Image capture system having a folded optical path
AssigneeLexmark International, Inc.
InventorsMatthew Ryan Keniston, Robert White Milgate, III
Life of this patent
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Abstract
An image capture system including a platen for receiving a media sheet bearing an image to be captured; an illumination system for illuminating the media sheet; a mirror disposed in optical communication with the platen, for reflecting light from the illumination system reflected from the media sheet; and an optical sensor for receiving the light reflected by the mirror. The interrelationship between the platen, mirror and optical sensor is such that a location of a top edge of the mirror's primary reflection projected onto the platen is lower than a location of a bottom edge of the image's secondary reflection projected onto the platen. In this way, the image captured by the optical sensor is free of secondary reflections.
Claims23
An image capture system, comprising:
- a platen for receiving a media sheet bearing an image to be captured;
- an illumination system for illuminating the media sheet;
- a mirror disposed in optical communication with the platen, for reflecting light from the illumination system reflected from the media sheet;
- and
- an optical sensor for receiving the light reflected by the mirror;
- wherein a location of a top edge of the mirror's primary reflection projected onto the platen is positioned approximately lower than a location of a bottom edge of the image's secondary reflection projected onto the platen, the secondary reflection being an optical ghost image having a lower intensity than the primary reflection.
An image capture system, comprising:
- a platen for receiving a media sheet bearing an image to be captured;
- an illumination system for illuminating the media sheet;
- a mirror disposed in optical communication with the platen, for reflecting light from the illumination system reflected from the media sheet;
- and
- an optical sensor for receiving the light reflected by the mirror;
- wherein a location of a top edge of the mirror's primary reflection projected onto the platen is positioned approximately lower than a location of a bottom edge of the image's secondary reflection projected onto the platen;
- wherein the location of the top edge Fy of the mirror's primary reflection is approximately represented by:
- F
- y
- =
- D
-
-
- cot
-
-
- θ
-
- (
- G
- 2
- -
- A
-
-
- cot
-
-
- θ
- cot
-
-
- θ
- -
- G
- 2
-
- D
- +
- A
- )
-
-
- -
- (
- G
- 2
- -
- A
-
-
- cot
-
-
- θ
- cot
-
-
- θ
- -
- G
- 2
-
- D
- )
-
- +
- D
- and the location of the bottom edge Wy of the image's secondary reflection projected onto the platen is approximately represented by:
- W
- y
- =
- D
-
-
- A
-
-
- cot
-
-
- θ
- -
- (
- A
-
-
- cot
-
-
- θ
- +
- G
- 2
- )
-
- cos
-
-
- 2
-
-
- θ
-
-
- (
- A
-
-
- cot
-
-
- θ
- +
- G
- 2
- )
-
- sin
-
-
- 2
-
-
- θ
-
- +
- D
- where D is a distance between a focal point of the optical sensor and the platen, G is a width of an image target area to be captured, A is a distance between the platen and the mirror along a normal of the optical sensor, and θ is an angle between the platen and the mirror.
An image capture system for capturing an image of a sheet of media, comprising:
- an illumination system for illuminating the media sheet;
- a mirror disposed in optical communication with the media sheet, for reflecting light from the illumination system that is reflected from the media sheet;
- and
- an assembly having an optical sensor for receiving the light reflected by the mirror;
- wherein a magnitude of an edge of the mirror's primary reflection projected onto a plane containing the media sheet is less than a magnitude of an edge of the image's secondary reflection projected onto the plane, the secondary reflection being an optical ghost image having a lower intensity than the primary reflection.
Dependencies are inferred from the claim text.