Patent ID: 8748725

Claim:
A key switch for an electronic piano, for detecting a motion of a pivotal member which is one of a key, and a hammer that pivotally moves in accordance with depression of the key, as key depression information, comprising: a substrate on which first, second, and third stationary contacts are arranged side by side in a lengthwise direction of the pivotal member, each of the first to third stationary contacts comprising a common contact having a predetermined reference potential, and a non-common contact having a different potential from the reference potential, the common contact and the non-common contact being arranged in a direction orthogonal to the lengthwise direction of the pivotal member in a manner opposed to each other with a predetermined spacing therebetween, and at least one of the common contacts of each two stationary contacts adjacent to each other having an extended portion extending in the orthogonal direction in a manner inserted between two of the non-common contacts; an elastic switch body mounted on said substrate and configured to be opposed to the pivotal member when the key is in a key-released state; and first, second, and third movable contacts arranged side by side on said switch body in a manner opposed to the respective first to third stationary contacts, and configured to be sequentially brought into contact with the common contacts and non-common contacts of the first to third stationary contacts as said switch body is pressed by the pivotal member pivotally moving during key depression, to thereby output signals indicative of the key depression information.