JPS6155725A - Keyboard device - Google Patents

Abstract

PURPOSE:To prevent mis-input due to detour by applying processing in response to the closing state of plural key switches except the detour when the simultaneous closing state of plural key switches is detected. CONSTITUTION:When plural switches are depressed at the same time and plural switches in a Y line are closed, that is, switches SW1n, SW2n connected to X1, X2 lines are closed. An encoder 2 detects it to check the detour, the Y line except Yn is selected sequentially to input the switch state to all X lines. When the closing state is not identical to select the Yn line, since no detour is generated and its input is made effective. On the other hand, when the state is identical, it is discriminated as occurrence of detour, the discrimination is intermitted and the keyboard processing is executed again from the initial state. When it is discriminated that there is a detour only once, no code conversion is attained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a keyboard device υ, and in particular, the present invention relates to a keyboard device υ, in particular, a keyboard device that responds to a wrap-around state that occurs when a plurality of keys in a single-handed switch section are pressed at the same time. Regarding keyboard devices that do not.

[Problems to be solved by conventional technology and invention 3182
As shown in the figure, X line, Xi, X2 and Y line, Yl
, Y2, switches 5WII, 5W12, 5W21 are arranged in a matrix at the intersection with Y2.

When the key is set to - by using the SW 22, the wraparound becomes a problem. For example, as shown in FIG.
Let us take as an example a case where WII, 5W12, and 5W21 are pressed and closed, and switch SW22 is in the closed state. By selecting the Y1 line and sequentially selecting the XI and X2 lines, closed-state classes of 5WII and 5W12 can be detected, respectively. Next, if you select the Y2 line and then the X1 line, you can detect the closed state of SW21, but if you select the X2 line, a loop circuit as shown in the figure is formed by the broken line, and SW22 is apparently closed. It will be read as something.

The above is a problem because when selecting X lines one by one for one Y line selection, a loop circuit occurs in certain cases where SWI 1 is also closed, but it speeds up the readout. It is clear that if all the X lines are read out simultaneously for one Y line selection in order to achieve this, the above-mentioned erroneous reading will occur regardless of the specific relationship of 5W11 being closed.

As a general rule, key switches are not pressed at the same time [more than one key switch is pressed at the same time], but in the case of high-speed key touch operations by an experienced operator, or manual keystrokes in a specific pattern, multiple key switches may be pressed at the same time. It may be pressed down. It is possible to completely disable such cases, but from the perspective of improving operability, it is recommended to accurately input the pressed state of the key switch and allow subsequent devices to process accordingly. desired. That is, it is desired that the keymate device faithfully detect the closed state of the switch.

On the other hand, due to the above-mentioned wrap-around phenomenon), incorrectly entered information may be
BREAKJ - If it is something that has a special meaning in terms of processing, unlike a simple incorrect input of a character code,
Incorrect input must be avoided at all costs. Therefore, even if multiple key switches are pressed at the same time,
It is desired that the state be read out accurately.

Various measures have been proposed in the past to prevent such loopback.

In FIG. 3, a diode is provided in each switch to prevent circuitry. However, this method requires as many diodes as the number of switches, which increases the number of parts in the switch section and increases the cost. There is also the problem that the provision of the diode lowers the signal level, making it impossible to directly process it with the TTL circuit.

In FIG. 4, the important switches SWI and SW2 do not adopt a matrix configuration to prevent the occurrence of loop-around, while the other switches 5WII to 5W22 are configured to ignore even if the loop-around occurs.

However, this method essentially cannot prevent erroneous inputs, and there is a problem in that the efficiency of the circuit configuration in the part that does not use the matrix structure is reduced.

Other methods include methods that determine wraparound based on the detection time interval of key switch presses, but this method has the problem that the responsiveness of key switch input decreases.

[Means to solve the problem]

In the present invention, a plurality of X
In a keymate device that detects the closed state of one of a plurality of key switches connected to each of the intersections of lines, when the closed state of a plurality of key switches is detected at the same time, There is provided a keymate device characterized in that it performs processing in response to the closed state of a plurality of key switches, rather than based on the phenomenon of repeated use of key switches provided.

[For production]

In the present invention, when the closed state of a plurality of switches is detected,
It is determined whether or not this is due to a wraparound phenomenon, and if it is due to a wraparound phenomenon, no proper code conversion is performed. on the other hand,
If it is not due to a wrap-around phenomenon, code conversion is performed according to the closed states of the plurality of switches.

Further, in order to prevent loopback, no special processing is performed on the key switch section, and the above-mentioned processing is performed on the encoder side.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram of a key-lock device as an embodiment of the present invention. In FIG. 1, the device includes Xl to XE
It consists of a keyboard switch section 1 having a plurality of key switches provided at the intersection of the X line up to and the Y line up to YIA-YE, and a keyboard encoder 2. The keyboard encoder 2 includes a Y line selection circuit 22 that selects the Y lines of the keyboard switch section 1 one by one, and a Y line selection circuit 22 that selects the X lines all at once and selects one of the switches connected to the Y line selected by the Y line/selection circuit. An X-line selection reading circuit 21 that reads a key switch that has been pressed and is in a closed state, a rotation determination circuit 23 (to be described later), a code conversion circuit 25 that converts a code corresponding to a character that corresponds to the read key switch, and these circuits. Control circuit 2 that controls
The device keyboard switch section 1 consisting of 4 has only a plurality of switches arranged in a matrix, and no diodes or the like are connected thereto.

