TWI476638B - Method of keyboard scan and keyboard applied the method - Google Patents

Description

Keyboard scanning method and keyboard using the same

The present invention relates to a scanning method, and more particularly to a keyboard scanning method.

In order to reduce the loop impedance, the membranes on the market generally use silver wires for the wires on the thin film circuits, but the price of silver is getting higher and higher. Therefore, the industry has developed a price difference of 20% to 30% with silver. Carbon printing forms a thin film circuit to replace the above-described thin film circuit using a silver powder line.

Referring to FIG. 1 , it is a schematic circuit diagram of a conventional membrane keyboard 1 , which mainly includes a controller 11 , a thin film circuit board 12 electrically connected to the controller 11 , and a plurality of buttons 13 . The thin film circuit board 12 is provided with a plurality of row lines (scanning lines) P0.0~P0.7 and a plurality of column lines (return lines) P1.0~P1.7 which are printed with carbon powder and are staggered in a matrix. The button 13 is correspondingly disposed at the intersection of the row lines P0.0~P0.7 and the column lines P1.0~P1.7 to guide the corresponding row lines P0.0~P0.7 and the column line P1. .0~P1.7, and the controller 11 has a plurality of first resistors R1 and SWs corresponding to the row lines P0.0~P0.7, and corresponding column lines P1.0~P1.7. a plurality of second resistors R2, one end of each of the first resistors R1 is connected to a certain voltage VCC, and the other end is electrically connected to a corresponding row line P0.0~P0.7, and one end of each switch SW and a corresponding row line P0.0 ~P0.7 is electrically connected and the other end is grounded. Each of the second resistors R2 is connected to a corresponding column line P1.0~P1.7 at one end, and the other end is connected to the constant voltage VCC.

In addition, each row line P0.0~P0.7 has a line resistance R3 between the two buttons 13 and the resistance of the line resistance R3 is not the same. Similarly, each column line P1.0~P1.7 There is also a line resistance R4 between the two buttons 13 and the resistance of the line resistance R4 is not the same. And since the impedance of the row line P0.0~P0.7 and the column line P1.0~P1.7 made of carbon powder is higher than that of the silver line, the first connection with the row line P0.0~P0.7 The resistance of the resistor R1 and the second resistor R2 connected to the column lines P1.0 to P1.7 is also relatively increased.

When the row lines P0.0~P0.7 are to be scanned, a scan module 14 in the controller 11 sequentially turns on the switches SW corresponding to the row lines P0.0~P0.7, for example, scanning. When the line is P0.0, the row line P0.0 is at the low level (ground), while the other line lines P0.1~P0.7 are still at the high level, and then the column lines P1.0~P1 are sequentially read. .7, at this time, if a button is pressed, for example, the button K11 at the intersection of the row line P0.0 and the column line P1.0 is pressed, the row line P0.0 and the column line P1.0 are guided to form, for example, The equivalent circuit shown in Figure 2.

However, due to the relationship between the capacitance C and/or the stray capacitance inside the controller 51, the line resistance R4 of the column line P1.0 and the second resistor R2 connected to the column line P1.0 will affect the RC time of charging and discharging of the capacitor C. Therefore, the second resistor R2 connected to the column line P1.0 will cause the RC time to increase, so that when the column line P1.0 is connected to the row line P0.0 at the low level, as shown in FIG. 3, the column line P1 .0 cannot be quickly pulled down to the low level and must be delayed by a falling time TD. Similarly, when the row line P0.0 is scanned and returns to the high level state, and the column line P1.0 is still connected to the row line P0.0, the column line P1.0 also needs to be delayed by a rise time TU to be returned. To high standards. Therefore, in order to avoid the rising time TD and the falling TU time of the column line P1.0~P1.7, the scanning time is not overlapped, and the scanning module 14 needs to scan the scanning time of each line P0.0~P0.7. Elongated, but this results in poor scanning efficiency, so that there will be doubts about word drop when typing quickly.

