Light source device for endoscope using DMD

• US 6,464,633 B1
• Filed: 08/17/2000
• Issued: 10/15/2002
• Est. Priority Date: 08/23/1999
• Status: Expired due to Term

• Current Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Original Assignee: Olympus Optical Company Ltd. (Olympus Corporation)
• Inventors: Hosoda, Seiichi, Yamaki, Masahide, Koshikawa, Yutaka
• Primary Examiner(s): MULCAHY, JOHN M
• Application Number:
  US09/641,058
• Time in Patent Office: 789 Days
• Field of Search: 600/160, 600/178, 600/180, 600/181, 362/574, 348/68-70
• US Class Current: 600/178
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/0646 with illumination filters
• CPC Class Codes: A61B 1/0655 Control therefor
• CPC Class Codes: A61B 1/0669 at proximal end of an endoscope
• CPC Class Codes: A61B 1/2736 Gastroscopes
• CPC Class Codes: G02B 23/2461 Illumination
• CPC Class Codes: G02B 23/2469 using optical fibres
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes
• CPC Class Codes: H04N 23/56 provided with illuminating means

Abstract

A larger number of micromirrors arranged on an illumination optical path of a lamp in a light source device for supplying an illumination light to an endoscope and by using a silicon chip as a base are arranged the micromirrors in a two-dimensional are set at two angles. When the micromirrors are set at one of the two angles, a reflected light is supplied to the light guide. When the micromirrors are set at the other angle, the micromirrors are driven such that the reflected light is not supplied to the light guide. An intensity of illumination light supplied to the light guide or the like is adjusted at a high speed by using a brightness level by selected the micromirrors at the two angles respectively, so that an endoscope image which can be easily observed is obtained.

Claims

1. A light source device used in an endoscope device comprising:

a light source lamp, arranged at a predetermined position in the light source device, for generating light supplied to an endoscope;

a mirror device which uses a silicone chip as a base, which is arranged on an optical path of the light in the light source device, and which has reflective surfaces formed by a plurality of micromirrors for receiving the light,

the micromirrors being movable in a predetermined angular range;

a receptacle to which a light guide for transmitting the light to an object to be photographed is connected, and which has a face on a proximal side of the light guide arranged at a predetermined position in the light source device;

an optical system which is arranged on an optical path of reflected light from the micromirrors from the light generated by the light source lamp when the angles of the micromirrors are at a predetermined position, and which directs the reflected light to the end on the proximal side of the light guide,

the optical system forming an optical positional relationship between the micromirrors and the face on the proximal side of the light guide;

a light adjustment circuit for outputting an adjustment signal for adjusting the light incident on the optical system;

a mirror device drive circuit for outputting a drive signal for setting each of the micromirrors formed in the mirror device at a position on the basis of the adjustment signal output from the light adjustment circuit,

the mirror device drive circuit operating the plurality of micromirrors at an angle at which at least some reflected light by the micromirrors from the light generated by the light source lamp is incident on the optical system and an angle at which the reflected light is not incident on the optical system.

2. A light source device according to claim 1, wherein in the mirror device, the micromirrors are two-dimensionally arranged in an arrangement state in which reflected light reflected by one of the micromirrors is incident on the light guide connected to the connector support through the optical system when the micromirror is set at an angle at which the micromirror directs reflected light in a first direction, and reflected light reflected by the micromirror is not incident on the optical system and is not incident on the light guide connected to the connector support when the micromirror is set at an angle at which the micromirror directs reflected light in a second direction different from the first direction.

3. A light source device according to claim 1, wherein a light distribution of light from the distal end of the light guide can be adjusted by the light adjustment circuit.

4. A light source device according to claim 1, wherein the optical system is a condensation optical system, and the condensation optical system condenses the light reflected by the mirror device on the face of the proximal side of the light guide arranged at an almost pupil position with respect to the micromirrors.

5. A light source device according to claim 1, wherein the optical system uniformly distributes light incident on the mirror device.

6. A light source device according to claim 1, wherein the optical system guides light reflected by the mirror device to the face of the proximal side of the light guide arranged at an almost image forming position with respect to the micromirrors.

7. A light source device according to claim 6, further comprising a video processing device for generating a video signal responsive to an image pickup element arranged in the endoscope, the video processing device having a decision circuit for deciding whether the luminance level of the video signal departs from a reference range.

8. A light source device according to claim 7, wherein the mirror device drives the mirror device such that an intensity of light irradiated on a part of the object corresponding to a video signal portion which is determined by the decision circuit when a portion which departs from the reference range.