JPH0750423B2 - Key input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a key input device.

(B) Conventional Technology A key input device having a large number of keys is currently applied to an input device such as a teletype, teletex, word processor, computer input desk or other communication and information processing control.

In this type of key input device, as disclosed in Japanese Patent Publication No. Sho 60-49921, when one key is continuously energized for a long time, a code corresponding to the energized key is repeatedly output. ing.

(C) Problems to be Solved by the Invention However, in the N-key rollover type key input device capable of energizing the other key while keeping one key energized, the repeat function as described above is provided. Was not adopted.

The reason for this is as shown in FIG.
When the keys are sequentially activated, the first code corresponding to the first key is first output, and then in response to the activation of the second key, the first code is replaced with the first code. When the second code is output and the third code is output instead of the second code in response to the activation of the third key, the third key is subsequently released from the activation. This is because, since the first and second keys are in the activated state, it is very difficult to determine which key should output the code.

One method for solving the above problem is to output the code for the key that is first determined to be in the activated state in the scanning operation to detect the activated state of the key after the third key is released. Although a method is conceivable, in this method, the code is output according to the scanning order of the keys instead of the biasing order of the keys, so that there is a problem that an undesired code is output to the operator.

(D) Means for Solving the Problems The present invention has been made in view of the above problems, and is capable of energizing the other key while keeping the one key energized.
The purpose is to enable the repeat function to be adopted even in a key rollover type key input device, and its structural feature is that a key switch group having a plurality of keys and the state of each key of the key switch group are A key input device comprising a key state storage section to be stored and a control section which outputs a repeat request signal according to the state of each key, and which is capable of energizing another key while holding one key energized state. ,
The control unit scans the group of key switches to detect the state of each key, and compares the detection result with the contents of the key state storage unit to detect the newly turned on key and the newly turned off key. Detecting and stopping the output of the repeat request signal only when the newly turned off key is the newly turned on key in the detection.

(E) Operation In such a configuration, the output of the code is stopped when the key that is finally turned on (energized) is turned off (released).

(F) Embodiment FIG. 1 shows an embodiment of the present invention, in which (1) is a control unit composed of, for example, a microcomputer, and the control unit controls each part described below based on a control program described later. Take charge.

(2) is a key switch group, and the key switch group is provided with a key (3) at each intersection of a plurality of X-rays Xo to Xn and a plurality of Y lines Yo to Ym as shown in FIG.

(4) is a Y decoder, which responds to the key scan signal sent from the control unit (1) through the Y output port (5) to connect the Yo to Ym lines in the key switch group (2). to scan. Reference numeral (6) is an X input port, which controls the data of every n + 1 bits output from the Xo to Xn lines in response to the scanning of the Yo to Ym lines.
Send to.

(7) is a program ROM (read only memory), and the ROM stores codes corresponding to the control section program and each key of the key switch group (2).

Reference numeral (8) is a memory RAM (random access memory), and Yo to Ym output from the X input port (6) by the scan operation as shown in FIG.
There is a key state storage unit (8a) that stores Xn-ray output.

(9) is an output port, and a repeat request signal FKBCTL for requesting repeated display of a code corresponding to each key of the key switch group (2) and a character / symbol corresponding to the code is output from the output port. It

4 and 5 are flowcharts showing the control operation controlled by the control unit (1) based on the above control program,
The operation will be described based on the flowchart. For convenience of explanation, the number of X lines and Y lines of the key switch group (2) is 8
And 16. Therefore, n and m are 7 and 15, respectively. In addition, all the values of the areas and counters described below are stored in the memory RAM (8).

First, in the S1 step, the contents of the NK, FK, TK and the key state storage section (8a) where the code corresponding to the key is stored are set to "0"
Reset to.

In a succeeding S2 step, the key switch group (2) is scanned to detect a newly activated key or a newly released key. Specifically, it is performed based on the flowchart shown in FIG.

That is, first, in step _S201 , the counter M is set to "0", and then in step _S202 , the control unit (1) sets Y
Outputs a scan signal to the Y decoder (4) to scan a line in the Y _M lines, to output the status of each key of Y _M line. 8-bit status signal output from the X input ports in response (6)斯Ru scanning operation is stored in the output save area RX at S ₂₀₃ step.

Then, the logical operation of _{(Y M RX) * RX ......} (i) between the content of Y _M region of the contents and the key state storage unit of the RX in S ₂₀₄ step (8a) is carried out. The symbol "" is an exclusive OR symbol, and "*" is an AND symbol.

When such a calculation result is not "0", that is, when there is a newly activated key, the process proceeds to step _S205 .

Program code in the S ₂₀₅ step corresponding to the key is determined to have been newly energized in the S ₂₀₄ step
Area N is read from ROM (7) and is followed by step _S206.
Store in K.

After that, the process proceeds to step _S207 , where the contents of the output save area RX are stored in the key state storage unit (8a) as Y _M
After writing in the area, proceed to step S3.

Returning to S ₂₀₄ step, the process when the operation result is "0", the operation proceeds to S ₂₀₈ step. In step S ₂₀₈ , the operation (Y _M RX) * Y _M (ii) shown in the following equation (ii) is performed, and when the result is not “0”, that is, when there is a newly released key, the processing is S Go to step ₂₀₉ .

