JPS61279917A - Input device - Google Patents

Abstract

PURPOSE:To extract accurately the ON state of a contact set on a matrix with a small number of signal lines without using a current detour preventing diode, by using an extracting circuit having a prescribed function. CONSTITUTION:Plural contacts are allocated to matrix blocks 40-42 by weighting. An extracting circuit 9 checks the combination of four contacts in terms of weighting when an image is produced by the ON states of three contacts and then four contacts are apparently turned on. When said combination is equivalent to a certain specific one, three specific contacts are extracted out of four contacts as those that are not equivalent to the image. Thus it is possible to extract accurately the ON states of the contacts arranged in a matrix form with use of a small number of signal lines and without using a current detour preventing diode.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an input device having a plurality of contacts, and more specifically, an input device that extracts the ON state of the plurality of contacts and uses it as an input foot. Regarding.

[Background of the invention]

Figure 2 shows a 10-block diagram of a general input device. 01 is a scanning circuit, 2 is a decoder circuit, 5 is a selector circuit,
4 is a contact group corresponding to the key input, 5 is a scanning signal line to the decoder circuit 2, 6 is a scanning signal line to the selector circuit 5, 7 is a select signal line of the selector circuit 6, and 8 is a scanning circuit 1 This is a key code output signal line from the main circuit to other circuits (for example, the main circuit of the information processing device).

A method for extracting the contact ON/OFF state of the conventional input device in the above configuration will be explained below.・The output side 0 to 7 of the tecoder circuit 2 is extracted by the combination of the 3 pins A, B, and C on the scanning signal line 5. The selector circuit 3 is sequentially scanned and similarly
The input sides 0 to 7 of the contact group 4 are sequentially scanned, and each contact of the contact group 4 is sequentially scanned, and the ON/OFF information of the contacts is outputted from the select signal line 7. That is, when the select signal line 7 is at a high level, the contact being scanned is on, and when the select signal line 7 is at a low level, the contact is off. In this way, the scanning circuit 1 sequentially changes the signals of the scanning signal line 5 and the scanning signal line 6 (a combination of 3 bits A, B, and C) to check the on/off state of the contact, and determines the on state of the contact. When extracted, the key code is output from the key code output signal line 8. Here, the opening point of such an extraction method is located at the contact group 4 on the matrix line formed by the output lines (0 to 7) of the 0 decoder circuit 2 and the input lines (0 to 7) of the selector circuit 30, as shown below. If three of the contacts are turned on at the same time, a state will occur in which the contacts that are not turned on will appear to be pseudo turned on. For example, when the three contacts 401, 402, and 403 are turned on, and the output line of the decoder circuit 2 and the input line of the selector circuit 3 connect the contact 404 to the When selected, current flows through the contacts 402, 401, and 403, and the contact 404 is extracted as an on state.9o In this way, an image is generated and the contact that is off in the next case is extracted as on. Therefore, it is preferable as a contact extraction method.

In order to solve the above problem, it is common practice to prevent the previous image by inserting a current sink prevention diode in series with each contact, which is bad and expensive. There are many problems such as the need for space for diodes, the number of parts per unit, and lower reliability. Therefore, a method has been proposed to extract the on state of multiple contacts without using diodes. There are n.

In JP-A-58-161026, the state in which six contacts are turned on at the same time when three keys of an input device are operated at the same time has a meaning when inputting keys at high speed, especially when used in combination with character keys such as the shift key. Focusing on the fact that this often occurs when operating keys, we have proposed a matrix block configuration as described below.

FIG. 3 illustrates a conventional matrix block configuration as disclosed in Japanese Patent Application Laid-Open No. 58-161026.

40 and 41 are arranged in two independent matrix blocks and are a group of next contact points, so that they are not connected to each other. Here, the contact group 40 corresponds to keys that are operated in combination with character keys, such as a shift key, and the contact group 41 corresponds to character keys.

In this way, for example, the shift key of contact group 40, the character key ", A" of contact group 41, the character key r of contact group 410,
Even if YJ inputs at high speed and all six keys are turned on at the same time, no image will be generated.

However, if the matrix blocks are arranged separately as described above, the intersection point 64 of the matrix lines in FIG.
Contacts can only be placed at 40 of the points.

In this way, the input device proposed in JP-A-58-16026 requires many signal lines to arrange the same number of contacts as the general input device shown in FIG. As a result, signal line layout space is required, the number of parts increases, the size increases, and the price increases.
There was a problem of decreased reliability.

[Purpose of the invention]

To provide an input device that can reliably extract the on state of a group of contacts arranged on an I-IJ box without using a current sink prevention diode and with a small number of signal lines. There is K.

