Displacement detection device and power saving method thereof
AssigneePixart Imaging Inc.
InventorsYu-Hao Huang, Ming-Tsan Kao, Sen-Huang Huang
Life of this patent
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Abstract
A displacement detection device includes an image sensor, a light source and a processing unit. The image sensor is configured to successively capture images. The light source provides light with an emission frequency and an emission duration for the image sensor in capturing the images. The processing unit is configured to calculate a displacement according to the images and to adjust both the emission frequency and the emission duration according to the displacement.
Claims20
A displacement detection device, comprising:
- an image sensor configured to successively capture images at a fixed sampling frequency;
- a light source configured to provide light with an emission frequency and an emission duration for the image sensor in capturing the images, wherein the emission duration is a time interval that the light source is turned on each time;
- and
- a processing unit configured to
- calculate, according to a correlation between the images captured by the image sensor, a displacement of the displacement detection device with respect to a work surface, and
- adjust both of the emission frequency and the emission duration according to a comparison between the displacement and at least one threshold,
- wherein when the emission frequency is increased, the emission duration is shortened and
- wherein when the emission frequency is decreased, the emission duration is extended.
A displacement detection device, comprising:
- an image sensor configured to successively capture and output images with an image gain and a fixed sampling frequency;
- a light source configured to provide light with an emission frequency and an emission duration for the image sensor in capturing the images, wherein the emission duration is a time interval that the light source is turned on each time;
- and
- a processing unit configured to
- calculate, according to a correlation between the images captured by the image sensor, a displacement of the displacement detection device with respect to a work surface, and
- adjust all of the emission frequency, the emission duration and the image gain according to a comparison between the displacement and at least one threshold,
- wherein when the emission frequency is increased, the emission duration is shortened and
- wherein when the emission frequency is decreased, the emission duration is extended.
A power saving method of a displacement detection device, comprising:
- successively capturing images with an image sensor at a fixed sampling frequency;
- calculating, by a processing unit and according to a correlation between the images captured by the image sensor at the fixed sampling frequency, a displacement of the displacement detection device with respect to a work surface;
- and
- adjusting both of an emission frequency and an emission duration of a light source according to a comparison result of comparing the displacement with at least one threshold, wherein the emission duration is a time interval that the light source is turned on each time,
- wherein when the emission frequency is increased, the emission duration is shortened, and
- wherein when the emission frequency is decreased, the emission duration is extended.
Dependencies are inferred from the claim text.