Optical scanner

• US 4,538,181 A
• Filed: 04/06/1984
• Issued: 08/27/1985
• Est. Priority Date: 02/28/1983
• Status: Expired due to Term

• Current Assignee: Westinghouse Electric Corporation (Paramount Global (f/k/a ViacomCBS Inc.))
• Original Assignee: Kollmorgen Technologies Corporation
• Inventors: Taylor, William H.
• Primary Examiner(s): Britton, Howard W.
• Assistant Examiner(s): Kostak, Victor R.
• Application Number:
  US06/597,645
• Time in Patent Office: 508 Days
• Field of Search: 358/208, 358/206, 358/199, 358/285, 358/293, 358/205, 350/6.5, 350/6.9, 350/3.71, 250/236
• US Class Current: 348/205
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: H04N 3/09 for electromagnetic radiation in the invisible region, e.g. infrared

Abstract

An optical scanner for orthogonal scanning in read and/or write modes has a framing mirror (20) for linear vertical scanning and a rotating disc (30) with a circular array of concave reflectors (32) for horizontal scanning. Primary imagers (24, 164) focus the linear vertical scan onto a strip mirror (26) which reflects the scanned pixels to the concave reflectors. Preferably, the concave reflectors reflect the pixel image in a collimated beam which is focused by a collection optic (38, 200) onto radiation detector (40). Image rotator (221), collection aperture defining device (270, 272), aperture shading device (290), and a device for suppressing spurious radiation are also provided.

Claims

1. A raster scanning system for providing a video type image including parallel linear scan image elements, the improvement including:

a rotating scanning disc including a circular array of concave reflectors on a plane surface thereof;

an imaging means configured to coincide with the scanning sweep of the concave reflectors and separated from said concave reflectors by a distance equal to the focal length of said concave reflectors; and

radiation emitting means positioned to emit radiation at a controlled intensity toward said array of concave reflectors to form a linear scanning image redirected from said imaging means.

2. The system according to claim 1 further including means for forming radiation from said radiation emitting means into a collimated beam directed toward said array of concave reflectors.

3. The system to claim 1 wherein said radiation emitting means emits radiation in the visible light spectrum.

4. A scanning system for scanning a scene in an orthogonal pattern comprising:

a framing mirror to provide linear traces of a scan of the scene in one direction;

means for forming an image of said linear trace at a locus of foci lying upon a spherical image surface;

a rotating scanning disc having a circular array of concave reflectors on a plane surface thereof;

a convex strip mirror configured as a section of a cone taken normal to the cone axis to coincide with said locus of foci and to redirect said trace to said concave reflectors, said strip mirror being disposed at a distance from said concave reflectors by a distance equal to the focal length of said concave reflectors; and

detection means for detecting the intensity of radiation reflected from said strip mirror by said concave reflectors.

5. The new scanning system according to claim 4 wherein said means for forming an image of said linear trace further comprise a primary imaging mirror having a spherical contour.

6. The scanning system according to claim 4 wherein radiation reflected from said strip mirror by said concave reflectors emerges from said concave reflectors in a collimated beam and is focused upon said detection means by a collection optic.

7. The scanning system according to claim 6 further comprising image rotation means disposed in the optical path between said concave reflectors and said collection optic.

8. The scanning system according to claim 7 wherein said image rotation means further comprise a paraboloidal roof-type mirror.

9. In a scanning system wherein a scene is scanned in an orthogonal pattern including linear scanning traces in one of the orthogonal directions focused at a locus of foci, the improvement comprising:

a rotating scanning disc including a circular array of concave reflectors on a plane surface thereof;

an image means configured and dimensioned to coincide with the locus of foci and on which the linear scanning trace appears such that said image means redirects the focused radiation of the scanning trace to the concave reflectors; and

radiation detecting means positioned to detect the intensity of radiation reflected from said image means by said concave reflectors.

10. The system according to claim 9 wherein said concave reflectors are parabolic.

11. The system according to claim 9 wherein said concave reflectors are spherical.

12. A system according to claim 9 wherein said radiation detection means includes multiple detectors located to successively detect radiation from the same point of the scene being scanned.

13. The system according to claim 9 wherein said radiation detection means includes a plurality of detectors located to simultaneously detect radiation from different linear traces of the scene being scanned.

14. The system according to claim 9 wherein said radiation detection means is an infrared detector.

15. The system according to claim 9 wherein said radiation detection means is an ultraviolet radiation detector.

16. The system according to claim 9 wherein said radiation detection means detects visible light.

17. The system according to claim 9 wherein said radiation detection means including a plurality of detectors each capable of detecting radiation in a different spectral region.

18. The system according to claim 9 further comprising means for suppressing potential spurious radiation.

19. The system according to claim 18 wherein said means for suppressing potential spurious radiation further comprise reflective surfaces oriented to reflect radiation from the detector back to the detector.

