摘要 |
A position detecting devices includes a scale, a sensor, and a control section. The scale has a plurality of light emitting elements located at spacings along a direction in which a movable member is moved. Mounted on the member, the sensor detects light from at least one of the elements within a predetermined detection range longer than a largest one of the spacings, and outputs a light reception signal according to a position where the light is received within the range. The control section drives the elements individually, receives the signal from the sensor, and has a storage section for storing information on positions of the elements in the scale. Upon receipt of the signal, the control section retrieves from the storage section information on a located position of one of the light emitting elements that is being driven, and calculates a position of the member based on the retrieved information and the received signal.
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