Patent ID: 9448089
Filing Date: 2016-09-20
CPC Classification: G01D

Claim Text:
1. An optical encoder, comprising: a plurality of light receiving elements configured to receive light that has passed through or been reflected by a scale having a lattice of pitch P, and said plurality of light receiving elements collectively further configured to output a signal of a first phase, a signal of a second phase, a signal of a third phase, and a signal of a fourth phase, the first, second, third, and fourth phases being offset from each other by an integer multiple of 1/4P, wherein 1/4P is equal to 90°, and wherein the plurality of light receiving elements all have a same vertical width, the plurality of light receiving elements comprise 12·N light receiving elements arranged in a lateral direction and spaced apart by P/60 or 2P/60, wherein N is a natural number, the plurality of light receiving elements are arranged such that any four of said light receiving elements arranged next to each other include a light receiving element outputting the signal of the first phase, a light receiving element outputting the signal of the second phase, a light receiving element outputting the signal of the third phase, and a light receiving element outputting the signal of the fourth phase; the light receiving elements outputting the signal of the first phase include a light receiving element defining a lateral width of 7P/60, a light receiving element defining a lateral width of 13P/60, and a light receiving element defining a lateral width of 20P/60; the light receiving elements outputting the signal of the second phase include a light receiving element defining a lateral width of 7P/60, a light receiving element defining a lateral width of 13P/60, and a light receiving element defining a lateral width of 20P/60; the light receiving elements outputting the signal of the third phase include a light receiving element defining a lateral width of 7P/60, a light receiving element defining a lateral width of 13P/60, and a light receiving element defining a lateral width of 20P/60; and the light receiving elements outputting the signal of the fourth phase include a light receiving element defining a lateral width of 7P/60, a light receiving element defining a lateral width of 13P/60, and a light receiving element defining a lateral width of 20P/60.