Optical pointing device with variable focus
First Claim
Patent Images
1. An optical pointing device comprising:
- a support structure operable to move across a work surface;
an illumination source, coupled to the support structure, operable to illuminate a region of the work surface;
an imaging system coupled to the support structure comprising;
an optical sensor array; and
an optical coupling system operable to receive light from the illuminated region ofthe work surface and transmit the received light to the optical sensor anay;
an auto-focus circuit operable to focus an image of the illuminated region of the work surface on the optical sensor array, the auto-focus circuit outputting a focus control signal; and
a motion detection circuit coupled to the optical sensor array operable to detect motion of the optical pointing device, the motion detection circuit receiving the focus control signal output by the auto-focus circuit, the focus control signal causing the motion detection circuit to be disabled if the auto-focus circuit determines that the image of the illuminated region is not sufficiently in focus.
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Abstract
A method and apparatus for focusing an image of a work surface on an optical sensor array in an optical pointing device. Light from a region of the work surface is captured by an imaging system incorporating an optical coupling system and the optical sensor array. The focus of the imaging system is adjusted in accordance with the distance between the optical pointing device and the work surface. The distance may be sensed, or inferred by adjusting the imaging system to maximize the focus of the image.
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Citations
30 Claims
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1. An optical pointing device comprising:
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a support structure operable to move across a work surface; an illumination source, coupled to the support structure, operable to illuminate a region of the work surface; an imaging system coupled to the support structure comprising; an optical sensor array; and an optical coupling system operable to receive light from the illuminated region of the work surface and transmit the received light to the optical sensor anay; an auto-focus circuit operable to focus an image of the illuminated region of the work surface on the optical sensor array, the auto-focus circuit outputting a focus control signal; and a motion detection circuit coupled to the optical sensor array operable to detect motion of the optical pointing device, the motion detection circuit receiving the focus control signal output by the auto-focus circuit, the focus control signal causing the motion detection circuit to be disabled if the auto-focus circuit determines that the image of the illuminated region is not sufficiently in focus. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method for focusing an image of a work surface on an optical sensor array in an imaging system of an optical pointing device, the method comprising:
- coupling light from a region of the work surface through an optical coupling system in the imaging system to the optical sensor array; and
determining the motion of the optical pointing device with a motion detection circuit;
adjusting the focus of the imaging system in accordance with the distance between the optical pointing device and work surface such that an image of a work surface is focused on the optical sensor array;
determining whether the image of the work surface is sufficiently focused on the optical sensor array; and
producing a control signal in the imaging system that causes the motion detection circuit to be disabled if a determination is made that the image of the work surface is not sufficiently focused on the optical sensor array. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23)
- coupling light from a region of the work surface through an optical coupling system in the imaging system to the optical sensor array; and
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24. An apparatus for sensing motion of a structure across an illuminated work surface, the apparatus comprising:
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an imaging means coupled to the structure, the imaging means comprising; an optical sensing means for producing an image of the illuminated work surface; and an optical coupler for receiving light from the illuminated work surface and transmitting the received light to the optical sensing means; a focus means for adjusting the imaging means such that an image of the illuminated work surface is focused on the optical sensing means, the focus means outputting a focus control signal; and a motion detection means for determining motion of the structure from successive images of the illuminated work surface, the motion detection means receiving the focus control signal output by the focus means, the focus control signal causing the motion detection means to be disabled if the focus means determines that the image of the illuminated region is not sufficiently in focus. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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Specification