Capacitive keyboard

Abstract

Provided is a capacitive keyboard that can detect with high accuracy a pressed key and a pressing amount of the pressed key. The capacitive keyboard comprises: a drive circuit 11 that alternately switches the voltages of drive lines M from an L level to a H level; a sensing circuit 12 that is connected to sensing lines N, selects a single sensing line from among the sensing lines N and detects a voltage generated in the selected sensing line; and a control circuit 15. The control circuit 15 is provided with: a storage unit 44 that includes storage areas that correspond to respective keys; a storage control unit 42 that obtains voltages generated in the sensing lines and stores the obtained voltages in storage areas that correspond to the respective keys; and a correction processing unit 43that corrects a voltage generated due to operation of a - key by using the voltage stored in a storage area corresponding to another key when the - key is operated. As a result, high accuracy detection is possible even in a case where a plurality of keys are pressed simultaneously.

Description

technical field [0001] The invention relates to an electrostatic capacitive keyboard, which has a plurality of electrostatic capacitive keys arranged in a matrix. Background technique [0002] As a keyboard used in a personal computer or the like, a capacitive keyboard having a plurality of capacitive keys has been proposed and put into practical use. The electrostatic capacitive keyboard has a plurality of driving lines and a plurality of sensing lines intersecting with each driving line, and electrostatic capacitive keys are respectively arranged at the intersections of each driving line and each sensing line. And, once any one of a plurality of keys is pressed, the electrostatic capacity between the pair of electrodes present at the key increases, so that current flows from the drive line to the sense electrode via the pressed key. survey line. By detecting this current, it is possible to know which key is pressed (for example, refer to Patent Document 1). [0003] Bel...

AI Technical Summary

Problems solved by technology

However, although the technology disclosed in Patent Document 1 can detect whether a key is pressed, it is difficult to detect the amount of pressing of the key.

Also, in the case of pressing multiple buttons at the same time, the problem that the pressing amount of each button cannot be accurately detected will also occur.

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