Furthermore, when only one button is pressed, for example, the button K13 at the intersection of the row line P0.2 and the column line P1.0, the equivalent circuit is as shown in FIG. 4, and the scanning module 12 of the controller 11 can be A partial pressure V1 of the column line P1.0 is obtained. However, when a plurality of buttons such as K11, K12, and K13 are simultaneously pressed, and the same column line, for example, P1.0, is simultaneously connected to a plurality of row lines, for example, P0.0, P0.1, and P0.2, When scanning to the row line P0.2, the equivalent circuit will be as shown in Fig. 5. The button K13 is connected to the row line P1.0 and the row line P0.2, and the buttons K11 and K12 also make the row line P0.0. , P0.1 and the first resistor R1 connected in series on the row lines P0.0, P0.1 are connected (parallel) to the column line P1.0, and the scan module 12 is determined to obtain the column line P1.0. The pressure V1' will be different from (higher than) the partial pressure V1 of the single button K13, and the controller 14 will be misjudged that the button K13 is an invalid button. Similarly, the above problem occurs when a plurality of buttons are simultaneously pressed to cause the same row line to be simultaneously connected to a plurality of column lines.

Accordingly, it is an object of the present invention to provide a keyboard scanning method that can efficiently scan and prevent false positives from occurring and a keyboard device to which the scanning method is applied.

In order to achieve the above object, the keyboard used in the keyboard scanning method of the present invention comprises a controller, a plurality of row lines and column lines arranged in a matrix staggered, and a plurality corresponding to the intersection of the row lines and the column lines, Leading the corresponding row and column line buttons, wherein each of the row lines is connected to a first level signal via a first resistor, and each of the column lines is guided by the second resistor and the first level signal And the controller can control whether the first resistors are connected to the corresponding row lines, and whether the second resistors are connected to the corresponding column lines; and the keyboard scanning method comprises: (A The controller first controls each of the first resistors to be non-conductive with the corresponding row lines, and controls each of the second resistors to be non-conductive with the corresponding column lines, and then sends a scan signal to a row line to be scanned. (B) The controller sequentially reads the signals on each of the column lines, and before the column lines are read, the column lines are connected to the corresponding second resistors, and the signals on the column lines are read. After that, the column line is not connected to the corresponding second resistor; (C) repeating steps (A) and (B), straight Full scan row line portion.

Preferably, a scan module for performing the steps (A), (B) and (C) is preset in the controller.

Preferably, the scanning signal connects the scanned row line to a second level signal.

Preferably, in step (C), when scanning the entire row line, the controller further controls each of the first resistors to be connected to the corresponding row line, and controls each of the second resistors and the corresponding column. Line lead.

Preferably, the first level signal is a high level signal, and the second level signal is a low level signal.

In addition, a keyboard for applying the keyboard scanning method of the present invention includes: a plurality of row lines and column lines arranged in a matrix staggered; a plurality of buttons corresponding to the intersections of the row lines and the column lines, to guide the phase Corresponding row and column lines; a plurality of first resistors corresponding to the row lines, one end of each of the first resistors is connected to a first level signal; a plurality of second resistors corresponding to the column lines, each One end of the second resistor is connected to the first level signal; a plurality of first switches corresponding to the row lines are respectively connected between the corresponding row lines and the first resistor; a plurality of corresponding lines are corresponding to the lines a second switch of the line, one end of which is connected to the corresponding row line, and the other end is connected to a second level signal; a plurality of third switches corresponding to the column lines are respectively connected to the corresponding column line and the second line Between the resistors; and a controller that controls the first switch and the third switch to be non-conducting before scanning a line, and then controls the second switch corresponding to the scanned row line to be turned on, and reads Each column line and controls the column line to be read Corresponding to the third switch is turned on, and the read signal of the column line, the third switch control line is read with the column corresponding to non-conductive.

Preferably, when the controller scans a row line, the column lines are sequentially read, and then the next row line is scanned until all the line lines have been scanned.

Preferably, a scan module is preset in the controller, and the controller executes the scan module to perform the operations of scanning the row lines and reading the column lines.

Preferably, the first resistor, the second resistor, the first switch, the second switch and the third switch are built in the controller.

Preferably, after scanning the entire row of the scanning module, the scanning module controls the first switch and the third switch to be turned on.

Preferably, the first level signal is a high level signal, and the second level signal is a low level signal.

Preferably, the keyboard is a film type keyboard.

The effect of the present invention is that the controller does not conduct the first resistors and the corresponding row lines before scanning the row lines of the keyboard, and the second resistors and the corresponding column lines are not Leading, and sequentially scanning each of the row lines, thereby shortening the falling time of the column line level transition with the scanned row line when the button is pressed, thereby effectively shortening the scanning time and improving scanning Efficiency, avoiding the problem that the above-mentioned conventional technology loses characters due to excessive scanning time during fast typing. Moreover, each time the controller scans a row of lines, the column lines are sequentially read, and only the column lines to be read and the corresponding second resistors are connected, thereby avoiding the same column line or the same line line. When multiple buttons are pressed at the same time, some buttons are affected by other parallel buttons, and the controller misjudges that the buttons are invalid buttons, which actually achieves the efficacy and purpose of the present invention.

