Light source device, imaging apparatus and endoscope apparatus

• US 8,790,253 B2
• Filed: 06/13/2009
• Issued: 07/29/2014
• Est. Priority Date: 06/13/2008
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: Sunagawa, Hiroshi, Mizuyoshi, Akira
• Primary Examiner(s): Leubecker, John P
• Assistant Examiner(s): Torres Diaz, Arnaldo
• Application Number:
  US12/484,198
• Publication Number:
  US 20090312607A1
• Time in Patent Office: 1,872 Days
• Field of Search: 600/178, 600/179, 600/181, 600/182, 362/84, 362/574
• US Class Current: 600/180
• CPC Class Codes: A61B 1/05 characterised by the image sensor, e.g. camera, being in the distal end portion
• CPC Class Codes: A61B 1/063 for monochromatic or narrow-band illumination
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/0653 with wavelength conversion
• CPC Class Codes: A61B 1/0655 Control therefor
• CPC Class Codes: A61B 1/0661 Endoscope light sources
• CPC Class Codes: A61B 1/07 using light-conductive means, e.g. optical fibres
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0086 using infrared radiation

Abstract

A light source device includes a first light source, a second light source having an emission wavelength that is different from the first light source, and a phosphor that is disposed to be distant from the first light source and the second light source and absorbs light in a predetermined excitation wavelength band to emit fluorescence. The phosphor is disposed on an emission light optical path that is shared by the first light source and the second light source. The emission wavelength of the first light source is in the predetermined excitation wavelength band. The emission wavelength of the second light source is outside of the predetermined excitation wavelength band.

Claims

1. An imaging apparatus, comprising:

a light source device;

an imaging device including an imaging element that detects light from a light irradiation area to which the light source device irradiates light, so as to produce an image signal;

a first light source;

a second light source having emission wavelengths that are different from an emission wavelength of the first light source, wherein the second light source includes a plurality of light sources that have the emission wavelengths different from each other;

a phosphor that is disposed to be distant from the first light source and the second light source and absorbs light in a predetermined excitation wavelength band to emit fluorescence;

a control section that controls the first light source and the second light source,

wherein the phosphor is disposed on an emission light optical path that is shared by the first light source and the second light source,

wherein the emission wavelength of the first light source is in the predetermined excitation wavelength band,

wherein the emission wavelengths of the second light source are outside of the predetermined excitation wavelength band,

wherein the control section switches between an emission of the first light source and an emission of the second light source, in every imaging frame of the imaging device,

wherein light emitted from the second light source includes blue light, and

wherein the emission light optical path shared by the first light source and the second light source comprises a single-core optical fiber;

a dichroic prism for coupling light emitted from the first light source and the light emitted from the second light source into the single-core optical fiber;

a converging lens for converging the light emitted from the first light source and the light emitted from the second light source, which are coupled on a same optical axis by the dichroic prism, into one end of the single-core optical fiber; and

an illumination optical member located on another end of the single-core optical fiber for holding the phosphor.

2. The imaging apparatus according to claim 1, wherein the single-core optical fiber that is provided between (i) the first light source and the second light source and (ii) the phosphor.

3. The imaging apparatus according to claim 2, wherein light obtained by coupling light emitted from the first light source and the light emitted from the second light source is introduced into the optical fiber.

4. The imaging apparatus according to claim 1, wherein white light is produced by the fluorescence, which the phosphor emits in a response to light emitted from the first light source.

5. The imaging apparatus according to claim 1, wherein the first light source includes a blue laser light source that emits a blue laser beam.

6. The imaging apparatus according to claim 1, wherein the second light source includes a laser light source that emits a laser beam.

7. The imaging apparatus according to claim 1, further comprising:

an excitation light cut filter that is disposed in front of the phosphor on an optical path, the excitation light cut filter that absorbs excitation light from the first light source.

8. The imaging apparatus according to claim 1, wherein the excitation wavelength band is defined as that if light having a wavelength in the excitation wavelength band is irradiated onto the phosphor, the irradiated light substantially excites the phosphor.

9. The imaging apparatus according to claim 8, wherein the excitation wavelength band is a full width at half maximum of a light emission efficiency of the phosphor.

10. The imaging apparatus according to claim 1, wherein light emitted from the first light source has a wavelength that is shorter than a short-wavelength-side detection limit of a spectral sensitivity characteristic of the imaging element.

11. An endoscope apparatus comprising:

the imaging apparatus according to claim 1; and

an endoscope insertion portion that emits, from a front end thereof, at least one of illumination light from the first light source and illumination light from the second light source.

12. The endoscope apparatus according to claim 11, wherein the light emitted from the second light source further includes green light.

13. The endoscope apparatus according to claim 11, wherein the light emitted from the second light source further comprises at least one of red light and infrared light.