Scanned beam image capture device with a plurality of scan regions

• US 7,075,687 B2
• Filed: 06/12/2004
• Issued: 07/11/2006
• Est. Priority Date: 08/05/1999
• Status: Expired due to Term

• Current Assignee: Microvision, Inc.
• Original Assignee: Microvision, Inc.
• Inventors: Lippert, Thomas M., Tegreene, Clarence T.
• Primary Examiner(s): AMARI, ALESSANDRO V
• Application Number:
  US10/866,138
• Publication Number:
  US 20040223202A1
• Time in Patent Office: 759 Days
• Field of Search: 359/201, 359/202, 359/204, 359/212, 359/213, 359/223, 359/216, 250/235, 250/216, 235/454, 235/462.11, 235/462.12
• US Class Current: 359/204.1
• CPC Class Codes: G02B 26/08 for controlling the direction of light in light guides G02B6/35

Abstract

A display apparatus includes a scanning assembly that scans about two or more axes, typically in a raster pattern. A plurality of light sources emit light from spaced apart locations toward the scanning assembly such that the scanning assembly simultaneously scans more than one of the beams. The scanning assembly includes a plurality of mirrors that sweep their respective beams through respective regions of an image field. The regions are immediately adjacent so that an overall image is produced by “tiling” of the regions. Because sweeps of the scanning assembly scan a plurality of tiles simultaneously the resolution and/or field of view of a display for a given scan angle and mirror size is increased relative to a single mirror sweeping a single beam. In alternative embodiments, tiling is used for imaging. Also, various approaches to controlling the frequency responses of the various scanners are described, including active control of MEMs scanners and passive frequency tuning.

Claims

1. A method of capturing an image, comprising:

scanning a first beam of light having a first wavelength through a first scan pattern;

collecting at least a portion of the light scattered from the first scan pattern with a detector configured to receive the first wavelength;

scanning a second beam of light having a second wavelength through a second scan pattern;

collecting at least a portion of the light scattered from the second scan pattern with a detector configured to receive the second wavelength;

converting the light collected from the first and second scan patterns into one or more electrical signals; and

processing the one or more electrical signals to detect an image of a field of view corresponding to the first and second scan patterns.

2. The method of capturing an image of claim 1

wherein the first and second scan patterns are generated by respective first and second scanning assemblies.

3. The method of capturing an image of claim 1

wherein the first and second scan patterns are generated by a single scanning assembly.

4. The method of capturing an image of claim 1

wherein the first and second scan patterns form substantially non-overlapping tiles of the field of view.

5. The method of capturing an image of claim 1

wherein the first and second scan patterns form interleaved lines across the field of view.

6. The method of capturing an image of claim 1

wherein the first and second beams of light are emitted from the same source.

7. The method of capturing an image of claim 1

wherein the first and second beams of light are emitted from separate sources.

8. The method of capturing an image of claim 7

wherein the first and second beams of light have different wavelengths.

9. The method of capturing an image of claim 1

wherein the first and second scan patterns are formed substantially simultaneously.

10. The method of capturing an image of claim 1

wherein the light is collected by one or more detectors aligned to collect descanned light.

11. The method of capturing an image of claim 1

wherein the light is collected by one or more detectors aligned to collect light directly from the scan patterns.

12. The method of capturing an image of claim 1

wherein processing includes detecting machine-readable indicia.

13. The method of capturing an image of claim 12

wherein processing includes detecting a bar code symbol.

14. The method of capturing an image of claim 1

wherein processing includes decoding machine-readable indicia.

15. The method of capturing an image of claim 14

wherein processing includes decoding a bar code symbol.

16. The method of capturing an image of claim 15, further comprising:

displaying information corresponding to the information in the bar code symbol.

17. The method of capturing an image of claim 1

wherein processing includes determining an image of the field of view.

18. The method of capturing an image of claim 17, further comprising:

transmitting the image of the field of view.

19. The method of capturing an image of claim 17, further comprising:

displaying an image of the field of view.

20. The method of capturing an image of claim 1

wherein the scan patterns are substantially raster patterns.

21. The method of capturing an image of claim 20

wherein the raster patterns are corrected to reduce raster pinch.

22. An apparatus for capturing an image, comprising:

a first emitter operable to emit a first beam of light at a first wavelength;

a second emitter operable to emit a second beam of light at a second wavelength;

a scanner aligned to receive the first and second beams of light and operable to scan the first and second beams in respective first and second scan patterns in a field of view;

at least one first detector aligned to receive at least portions of the light at the first wavelength scattered from the first scan pattern;

at least one second detector aligned to receive at least portions of the light at the second wavelength scattered from the second scan pattern; and

an electronic controller operable to receive electrical signals from the at least one first detector and the at least one second detector representative of the intensity of the received scattered light portions.

23. The apparatus for capturing an image of claim 22

wherein the first and second emitters are lasers.

