Rotary encoder and input device using the same
First Claim
1. A rotary encoder comprising:
- a light receiving unit including a first light receiving element and a second light receiving element which receive light emitted from a light emitting element via slits formed at a rotary disk and respectively generate detection signals whose phases differ from each other substantially by 90°
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a first waveform shaping circuit which compares the detection signal from said first light receiving element with a reference value and generates a first detection output of a rectangular waveform;
a second waveform shaping circuit which compares the detection signal from said second light receiving element with the reference value and generates a second detection output of a rectangular waveform;
a peak hold circuit which receives the detection signal from said first light receiving element and holds the peak value thereof; and
a reference value generating circuit which generates the reference value depending on the peak value held at said peak hold circuit.
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Accused Products
Abstract
The present invention includes a light receiving unit having a first and second light receiving element which receive light emitted from a light emitting element via slits formed at a rotary disk and respectively generate detection signals whose phases differ from each other substantially by 90°. A first waveform shaping circuit compares the detection signal from the first light receiving element with a reference value and generates a first detection output of a rectangular waveform. A second waveform shaping circuit compares the detection signal from the second light receiving element with the reference value and generates a second detection output of a rectangular waveform. A peak hold circuit receives the detection signal from the first light receiving element and holds the peak value thereof. A reference value generating circuit generates the reference value depending on the peak value held at the peak hold circuit.
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Citations
15 Claims
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1. A rotary encoder comprising:
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a light receiving unit including a first light receiving element and a second light receiving element which receive light emitted from a light emitting element via slits formed at a rotary disk and respectively generate detection signals whose phases differ from each other substantially by 90°
;a first waveform shaping circuit which compares the detection signal from said first light receiving element with a reference value and generates a first detection output of a rectangular waveform; a second waveform shaping circuit which compares the detection signal from said second light receiving element with the reference value and generates a second detection output of a rectangular waveform; a peak hold circuit which receives the detection signal from said first light receiving element and holds the peak value thereof; and a reference value generating circuit which generates the reference value depending on the peak value held at said peak hold circuit. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A rotary encoder comprising:
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a light receiving unit including a first light receiving element and a second light receiving element which receive light emitted from a light emitting element via slits formed at a rotary disk and respectively generate detection signals whose phases differ from each other substantially by 90°
;a first waveform shaping circuit which compares the detection signal from said first light receiving element with a first reference value and generates a first detection output of a rectangular waveform; a second waveform shaping circuit which compares the detection signal from said second light receiving element with a second reference value and generates a second detection output of a rectangular waveform; a first peak hold circuit which receives the detection signal from said first light receiving element and holds the peak value thereof as a first peak value; a first reference value generating circuit which generates the first reference value depending on the first peak value held at said first peak hold circuit; a second peak hold circuit which receives the detection signal from said second light receiving element and holds the peak value thereof as a second peak value; and a second reference value generating circuit which generates the second reference value depending on the second peak value held at said second peak hold circuit. - View Dependent Claims (8)
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9. An input device comprising:
- first and second rotary encoders each comprising, a light receiving unit including a first and second light receiving element which receive light emitted from a light emitting element via slits formed at a rotary disk and respectively generate detection signals whose phases differ from each other substantially by 90°
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a first waveform shaping circuit which compares the detection signal from said first light receiving element with a reference value and generates a first detection output of a rectangular waveform;
a second waveform shaping circuit which compares the detection signal from said second light receiving element with the reference value and generates a second detection output of a rectangular waveform;
a peak hold circuit which receives the detection signal from said first light receiving element and holds the peak value thereof; and
a reference value generating circuit which generates the reference value depending on the peak value held at said peak hold circuit;a first disk rotating mechanism which is disposed for X direction in a XY coordinate system and causes said rotary disk to rotate in said first rotary encoder; a second disk rotating mechanism which is disposed for Y direction in the XY coordinate system and causes said rotary disk to rotate in said second rotary encoder; and a ball which is coupled to said first and second disk rotating mechanisms and causes said first and second rotary encoders to rotate. - View Dependent Claims (10, 11, 12, 13, 14, 15)
- first and second rotary encoders each comprising, a light receiving unit including a first and second light receiving element which receive light emitted from a light emitting element via slits formed at a rotary disk and respectively generate detection signals whose phases differ from each other substantially by 90°
Specification