To measure a distance from an endoscope tip to an observation part in non-contact and without using a forceps channel by detecting measurement light and reference light made to interfere in an interference optical system and computing the distance from the tip of an introduction tube to the part based on the output.
This endoscope is provided with an illumination light source 10, a condensing lens 11 and a light guide 12 composed of an optical fiber. The light guide 12 is housed inside the introduction tube 14 to be introduced inside a living body 13 and the tip part of a polarization plane maintaining fiber 15 is housed inside the introduction tube 14. The rear end of the polarization plane maintaining fiber 15 is put out of the introduction tube 14 and a measurement light irradiation system for making the measurement light L2 be incident from the rear end to the inside of the polarization plane maintaining fiber 15 is provided on the outside of the introduction tube 14. The interference optical system 100 for making the measurement light L2 and the reference light L3 interfere is disposed at the outside of the introduction tube 14. Also, a photodetector 43 for detecting the intensity of the measurement light L2 and the reference light L3 synthesized by a beam splitter 41 is provided and connected to an arithmetic circuit 44.
TOIDA MASAHIRO
MIYAGAWA ICHIRO
| JPH04135550A | 1992-05-11 | |||
| JPH04265834A | 1992-09-22 | |||
| JPS6249208A | 1987-03-03 | |||
| JPS5789842A | 1982-06-04 | |||
| JPH0370108U | 1991-07-12 | |||
| JPH06511312A | 1994-12-15 | |||
| JPS6120488Y2 | 1986-06-20 |
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