Light source device and endoscope apparatus comprising the same

Patent metadata

Field	Value
Publication number	US-9303830-B2
Application number	US-201414293551-A
Country	US
Kind code	B2
Filing date	Jun 2, 2014
Priority date	Dec 26, 2007
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A light source device includes a first semiconductor light source, a second semiconductor light source, and a wavelength converter. The first semiconductor light source emits light in a first wavelength range. The second semiconductor light source emits light in a second wavelength range different from the first wavelength range. The wavelength converter absorbs the light in the first wavelength range to emit light in a third wavelength range different from either of the first wavelength range and the second wavelength range, and transmits the light in the second wavelength range substantially entirely.

First claim

What is claimed is:

1. An endoscope apparatus comprising:
a first light source configured to emit a first light having a first wavelength range;
a second light source configured to emit a second light having a second wavelength range;
an optical fiber arranged in an inserting portion, wherein the optical fiber is configured to guide the first light emitted by the first light source and the second light emitted by the second light source; and
a first phosphor arranged on an inserting end of the inserting portion,
wherein the first phosphor is configured to receive the first light guided by the optical fiber and the second light guided by the optical fiber,
wherein, based on wavelength conversion and transmission characteristics of the first phosphor, the first phosphor is configured to:
wavelength convert at least a part of the first light having the first wavelength range into a third light in a third wavelength range, the third wavelength range including a longer wavelength than wavelengths in the first wavelength range;
transmit at least another part of the first light having the first wavelength range; and
emit the third light in the third wavelength range and the transmitted at least another part of the first light together as a mixed light; and

wherein, based on the wavelength conversion and transmission characteristics of the first phosphor, the first phosphor is further configured to transmit at least a part of the second light having the second wavelength range.

2. The endoscope apparatus according to claim 1 , further comprising a second phosphor having substantially the same wavelength conversion and transmission characteristics as the first phosphor, wherein the first phosphor and the second phosphor are arranged on the inserting end of the inserting portion.

3. The endoscope apparatus according to claim 2 , further comprising a photocoupler configured to optically couple the first light having the first wavelength range emitted by the first light source and the second light having the second wavelength range emitted by the second light source to cause the optically coupled first light and second light to enter the optical fiber.

4. The endoscope apparatus according to claim 3 , wherein the photocoupler comprises:
a first incident end optically connected to the first light source;
a second incident end optically connected to the second light source;
a first exit end optically connected to the first phosphor; and
a second exit end optically connected to the second phosphor,
wherein the photocoupler is configured to distribute the first light having the first wavelength range entering the first incident end of the photocoupler to the first exit end and the second exit end of the photocoupler with substantially equal light intensity proportions, and
wherein the photocoupler is configured to distribute the second light having the second wavelength range entering the second incident end of the photocoupler to the first exit end and the second exit end of the photocoupler with substantially equal light intensity proportions.

5. The endoscope apparatus according to claim 3 , comprising:
two of the first light source;
two of the second light source;
two of the photocoupler; and
two of the optical fiber,
wherein one of the first light sources, one of the second light sources, one of the photocouplers, and one of the optical fibers are optically connected to the first phosphor, and
wherein the other of the first light sources, the other of the second light sources, the other of the photocouplers, and the other of the optical fibers are optically connected to the second phosphor.

6. The endoscope apparatus according to claim 2 , further comprising an image sensor arranged on the inserting end of the inserting portion between the first phosphor and the second phosphor.

7. The endoscope apparatus according to claim 6 , further comprising heat-insulating material arranged between the first phosphor and the image sensor and between the second phosphor and the image sensor, wherein the heat-insulating material is configured to insulate the image sensor from heat generated by the first phosphor and the second phosphor.

8. The endoscope apparatus according to claim 1 , further comprising:
a first light source driving circuit configured to drive the first light source to switch between emitting the first light and not emitting the first light; and
a second light source driving circuit configured to drive the second light source to switch between emitting the second light and not emitting the second light.

9. The endoscope apparatus according to claim 1 ,
wherein the first wavelength range is a blue color wavelength range that is approximately 430 nm to 480 nm,
wherein the second wavelength range is a violet color wavelength range that is approximately 430 nm or less, and
wherein the third wavelength range is broader than the first wavelength range, the third wavelength range is broader than the second wavelength range, and the third wavelength range includes light in a yellow color wavelength range including a wavelength of 530 nm.

10. The endoscope apparatus according to claim 9 ,
wherein the first phosphor is a cerium-activated phosphor, and
wherein the first wavelength range is within an absorption range of an absorption spectrum of the cerium-activated phosphor.

11. The endoscope apparatus according to claim 9 ,
wherein the first phosphor is a garnet-based phosphor, and
wherein the first wavelength range is within an absorption range of an absorption spectrum of the garnet-based phosphor.

12. The endoscope apparatus according to claim 11 ,
wherein the garnet-based phosphor is a phosphor of cerium-activated yttrium-aluminum-garnet, and
wherein the second wavelength range is at least one of approximately 430 nm or less and approximately 480 nm or more.

13. The endoscope apparatus according to claim 12 ,
wherein the wavelength conversion and transmission characteristics of the first phosphor are selected such that the phosphor emits:
a first illumination light comprising the mixed light, wherein the illumination light is a white light; and
a second illumination light comprising the transmitted at least a part of the second light, and

wherein the endoscope apparatus further comprises a driving circuit configured to drive the first light source and the second light source independently such that the first phosphor emits the first illumination light for performing ordinary observation and the second illumination light for performing special light observation independently.

14. The endoscope apparatus according to claim 13 , wherein the second wavelength range of the second light emitted by the second light source and the wavelength conversion and transmission characteristics of the first phosphor are selected such that the second illumination light has a wavelength range within an absorption range of hemoglobin.

15. The endoscope apparatus according to claim 1 , wherein a wavelength corresponding to a peak intensity of the second light is shorter than a wavelength corresponding to a peak intensity of the first light.

16. The endoscope apparatus according to claim 1 ,
wherein the first light source comprises a first semiconductor laser, and
wherein the second light source comprises a second semiconductor laser.

17. The endoscope apparatus according to claim 1 , wherein the wavelength conversion and transmission characteristics of the first phosphor are selected such that:
an absorption range of the first phosphor is defined a

Assignees

• Olympus Corp

Inventors

• Ito Takeshi

Classifications

• H01S5/4087

  emitting more than one wavelength · CPC title

• F21V9/08

  for producing coloured light, e.g. monochromatic; for reducing intensity of light (with provision for controlling the colour F21V9/40) · CPC title

• A61B1/0676

  at distal tip of an endoscope · CPC title

• G02B6/001

  the light being emitted along at least a portion of the lateral surface of the fibre · CPC title

• H01S5/4025

  Array arrangements, e.g. constituted by discrete laser diodes or laser bar (H01S5/42 takes precedence) · CPC title