Optical encoder and operating method thereof
AssigneePixart Imaging Inc.
InventorsChung-Wen Lo, Hsin-Chia Chen
Life of this patent
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Abstract
The present disclosure is related to an optical encoder which is configured to provide precise coding reference data by feature recognition technology. To apply the present disclosure, it is not necessary to provide particular dense patterns on a working surface or any reference object with particular markers. The precise coding reference data can be generated by detecting surface features of the working surface.
Claims14
An optical encoder, comprising:
- a light emitter having a contact point and configured to emit light to a detection surface;
- a light sensing matrix having a plurality of pixels and configured to detect reflected light from the detection surface to generate detected signals;
- and
- a processing unit coupled to the contact point of the light emitter, and configured to
- store reference data corresponding to at least one reference position in a registration mode according to the detected signals,
- generate comparison image data according to the detected signals in a comparison mode and compare the comparison image data with the reference data to determine a current position, and
- update at least a part of the reference data in the comparison mode when a difference value between the comparison image data corresponding to the current position and the reference data exceeds an identification threshold or when a difference value between the comparison image data other than the current position and the reference data is smaller than an update threshold.
An operating method of an optical encoder, the optical encoder comprising a light sensing unit configured to detect reflected light from a detection surface to generate detected signals and a processing unit configured to process the detected signals, the operating method comprising:
- entering a registration mode in which the processing unit stores reference data corresponding to at least one reference position according to the detected signals;
- entering a comparison mode in which the processing unit generates comparison image data according to the detected signals and compares the comparison image data with the reference data to determine a current position;
- and
- updating, in the comparison mode, at least a part of the reference data when a difference value between the comparison image data corresponding to the current position and the reference data exceeds an identification threshold or when a difference value between the comparison image data other than the current position and the reference data is smaller than an update threshold.
An optical encoder, comprising:
- a light emitter having a contact point and configured to emit light to a detection surface;
- a light sensing matrix having a plurality of pixels and configured to detect reflected light from the detection surface to generate images;
- and
- a processing unit coupled to the contact point of the light emitter,
- wherein the processing unit is configured to, in a registration mode,
- identify a start position repeatedly detected according to the images to determine an operation range, and
- store reference data corresponding to an original position and at least one reference position within the operation range,
- wherein the processing unit is further configured to, in a comparison mode,
- generate comparison image data according to the images, and
- compare the comparison image data with the reference data to accordingly determine a current position, and
- wherein the processing unit is further configured to update at least a part of the reference data when a difference value between the comparison image data corresponding to the current position and the reference data exceeds an identification threshold, or when a difference value between the comparison image data other than the current position and the reference data is smaller than an update threshold.
Dependencies are inferred from the claim text.