JPH0642276Y2 - Key input device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a key input device used for inputting data to an instrument or a controller, and particularly under a small signal line group. The present invention relates to a key input device capable of arranging a large number of keys.

[Conventional technology]

2. Description of the Related Art In a key input device used as a data input device for instruments and controllers, row line groups and column line groups are arranged in a matrix. Key groups are arranged in a matrix at intersections of the line groups, and by operating one of the key groups, a change in electrical state, for example, a change in potential, is caused in each line group. The change in the potential caused by this key operation is read as binary data by the host processor or the like via each input port to which each line group is connected, and which key is operated is detected from this binary data group, Data defined corresponding to the key is input.

The above-mentioned key input device is roughly classified into a scanning type and a non-scanning type. In the scan type, one of the row lines and one of the column lines at the intersection is made conductive by a key operation, and one of the row line group or the column line group, for example, the column line group is sequentially supplied with a predetermined potential. It is configured to detect one of the operated key groups by detecting one of the row line groups that has changed to a predetermined potential in synchronization with this.

On the other hand, in the non-scan type key input device,
One of the row line group and one of the column line group at the intersection is changed to the reference potential such as the ground potential at the same time by the key operation, and one of the row line group and one of the column line group are changed to a predetermined potential. Is configured to detect one of the operated key groups from the combination.

In the above-mentioned scan-type key input device, an output port for changing (scanning) each column line group to a predetermined potential one by one, and a row line changed to a predetermined potential in synchronization with the scanning of this column line group. An input port for detecting one of the groups is installed. Further, in the non-scan type key input device, each of the row line group and the column line group is connected in order to detect one of the row line group and one of the column line group which have changed to the reference potential.
Input ports are installed. The binary data of each input port is read as parallel data having a predetermined bit width by the processor of the host device via the bus and processed.

[Problems to be solved by the device]

In the above-described key input device, the number of row line groups and column line groups increases with the total number of key groups regardless of whether the scanning method or the non-scanning method is adopted. When the number of row line groups and the number of column line groups are the same under the fixed total number of key groups, the sum of both is minimum. In this case, the number of each line group increases almost in proportion to the square root of the total number of key groups. The increase in the row line group and the column line group causes problems such as increase in size and complexity of hardware such as flat cables, connectors, and buses, and increase in bit width of input data to be processed by the processor. In particular, the data width processed by a general-purpose processor is a multiple of 8 such as 8 bits and 16 bits, so even if the total number of key groups is increased slightly from 64 bits, There is a problem that the device becomes expensive because it needs to be increased to 16 bits.

Therefore, an object of the present invention is to provide a key input device which realizes cost reduction by reducing the number of row line groups and column line groups and the bit width of input data.

[Means for Solving the Problems]

The key input device of the present invention for solving the above problem is configured to reduce the number of lines in each line group and the bit width of input data by using both the scan system and the non-scan system.

That is, the key input device of the present invention comprises a first and a second input port to which a row line group and a column line group are respectively connected, and an output port to which a scanning line group branched from one line group is connected. Scanning through the scan type first key group, the non-scan type second key group, and the output port, and reading the binary data group from the first and second input ports. And a processor for processing.

Then, this processor is provided with two of the first and second input ports.
At least one of the value data group is read in synchronization with scanning, at least the other is read without performing the scanning, and whether the binary data read from each input port includes a reference value. It is determined whether or not it is determined which one of the first and second key groups has been operated according to the determination result, and the determination result and the binary data read from each of the input ports. Based on this, the operated key is detected.

[Action]

According to the key input device of the present invention, a scan type data input mode in which at least one of the binary data groups of the first and second input ports is read in synchronization with scanning, and at least the other is not scanned. Non-scan data input mode of reading is staggered (in time division)
Done. Then, it is determined which of the first and second key groups has been operated depending on whether or not each of the binary data groups read in each data input mode includes a reference value (significant value). Then, the operation key is detected based on the determination result. With such a configuration, the number of row lines and column lines can be reduced.