The foregoing and other objects, features, and advantages of the invention are set forth in the <RTIgt;

As shown in FIG. 6 , it is a circuit construction of a preferred embodiment of the keyboard of the present invention. The keyboard 5 of the present embodiment is a thin film keyboard, but is not limited thereto. Referring to FIG. 7 , it is a preferred embodiment of the keyboard scanning method of the present invention, which is applied to the thin film keyboard of the embodiment, but not limited thereto, that is, the keyboard scanning method of the embodiment can also be applied. In other non-membrane keyboards having a similar circuit construction to a membrane keyboard. The keyboard 5 mainly includes a controller 51, a thin film circuit board 52 electrically connected to the controller 51, and a plurality of buttons 53. In order to save the manufacturing cost, the film circuit board 52 is provided with a plurality of row lines (scanning lines) printed with carbon powder and staggered in a matrix. In this embodiment, eight line lines P0.0 to P0.7 are taken as an example. For the plurality of column lines (return lines), the eight column lines P1.0 to P1.7 are taken as an example. The buttons 53 are correspondingly arranged at the intersection of the row lines P0.0~P0.7 and the column lines P1.0~P1.7 to guide the corresponding (intersecting) line lines P0.0~P0.7. With column line P1.0~P1.7.

The controller 51 has a plurality of first resistors R1, a plurality of first switches SW1 and a plurality of second switches SW2 corresponding to the row lines P0.0 to P0.7, and corresponding column lines P1.0 to P1.7. The plurality of second resistors R2 and the plurality of third switches SW3. One end of each of the first resistors R1 is connected to a first level signal, for example, a constant voltage VCC of a high level, and the other end is electrically connected to the corresponding row line P0.0~P0.7 through the corresponding first switch SW1. ,As shown in Figure 6. And one end of each of the second switches SW2 is electrically connected to the corresponding row line P0.0~P0.7, and the other end is connected to a second level signal, such as a constant voltage or ground of a low level. For example. Each of the second resistors R2 is connected to the first level signal at one end, and the other end is electrically connected to the corresponding column line P1.0~P1.7 through the corresponding third switch SW3.

Moreover, each line P0.0~P0.7 has a line resistance R3 between the two buttons 53 and the resistance of the line resistance R3 is not the same. Similarly, each column line P1.0~P1.7 There is a line resistance R4 between the two buttons 53 and the resistance of the line resistance R4 is also different.

The controller 51 can control whether the first switch SW1, the second switch SW2, and the third switch SW3 are turned on or not. Specifically, the controller 51 further includes a scanning module for detecting whether the buttons are pressed. 54. It can control whether the first switch SW1, the second switch SW2, and the third switch SW3 are turned on or not during the scanning process to perform a key scanning process. That is, the scanning module 54 of the embodiment scans the row lines P0.0~P0.7 sequentially, and sequentially reads the signals on the column lines P1.0~P1.7 to determine the same. Whether the button 53 is pressed or not will be further described below.

The keyboard scanning method of this embodiment is as shown in FIG. 7. First, as step 61, the scanning module 54 first controls the first switch SW1 and the second switch SW2 before scanning each row line P0.0~P0.7. And the third switch SW3 is not turned on, so that each of the first resistors R1 and the corresponding row lines P0.0~P0.7 are not connected, and each of the second resistors R2 is also corresponding to the column line P1.0~ P1.7 is not connected, and then sends a scan signal to the scanned row line. For example, when scanning the row line P0.0, the second switch SW2 corresponding to the row line P0.0 is turned on, so that the row line P0. 0 is connected to the second level signal (ground). At this time, if the button K11 at the intersection of the row line P0.0 and the column line P1.0 is pressed, and the column line P1.0 is connected to the row line P0.1, The equivalent circuit is shown in FIG. 8. Since the second resistor R2 corresponding to the column line P1.0 is not connected to the column line P1.0, the internal capacitance C (and/or other stray capacitance) of the controller 51 is shortened. The RC time of charge and discharge, so when the column line P1.0 is connected to the row line P0.1 at the low level, the column line P1.0 can be quickly converted into a low level state, and the shortening is shown in FIG. The falling edge time TD. Thereby, the scanning time can be effectively shortened, the scanning efficiency can be improved, and the problem that the above-mentioned conventional technology loses characters due to the long scanning time during fast typing can be avoided.

