ENDOSCOPE WITH OPTICAL FIBER AND FIBER OPTICS SYSTEM

• US 20080161648A1
• Filed: 01/02/2007
• Published: 07/03/2008
• Est. Priority Date: 01/02/2007
• Status: Active Grant

• Current Assignee: Hoya Corporation, University of Washington
• Original Assignee: Pentax Corporation (Hoya Corporation), University of Washington
• Inventors: KARASAWA, Satoshi
• Granted Patent: US 7,496,259 B2
• Time in Patent Office: Days
• US Class Current: 600/182
• CPC Class Codes: A61B 1/00096 Optical elements
• CPC Class Codes: A61B 1/0017 Details of single optical fibres, e.g. material or cladding
• CPC Class Codes: A61B 1/00172 with means for scanning
• CPC Class Codes: A61B 1/07 using light-conductive means, e.g. optical fibres
• CPC Class Codes: A61B 5/0062 Arrangements for scanning
• CPC Class Codes: Y10S 385/902 Nonbundle fiberscope devices

Abstract

An endoscope has an optical fiber and at least one photo-detector. The optical fiber has a core that transmits illuminating light and at least one cladding that surrounds the core and transmits reflected light. The cladding has a refraction slope surface that is tapered toward a direction opposite the tip portion of the optical fiber. The photo-detector detects the reflected light that exits from the refraction slope surface by refraction.

Claims

1. An endoscope comprising:

an optical fiber having a core that transmits illuminating light and at least one cladding that surrounds the core, the cladding transmitting reflected light;

at least one photo-detector that detects the reflected light,

the cladding comprising a refraction slope surface that is tapered toward a direction of a proximal end of the optical fiber, the photo-detector detecting reflected light that exits from the refraction slope surface; and

an actuator that vibrates a tip portion of the optical fiber so as to scan the illuminating light over an observed portion, the tip portion being defined at a front end of the endoscope, and

the refraction slope surface being formed at a portion of the optical fiber so as to be positioned rearward of the actuator with respect to the front end of the endoscope.

2. The endoscope according to claim 1, further comprising a resin surrounding the refraction slope surface, the resin having a refractive index higher than a refractive index of cladding.

3. The endoscope according to claim 2, wherein the resin comprises polymethyl methacrylate (PMMA).

4. The endoscope according to claim 2, wherein the resin is transparent.

5. The endoscope according to claim 2, wherein the refractive index of the resin is defined such that the reflected light exiting from the refraction slope surface progresses toward the photo-detector.

6. The endoscope according to claim 1, wherein the optical fiber comprises a single-mode optical fiber.

7. The endoscope according to claim 1, wherein the optical fiber comprises a single-cladding optical fiber.

8. The endoscope according to claim 1, wherein the optical fiber comprises a double-cladding optical fiber.

12. The endoscope according to claim 1, wherein the refraction slope surface is formed at a portion of the optical fiber adjacent to a proximal end of the endoscope.

13. The endoscope according to claim 1, wherein the photo-detector comprises a photodiode.

14. The endoscope according to claim 1, wherein the photo-detector is positioned such that a photo-receiving area of the photo-detector faces in a direction along a longitudinal axis of optical fiber.

15. The endoscope according to claim 14, further comprising a glass lens that is positioned in front of the photo-receiving area and refracts the reflected light toward the photo-receiving area.

16. The endoscope according to claim 1, wherein the photo-detector is oriented at an angle relative to a longitudinal axis of

the optical fiber so as to face the refraction slope surface.

17. The endoscope according to claim 1, wherein a plurality of photo-detectors are positioned laterally with respect to the optical fiber.

18. The endoscope according to claim 1, wherein an angle of the refraction slope surface relative to a longitudinal axis of optical fiber is defined such that the reflected light exiting from the refraction slope surface progresses toward the photo-detector.

19. The endoscope according to claim 1, wherein the refraction slope surface is positioned symmetrical with respect to a center axis of the optical fiber.

20. The endoscope according to claim 1, wherein the cladding further comprises an attenuation slope surface opposing the refraction slope surface.

21. The endoscope according to claim 20, further comprising a shield member that covers the attenuation slope surface.

22. The endoscope according to claim 1, wherein

the refraction slope surface comprises a conical surface.

23. The endoscope according to claim 1, wherein the refraction slope surface is formed by etching the cladding.

9. (canceled)

10. The endoscope according to claim 9, wherein the actuator comprises a tubular piezoelectric actuator.

11. (canceled)

24. An endoscope tip portion comprising:

an actuator that vibrates a tip portion of an optical fiber so as to scan illuminating light exiting from the tip portion over an observed portion, the tip portion being defined at a front end of the endoscope, the optical fiber having a core that transmits the illuminating light and at least one cladding that surrounds the core and the cladding transmitting reflected light; and

at least one photo-detector that detects the reflected light,

the cladding comprises a refraction slope surface that is tapered toward a direction of a proximal end of the optical fiber, the photo-detector detecting reflected light that exits from the refraction slope surface, and the refraction slope surface being formed at a portion of the optical fiber so as to be positioned rearward of the actuator with respect to the front end of the endoscope.

25. An endoscope System, comprising:

a light source that emits illuminating light;

an optical fiber having a core that transmits the illuminating light and at least one cladding that surrounds the core, the cladding transmitting reflected light;

at least one photo-detector that detects the reflected light,

wherein the cladding comprises a refraction slope surface that is tapered toward a direction of a proximal end of the optical fiber, the photo-detector detecting reflected light that exits from the refraction slope surface; and

an actuator that vibrates a tip portion of the optical fiber so as to scan the illuminating light over an observed portion, the tip portion being defined at a front end of the endoscope, and

the refraction slope surface being formed at a portion of the optical fiber so as to be positioned rearward of the actuator with respect to the front end of the endoscope.

26-34. -34. (canceled)