Hereinafter, the present invention will be described in more detail with reference to examples.

〔Example〕

FIG. 1 is a block diagram showing a configuration of a key switch unit 10 of a key input device according to an embodiment of the present invention, excluding a processor of a host device.

12 is a group of 8 row lines, 13 is a group of 8 column lines, 21 is a first input port to which the row line group 12 is connected, 22 is a second input port to which a column line group is connected, 23 Is an output port to which eight scanning line groups branched from the column line group 13 are connected. M1 is the first key group consisting of a maximum of 64 keys arranged at the intersection of the row line group 12 and the column line group 13, and M2 is also the intersection of the row line group 12 and the column line group 13. It is a second key group consisting of a maximum of 64 keys arranged in the.

Further, 11 is a connector, 14 is a ground wire, 20 is a printed wiring board, 24 is a pull-up resistor connected to the row line group 12 and the column line group 13, and 25 is a diode.

Each key constituting the first key group M1 is, as shown in FIG. 2 (b), one of the row line group 12 and the column line group 13 at the intersection where each key is arranged by each operation. It is configured to make the two electrically conductive. Each key constituting the second key group M2 is, as shown in FIG. 2 (c), one of the row line group 12 and one of the column line group 13 at the intersection where each key is arranged by each operation. By contacting the ground surface 14A connected to the ground potential line 14, the potentials of the row line and the column line at the intersection are both changed to the ground potential.

The scanning line group connected to the output port 23 is sequentially changed to the ground potential one by one under the control of a host device (not shown) or the like. Along with this scanning and key operation, the pull-up resistor 24 changes the potential of the row line group 12 and the column line group, which are maintained at an appropriate positive potential, for example, 5 V, to the ground potential. In this example, the ground potential is logic "1" and 5 volts is logic "0". Significant "1" generated by key operation
An 8-bit wide binary data group including only one is read and processed by a processor (not shown) via the first and second input input ports 21 and 22 and the data bus.

The reading of data from the input port by this processor and the process of fetching key input data based on this read data will be described.

Step A. First, the processor starts the scanning of the column line group 13 via the output port 23 and the scanning line group, and the first line is synchronized with this scanning.
Eight 8-bit wide binary data groups are sequentially read out from the input port 21 of and are temporarily stored.

Step B. Next, in step A, the processor determines the first input port 21
8 binary data groups of 8 bit width read from are inspected, and if none of them contains a significant "1", that is, 8 read data of 8 bit width is Is all “0” ([00] _H ), the first key group M
It is determined that no key operation has been performed in either 1 or the second key group M2, and the initial state for the next key input detection process is restored. That is, if a key operation is performed with either the first key group M1 or the second key group M2, a significant "1" must appear in one of the line line groups. .

Step C. If the processor includes a significant "1" in any of the eight 8-bit wide binary data groups read from the first input port 21 in Step A, the processor It is determined that a key operation has been performed on either the group M1 or the second key group M2. In this case, the processor reads 8-bit wide binary data from the second input port 22 without scanning from the output port 23.

Step D. Next, the processor proceeds to the second input port 22 in Step C.
Check the binary data of 8-bit width read from, and if it does not contain significant "1", that is, all "0"
If so, it is determined that the key operation has been performed with the first key group M1. Because it is already known in step C that a key operation is performed with any key group, and if this key operation is performed with the second key group, the second input port 22 This is because the read binary data cannot be all "0". Based on the determination result, the processor reads the input data by the key operation of the first key group M1 from the first input port 21 in step A and fetches it based on the eight binary data groups which are being stored. To capture this data, first of all, the column line number is detected based on which of the 8 data read in 8 times contains the significant "1", and then this The number of the row line is detected from what bit the data contains a significant "1",
The key number operated by the first key group M1 is determined from the combination of the numbers thus detected, and the data defined in advance corresponding to the determined key number is addressed to the key number. It is performed by reading as input data from a ROM or the like.

