Segmented reflective optical system

• US 8,345,325 B2
• Filed: 07/26/2006
• Issued: 01/01/2013
• Est. Priority Date: 07/26/2006
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Arterberry, John Herman, Majette, Mark W., Schmidt, Jack H, Schissler, Dennis J
• Primary Examiner(s): Worku, Negussie
• Application Number:
  US12/375,121
• Publication Number:
  US 20100002273A1
• Time in Patent Office: 2,351 Days
• Field of Search: 358/474, 358/497, 358/513, 358/514, 358/461, 358/488, 358/448, 358/496
• US Class Current: 358/475
• CPC Class Codes: B23P 15/008 Rocket engine parts, e.g. nozzles, combustion chambers
• CPC Class Codes: H04N 1/03 with photodetectors arranged in a substantially linear array
• CPC Class Codes: H04N 1/0305 with multiple folds of the optical path
• CPC Class Codes: H04N 1/1934 Combination of arrays
• CPC Class Codes: H04N 1/1935 Optical means for mapping the whole or part of a scanned line onto the array
• CPC Class Codes: H04N 2201/02439 Positioning method
• CPC Class Codes: H04N 2201/02466 Mounting or supporting method
• CPC Class Codes: Y10T 156/10 Methods of surface bonding and/or assembly therefor
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

An optical system, used for scanning, forms an image using reflective optical surfaces. The system may be telecentric, and may form an image that is reduced in size as compared with the scanned original. Several image-forming optical channels may be combined to form a page-wide scanning array.

Claims

1. A scanner optical system, comprising:

at least two discrete image-forming optical channels;

a generally linear electronic light sensor segment in each image-forming optical channel; and

at least two non-planar minor segments in each discrete image-forming optical channel;

and wherein each discrete image-forming optical channel forms an image of a discrete portion of a scan line on the sensor segment using the at least two non-planar mirror segments.

2. The scanner optical system of claim 1, wherein each discrete channel forms the image without the use of any refractive element having optical power.

3. The scanner optical system of claim 1, further comprising:

a multi-purpose optical element, the multi-purpose optical element further comprising, for each discrete image-forming optical channel, an optical aperture and the at least two non-planar minor segments.

4. The scanner optical system of claim 1, wherein the discrete scan line portions imaged by adjacent discrete channels overlap.

5. The scanner optical system of claim 1, wherein at least one of the non-planar minor segments is aspheric.

6. The scanner optical system of claim 1, further comprising at least one page-wide planar minor, and wherein a light path of each discrete channel is folded for compactness.

7. The scanner optical system of claim 6, wherein at least one page-wide planar mirror further comprises:

a first side;

a second side opposite the first; and

a first-surface mirror coating on both sides;

and wherein, in the course of forming an image of the discrete scan line portion, light from the discrete scan line portion reflects from both sides.

8. The scanner optical system of claim 1, wherein each discrete image-forming optical channel is substantially telecentric in object space.

9. The scanner optical system of claim 1, wherein the image formed by each discrete image-forming channel is reduced in size in relation to the imaged discrete scan line portion.

10. The scanner optical system of claim 9, wherein the image formed by each discrete image-forming channel is nominally one half the size of the imaged discrete scan line portion.

11. An imaging device, comprising:

a carriage comprising at least discrete two image-forming optical channels, each discrete channel forming an image of a discrete portion of a scan line;

at least two non-planar minor segments in each discrete image-forming optical channel; and

a generally linear electronic light sensor in each discrete image-forming optical channel;

and wherein the image is formed in each discrete image-forming optical channel on the respective generally-linear electronic light sensor using the respective two non-planar minor segments.

12. The imaging device of claim 11, wherein the imaging device is one of a flatbed scanner, a sheetfeed scanner, a photocopier, a facsimile machine, and a multifunction imaging device.

13. The imaging device of claim 11, configured to scan a reflective original item.

14. The imaging device of claim 11, configured to scan a transmissive original item.

15. The imaging device of claim 11, further comprising a multi-purpose optical element, the multipurpose optical element comprising for each discrete image-forming optical channel the two non-planar minor segments and an optical aperture.

16. The imaging device of claim 11, wherein each discrete image-forming optical channel is substantially telecentric in object space.