Program code in the S ₂₀₉ step corresponding to the key is determined to have been newly released in the S ₂₀₄ step
Area F is read from ROM (7) and in subsequent S ₂₁₀ step
Store in K. Thereafter, the process proceeds to step _S207 .

Returning to S ₂₀₈ step, the process when the operation result in斯Ru step is "0", the operation proceeds to S ₂₁₁ step.

In step S ₂₁₁ , the value of the counter M is incremented by “1”, and in step S ₂₁₂ , the counter M is incremented.
It is determined whether the content of is larger than the numerical value m corresponding to the number of Y lines. In this determination, when it is determined that “M> m”, that is, when the scanning for all the Y lines of the key switch group is completed, the process proceeds to step S3. In addition, “M ≦
processing is determined that m "returns to S ₂₀₂ step.

Therefore, in S ₂₀₁ to S ₂₁₂ step detects a key state has changed by comparing each key state during the current scan operation once the time before the scanning operation thereof, the newly energized key exists If so, the code corresponding to the key is stored in the area NK, and if the newly released key exists, the code corresponding to the key is stored in the area FK.
When a key whose state is changed is found, the scanning operation thereafter is stopped. Further, since the state of each key on the Y line to which the above-mentioned changed state belongs is always stored in a predetermined area of the key state storage unit, the latest key state is stored in the key state storage unit. It will be.

Returning to FIG. 4, when step S2 ends, the process proceeds to step S3.

In step S3, it is determined whether the content of the area NK is "0". When it is determined that "NK = 0" is not determined in this determination, that is, when there is a newly activated key in the key scanning operation of step S2, the process proceeds to step S4.

In the S4 step, the area NK is compared with the area TK in which the latest code output via the output port (9) is stored as described later, and when “NK = TK”, the process returns to the S2 step and the “NK When ≠ TK, go to step S5.

In step S5, it is determined whether or not the content of the area TK is "0". When "TK = 0", the process jumps to step S7. When "TK ≠ 0", the END code is transmitted through the output port (9) in step S6. Thereafter, the process proceeds to step S7.

In the step S7, the contents of the area NK are sent out from the output port (9), and in the following step S8, the output of the repeat request signal FKBCTL from the output port (9) is started.

Next, in step S9, the contents of area TK are written in area NK, and the process returns to step S2. Returning to step S3, if "NK = 0" is determined in this step,
The process proceeds to step S10.

In S10 step, the contents of area FK and area TK are compared,
When "FK ≠ TK", the process returns to step S2.

When "FK = TK", that is, when it is determined that the code corresponding to the newly released key and the latest code output from the output port (9) are the same, steps S11 to S13 are sequentially performed. After that, the process returns to step S2.

Output of repeat request signal FKBCTL is stopped in step S11, and END code is output in the following step S12 (9)
And the areas NK, TK, and FK are all cleared to "0" in step S13.

Next, as an example, the output state from the output port (9) when the first, second and third keys are sequentially energized as shown in FIG. 6 and then the third key is first released will be described. To do.

First, when the first key is activated at time t ₁ , S ₁ to S 5 and S 7
Steps S8 to S8 are sequentially processed, the code A corresponding to the first key is output, and the transmission of the repeat request signal FKBCTL is started.

Then the second key is activated at time t ₂ S2 to S9
The steps are sequentially processed, and the END code E and the code B corresponding to the second key are sequentially output. Furthermore, at time t ₃ , the third
When the key is activated, steps S2 to S9 are sequentially processed and EN
The D code E and the code C corresponding to the third key are sequentially output. The third when the key is released S2, S3 at time t _4, are sequentially processed S10~S13 step, sending a repeat request signal FKBCTL is stopped with END code E is sent.

In the system to which the device of this embodiment is connected, while the repeat request signal FKBCTL is being sent, the repeat process is performed on the code corresponding to the output key. Also, the END code is a code indicating the change and end of the output code.

(G) Effect of the Invention In the key input device of the present invention, when the lastly activated key is released, the repeat request signal is stopped, so that an undesired code is output even in the N-key rollover type input device. The repeat function can be realized without any need.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a block diagram, and FIG.
FIG. 6 is a circuit diagram of a key switch group, FIG. 3 is a schematic diagram showing a key state storage unit, FIGS. 4 and 5 are flowcharts for explaining the operation, and FIG. 6 is a timing chart for explaining the operation. Is. (1) …… Control unit, (2) …… Key switch group, (8a)
...... Key state storage section.

Claims (1)

[Claims] 1. A key switch group having a plurality of keys, a key state storage section for storing the state of each key of the key switch group, and a control section for outputting a repeat request signal according to the state of each key. In a key input device capable of energizing one key while maintaining the energized state of one key, the control unit scans the key switch group to detect the state of each key and the result of the detection. By detecting the newly turned-on key and the newly turned-off key by comparing the contents of the key state storage unit with the contents of the key-state storage section, and only when the newly-turned-off key is the newly turned-on key in the detection. A key input device characterized by stopping output of a repeat request signal.