Step E. If the significant 8-bit binary data read from the second input port 22 in Step C contains a significant "1", the processor operates the second key group M2. It is determined that it has been performed. Because the scanning from the output port 23 is not performed at the time of reading the data from the second input port 22, even if the key scanning is performed with the first key group M1, the significant "1" is generated. "Is not possible to appear. When the processor makes such a judgment, the processor judges that the significant “1” among the eight binary data read from the first input port 21 in step A.
The line number is detected from the number of bits in which this data contains a significant "1". Subsequently, the processor proceeds to the input port 22 in step C.
The number of the column line is detected from what bit the binary data of 8-bit width read from contains the significant "1", and the second number is detected from the combination of the numbers thus detected.
The number of the key operated by the key group of is confirmed and the input data defined corresponding to this key number is taken in.

As described above, the case where the data group is first read from the first input port 21 in synchronization with the scanning from the output port 23 and then the data is read from the second second port without performing the scanning Explained. However, this reading sequence may be reversed.

In addition, when the width of the data bus is 16 bits, the data may always be read simultaneously from the first and second input ports 21 and 22, and unnecessary portions may be ignored or discarded. .

Since the keyboard of the present invention combines the scanning method and the non-scanning method, it is possible to identify the pair of two keys operated simultaneously in the second key group M2 based on the scanning timing. The following effects are produced.

To illustrate this with reference to FIG. 2 (a), in the second key group M2, the key pair of the key 1A (1, A respectively indicate corresponding row and column lines) and the key 3C (same as above). Column line A when the key pair 3A, 11C is operated.
Since ~ H is scanned for the key group M1, the above two types of key pairs can be discriminated by which column line scans "1" in which row line.

[Effect of device]

As described in detail above, the key input device of the present invention is
Since the configuration uses both scan-type key groups and non-scan-type key groups, it is possible to arrange a large number of keys with a small number of row lines and column lines, and realize a low-cost device. The effect of being able to be played is exhibited.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a key switch unit excluding a processor of a host device in a key input device according to an embodiment of the present invention, and FIG. 2 is a block diagram showing details of first and second key units. It is a figure. 12 …… Row line group 13 …… Column line group 14 …… Grounding wire M1 …… First key group M2 …… Second key group 21 …… First input port 22 …… Second input port 23 ...... Output port 14

Claims (2)

[Scope of utility model registration request] 1. A first input port to which one of the row line group and the column line group is connected, and a second input port to which the other line group of the row line group and the column line group is connected. An input port, an output port to which a scanning line group branched from the one or the other line group is connected, and arranged at the intersection of the one line group and the other line group,
A first key group that conducts between one of the line groups and one of the other line groups at each intersection by operation, and is arranged at the intersection of the one line group and the other line group,
A second key group that changes one potential of one line group and the other line group of each intersection to a reference value by operation, and one potential of each scanning line group connected to the output port. While performing a scan to sequentially change to the reference value,
A processor for reading binary data discriminated according to whether or not it is the reference value from the first and second input ports, wherein the processor stores binary data of the first and second input ports. At least one of them is read in synchronization with the scanning, at least the other is read without performing the scanning, and whether the reference value is included in each of the binary data read from each of the input ports. It is determined whether or not one of the first and second key groups has been operated according to the determination result, and the operation is performed based on the determination result and the binary data read from each of the input ports. A key input device characterized by detecting a generated key. 2. The processor according to claim 1, wherein the processor: A. reads the binary data group from the first input port in synchronization with the scan, and B. synchronizes with the scan in the first input port. If the reference value is not included in any of the binary data group read from, it is determined that there is no key operation, and C. Binary data read from the first input port in synchronization with each scan. If any one of the groups includes the reference value, the binary data is read from the second input port without performing the scanning, and D. In the binary data read from the second input port, If the reference value is not included in the above, it is determined that the first key group has been operated, and the operated key is detected in A based on the binary data group read from the first input port. , E. Read from the second input port When the reference value is included in the binary data, it is determined that the second key group has been operated, and the operated key is read from the first input port by A in the binary data group. And a binary input data read from the second input port in the above C, for detection based on the combination.