Patent ID: 11885828
Assignee: PIXART IMAGING INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. An optical encoder, comprising:
a phase shifter circuit, configured to receive a first input signal, a second input signal, a third input signal and a fourth input signal, and output multiple phase shifted signals based on the first input signal, the second input signal, the third input signal and the fourth input signal;
a comparison circuit, comprising multiple hysteresis comparators each being configured to compare a couple of phase shifted signals among the multiple phase shifted signals using an operation hysteresis level; and
a frequency detector, configured to detect a signal frequency according to at least one of the first input signal, the second input signal, the third input signal and the fourth input signal, and select the operation hysteresis level of each of the multiple hysteresis comparators according to the detected signal frequency.