Endoscopes

• US 3,901,220 A
• Filed: 06/29/1973
• Issued: 08/26/1975
• Est. Priority Date: 07/24/1972
• Status: Expired due to Term

• Current Assignee: Mituhiro Tokuhara, Takeo Koyasu
• Original Assignee: Mituhiro Tokuhara, Takeo Koyasu
• Inventors: Koyasu, Takeo, Tokuhara, Mituhiro
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Layton, Henry S.
• Application Number:
  US05/375,071
• Time in Patent Office: 788 Days
• Field of Search: 128/4,6,7,8 350/168
• US Class Current: 600/176
• CPC Class Codes: A61B 1/00165 with light-conductive means, e.g. fibre optics A61B1/07 takes precedence
• CPC Class Codes: A61B 1/00177 for 90 degrees side-viewing
• CPC Class Codes: A61B 1/00179 for off-axis viewing

Abstract

An endoscope provided with a color-dispersion prism or diffraction grating incorporated in front of the distal end of a fiberscope bundle within the endoscope protective sheath to perform functions of changing the optical axis for incident light issuing from an object to be examined and simultaneously of color-dispersion of said light, while an image-forming light focused on the distal end of the fiberscope bundle and emerging from the proximal end of the fiberscope bundle is allowed to pass through a color-redintegration optical system, thereby to provide an image of improved quality.

Claims

1. An endoscope for inspecting an object, comprising a protective sheath, a fiberscope bundle for transmitting an optical image accommodated within said protective sheath, said fiberscope bundle having distal and proximal end surfaces, a first optical system located adjacent the distal end surface of said fiberscope bundle so as to introduce light from the object to be inspected from a direction lateral of said protective sheath toward the front end surface of said fiberscope bundle, said optical system being composed of first optical means effective to bend the optical axis of said incident light beam as well as to cause color-dispersion of said incident light beam and second optical means cooperating with said first optical means to form an image of said incident light beam on the distal end surface of said fiberscope bundle, and a second optical system having a substantially linear optical axis and located adjacent to the proximal end surface of said fiberscope bundle for redintegrating the image emitted from the rear end surface of the fiberscope bundle.

2. An endosCope as described in claim 1, wherein the first optical means includes a color dispersion prism arranged to position one of its surfaces other than the light-striking and light-emerging surfaces adjacent the distal end of a bundle for illuminating an object to be examined so that the object is illuminated by reflection from said surface of the prism.

3. An endoscope as described in claim 1, wherein said first optical means includes two or more prismatic wedges.

4. An endoscope as in claim 1, characterized by employing an optical system comprising a plurality of the adjustable lenses with variable focuses serving as the second optical means.

5. An endoscope as in claim 1, wherein said first optical means include reflection grating.

6. An endoscope as described in claim 1, wherein the first optical means includes a color dispersion prism with at least one totally reflecting surface so that while incident rays of light from the object to be examined are dispersed by said prism, the optical axis for the incident light is simultaneously changed thereby.

7. An endoscope as in claim 6, characterized by employing a roof-shaped pentagonal prism to obtain an erect image of the object and serving as a color-dispersing prism.

8. An endoscope for inspecting an object, comprising a protective sheath, a fiberscope bundle having front and rear end surfaces for transmitting an optical image accommodated within said protective sheath, an optical system located adjacent to the front end surface of said fiberscope bundle to introduce light from an object to be inspected transverse to the longitudinal direction of the bundle at the front end toward the front end surface of said fiberscope bundle, said optical system having first optical means for bending the optical axis of the light from the object transversely and for causing color dispersion and second optical means cooperating with said first optical means, for forming an image of said incident light beam on the front end surface of said fiberscope bundle, a recording medium located adjacent to the rear end surface of said fiberscope bundle for recording an emerging image emitted from the rear end surface of the fiberscope bundle, and image forming optical system for forming an image of the light beam emitted from the rear end surface of said fiberscope bundle on said recording medium.

9. An endoscope as in claim 8, wherein said bundle defines a longitudinal direction and wherein said first optical system includes third optical means within the sheath for directing light from a direction transverse to the longitudinal direction of the bundle toward the first optical means.

10. An endoscope as in claim 9, wherein said first optical means receives the light coming from said third optical means and redirects the light toward the longitudinal direction of the bundle.

11. An endoscope for inspecting an object, comprising a bundle of optical fibers defining a longitudinal direction and having a distal end and a proximal end, a sheath surrounding the bundle, first light transmitting means within the sheath beyond the distal end of the bundle for transmitting light from a direction transverse to the longitudinal direction of the bundle into the sheath from the object, light control means in the path of light through said light transmitting means for bending the light transversely into the longitudinal direction of the bundle and simultaneously causing color dispersion of the light onto the distal end of the bundle, said light control means being located within the sheath beyond the distal end of the bundle, and reconstituting means beyond the proximal end of the bundle for reconstituting the image appearing at the proximal end of the bundle.