| 摘要 |
PROBLEM TO BE SOLVED: To suppress expansion of a mounting space while configuring a matrix circuit using an ordinary switch capable of cost reduction and an external resistor, the matrix circuit being capable of accurately detecting pressed keys even in the case where three keys are simultaneously pressed.SOLUTION: A key matrix circuit includes two key scan output signal lines and a plurality of key return input signal lines which are disposed side by side so as to cross the two key scan output signal lines. Each of the key scan output signal lines and each of the key return input signal lines are connected by key switch wiring including a key switch, respectively. The key switch wiring connected with at least one key scan output signal line has a basic configuration in which key switch wiring including a signal control resistor is used alternately. |