Then, in step 62, the scan module 54 sequentially reads the signals on the column lines P1.0~P1.7, and reads each column line, such as the column line P1.0, before the column. The third switch SW3 corresponding to the line P1.0 is turned on, so that the column line P1.0 and the corresponding second resistor R2 are connected to read the signal on the column line P1.0, and the column line P1 is obtained. The partial pressure V2 on .0 is further determined based on the partial pressure V2 whether or not the button K11 is actually pressed. After reading the column line P1.0 signal, the third switch SW3 corresponding to the column line P1.0 is not turned on, so that the column line P1.0 and the corresponding second resistor R2 are not connected, and then continue reading. Remove one column line, and so on, until all column line lines P1.0~P1.7 are read.

Thereby, when a plurality of buttons on the same column line are simultaneously pressed, for example, the three buttons K11, K12, and K13 at the intersection of the column line P1.0 and the line lines P0.0, P0.1, and P0.2 are simultaneously pressed. When scanning to the row line P0.2, since the first switch SW1 corresponding to the row lines P0.1 and P0.2 is not turned on, the line resistances on the row lines P0.1 and P0.2 and the line lines The first resistor R1 corresponding to P0.1 and P0.2 will not be connected (parallel) to the column line P1.0 at the same time, as shown in FIG. 4, that is, the equivalent circuit at this time and when the button K13 is pressed separately. The same, therefore, even if a plurality of buttons K11, K12, K13 on the same column line P1.0 are simultaneously pressed, when scanning to the row line P0.2, the divided voltage V1 on the column line P1.0 is still pressed separately. When the single button K13 is the same, it is not affected by other line lines P0.1 and P0.2, so it can be effectively avoided that when the plurality of buttons K11, K12, K13 on the same column line are simultaneously pressed, the controller 54 misjudges the button. K13 occurs when an invalid button is pressed. Similarly, when a plurality of buttons on the same line are simultaneously pressed, the above scanning method can also prevent the controller 54 from misjudged that the pressed button is an invalid button.

Then, in step 63, the scanning module 54 determines whether all the line lines P0.0~P0.7 have been scanned, and if not, repeats the above steps 61 and 62 until the line line P0.0~P0.7 of the entire part is scanned. . After all the line lines P0.0~P0.7 are scanned, all the first switch SW1 and the third switch SW3 are turned on, so that all the line lines P0.0~P0.7 and the column lines P1.0~P1 are turned on. .7 maintains a high level state, which avoids some line or column lines before scanning, which is at a low level, causing misjudgment during scanning.

In addition, it is worth mentioning that in order to further determine the correctness of the scan result, the scan module 54 usually repeats the entire scan process of FIG. 7 2 to 3 times to determine that the pressed button is indeed a valid button (also That is, it is determined that the button is actually pressed).

In summary, the controller 54 of the above embodiment first orders the first resistors R1 and the corresponding row lines P0.0~P0 before scanning the row lines P0.0~P0.7 of the keyboard 5. 7 is not conductive, and the second resistors R2 are not connected to the corresponding column lines P1.0~P1.7, and then the row lines P0.0~P0.7 are sequentially scanned. Therefore, when a button is pressed, the falling time TD of the line level shifting with the scanned row line can be shortened, thereby effectively shortening the scanning time, improving the scanning efficiency, and avoiding the above-mentioned prior art during fast typing. The problem of missing words due to excessive scanning time. Moreover, each time the controller 54 scans a line, the column lines are sequentially read, and only the column lines to be read and the corresponding second resistor R2 are connected, thereby avoiding the same column line or the same When a plurality of buttons on one line are simultaneously pressed, the controller 54 misjudges that the pressed button is an invalid button, and the effect and purpose of the present invention are indeed achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

5. . . keyboard

51. . . Controller

52. . . Thin film circuit board

53, K11, K12, K13. . . button

54. . . Scanning module

61~64. . . step

P0.0~P0.7. . . Line

P1.0~P1.7. . . Column line

R1. . . First resistance

R2. . . Second resistance

R3, R4. . . Line resistance

SW1. . . First switch

SW2. . . Second switch

SW3. . . Third switch

V1, V1', V2. . . Partial pressure

VCC. . . Constant voltage

1 is a schematic diagram showing the circuit structure of a conventional thin film type keyboard;

2 is an equivalent circuit diagram when the button K11 at the intersection of the row line P0.0 and the column line P1.0 of the conventional film type keyboard is pressed;

