Patent ID: 8481915

Claim:
An optical encoder, comprising: a scale that has latticed scale markings; a detecting head that comprises a light-emitting element that emits light onto the scale and a light-receiving element that receives the light emitted by the light-emitting element to be reflected or transmitted by the scale; and a connector connected to the detecting head via a cable, the optical encoder measuring a position of the detecting head relative to the scale based on the light received by the light-receiving element, wherein the connector comprises a display that displays a status of the light received by the light-receiving element and a controller that controls the display, the controller comprises a display controller that controls the display based on an electric signal outputted in accordance with an intensity of the light received by the light-receiving element, the optical encoder is arranged as an incremental optical encoder that employs a multiphase sine wave signal with a predetermined center voltage as the electric signal, the controller comprises an amplitude calculator that calculates an amplitude of the multiphase sine wave signal based on the predetermined center voltage of the multiphase sine wave signal and an instantaneous value of the multiphase sine wave signal, and the display controller controls the display based on the amplitude of the multiphase sine wave signal calculated by the amplitude calculator.