Reference signal generation apparatus and reference signal generation system

摘要

A reference point detection light-receiving unit receives light from a reference point detection pattern by first to fifth light-receiving elements. The first to fifth light-receiving elements are arranged in a first direction and outputs first to fifth signals, respectively. A reference signal generation circuit outputs a reference signal that starts at a period where a level of a signal, which is obtained by adding first and second signals, and a level of a signal, which is obtained by adding third and fourth signals, will become equal, and ends at a period where a level of a signal, which is obtained by adding the second and third signals, and a level of a signal, which is obtained by adding fourth and fifth signals, become equal.

主权项

1. A reference signal generation apparatus comprising:
a reference point detection light-receiving unit that receives light from a reference point detection pattern, the light being emitted from a light source; and a reference signal generation circuit that generates a reference signal from a reading result of the reference point detection pattern read by the reference point detection light-receiving unit, wherein the reference point detection light-receiving unit comprises: first to third light-receiving elements that are aligned in order in a first direction, output a reading result of the reference point detection pattern as first to third signals, respectively, and have a first width in the first direction, the first direction being a reading direction of the reference point detection pattern; a fourth light-receiving element that is disposed between the first light-receiving element and the second light-receiving element, outputs the reading result of the reference point detection pattern as a fourth signal, and has a second width in the first direction; and a fifth light-receiving element that is disposed between the second light-receiving element and the third light-receiving element, outputs the reading result of the reference point detection pattern as a fifth signal, and has the second width in the first direction, and the reference signal generation circuit outputs the reference signal that starts at a period where levels of a sixth signal, which is obtained by adding the first signal and the fourth signal, and a seventh signal, which is obtained by adding the second signal and the fifth signal, become equal, and ends at a period where levels of an eighth signal, which is obtained by adding the fourth signal and the second signal, and a ninth signal, which is obtained by adding the fifth signal and the third signal, become equal.