[Summary of the invention]

The present invention divides a plurality of contacts into a plurality of matrix blocks by weighting, and when an image is generated by the on state of three contacts and the upper four contacts are apparently in the on state, the weights of the four contacts are Combination of contacts t-
An extraction circuit is provided which extracts specific three contacts from among the four contacts as contacts that do not correspond to the image when the combination corresponds to a specific combination.
This makes it possible to extract up to five points of contact.

Mayu divides multiple contacts into multiple matrix blocks and creates a matrix block in which no contacts are placed, and when an image is generated from the on state of the three contacts and the top four contacts are apparently on state. , Check whether any of the four contacts belong to a matrix block in which no contacts are placed, delete the contacts that are not placed as images, and extract the remaining three contacts. The circuit is designed so that up to five contacts can be extracted at the same time. [Embodiment of the Invention] Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an input device showing a first embodiment. In the figure, circuits having the same functions as those in FIGS. 2 and 3 are assigned the same numbers.

9 is an extraction circuit, which includes a control circuit 90, ROM 91, RA
It is composed of M92.

The contact group is weighted and divided into five blocks depending on how it is used. 40 is a shift key that has meaning when used in conjunction with a character key, and is given the highest weight, 41 is a group of contact points that have meaning when used alone or in conjunction with a shift key, and is given a medium weight, and 42 is information processing. It is given the lowest weight among the contact points that are used infrequently or infrequently and have meaning when used alone, such as function keys used when editing characters on the device.

Here, the combinations in which the four contacts are turned on at the same time are as shown below.

(1) Contact group 42 (4 keys) (2) Contact group 42 (2 keys) Ten contact group 40 (2 keys) (
3) Contact group 41 (4 keys) (4) Contact group 41 (2 keys) 10 contact group 42 (2 keys) (
5) Contact group 40 (1 key) 10 contact group 41 (2 keys)
+Contact group 42 (1 key) Since contact group 42 has the lowest weight among the four contacts in combination (5), the extraction circuit 9 determines this n as an image and extracts 6 points excluding contact group 42. However, in combinations (1), (2)* (3), and (4), contact extraction operation is prohibited. However, combinations (1), (3
), (4) are points that do not include the contact group with the highest weight, and combination (2) is a combination that rarely occurs in that there is no such usage method, so such a combination is used. In this case, there is no practical problem even if the contact extraction operation is prohibited.

The ROM 91 stores a control block that defines the combination of the contacts and the operation of the extraction circuit.

FIG. 4 is a diagram showing a program flowchart for the operation of the extraction circuit 9 of the first embodiment.

In the figure, BUF is a buffer provided in the RAM 92 to store contact information, 1 indicates a counter provided in the RAM 92, and the contact information in the buffer can be specified by writing Q, BUF (1). . Contact information consists of contact attribute code and key code. Contact attribute code is 0,
1.2, and the contact group 40, the contact group 41, and
It corresponds to the contact group 42. The key code corresponds to a number from 0 to $6F ($ indicates a hexadecimal number) corresponding to the contact point.

The operation of the extraction circuit 9 will be explained below with reference to FIG.

First, step S2. In S3, the buffer and counter are initialized. In S4, the on/off state of the no/low contact of the select signal line 7 is determined, and when it is on, the
6, the information of the contact point which is Zion is accumulated in the buffer nl
The counter is incremented by +1. When all the contacts have been scanned, the number of contacts turned on at the same time is checked in S8, and if the number of contacts turned on at the same time is 3 or less, all the key codes in the buffer are output from the key code output signal line 8 in S11. If there are four or more me codes, s9 is performed.

The S9 examines the four key combinations and selects the combination (
In case 5), after deleting the contact information of the contact group 42 from the buffer, key code output processing S11 is performed, and in cases other than n, the key code is not output and the steps from S2 onwards are repeated again.

As described above, in this embodiment, since contacts can be placed at all matrix line intersections, the number of signal lines can be saved, and up to three contacts can be turned on without any problem in the normal method of using the input device. It has the effect of extracting the state.

FIG. 5 is a block diagram of an input device showing a second embodiment. In the figure, circuits having the same functions as those in FIGS. 1, 2, and 3 are assigned the same numbers.

The extraction circuit 9 is a ROM 95% three-state buffer 99
, an AND circuit 97, and an OR circuit 96.

41 corresponds to a contact group such as character keys, and 40 corresponds to a key used in conjunction with character keys such as a shift key.
No contacts are placed at the matrix line intersections where an image occurs when three contacts are turned on simultaneously across two contact groups. ◇Correspondingly, no contacts are placed in the ROM95 at matrix line intersections. $5F ($ indicates a hexadecimal number) is set to the address of the contact, and a key code of 0 to $2A is set to the address of the contact.