The operation of the apparatus shown in FIG. 1 will now be described with reference to chart 70 in FIG.

First, a case will be described in which only one switch swrrln at the intersection of the Yn line and the Xm line is pressed and is in the closed state.

An index (or counter) n for selecting the Y line is set to an initial state n=1.

(Step: 5OO1). As a result, the jOY line selection circuit 22 selects the Y1 line to low (L) level (S
OO2). Next, based on a command from the control circuit 24, the X line selection and reading circuit 21 sets all the X lines to high (H) level and reads the values at that time (8003). The read data is led to the loop determination circuit 23, where it is determined whether or not there is a pressed key (SOO4). Under the above conditions, there is no press key switch. Therefore, the control circuit 24 must determine whether the index n has reached the final value E (5oos), n =
Since n is 1, n is incremented (3006
).

When the above processing is performed for the υY line where n = n, the signal of the line becomes L, and it is detected that there is a pressed key (8004). The rotation determination circuit 23 checks whether there are two or more pressed keys (SOO7)
. Under the above conditions, there is only one piece, so step 8008
At , code conversion is performed to a code corresponding to SwImn, and the code is sent to the host side. Code conversion and sending to the host side can be performed only when there is a change from the previous time. It is also possible to hold the current value and send it only when requested by the host side.

Next, a case where a plurality of switches are pressed simultaneously will be described. In such a case, multiple switches for one Y line are in the pressed state, and when that Y line is selected, multiple switches are in the closed state φ at the same time.
(Case 1), only one switch is pressed down for one Y line, but there are also switches pressed for other Y lines (Case 2) , the following case (Case 3) is considered when both of the above cases occur simultaneously.

Regarding case 2, the encoder described above detects the closed state of one switch for each Y line, and then performs code conversion for the seventh input, and performs code conversion for the other Y lines in the same way. I do. Therefore, according to the normal processing operation described above, it is possible to sequentially read the pressed states of a plurality of switches and perform code conversion.

Case 1 will be described. Regarding the Yn line, Xi,
Two sw,n connected to the X2 line.

We assume that 5W2n is closed.

In FIG. 5, when it is determined that a pressed key is present in step SOO'4, and it is detected that there are two or more pressed keys (SO
O7), the transfer check process begins. In other words, the wraparound check is for other Y lines except Y (SOIO to 5O
13) Select the Y lines one after another (SO14) and select all the X lines at that time and input the switch status (80
15). If the switch closed state at this time is not the same as the value when the Y line is selected, the input is considered valid because no cycle reduction has occurred. On the other hand, if this is not the case, it is considered that the input data is due to wraparound as shown in FIG. 2, and the input data is invalidated (8016).

That is, if it is determined that wraparound exists, the determination process is interrupted, the process returns to node 1 in FIG. 5, and the key gate process is restarted from the initial state.

On the other hand, if the pressed key state of any of the other Y lines is not the same as that of the Yn line, each is considered to be valid, so move from step 8017 to node 3, SW, n, 5W2
Code conversion is performed for n.

Case 3 is processed as a combination of Case 1 and Case 2 above. In other words, if it is determined that there is wraparound due to case 1 even once, code conversion is not performed. Otherwise, code conversion is performed for multiple pressed switches.

In the embodiments described above, a case has been described in which X lines are searched all at once in order to search for a key switch at high speed. Therefore, for example, 5W1n, 5W2n and 5W1(n+
1) S on the X1 line like '5W2(n+1)
W t SWl (n+ 1 ), 5W2n on the X2 line.

If there are switches pressed at the same time, such as n5W2(n+,), it will be determined that there is a round trip, but it is extremely rare for such a phenomenon to occur at the same time. Therefore, in such a case, no particular problem arises even if code conversion is not performed for the a number of switches.

In addition, if it is determined that wraparound exists, return to ■,
It is also possible to select the next Y line, and in this case, the key press states of all Y lines without wraparound can be detected.

The above embodiment has been described with reference to the flowchart shown in FIG. 5, but since this processing is sequential and relatively simple, it can be realized by either a microprocessor or a logic circuit. Needless to say. In particular, a device with a built-in microprocessor as a keypad device can be easily realized by adding the above-mentioned processing function to the conventional processing function.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent erroneous input due to wraparound without complicating the keyboard switch section, and it is of course possible to detect the closed state when a single keyboard switch is pressed. Even if a plurality of keyboard switches are pressed (7'C), the closed state of a plurality of key gate switches can be detected, except in the case of wraparound.

[Brief explanation of drawings]

FIG. 1 shows a key as an embodiment of the present invention. - A configuration diagram of the board device, and Figure 2 is a circuit diagram showing the wrap-around phenomenon of the switch.
3 and 4 are conventional circuit diagrams, and FIG. 5 is a flowchart showing the operation of the apparatus shown in FIG. 1. (Explanation of symbols,) 1...Key is a single hand switch section, 2...Keyboard encoder, 21...X line selection/reading circuit, 22...
・・X line selection circuit, 23 ・・Conversion determination circuit, 2
4...' control circuit, 25... code conversion circuit.

Claims (1)

[Claims] 1. In a keyboard device that detects the closed state of one of a plurality of key switches connected to each of the intersections of a plurality of X lines and Y lines arranged in a matrix, The present invention is characterized in that when the closed state of a switch is detected, processing is performed in response to the closed state of a plurality of key switches, except when the above-mentioned case is based on the wrap-around phenomenon of the key switches arranged in a matrix. keyboard device.