x) is the first voltage value; and when the NPN type bipolar junction transistor BJT (x) is on the When the scan period (k) is non-conducting, the output voltage Rout (x) is a second voltage value. The keyboard device according to item 1 of the scope of patent application, further comprising a first connector and a second connector, wherein the first connector and the M driving circuits DC (1) ~ DC (M) The N transition circuits TC (1) ~ TC (N) and the control module are arranged on a computer motherboard, and the second connector and the M line signal lines C (1) to C ( M), the N column signal lines R (1) ~ R (N) and the MxN key units KU (1,1) ~ KU (M, N) are arranged on a keyboard module, where when the When the keyboard module is assembled on the computer motherboard, the first connector is connected to the second connector, so that the M driving circuits DC (1) ~ DC (M) are electrically coupled to the M line signals. Lines C (1) ~ C (M), and the N transition circuits TC (1) ~ TC (N) are electrically coupled to the N column signal lines R (1) ~ R (N). The keyboard device according to item 1 of the scope of patent application, wherein the control module includes: a controller including a controller output port and Q row selection ports, where Q is a positive integer less than M; and A demultiplexer includes a demultiplexing input port, Q line setting ports, and M drive output ports. The demultiplexing input port is electrically coupled to the controller output port and the Q line setting port system. They are electrically coupled to the Q row selection ports, respectively, and the M drive output ports are respectively electrically coupled to the M drive circuits. The keyboard device according to item 1 of the scope of patent application, wherein the control module further includes: a controller, including a controller input port and P column selection ports, where P is a positive integer less than N; and one more A multiplexer includes a multiplexed output port, P row setting ports, and N transition input ports. The multiplex output port is electrically coupled to the controller input port, and the P row setting ports are electrically coupled. Ports are selected in the P columns, and the N transition input ports are electrically coupled to the N transition circuits, respectively. The keyboard device according to item 1 of the patent application scope, wherein the keyboard device further includes a booster circuit, the booster circuit is electrically coupled to the M driving circuits DC (1) ~ DC (M), and the booster The circuit is used to increase the scanning voltage. The keyboard device according to item 1 of the scope of patent application, wherein in the scan period scan (k), when the M key units KU (1, x) ~ KU (M, x) located in the x-th column are all When pressed, the key unit KU (k, x) transmits the scanning voltage of the row of signal lines C (k) to the column of signal lines R (x); and the rows outside the k-th row and the first (M-1) key sheet at the intersection of x columns The elements KU (1 ~ (k-1), x) and KU ((k + 1) ~ M, x) are the line signal lines C (1) ~ C (k-1), C (k + 1) The unscanned voltage on ~ C (M) is transmitted to the column signal line R (x), wherein the output voltage Rout (x) generated by the transition circuit TC (x) is the first voltage value.