JP2568227B2 - Key output device - Google Patents

Description

The present invention relates to a key data output device such as a keyboard for outputting key data to various information processing devices.

(Prior Art) In information processing devices such as computers and word processors, a keyboard is most commonly used for inputting operator information.

FIG. 2 shows a block diagram of a key data output device which is generally used in the past for controlling a keyboard.

The figure shows a key matrix 1 in the keyboard, a key data output device 2 for controlling the key matrix 1, and a host device 3. In general, a keyboard has a large number of keys (not shown) arranged in a predetermined order. In the keyboard, a key matrix 1 made of so-called matrix-shaped wiring and capable of recognizing a depressed key is accommodated. There is. The key data output device 2 is a central processing unit (CPU)
4, read only memory (ROM) 5, buffer (random access memory), and interface 7
It consists of and. The central processing unit 4 is a circuit composed of a microprocessor or the like that controls the scanning of the key matrix 1 to read the pressed state of the keyboard keys. The read only memory 5 is a memory that stores an operation program of the central processing unit 4. The buffer 6 is a storage device for temporarily storing the key data corresponding to the depressed key. The interface 7 is a circuit that controls transmission of key data to the host device 3 connected to the interface 7.

 Such a device basically operates as follows.

First, the central processing unit 4 scans all the key switches of the key matrix 1 connected to the drive line 8 by the drive of the drive line 8 and reads out the on / off state thereof. The ON / OFF state of this key switch is controlled by the central processing unit 4 through the sense line 9.
To enter. Here, information regarding the on / off states of all the key switches 2 will be referred to as key matrisk information.

The buffer 6 always stores the previously read key matrix information. Then, the central processing unit 4 compares the previous key matrix information with the key matrix information read this time, and checks whether there is a difference between them. If there is a difference between the two, it is because one of the key switches has been pressed, so the key data corresponding to that key switch is stored in the buffer 6 as valid key data. or,
The key matrix information for the previous time is updated to the key matrix information read this time and stored in the buffer 6.

While repeatedly performing such operations at regular intervals,
The key data stored in the buffer 6 based on the valid key is transmitted to the host device 3 through the interface 7.

(Problems to be Solved by the Invention) By the way, in the device as shown in FIG. 2, for example, the host device 3 is put into a state (busy state) in which certain processing such as CRT (cathode ray tube) control is completed. In that case, the key data sent from the key data output device 2 cannot be processed.

Therefore, in order to inform the key data output device 2 of such a state, a line for transmitting a transmission instruction is provided between the key data output device 2 and the host device 3. For example, when the line is set to the high level, it is possible to transmit as if there is a transmission instruction from the host device 3, and when the line is to the low level, there is a transmission prohibition instruction from the host device 3. As
The key data output device 2 stops transmitting key data.

FIG. 3 shows a flowchart of key data transmission in the conventional device.

As described above, the central processing unit 4 first performs a key matrix scan (step S1). If there is a valid key, the key data is stored in the buffer (step S2). If there is no valid key, the process directly proceeds to step S3. Next, it is judged whether or not there is a transmission instruction from the higher-level device 3 (step S3). And
If there is a transmission instruction from the host device 3, the buffer 6
Key data is read from and transmitted (step S
Five). If there is no transmission instruction, the process directly proceeds to step S6. Next, it is determined whether or not a repeat key is present (step S
6). Then, the key data of the repeat key is stored in the buffer (step S7).

Now, generally, when the operator operates the keyboard, one key data is input by the operation of depressing the key switch once and then opening it again. on the other hand,
There is a method in which the same data is repeatedly input by keeping the key switch depressed. This is called a repeat key, but usually
This method is often used for cursor scrolling.

More specifically, the key data transmission process including such a method is performed as follows.

FIG. 4 shows a transmission time chart of the key data output from the key data output device 2 to the host device 3.