The scanning circuit 1 sequentially applies scanning signals to the scanning signal line 5 and scanning signal line 6 to the decoder circuit 2 and selector circuit 3, and transmits the on/off state of the contact point to the select signal line 70 low/low/
Output as high. The scanning signal line 5 and the scanning signal line 6 are R.
The signal is input to the address input terminal of the OM95, and the select signal line 7 is input to the tick select terminal. When the contact is turned on and the select signal line goes low.

ROM95 follows the address input, key code 0~$2
Ai output. The low output of the AND circuit 97 and the low output of the select signal line 70 are input to the OR circuit 96.
6 outputs a low signal and inputs it to the gate terminal of the three-state buffer 99, and the three-state buffer 99 is enabled and outputs the key code through the key code output signal line 8.

When five contacts in the contact group 40 and contact group 41 are turned on and an image is generated, three key codes are output from the ROM 95, and the fourth contact (the contact is not placed) generated by the image is output. $3F is output as the key code for (not available). The output of the AND circuit 97 is high, and the output of the JOR circuit 96 is high, thereby placing the three-state buffer 99 in a high impedance state.

As described above, according to this embodiment, n can be reliably set to 3 even when 3 contacts are intentionally turned on.
In addition to being able to extract the ON state of one contact point, the input device can be configured with a smaller number of signal lines than the input device of the known example, which is more common than the first embodiment.

As a third embodiment, FIG. 6 shows an extraction circuit 9t-MPU (
1 shows a block diagram of an input device configured with a Micro Processing Unit. In the figure, circuits having the same functions as those in FIG. 7 are given the same numbers or assignments.

Reference numeral 100 denotes an MPU, which performs input/output with other circuits via an interface 7/8 1o1. In this embodiment, the control circuit 90 of the first embodiment is replaced with M P Uloo,
Control program of the first embodiment (shown in FIG. 4) t-R
By placing it inside the OM91, it is possible to easily obtain the same effect as the first embodiment.

As a fourth embodiment, the extraction circuit 9t-MP of the second embodiment
An input device configured by U can be considered. In this case, the configuration is the same as the third embodiment except for the arrangement of the contacts.

FIG. 7 is a diagram showing a 70-frame flowchart of operations of the MPU in the fourth embodiment. In FIG. 7, steps having the same functions as those in FIG. 4 are given similar symbols.
Stella except T9 and T10; 1 is common to all.

As described above, this embodiment can easily achieve the same effects as the second embodiment.

〔Effect of the invention〕

The present invention provides an input device that can reliably extract the on-state of contacts arranged in a matrix, without using a diode to prevent current flow, and with a small number of signal lines. There are some effects that can be done.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an input device showing a first embodiment of the present invention, Fig. 2 is a block diagram of a general input device, and Fig. 3 is a block diagram of a general input device. 4 is a flowchart of an operation program of the extraction circuit of the first embodiment, and FIG. 5 is a block diagram of an input device showing the second embodiment of the present invention. Fig. 6 is a block diagram of an input device in which the extraction circuit is composed of an MPU, and Fig. 7 is a block diagram of an MPU of the fourth embodiment.
It is a figure which shows the operation|movement turogram flowchart. 9...Extraction circuit, 90...Control circuit, 91...R
OM92...RAM, 5.6...Scanning signal line, 7.
...Select signal line, 8...Key code output signal line.

Claims (1)

[Claims] 1) A plurality of contacts are arranged in a matrix, each of the contacts is connected to a decoder circuit and a selector circuit, and the on state of a specific contact is determined by scanning input to the decoder circuit and the selector circuit. In the input device configured to extract the plurality of contacts, the plurality of contacts are divided into a plurality of matrix blocks with different weightings, and when the ON state of at least four contacts is detected, from the weighting of the four contacts. The device is equipped with a determination means for examining the combination of contacts seen and determining whether the combination corresponds to a certain specific combination, and based on the determination result, specific three contacts are extracted from the four contacts. An input device characterized by: 2) The input device according to claim 1, wherein the determining means comprises a microprocessor. 3) In the input device according to claim 1, when the plurality of contacts are divided into a plurality of matrix blocks including a matrix block in which no contacts are arranged, and the ON state of at least four contacts is detected. , said 4
A determining means is provided for determining whether or not there is a contact belonging to a matrix block in which the contact is not arranged among the two contacts, and when the contact is present, the remaining three contacts excluding the contact are extracted. An input device characterized by: 4) The input device according to claim 3, wherein the determining means comprises a microprocessor.