US 11,874,147 B2 · Optical encoder with alignment photodiodes

Abstract

There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

Claims20

Dependent claims

An optical encoder, comprising:

an optical sensor, configured to receive modulated light from an encoding medium, and comprising:
a detection photodiode array, arranged opposite to the encoding medium, and photodiodes of the detection photodiode array are periodically arranged along a direction by a distance;
and
a first photodiode and a second photodiode, respectively arranged at two sides of the detection photodiode array in the direction, each of the first photodiode and the second photodiode having a trapezoid sensing surface, and separated from the detection photodiode array by three times of the distance in the direction.

1 more element

Dependencies are inferred from the claim text.

Optical encoder with alignment photodiodes

Life of this patent

Optical encoder with alignment photodiodes

Life of this patent

Abstract

Claims20