3 is a schematic diagram showing the change of the position when the row line P0.0 and the column line P1.0 of the conventional film type keyboard are guided;

4 is an equivalent circuit diagram when scanning the row line P0.2 and reading the column line P1.0 when the button K12 at the intersection of the row line P0.2 and the column line P1.0 of the conventional film type keyboard is pressed;

5 is an equivalent circuit diagram when scanning the row line P0.2 and reading the column line P1.0 when the buttons K11, K12, and K13 on the column line P1.0 of the conventional film type keyboard are simultaneously pressed;

Figure 6 is a schematic view showing the circuit configuration of a preferred embodiment of the keyboard device of the present invention;

7 is a flow chart of a preferred embodiment of a keyboard scanning method of the present invention;

8 is an equivalent circuit diagram when the button K11 at the intersection of the row line P0.0 and the column line P1.0 of the keyboard is pressed in the embodiment; and

Fig. 9 is an equivalent circuit diagram of the scanning of the row line P0.0 and the reading of the column line P1.0 when the button K11 at the intersection of the row line P0.0 and the column line P1.0 of the keyboard is pressed in the embodiment.

61~64. . . step

Claims (12)

A keyboard scanning method, the keyboard includes a controller, a plurality of row lines and column lines arranged in a matrix staggered, and a plurality of corresponding lines are arranged at intersections of the row lines and the column lines to guide corresponding row lines and columns a button of the line, wherein each of the line lines is connected to a first level signal via a first resistor, each of the line lines is connected to the first level signal via a second resistor, and the controller can control each Whether the first resistor is connected to the corresponding row line or not, and controlling whether the second resistor is connected to the corresponding column line; and the keyboard scanning method comprises: (A) the controller first controlling each of the first The resistor is not connected to the corresponding row line, and controls each of the second resistors to be non-conductive with the corresponding column line, and then sends a scan signal to a row line to be scanned; (B) the controller reads sequentially Taking the signal on each of the column lines, and before reading each column line, routing the column line to the corresponding second resistor, and after reading the signal on the column line, making the column line correspond to the corresponding line The second resistor is not conductive; and (C) repeats steps (A) and (B) until the entire line of the line is scanned. According to the keyboard scanning method of claim 1, wherein the controller has a scanning module for performing the steps (A), (B) and (C). The keyboard scanning method of claim 2, wherein the scanning signal connects the scanned row line to a second level signal. The keyboard scanning method according to claim 3, wherein in the step (C), when scanning the entire row line, the controller further controls each of the first resistors and the corresponding row line to be connected, and Each of the second resistors is controlled to be in contact with a corresponding column line. According to the keyboard scanning method of claim 3, the first level signal is a high level signal, and the second level signal is a low level signal. A keyboard comprising: a plurality of rows and columns arranged in a matrix staggered; a plurality of buttons corresponding to the intersections of the row and column lines to guide the corresponding row and column lines; Corresponding to the first resistance of the row lines, one end of each of the first resistors is connected to a first level signal; a plurality of second resistors corresponding to the column lines, one end of each of the second resistors is connected to the first resistor a level switch signal; a plurality of first switches corresponding to the row lines, each connected between the corresponding row line and the first resistor; a plurality of second switches corresponding to the row lines, one end connected to the phase Corresponding row line, the other end is connected to a second level signal; a plurality of third switches corresponding to the column lines are respectively connected between the corresponding column line and the second resistor; and a controller Before scanning a line, the first switch and the third switch are controlled to be non-conducting, and then the second switch corresponding to the scanned row line is controlled to be turned on, and each column line is read, and controlled and read. The third switch corresponding to the column line is turned on, and the column is read After the signal, the third switch control line is read with the column corresponding to non-conductive. According to the keyboard of claim 6, wherein when the controller scans a row line, the column lines are sequentially read, and then the next line line is scanned until all the line lines have been scanned. According to the keyboard of claim 7, wherein the controller has a scanning module preset, and the controller executes the scanning module to perform the scanning of the row lines and the reading of the column lines. . The keyboard of claim 8, wherein the first resistor, the second resistor, the first switch, the second switch, and the third switch are built in the controller. According to the keyboard of claim 8 or 9, wherein the scanning module scans the entire line of the line, the first switch and the third switch are controlled to be turned on. The keyboard of claim 10, wherein the first level signal is a high level signal and the second level signal is a low level signal. The keyboard of claim 6 wherein the keyboard is a film type keyboard.