Key input device and key input identification method thereof

Abstract

The invention relates to a key input device and a key input identification method thereof. The key input device is provided with at least one key input circuit and a control unit, wherein the key input circuit comprises a plurality of keys and a plurality of serially-connected resistors, the plurality of keys are connected among serially-connected nodes of the resistors and a first potential; the resistors at the end parts of the plurality of serially-connected resistors are connected with the control unit, the control unit is used for determining the input keys according to input voltages which are generated in a way that the keys are input and input to the control unit; and in a period that one key of the plurality of keys is input, under the condition that the input voltage smaller than that of one key is input by the other key, if the time that the other key is input is shorter than the specified time, the control unit enables the input of the other key to be invalid and the input of one key is continuously invalid. The invention can reduce key input operations caused by misoperation different from intention of an operator, and can furthest enable the key input operation corresponding to the intension of the operator to be invalid.

Description

technical field [0001] The present invention relates to a key input device and a key input recognition method thereof, in particular to a key input device and a key input recognition method for detecting opening and closing of a switch by using a key scanning method such as an A / D converter. Background technique [0002] In the existing key input device using the key scanning method of the A / D converter, the number of keys allocated to one key input circuit is reduced in consideration of the errors caused by the voltage dividing resistor and the A / D converter, Set multiple key input circuits. In the case of simultaneous input of keys provided in different key input circuits, the input keys can be detected, but in the case of simultaneous input of keys provided in the same key input circuit, only the input voltage can be detected Small keys. Specifically, when any key is input first and then other keys located in the same key input circuit are input later, if the input volt...

AI Technical Summary

Problems solved by technology

[0004] However, sometimes the operator may mistakenly input other keys due to various reasons in the state of inputting the correct key. At this time, the key input device disclosed in Patent Document 1 will regard both correct key input and wrong key input as is invalid

In this way, the operator needs to perform the correct key input again, so not only the operation is troublesome, but also the operator is confused.

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