EP0084435A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Endoscopes having a focus state detector
Assignee: Olympus Corp
•
Filing: 1983-01-13
•
Granted: —
•
Expires: 2003-01-13
Abstract
Abstract An endoscope provided with a focus state detector, wherein light is projected through a light guide (33) to be reflected from an object and received by a light receiving means (11) provided with an optical aperture (15) or locally non-sensitive part of a small diameter or width to detect focusing. When an object to be recorded by a photo-graphic or television camera is low in contrast, such as an internal organ observed with an observing optical system of an endoscope, the depth of focus may be so shallow that it will be difficult to obtain a clear image of the object by fitting and setting the lens system in a well-focussed state. Therefore, embodiments of the present invention provide means for projecting a focus state detecting light-spot of high intensity onto the object (25) through the light-spot guide (33) from an external light source (32), and the intensity of the reflected light from the object (25) adjusted to give a unique value from the light receiving means, which indicates the correct focus setting with high precision.
Inventors
- 👤 Takeaki C/O Olympus Optical Co. Ltd. Nakamura
- 👤 Yoshio C/O Olympus Optical Co. Ltd. Shishido
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 16:54
CPC Classifications
A; A61; A61B; A61B1/00; A61B1/00163; A61B1/00188; A61B1/04; A61B1/045; G; G02; G02B; G02B23/00; G02B23/24; G02B23/2407; G02B27/00; G02B27/40
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
158 words
An endoscope having a focus state detector, means being provided to transmit illuminating light from a light source to a light-beam transmitting means within an endoscope via a light guide and a light-spot guide to project a light spot on to an object that is to be recorded as an optical image, the image of the illuminated object being passed back to a predetermined image forming surface via an observing optical system in the endoscope and thence through an adjustable lens system whose focusing state is monitored by said detector, which comprises a light receiving means using a photo- electric transducer element to assess whether there is a. clearly focussed image at said image forming surface, the light returning from said projected light-spot being directed to an optical aperture or locally non-sensitive part of said transducer having a shape and size matching that of the reflected light-spot formed in a position optically conjugate with said image forming surface.
Claim 2
Dependent Claim
158 words
An endoscope having a focus state detector, means being provided to transmit illuminating light from a light source to a light-beam transmitting means within an endoscope via a light guide and a light-spot guide to project a light spot on to an object that is to be recorded as an optical image, the image of the illuminated object being passed back to a predetermined image forming surface via an observing optical system in the endoscope and thence through an adjustable lens system whose focusing state is monitored by said detector, which comprises a light receiving means using a photo- electric transducer element to assess whether there is a. clearly focussed image at said image forming surface, the light returning from said projected light-spot being directed to an optical aperture or locally non-sensitive part of said transducer having a shape and size matching that of the reflected light-spot formed in a position optically conjugate with said image forming surface.
Claim 3
Dependent Claim
27 words
An endoscope as claimed in Claim 1, in which the light-emitting end face of said light-spot guide faces an optical aperture formed in the light receiving means.
Claim 4
Dependent Claim
27 words
An endoscope as claimed in Claim 1, in which the light-emitting end face of the light-spot guide faces an optical aperture adjacent to the light receiving means.
Claim 5
Dependent Claim
21 words
An endoscope as claimed'in any preceding Claim, in which the light-spot guide is formed by a branching of the light guide.
Claim 6
Dependent Claim
40 words
An endoscope as claimed in any preceding Claim, in which a light-spot source producing light of a wavelength different to that of the illuminating diagnosis light source is used to project onto the input end face of the light-spot guide.
Claim 7
Dependent Claim
41 words
An endoscope as claimed in any one of Claims 1 to 4, in which light is projected onto respective input end faces of a separate light guide and a light-spot guide by dividing components from a common illuminating diagnosis light source.
Claim 8
Dependent Claim
55 words
An endoscope as claimed in any one of Claims 1 to 4, in which said light-spot guide is formed by part of the light guide, which transmits light selectively to be projected on the spot, using a diaphragm stop arranged between the input end face of the light guide and the illuminating diagnosis light source.
Claim 9
Dependent Claim
21 words
An endoscope as claimed in Claim 5, in which said light-spot source has a light emitting characteristic in an infrared range.
Claim 10
Dependent Claim
25 words
An endoscope as claimed in any preceding Claim, in which said light receiving means is contained in a camera adaptor removably fitted to the endoscope.
Claim 11
Dependent Claim
29 words
An endoscope as claimed in any one of Claims 1 to 8, in which said light receiving means is contained in a camera device removably fitted to the endoscope.
Claim 12
Dependent Claim
29 words
An endoscope as claimed in any one of Claims 1 to 8, in which said light receiving means is contained in a camera device removably fitted to the endoscope.
Claim 13
Dependent Claim
66 words
An endoscope as claimed in any preceding Claim, in which said light-spot is transmitted to be reflected back through a light guide and form an image of said spot on said transducer element through a movable lens system, and a driving means automatically moving and setting said lens system under the control of the output of said transducer element so that a clear image is formed.
Claim 14
Dependent Claim
36 words
An endoscope as claimed in Claim 12, in which said driving means is controlled to move the lens system until the output level of said transducer has a unique value, which may be maximum or minimum.
Claim 15
Dependent Claim
30 words
An endoscope as claimed in Claim 13, in which the instant at which the output level of said transducer is at said unique value is confirmed by an indicating means.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.