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US 2003/0155492 A1Published application
Optical encoder
AssigneeCanon Kabushiki Kaisha
InventorsAkio Atsuta, Masahiko Igaki
Life of this patent
Estimating the term…
Abstract
In an optical encoder, an output signal of the encoder and a signal inverted from the output signal are respectively inputted to one input terminal and the other input terminal of a comparator constituting a circuit for electrically decomposing the output signal of the encoder, whereby it is possible to obtain a highly accurate electrical division circuit which is capable of removing the hysteresis of a comparator, noises and D.C. offset.
Claims4
An optical encoder, comprising:
- a scale having an optical grating formed thereon;
- a light source for irradiating the optical grating on the scale with light;
- a photoelectric receiving element for receiving a light from the light source through the optical grating on the scale to output an output signal corresponding to the received light;
- and
- a signal processing circuit for processing the output signal from the photoelectric receiving element to detect an amount of relative movement of the scale with respect to the photoelectric receiving element, the signal processing circuit comprising:
- a comparator adapted to receive as its input the output signal of the photoelectric receiving element, constituting an electrical division circuit for increasing a resolution through a electrical processing, and having a plurality of input terminals, a signal and another signal 180° out of phase with the signal being inputted to one input terminal and another input terminal, respectively.
3 more elements
Dependencies are inferred from the claim text.