20. The system according to claim 9 further comprising means defining a collection aperture corresponding to the scanning sweep of said rotating scanning disc.

21. The system according to claim 20 further comprising mesns for shading a portion of said collection aperture.

22. The system according to claim 9 wherein said linear scanning trace on said image means is separated from said concave reflectors by a distance equal to the focal length of said concave reflectors.

23. The system according to claim 22 wherein said imaging means is a strip mirror.

24. The system according to claim 23 wherein said strip mirror is a section of a toroidal surface.

25. The system according to claim 23 wherein said strip mirror is a section of a conical surface.

26. The system according to claim 23 wherein said strip mirror is a section of a spherical surface.

27. The system according to claim 22 wherein said concave reflectors are shaped so that radiant energy emerging therefrom is in a collimated beam and wherein said system further includes means for focussing said collimated beam on said radiation detecting means.

28. The system according to claim 27 wherein said means for focussing is a collector lens.

29. The system according to claim 27 wherein said means for focussing is a parabolic reflector.

30. The system according to claim 29 wherein said parabolic reflector rotates said collimated beam and effectively focuses said collimated beam on the axis of said scanning disc.

31. The system according to claim 27 further comprising image rotation means disposed in the optical path of said collimated beam between said concave reflectors and said focussing means.

32. The system according to claim 31 wherein said image rotation means further comprises a paraboloidal roof-type reflector.

33. A scanning system for providing an orthogonal scan of a scene including:

a framing mirror for providing a low speed vertical scan of the scene;

means for forming an image of said vertical scan at a locus of foci;

a rotating scanning disc including a circular array of concave reflectors on a planar surface thereof;

a strip mirror configured and dimensioned to coincide with the locus of foci and separated from said concave reflectors by a distance equal to the focal length of said concave reflectors for reflecting radiation from said locus of foci toward said circular array of concave reflectors; and

radiation detection means positioned to detect the intensity of radiation reflected by said strip mirror and at least one of said concave reflectors.

34. The system according to claim 33 wherein said strip mirror is a section of a conical surface.

35. The system according to claim 33 wherein said strip mirror is a section of a toroidal surface.

36. The system according to claim 33 wherein said strip mirror is a section of a spherical surface.

37. The system according to claim 33 wherein said strip mirror is a ribbon of reflective material.

38. The system according to claim 33 wherein said strip mirror is a reflective strip on a transparent substrate.

39. The system according to claim 33 further comprising means for shading said radiation detection means.

40. The system according to claim 33 further including radiation emitting means positioned to emit radiation at a controlled intensity toward said array of concave reflectors to form a linear scanning image.

41. The system according to claim 33 further including means for suppressing potential spurious radiation.

42. The system according to claim 41 wherein said means for suppressing potential spurious radiation further include reflective surfaces oriented to reflect radiation from the detector back to the detector.

43. The system according to claim 33 further comprising means defining a collection aperture corresponding to the scanning sweep of said rotating scanning disc.

44. The system according to claim 43 further comprising means for shading a portion of said collection aperture.

45. The system according to claim 33 wherein said means for forming an image of said vertical scan further include a telecentric imaging means located along the optical path between said framing mirror and said strip mirror so that a linear trace of said scene appears on said strip mirror in accordance with the position of the framing mirror.

46. The system according to claim 45 wherein said telecentric imaging means is a lens.

47. The system according to claim 45 wherein said strip mirror is a section of a conical surface.

48. The system according to claim 45 wherein said strip mirror is a section of toroidal surface.

49. The system according to claims 45 wherein said strip mirror is a section of a spherical surface.

50. The system according to claim 45 wherein said telecentric imaging means is a concave imaging mirror.

51. The system according to claim 50 further including a concentric meniscus lens in the optical path prior to said concave imaging mirror.

52. The system according to claim 50 wherein said concave imaging mirror has a spherical contour.

53. A scanning system according to claim 33 wherein radiation emerges from said concave reflectors in a collimated beam and wherein said system further includes a collector means for focussing said collimated beam on said radiation detection means.

54. The system according to claim 53 wherein said collector means is a lens.

55. The system in accordance with claim 53 further including at least one reflective surface between said array of concave reflectors and said collector means to fold the optical path.

56. A system according to claim 53 wherein the optical path toward said framing mirror is in line with the path to said radiation detection means.

57. The system according to claim 53 wherein said collector means is a parabolic reflector.

58. The system according to claim 57 wherein said parabolic reflector rotates said collimated beam and effectively focuses said collimated beam on the axis of said scanning disc.

59. The system according to claim 53 further including image rotation means disposed in the optical path of said collimated beam between said concave reflectors and said focusing means.

60. The system according to claim 59 wherein said image rotation means is a paraboloidal roof-type reflector.