17. The imaging device of claim 11, wherein the discrete scan line portions imaged by adjacent discrete image-forming optical channels overlap.

18. The imaging device of claim 11, wherein the image formed by each discrete image-forming optical channel is reduced in size as compared with the discrete scan line portion imaged.

19. A optical carriage for a scanner, comprising:

a carriage housing;

at least discrete two image-forming optical channels substantially contained within the carriage housing;

at least two non-planar minor segments in each discrete image-forming optical channel; and

a generally linear electronic light sensor in each discrete image-forming optical channel;

and wherein each discrete image-forming optical channel, using the non-planar mirror segments, forms an image on the light sensor of a discrete portion of the scan line.

20. The optical carriage of claim 19, further comprising a multi-purpose optical element that comprises for each discrete image-forming optical channel, the at least two non-planar mirror segments and an optical aperture.

21. The optical carriage of claim 19 wherein each discrete image-forming optical channel is substantially telecentric in object space.

22. The optical carriage of claim 19, further comprising a light source configured to illuminate the scan line on an original item.

23. The optical carriage of claim 22, wherein the light source emits light containing substantially all wavelengths in the visible spectrum.

24. The optical carriage of claim 23, wherein each generally-linear electronic light sensor further comprises at least a first row of pixels sensing light in a first subset of the visible spectrum, a second row of pixels sensing light in a second subset of the visible spectrum, and a third row of pixels sensing light in a third subset of the visible spectrum.

25. The optical carriage of claim 22, wherein the light source further comprises at least three light emitting devices that emit light of at least three different colors.

26. The optical carriage of claim 25, wherein each light emitting device is a light emitting diode.

27. The optical carriage of claim 25, wherein each generally linear electronic light sensor is sensitive to substantially the entire visible spectrum, and the optical carriage is configured to accomplish color scanning by reading each scan line multiple times, at least once with each different illumination color.

28. The optical carriage of claim 19, wherein one of the non-planar minor segments serves the function of an optical aperture.

29. A method of scanning, comprising:

forming, in an optical carriage module, images of at least two scan line segments, the optical carriage module comprising at least two discrete image-forming optical channels, each discrete image-forming optical channel further comprising a generally linear optical sensor and at least two non-planar reflective surfaces, and each discrete image-forming optical channel forming one of the images using the non-planar reflective surfaces of the discrete channel;

illuminating, with a light source, the scan line on an original item;

causing relative motion between the original item and the optical carriage; and

generating digital values representing the distribution of light on the generally linear optical sensors.

30. The method of claim 29, further comprising placing all of the non-planar reflective surfaces of all of the discrete channels and an optical aperture for each discrete channel on a multi-purpose optical element.

31. The method of claim 29, wherein illuminating the scan line further comprises illuminating the scan line with a light source that emits light containing substantially all wavelengths in the visible spectrum.

32. The method of claim 29, wherein illuminating the scan line further comprises illuminating the scan line with at least three light emitting devices, each light emitting device emitting light containing wavelengths in a subset of the visible spectrum.

33. The method of claim 32, further comprising performing single-pass color scanning.

34. The method of claim 32, further comprising performing multiple-pass color scanning.

35. The method of claim 29, further comprising:

generating a digital image of a calibration target using the optical carriage module;

characterizing alignment errors in the optical carriage module by analyzing the digital image of the calibration target; and

compensating, based on the characterization, for the alignment errors by adjusting digital pixel values in a subsequent scanned image.

36. A multi-purpose optical element in an optical system that comprises at least two discrete image-forming optical channels, each discrete image-forming optical channel forming an image of a discrete portion of a scan line on a generally linear electronic light sensor, the multi-purpose optical element comprising:

at least two non-planar minor segments associated with each discrete image forming optical channel; and

an optical aperture associated with each discrete image forming optical channel.

37. The multi-purpose optical element of claim 36, wherein during image formation, image-forming light in one discrete image-forming channel reflects from one non-planar minor segment of the discrete channel, then passes through the optical aperture of the discrete channel, and then reflects from the other non-planar mirror segment of the discrete channel.

38. The multi-purpose optical element of claim 36, wherein the at least two non-planar mirror segments and the optical aperture of one discrete image-forming channel are nominally identical to the at least two non-planar mirror segments and the optical aperture of another discrete image-forming channel.