Patent attributes
A displacement amount detecting apparatus is provided and includes: transmission member, transmitting a displacement on one end side thereof to a displacement on the other end side thereof; a sensor, disposed to face the other end side of the transmission member, and configured to output a value according to a distance between the sensor and the other end side of the transmission member; a calculation device, calculating a value for indicating the distance based on the value output by the sensor and a reference value; and a correction device, correcting the reference value. When the one end side is displaced in a first direction, the other end side is displaced in a second direction opposite to the first direction and away from the sensor. The correction device is configured to correct the reference value based on the value for indicating the distance calculated by the calculation device.