First, in the case of this figure, it is assumed that the transmission instruction input from the host device 3 is always at a high level and that the transmission instruction is always present [FIG. Here, the predetermined key is for a certain time T
It can only be pushed down. [Figure (b)]. Here, when the key is in the depressed state, the depressed key code is stored (timing). The pressed key code is, for example, the key data itself corresponding to the pressed key. After that, a predetermined cycle t
Then, it is determined whether or not the pressed state of the key is maintained (timing ,,). Then, the repeat key code is stored in the buffer each time it is confirmed that the depressed state is maintained [(c) in the figure]. This data is also a key code corresponding to a predetermined depressed key, for example, and has the same content as the depressed key code. When the key is finally released (timing), the release key code is stored. This release key code is a specific type of data for indicating that the predetermined key that has been pressed down is released.

From the above operation, as shown in FIG. 4 (d), the key data 10 is output to the higher-level device 3 following the storage of the key data so as to be delayed by a predetermined time.

Next, FIG. 5 shows an example in which the upper level device 3 drops the transmission instruction to the low level and there is the transmission prohibition instruction.

As shown in FIG. 5A, when a transmission prohibition instruction is given from the upper level device 3 for a predetermined time, a predetermined key is pressed down during this time, and a predetermined number of times (here, 3
Times) The repeat key code is stored. The key data 10 thus accumulated in the buffer 6 is read from the buffer 6 and transmitted to the host device when the transmission prohibition instruction is canceled and the transmission instruction is issued (timing) [FIG. d)].

However, for example, in a system having a function of scrolling the CRT screen display by one line when the operator presses a certain key once, the pressed state of that key is executed in order to execute the desired amount of scrolling by the operator. If you continue. In this case, if the host device always holds the state with the transmission instruction, the screen is scrolled in response to the pressing of the key, and when the target scroll is completed, the key is released to complete the scrolling work.

However, as shown in FIG. 5, when there is a transmission prohibition instruction from the host device while the key is being pressed, the repeat data is temporarily stored in the buffer and waits for the transmission instruction from the host device. . The key data is output after there is a transmission instruction from the host device, but normally, the operator does not recognize such a state, so press the key until the CRT display finishes the desired scrolling. Will continue. In this case, even if the CRT display scrolls by the desired amount and the operator releases the key, a certain amount of repeat data stored in the buffer during the previous transmission prohibition instruction is still sent to the host device. Will be done. As a result, the higher-level device continues scrolling, and as a result, scrolls more than the intended amount, and correction work is required for the excess amount.

Since such an operation adversely affects the operability of the keyboard by the operator, it is conventionally performed, for example, in Japanese Patent Publication No.
As shown in Japanese Patent Laid-Open No. 406, there is an improvement plan such that when the operator releases the key, the host device detects it and stops the subsequent processing. However, it is preferable that this type of device is configured to further reduce the judgment and burden on the host device.

The present invention has been made in view of the above points, and provides a keyboard control method that prevents the key data output device from transmitting such unnecessary data to a higher-level device and improves the operability of the keyboard. It is intended to be provided.

(Means for Solving Problems) According to the present invention, a key matrix in which a plurality of keys are arranged in a predetermined order, a control unit that scans the key matrix to sense a pressed state of the key, and the pressed key A buffer for temporarily storing key data corresponding to the key, a key press code corresponding to the key that has been pressed to be detected in the buffer, and the key is continuously pressed. If a key is stored, the repeat key code is stored in the buffer, and the key is provided with a control unit that reads the push key code and the repeat key code from the buffer in response to a transmission instruction from the host device and transmits the read key code and the repeat key code to the host device. In the data output device, when the control means stores the repeat key code in the buffer, it detects whether or not there is a transmission instruction from the host device. The repeat key code is stored in the buffer when there is an instruction to send or send, and the repeat key code is not stored in the buffer when there is no instruction to send.

(Operation) The above device stops storing the key data in the buffer when the host device issues a key data transmission prohibition instruction. Therefore, even if the operator continues to depress a predetermined key, the host device does not respond and the key data is not accumulated during that time. After that, if there is a data transmission instruction from the host device,
The host device responds as intended by the operator. That is, since unnecessary key data is not accumulated,
The malfunction of the host device can be prevented.

(Embodiment) FIG. 1 is a flow chart showing an embodiment of the keyboard control method of the present invention.

