Keyboard device

Abstract

The invention provides a keyboard device, which comprises a key module and a detection circuit. The key module comprises a plurality of keys, a plurality of scanning lines and a plurality of return lines. The scanning lines and the return lines intersect with each other and are coupled to the keys respectively. The detection circuit can detect a plurality of return voltage values on the return lines and generate a plurality of detection signals in order to indicate that a switch of each of the keys is in an on state or an off state. The detection circuit comprises a plurality of P-type transistors. A first end of each P-type transistor is coupled to a ground terminal, a control end of each P-type transistor is directly coupled to the corresponding return line, and a second end of each P-type transistor generates and outputs the corresponding detection signal.

Description

Technical field [0001] The invention relates to a keyboard device, in particular to a keyboard device that can avoid ghost keys and has low manufacturing cost. Background technique [0002] In order to avoid using too many wires to increase the manufacturing cost of the keyboard itself and cause inconvenience in actual assembly, the existing keyboard devices are mostly designed in a key matrix manner. For keyboard devices designed with a key matrix, based on the relationship between the physical characteristics of the key matrix itself, ghost keys are prone to occur. Among them, Taiwan Patent Publication No. I485991 details the main reasons for ghost keys. In order to avoid the occurrence of ghost keys, the general solution is to increase the size of the key matrix, or divide each key with a diode. However, such an approach will also greatly increase the manufacturing cost of the keyboard device. [0003] Therefore, Taiwan Patent Publication No. I485991 proposes a ghost key detec...

AI Technical Summary

Problems solved by technology

[0008] Since each return line (such as return line R1) needs to pass through two transistors (such as transistors Q1 and Q2) and a resistor (such as resistor R U1 ) to detect whether the button on the return line (return line R1) has been pressed. Once the number of return lines increases, the number of transistors and resistors used in the level detection circuit 315 will inevitably increase significantly. In this way, the Will significantly increase the manufacturing cost of the keyboard device

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