Optical sensor with telecentric optics
AssigneeXerox Corporation
InventorsRichard H. Tuhro, Robert P. Herloski
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Abstract
A substrate sensor system having a light source for radiating light toward a substrate position, a light sensor system positioned to receive light transmitted or reflected at the substrate, a lens that images the light transmitted or reflected at the substrate onto the light sensor system, and a telecentric stop between the lens and the light sensor system. Beneficially, such substrate sensor systems will include an electrical circuit that produces position information regarding the position of a substrate and/or the position of an image on a substrate.
Claims20
A position sensing system comprised of:
- a light source for emitting light onto a substrate;
- a lens for imaging a portion of said emitted light onto an image plane, wherein said imaged portion depends upon a position of said substrate in an x-y plane;
- a light sensor system at said image plane for producing electrical signals from said imaged light;
- an electrical circuit for determining said position of said substrate from said electrical signals;
- and
- a telecentric stop between said lens and said light sensor system, said telecentric stop for reducing variations of said imaged light caused by changes in position of said substrate in a z-direction.
An image sensing system comprised of:
- a substrate having an image area;
- a light source for emitting light onto said substrate;
- a lens for imaging a portion of said emitted light onto an image plane, wherein said imaged portion depends upon a position of said substrate in an x-y plane;
- a light sensor system at said image plane for producing electrical signals from said imaged light;
- an electrical circuit for determining said position of said substrate from said electrical signals;
- and
- a telecentric stop between said lens and said light sensor system, said telecentric stop for reducing variations of said imaged light caused by changes in position of said substrate in a z-direction.
Dependencies are inferred from the claim text.