Scanning beam device with detector assembly

• US 7,189,961 B2
• Filed: 02/23/2005
• Issued: 03/13/2007
• Est. Priority Date: 02/23/2005
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Johnston, Richard S., Melville, Charles D.
• Primary Examiner(s): PYO, KEVIN K
• Application Number:
  US11/065,224
• Publication Number:
  US 20060186325A1
• Time in Patent Office: 748 Days
• Field of Search: 250/234, 250/227.11, 250/239, 250/216, 250/225, 600/473, 600/476, 600/478
• US Class Current: 250/234
• CPC Class Codes: G02B 23/2423 of the distal end
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements

Abstract

The present invention provides scanning beam devices that have one or more detectors positioned within a housing of the device. The detector(s) may be disposed anywhere within the housing to receive light reflected from the target area. In one embodiment, an optical assembly of the device transmits a first portion of the reflected light to a scanning element, and a second portion of the reflected light to the detectors. In another embodiment, the optical assembly is configured to transmit substantially all of the reflected light to the scanning element. In such embodiments, the scanning element will be adapted to allow the light to exit the scanning element and impinge on the detector(s) within the housing.

Claims

1. A scanning beam device comprising:

a drive assembly;

a scanning element coupled to the drive assembly so that the scanning element moves and light emitted from the scanning element scans laterally;

a housing that surrounds the drive assembly and the scanning element;

one or more detectors positioned within the housing and spaced from the scanning element; and

an optical assembly disposed substantially at a distal end of the housing assembly, the optical assembly adapted to direct the light from the scanning element to a target area distal of the optical assembly and adapted to direct at least a portion of light reflected from the target area to the one or more detectors;

wherein the scanning element delivers a linearly polarized light to the target area so that the light reflected from the target area comprises multiple polarization states depending on the nature of the target area,

wherein at least one element of the optical assembly comprises a birefringent material that directs light reflected from the target area that is of a first polarization to the scanning element and light reflected from the target area that is of a second polarization to the one or more detectors.

2. The device of claim 1 wherein the housing comprises a substantially tubular body and at least one detector is coupled to the substantially tubular housing.

3. The device of claim 1 wherein the one or more detectors are positioned within the housing and coupled to the optical assembly.

4. The device of claim 1 wherein the one or more detectors are positioned around the drive assembly.

5. The device of claim 1 wherein the one or more detectors are embedded into a portion of the optical assembly.

6. The device of claim 1 wherein the optical assembly comprises a first portion that is adapted to direct a first portion of the light reflected from target area to the scanning element, and a second portion that is configured to direct a second portion of the light reflected from the target area to the one or more detectors.

7. The device of claim 6 wherein the second portion of the optical assembly is adapted to scatter light within the housing or focus light away from the scanning element.

8. The device of claim 6 wherein the first portion of the optical assembly is a central area of the optical assembly around a longitudinal axis of the optical assembly and the second portion of the optical assembly is an annular area that surrounds at least a portion of the central area.

9. The device of claim 8 wherein the second portion of the optical assembly comprises an annular region of a distal most lens in the optical assembly.

10. The device of claim 6 wherein the second portion of the optical assembly is frosted so as to cause the light reflected from the target area to scatter within the housing.

11. The device of claim 6 wherein a shape of the second portion of the optical assembly is modified relative to the shape of the first portion of the optical assembly.

12. The device of claim 1 wherein the optical assembly comprises at least one diffractive element, wherein the at least one diffractive element directs at least a portion of light reflected from the target area to the one or more detectors.

13. The device of claim 1 wherein the scanning element comprises an optical fiber that comprises a core disposed within cladding.

14. The device of claim 1 wherein the device is an endoscope.

15. A method of scanning a target area, the method comprising:

positioning a scanning beam device adjacent the target area, the scanning beam device comprising a housing that houses an optical assembly, a scanning element, and one or more detectors;

delivering light from the scanning element through the optical assembly and onto the target area;

moving the scanning element within the housing so as to scan the light laterally across the target area; and

receiving light reflected from the target area back into the optical assembly,

wherein the optical assembly delivers a first portion of the light reflected from the target area onto the scanning element and focuses a second portion of the light reflected onto the one or more detectors in the housing of the scanning beam device or scatters the second portion of the light reflected from the target area within the housing of the scanning beam device so that the second portion of the light reflected from the target area impinges on the one or more detectors in the housing of the scanning beam device;

wherein delivering light comprises delivering linearly polarized light from the scanning element through the optical assembly,

wherein the optical assembly comprises a birefringent material so that the first portion of the reflected light has the same polarization as the light delivered from the scanning element and the second portion of the reflected light has a perpendicular polarization to the first portion of the reflected light.

16. The method of claim 15 wherein delivering the first portion of the reflected light is carried out by delivering the first portion of the light reflected from the target area through a first portion of the optical assembly, and focusing/scattering the second portion of the light reflected from the target area is carried out by delivering the light reflected from the target area through a second portion of the optical assembly.

17. The method of claim 16 wherein the second portion of the optical assembly comprises a frosted surface or surface shape that differs from the first portion of the optical assembly.

18. The method of claim 16 wherein focusing/scattering is carried out by one or more diffractive elements in the second portion of the optical assembly.

19. The method of claim 16 comprising embedding one or more detectors into the second portion of the optical assembly.

20. The method of claim 15 wherein the scanning element comprises an optical fiber that comprises a core disposed within cladding.

21. The method of claim 15 wherein the scanning beam device is an endoscope.

22. A scanning beam device comprising:

an optical fiber comprising a core and cladding;

a drive assembly coupled to the optical fiber;

a housing that surrounds the drive assembly and the optical fiber;

one or more detectors positioned within the housing and spaced from the optical fiber to detect light that is allowed to leave the core and cladding of the optical fiber; and

an optical assembly disposed substantially at a distal end of the housing assembly, the optical assembly configured to direct light reflected from the target area to the core of the optical fiber.

23. The device of claim 22 wherein the one or more detectors are positioned within the housing proximal to the optical assembly.

24. The device of claim 22 wherein at least a portion of the optical fiber is etched to allow light to exit the cladding.

25. The device of claim 24 wherein the optical fiber comprises a sloped transition region between an etched portion of the optical fiber and an un-etched portion of the optical fiber.

26. The device of claim 25 wherein a slope of the transition region is angled relative to a longitudinal axis of the optical fiber.

27. The device of claim 22 wherein the device is an endoscope.

28. A method of scanning a target area, the method comprising:

positioning a scanning beam device adjacent the target area, the scanning beam device comprising a housing that houses an optical assembly, an optical fiber comprising a core and cladding, and one or more detectors;

delivering light from a distal end of the optical fiber through the optical assembly and over a target area; and

receiving light reflected from the target area back into the optical assembly, wherein the optical assembly focuses substantially all of the light reflected from the target area into the core of the optical fiber,

allowing the reflected light to exit the cladding and core of the optical fiber so that it can be detected by the one or more detectors in the housing.

29. The method of claim 28 wherein the optical fiber is etched to allow light to exit the cladding.

30. The method of claim 29 wherein the etched optical fiber comprises a sloped transition region between an etched portion of the optical fiber and an un-etched portion of the optical fiber.

31. The method of claim 30 wherein a slope of the transition region is angled relative to a longitudinal axis of the optical fiber.

32. The method of claim 28 wherein the scanning beam device is an endoscope.