Canon Precision Inc.

Ryo Sasaki

Kousuke Kudo

An encoder comprises first and second sensors which reads first and second tracks, the first and second sensors being arranged in a radial direction to face each other, and a processor which generates a first position signal based on first and second periodic signals based on a signal obtained by reading the first and second tracks by the first sensor, and generates a second position signal based on third and fourth periodic signals based on a signal obtained by reading the first and second tracks by the second sensor, wherein the processor generates an absolute position signal indicating an absolute position of at least one of the scale, the first sensor, or the second sensor based on the first and second position signals and the first and third periodic signals.

Absolute rotary encoder and apparatus

An encoder includes a scale having a pattern column with patterns periodically changing a physical characteristic, a detection element array disposed movable relatively to the scale and including detection elements configured to detect light from the pattern column are arranged in a moving direction, a signal processor configured to convert an output signal from the detection element array into position information. The detection element array includes first to fourth detection elements are arranged in order of the first detection elements, the second detection elements, the first detection elements, the second detection elements, the third detection elements, the fourth detection elements, the third detection elements, and the fourth detection elements. The signal processor generates a first signal based on an output signal from the first and third detection elements and a second signal based on an output signal from the second and fourth detection elements.

Encoder and image capturing apparatus

An encoder includes a scale having a continuous part where physical characteristics varies and a discontinuous part that interrupts the continuous part, a detector that be relatively displaced with respect to the scale and that detects the physical characteristics of the scale, and a processor that detects an origin of the scale on the basis of a signal for displacement detection output from the detector. The detector includes a sensitive part having sensitivity contributing to the signal for displacement detection and an insensitive part having no sensitivity contributing to the signal for displacement detection. The processor detects the origin on the basis of signal intensity of each of signals for displacement detection that the detector outputs when the sensitive and insensitive parts detect physical characteristics of the discontinuous part.

Encoder including an origin position detection function

An origin detector includes detecting element groups having a first to a fourth detector, is configured so that a first signal sensitivity of the detectors of a center is larger than a second signal sensitivity of the detectors of a periphery, reads an origin detecting pattern including an origin pattern having a length along a detecting direction of a part having a physical characteristic different from an origin peripheral part larger than a length along the detecting direction of each detecting element group, and outputs a first signal using the first and third detectors, and a second signal using the second and fourth detectors. A processor acquires a third signal from the first signal and a first threshold, and a fourth signal from the second signal and a second threshold, and outputs a fifth signal using the third and fourth signals as an origin signal.

Apparatus having an encoder with an origin detection pattern

An encoder includes a scale including an origin detecting pattern, an origin detector, and a processor. The origin detector includes a plurality of detecting element groups including a first, second, third, and fourth detectors. The first and second detectors and the third and fourth detectors are symmetrically arranged to a center of each detecting element group, respectively. A part of the origin detecting pattern having a physical characteristic different from an origin peripheral part is shorter than each detecting element group. The origin detector outputs a first signal from the first and third detectors, and a second signal from the second and fourth detectors. The processor outputs a fifth signal based on a third signal from the first signal and a first threshold, and a fourth signal from the second signal and a second threshold as an origin signal.

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Hirosaki, Japan

Ryo Sasaki