24. The apparatus for capturing an image of claim 22

wherein at least one of the first and second emitters is operable to emit a modulated beam of light.

25. The apparatus for capturing an image of claim 22

wherein the first and second emitters are operable to emit differing wavelengths of light.

26. The apparatus for capturing an image of claim 22

wherein the first and second emitters are separated and the first and second scan patterns are substantially non-overlapping.

27. The apparatus for capturing an image of claim 22

wherein the at least one detector is aligned to receive scattered light off the scanner;

whereby the at least one detector collects descanned light.

28. The apparatus for capturing an image of claim 22

wherein the at least one detector is aligned to receive scattered light from the field of view;

whereby the at least one detector is a staring detector.

29. The apparatus for capturing an image of claim 22

wherein the first and second emitters are operable to emit light at different first and second wavelengths;

wherein the at least one detector includes first and second detectors; and

further comprising;

at least one first filter aligned with the first detector and operative to substantially prevent the second wavelength of light from impinging upon the first detector.

30. The apparatus for capturing an image of claim 29, further comprising:

at least one second filter aligned with the second detector and operative to substantially prevent the first wavelength of light from impinging upon the second detector.

31. The apparatus for capturing an image of claim 22

wherein the electronic controller is further operable to decode the at least one electrical signal representative of the intensity of the received scattered light portions.

32. The apparatus for capturing an image of claim 31

wherein the electronic controller is further operable to transmit an image corresponding to the at least one electrical signal representative of the intensity of the received scattered light portions.

33. The apparatus for capturing an image of claim 31

wherein the electronic controller is further operable to decode a machine readable indicia corresponding to the at least one electrical signal representative of the intensity of the received scattered light portions.

34. The apparatus for capturing an image of claim 31

wherein the machine readable indicia includes a bar code symbol.

35. The apparatus for capturing an image of claim 22

wherein the scanner includes a MEMS scanner.

36. The apparatus for capturing an image of claim 22

wherein the first and second scan patterns are two-dimensional scan patterns.

37. The apparatus for capturing an image of claim 36

wherein the first and second two-dimensional scan patterns are substantially raster scan patterns.

38. The apparatus for capturing an image of claim 37 further comprising:

a correction scanner operable to correct the substantially raster scan patterns to reduce raster pinch.

39. An apparatus for capturing an image, comprising:

a first scanning assembly operable to scan a beam of light at a first wavelength in a first scan pattern in a field of view;

a second scanning assembly operable to scan a beam of light at a second wavelength in a second scan pattern in the field of view;

a detector assembly including first and second detectors aligned to receive light reflected from the field of view, the detector assembly further comprising at least one first filter aligned with the first detector and operative to substantially prevent the second wavelength of light from impinging upon the first detector and operative to convert the received light at the first and second wavelengths into at least one electrical signal corresponding to the received light; and

an electronic controller operable to receive and decode the at least one electrical signal.

40. The apparatus for capturing an image of claim 39

wherein the first and second scanning assemblies each include:

an emitter operable to emit a beam of light, and

a scanning mirror operable to scan the beam of light.

41. The apparatus for capturing an image of claim 39

wherein at least one of the first and second scanning assemblies is operable to emit a modulated beam of light.

42. The apparatus for capturing an image of claim 39

wherein the first and second scanning assemblies are operable to scan beams of differing wavelengths of light.

43. The apparatus for capturing an image of claim 39

wherein the first and second scan patterns are substantially non-overlapping.

44. The apparatus for capturing an image of claim 39

wherein the at least one detector assembly includes two detectors, each aligned to receive scattered light off a respective scanning assembly;

whereby the detectors collect descanned light.

45. The apparatus for capturing an image of claim 39

wherein the at least one detector assembly is aligned to receive scattered light from the field of view;

whereby the at least one detector assembly comprises a staring detector.

46. The apparatus for capturing an image of claim 39 further comprising:

at least one second filter aligned with the second detector and operative to substantially prevent the first wavelength of light from impinging upon the second detector.

47. The apparatus for capturing an image of claim 39

wherein the electronic controller is further operable to transmit an image corresponding to the at least one electrical signal representative of the intensity of the received scattered light portions.

48. The apparatus for capturing an image of claim 47

wherein the electronic controller is further operable to decode a machine readable indicia corresponding to the at least one electrical signal representative of the intensity of the received scattered light portions.

49. The apparatus for capturing an image of claim 48

wherein the machine readable indicia includes a bar code symbol.

50. The apparatus for capturing an image of claim 39

wherein the first and second scanning assemblies each include a MEMS scanner.

51. The apparatus for capturing an image of claim 39

wherein the first and second scan patterns are two-dimensional scan patterns.

52. The apparatus for capturing an image of claim 51

wherein the first and second two-dimensional scan patterns are substantially raster scan patterns.

53. The apparatus for capturing an image of claim 52

wherein the first and second scanning assemblies each include a correction scanner operable to correct the substantially raster scan patterns to reduce raster pinch.