Optical semiconductor device
AssigneeKabushiki Kaisha Toshiba
InventorsAkihiro Tanaka, Hiroshi Suzunaga
Life of this patent
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Abstract
An optical encoder comprises a plurality of first photodiodes, a second photodiode and a circuit. The plurality of first photodiodes are arranged in a first direction, each of the first photodiodes has a light detecting part extending along a direction substantially perpendicular to the first direction. The second photodiode is arranged near tips of the first photodiodes, and has a light detecting part extending along the first direction. The circuit performs a calculation based on outputs of the first and second photodiodes.
Claims20
An optical encoder comprising:
- a first optical detector whose output changes with a movement along a first direction of a series of light and dark patterns of a pitch smaller than a predetermined value;
- a second optical detector whose output is constant with the movement along the first direction of the series of light and dark patterns having the pitch smaller than the predetermined value;
- and
- a circuit which performs a calculation based on the outputs of the first and second optical detectors.
An optical encoder comprising:
- a plurality of first photodiodes arranged in a first direction, each of the first photodiodes having a light detecting part having a longer axis along a second direction substantially perpendicular to the first direction;
- a second photodiode arranged near lengthwise tips of the first photodiodes, and having a light detecting part having a longer axis along the first direction;
- and
- a circuit which performs a calculation based on outputs of the first and second photodiodes.
An optical encoder comprising:
- a plurality of first photodiodes arranged in a first direction;
- a plurality of second photodiodes commonly connected to a same wiring, each of the second photodiodes being arranged between the first photodiodes;
- and
- a circuit which performs a calculation based on outputs of the first and second photodiodes.
Dependencies are inferred from the claim text.