US Patent 7215257 Depression judgment device

A depression-judgment apparatus which properly judges the ON/OFF of a key switch without being affected by chattering that occur when key switch is turned ON is provided. The depression-judgment apparatus of the present invention comprises a timer selector circuit capable of setting time from an outside, a depression-timer circuit for counting time by using the time set in the above-mentioned timer selector circuit as a cycle, a depression-memory section for inputting and memorizing information of whether the key switch is depressed or not when the above-mentioned depression-timer circuit is set for the predetermined value, and a depression-judgment circuit which judges that the above-mentioned key switch is depressed when the above-mentioned depression-memory section inputs the information n times (n is positive integer equal to or more than 2) or more in succession, that the above-mentioned key switch is depressed.