OPTICAL NAVIGATION DEVICE
First Claim
Patent Images
1. An optical navigation device, comprising:
- an image sensor configured to successively output a reference frame and a current frame;
an input/output (I/O) unit; and
a navigation processor configured tocalculate a displacement according to the reference frame and the current frame,compare the displacement with a displacement threshold, and transmit the displacement via the I/O unit,replace the reference frame by the current frame when the displacement is smaller than the displacement threshold,update a transition noise map according to a first ratio of the transition noise map and a second ratio of the current frame when the displacement is larger than the displacement threshold, andgenerate a fixed noise map when an update count, which is a number of times of updating the transition noise map, reaches a fixed predetermined counting threshold which is larger than 1.
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Abstract
There is provided a failure identification method of an optical navigation device including the steps of: constructing a fixed noise map according to image frames captured by an image sensor; calculating a feature value of the fixed noise map; identifying whether the fixed noise map is uniform or not according to the feature value; and generating an alert signal when the fixed noise map is non-uniform for indicating failure of the optical navigation device.
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Citations
20 Claims
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1. An optical navigation device, comprising:
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an image sensor configured to successively output a reference frame and a current frame; an input/output (I/O) unit; and a navigation processor configured to calculate a displacement according to the reference frame and the current frame, compare the displacement with a displacement threshold, and transmit the displacement via the I/O unit, replace the reference frame by the current frame when the displacement is smaller than the displacement threshold, update a transition noise map according to a first ratio of the transition noise map and a second ratio of the current frame when the displacement is larger than the displacement threshold, and generate a fixed noise map when an update count, which is a number of times of updating the transition noise map, reaches a fixed predetermined counting threshold which is larger than 1. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An optical navigation device, comprising:
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an image sensor configured to successively output a reference frame and a current frame; and a navigation processor configured to calculate a feature value of the current frame, update a transition noise map according to a first ratio of the transition noise map and a second ratio of the current frame, accumulate the feature value when the transition noise map is updated, generate a fixed noise map when an update count, which is a number of times of updating the transition noise map, reaches a fixed predetermined counting threshold which is larger than 1, and generate an alert signal when the accumulated feature value exceeds a feature threshold. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification