US3783270A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Focus indicating devices
Assignee: Olympus Corp
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Filing: 1972-05-17
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Granted: 1974-01-01
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Expires: 1992-05-17
Abstract
Abstract Focus indicating device for use in optical measuring devices comprises a light source, a condenser lens, a grating provided at its periphery with equidistant and parallel lines and adapted to be moved, an objective lens, an object to be measured and a photoelectric converter element. The grating is located in front of the photoelectric converter element and the light rays emanated from the light source after passing the objective lens, the object to be measured and the grating are impinged on the photoelectric converter element. The grating is moved such that the light rays are traversed by the lines of the grating to generate from the photoelectric converter element a signal for indicating the focal condition of the objective lens.
Inventors
- 👤 S Kamachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:45
CPC Classifications
G; G01; G01D; G01D5/00; G01D5/26; G01D5/32; G01D5/34; G01D5/36; G01D5/38; G02; G02B; G02B27/00; G02B27/40
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
191 words
A device for indicating the focus of an objective lens of a microscope while observing the image of an object to be tested through the objective lens, which comprises a microscope including an eyepiece, an objective lens and an object to be tested; and an optical system constituting a part of said microscope and including a light source, a condenser lens, a grating having upper and lower half portions provided with equidistant and parallel opaque lines and a photoelectric converter element, said grating being rotated at a speed faster than the residual image effect of eyes, whereby the light rays emanated from said light source and passed through said condenser lens is impinged on the upper half portion of said grating whose image produced on the object to be tested is impinged on the lower half portion of said grating to form a Moire pattern thereon and the correct focus position of said objective lens is indicated by the output signal of said photoelectric converter element when the contrast of said Moire pattern becomes maximum without preventing the observation of the surface of the object to be tested by said microscope.
Claim 2
Independent Claim
191 words
A device for indicating the focus of an objective lens of a microscope while observing the image of an object to be tested through the objective lens, which comprises a microscope including an eyepiece, an objective lens and an object to be tested; and an optical system constituting a part of said microscope and including a light source, a condenser lens, a grating having upper and lower half portions provided with equidistant and parallel opaque lines and a photoelectric converter element, said grating being rotated at a speed faster than the residual image effect of eyes, whereby the light rays emanated from said light source and passed through said condenser lens is impinged on the upper half portion of said grating whose image produced on the object to be tested is impinged on the lower half portion of said grating to form a Moire pattern thereon and the correct focus position of said objective lens is indicated by the output signal of said photoelectric converter element when the contrast of said Moire pattern becomes maximum without preventing the observation of the surface of the object to be tested by said microscope.
Claim 3
Dependent Claim
58 words
A focus indicating device as claimed in claim 1 wherein said grating consists of a first movable grating and a second fixed grating and the light rays emanated from said light source after passing through said first movable grating are reflected by the surface of said object and impinged through said second grating on said photoelectric converter element.
Claim 4
Dependent Claim
102 words
A focus indicating device as claimed in claim 2 wherein said second grating is provided at its front side with a glass plate adapted to elongate said light ray path and provided at its rear side with two photoelectric converter elements, said light ray path being passed through said second grating to one of said two photoelectriC converter elements and passed through said glass plate and said second grating to another photoelectric converter element, the outputs from said two photoelectric converter elements being supplied to a signal treating circuit whose output is supplied to a servomechanism adapted to control said objective lens.
Claim 5
Dependent Claim
79 words
A focus indicating device as claimed in claim 2 wherein said second grating is divided into two grating portions each of which is provided at its rear side with a photoelectric converter element, said light ray path being passed through said two second grating portions to said two photoelectric converter elements, the outputs from said two photoelectric converter elements being supplied to a signal treating circuit whose output is supplied to a servomechanism adapted to control said objective lens.
References Cited (Backward Citations)
US2254548A
Cited
US2818775A
Cited
US3175093A
Cited
US3520625A
Cited
US3454772A
Cited
US3542475A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |