Systems and methods for illuminating a platen in a print scanner
First Claim
1. A hybrid illumination system that provides illumination for a platen in a print scanner, comprising:
- an illumination source array that emits light from a plurality of discrete light sources;
at least one diffuser; and
a collimating lens, each diffuser being disposed between said illumination source array and said collimating lens such that at least a portion of the light emitted from said plurality of discrete light sources passes through each diffuser to said collimating lens as diffuse light, and wherein at least a first portion of light that exits said collimating lens falls on the platen as collimated light, and at least a second portion of light that exits said collimating lens falls on the platen as diffuse light.
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Accused Products
Abstract
Systems and methods for illuminating a platen are provided. A hybrid illumination system uses both diffusion and collimation to efficiently provide a flat, uniform illumination at a platen. One or more diffusers are disposed between the illumination source array and a collimating lens. An illumination system is provided which uses diffused light to illuminate a platen in a print scanner. The illumination system has an illumination source array and a light wedge. The light wedge reflects light internally which makes the illumination even more diffuse. Sources are divided into at least a center region and a perimeter region. The density of sources provided in the perimeter region is greater than in the center region to correct for natural light falloff in the illumination system. Intensity control can be performed individually or in groups.
177 Citations
34 Claims
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1. A hybrid illumination system that provides illumination for a platen in a print scanner, comprising:
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an illumination source array that emits light from a plurality of discrete light sources;
at least one diffuser; and
a collimating lens, each diffuser being disposed between said illumination source array and said collimating lens such that at least a portion of the light emitted from said plurality of discrete light sources passes through each diffuser to said collimating lens as diffuse light, and wherein at least a first portion of light that exits said collimating lens falls on the platen as collimated light, and at least a second portion of light that exits said collimating lens falls on the platen as diffuse light. - View Dependent Claims (2, 3, 4, 6, 7, 8, 9, 10, 13, 14, 15, 16, 17)
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5. (canceled)
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11-12. -12. (canceled)
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18-26. -26. (canceled)
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27. A method for providing efficient, uniform illumination to a platen, comprising:
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emitting light from a plurality of discrete sources;
randomizing at least part of the emitted light to obtain diffuse light;
collimating at least a part of the diffuse light to obtain collimated, diffuse light; and
illuminating the platen with the collimated, diffuse light such that an image of a print of a finger or palm placed on the platen can be obtained. - View Dependent Claims (28, 29, 31, 32, 33)
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30. (canceled)
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34-37. -37. (canceled)
Specification