First, the apparatus of the present invention is substantially the same as that described with reference to FIG. 2 in terms of its structure. Then, the program according to the processing procedure as shown in FIG. 1 is stored in the read-only memory 5 storing the operation program of the central processing unit 4.

The present invention will now be described with reference to the flowchart of FIG.
This will be described in detail with reference to the block diagram of the figure.

First, the central processing unit 4 scans the Mie matrix 1 of the keyboard (step S1). Then, the previous keyboard information stored in the buffer 6 and the keyboard information read this time are compared to determine whether or not there is an effective key (step S2). As described above, the difference between the two pieces of keyboard information is valid key information.
If there is a valid key, the key data corresponding to that key is stored in the buffer 6 (step S3). If there is no valid key, the process proceeds to step S4.

Next, the transmission instruction input from the higher-level device 3 to the interface 7 is read. Then, it is determined whether or not there is a transmission instruction (step S4). When there is a transmission instruction, the key data is read from the buffer 6 and transmitted to the higher-level device 3 (step S5). When there is no transmission instruction, that is, when a transmission prohibition instruction is issued, the process proceeds to step 6.

Next, it is judged whether or not the repeat key is included in the key matrisk information read this time (step
S6). If the repeat key is not included, the process proceeds to step S1. If the repeat key is included, the interface 7 determines again whether or not there is a transmission instruction from the higher-level device 3. Here, if there is a transmission prohibition instruction, the repeat data is ignored and the process returns to the keyboard scanning in step 1. Then, only when there is a transmission instruction, the repeat key is stored in the transmission buffer 6 (step S8).

As described above, according to the keyboard control method of the present invention,
The repeat data is not stored in the buffer while there is a transmission prohibition instruction from the host device. Therefore, even if the key data of the repeat key which is not transmitted to the host device is sequentially stored in the buffer at a predetermined cycle, the operation as in the conventional device is not performed. That is, if the transmission of the key data to the host device is interrupted while the operator is operating the repeat key, the accumulation of the key data of the repeat key is also interrupted, and the operation based on the repeat key of the host device is also interrupted. When the transmission of the key data is restarted, the key data of the repeat key is stored in the buffer again and is transmitted in order. As a result, useless repeat data transmission is prevented.

 The present invention is not limited to the above embodiments.

Even when the host device issues a key data transmission prohibition instruction, the pressing key code and the releasing key code of other keys except the repeat key code may be stored as usual. This is because an ordinary key operation is less likely to cause an error due to over-pressing of the key than a repeat key operation.

(Effect of the Invention) According to the present invention, when the host device gives a key data transmission prohibition instruction, the storage of the key data in the buffer is stopped, so that the key data is stored contrary to the intention of the operator. It is possible to prevent the host device from malfunctioning.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of a keyboard control method of the present invention, FIG. 2 is a block diagram of a key data output device suitable for implementation of the present invention, and FIG. 3 is a key data transmission flow chart showing a conventional keyboard control method. FIG. 4 is a key data transmission time chart, and FIG. 5 is a key data transmission time chart during a transmission prohibition instruction. 1 ... key matrix, 2 ... key data output device, 3
...... Host device, 4 ... Central processing unit, 5 ... Read-only memory, 6 ... Buffer, 7 ... Interface, 8 ... Drive line, 9 ... Sense line.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 61-18023 (JP, A) JP-A 58-161025 (JP, A) JP-A 60-251462 (JP, A) JP-A 61- 267111 (JP, A)

Claims (1)

(57) [Claims] 1. A key matrix in which a plurality of keys are arranged in a predetermined order, a control unit that scans the key matrix to sense a pressed state of the key, and temporarily stores key data corresponding to the pressed key. The buffer to be stored and the press key code corresponding to the press key when the key is pressed are stored in the buffer, and when the key is continuously pressed, the repeat key code is stored in the buffer. In a key data output device, which stores the data in a buffer and reads the pressed key code and the repeat key code from the buffer in response to a transmission instruction from the host device and sends the key data output device to the host device, When storing the repeat key code in the buffer, the presence / absence of a transmission instruction from the host device is detected. The key data output device, wherein the repeat key code is stored in the buffer, and the repeat key code is not stored in the buffer when there is no transmission instruction.