# US 4,395,704 A · Input device for electronic apparatus

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- Number: US 4,395,704 A
- Document ID: US4395704A
- Status: Granted
- Kind: A
- Application number: 06/304,311
- Filed: 1981-09-21
- Granted: 1983-07-26
- Earliest claimed: 1978-10-14
- Assignees: Canon Kabushiki Kaisha
- Inventors: Juji Kishimoto; Ichiro Sado; Mitsuo Cho
- Web page: https://patentgrep.com/patent/US4395704A

## CPC

- H03M 11/20: Dynamic coding, i.e. by key scanning (H03M11/26 takes precedence)
- H03M 11/02: Details
- H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C)

## Abstract

An input device for electronic apparatus includes key signal output lines each having plural key switches connected thereto and circuitry for separating the key signals into specific key signals thereby identifying the plural key switches.

## Claims

### Claim 1

An input device for electronic apparatus comprising:
a first plurality of spaced keys each for producing a signal;
a first key signal line to which each of said first keys is coupled for conducting a signal therefrom;
a plurality of first AND gate means each of which is coupled to said first key signal line; and
setting means for selecting any one of said plurality of said first AND gate means to transmit signals produced by only a portion of said keys, said setting means including memory means, a manual switch, a second key signal line, and second AND gate means for changing the output status of said memory means to select a different one of said first AND gate means to transmit signals produced by a different portion of said keys, an output of said second AND gate means being coupled to the input of said memory means, and an input of said second AND gate means being coupled to said manual switch by said second key signal line.

### Claim 2 (depends on 1)

An input device for electronic apparatus according to claim 1, further including means which enable said device to be folded.