US4009940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for producing optical interference pattern with continuously variable fringe spacing
Assignee: Takata Ophthalmic Instruments Co Ltd
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Filing: 1975-04-22
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Granted: 1977-03-01
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Expires: 1995-04-22
Abstract
Abstract First and second triangular prisms are bonded together at their bases with a semi-transparent reflecting material therebetween. A light beam from a laser is incident on the upstream face of the first prism and refracted thereby so as to be incident on the semi-transparent reflecting material at a predetermined angle to the longitudinal axis thereof. One component of the beam is reflected from the semi-transparent material and refracted by the first prism so as to emerge therefrom parallel to the axis of the semi-transparent material. Another component of the beam passes through the semi-transparent material and is refracted by the second prism so as to emerge therefrom parallel to the axis of the semi-transparent material. A lens converges the two beam components to produce an interference pattern. Linear movement of the laser or a plane reflector disposed between the laser and the first prism varies the point of incidence of the beam on the upstream face of the first prism and thereby the spacing between the first and second beam components emerging from the first and second prisms and the fringe spacing of the interference pattern.
Inventors
- 👤 Hitoshi Ohzu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:19
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/10; G02B27/14; G02B27/144; A; A61; A61B; A61B3/00; A61B3/10; A61B3/12; A61B3/1225; G01; G01B; G01B9/00; G01B9/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
228 words
Apparatus for producing an interference pattern of continuously variable fringe spacing, comprising: a coherent light beam source; a plane semi-transparent reflecting means; first and second prisms, the bases of the first and second prisms being parallel to the semi-transparent reflecting means and disposed closely adjacent to the opposite sides thereof, the beam source being arranged to radiate a coherent light beam onto the first prism at an angle so that the coherent light beam is refracted by the first prism so as to be incident on the semi-transparent reflecting means at a predetermined angle and split by the semi-transparent reflecting means into first and second beam components, the first beam component being reflected by the semi-transparent reflecting means and refracted by the first prism into a first beam path parallel to the semi-transparent reflecting means, the second beam component passing through the semi-transparent reflecting means and being refracted by the second prism into a second beam path parallel to the first beam path; and beam converging means to converge the first and second beam components to overlap and produce an interference pattern, the beam source being operative to displace the coherent light beam relative to the semi-transparent reflecting means in such a manner that the spacing between the first and second beam paths of the first and second beam components and thereby the fringe spacing are continuously variable.
Claim 2
Dependent Claim
228 words
Apparatus for producing an interference pattern of continuously variable fringe spacing, comprising: a coherent light beam source; a plane semi-transparent reflecting means; first and second prisms, the bases of the first and second prisms being parallel to the semi-transparent reflecting means and disposed closely adjacent to the opposite sides thereof, the beam source being arranged to radiate a coherent light beam onto the first prism at an angle so that the coherent light beam is refracted by the first prism so as to be incident on the semi-transparent reflecting means at a predetermined angle and split by the semi-transparent reflecting means into first and second beam components, the first beam component being reflected by the semi-transparent reflecting means and refracted by the first prism into a first beam path parallel to the semi-transparent reflecting means, the second beam component passing through the semi-transparent reflecting means and being refracted by the second prism into a second beam path parallel to the first beam path; and beam converging means to converge the first and second beam components to overlap and produce an interference pattern, the beam source being operative to displace the coherent light beam relative to the semi-transparent reflecting means in such a manner that the spacing between the first and second beam paths of the first and second beam components and thereby the fringe spacing are continuously variable.
Claim 3
Dependent Claim
15 words
The apparatus according to claim 1, in which the beam converging means comprises a lens.
Claim 4
Dependent Claim
16 words
The apparatus according to claim 1, in which the coherent light beam source comprises a laser.
Claim 5
Dependent Claim
26 words
The apparatus according to claim 1, further comprising an objective lens arranged downstream of the beam converging means to form an image of the interference pattern.
Claim 6
Dependent Claim
53 words
The apparatus according to claim 1, in which the beam source is arranged to radiate the coherent light beam perpendicular to the semi-transparent reflecting means, the apparatus further comprising a plane reflector movable along the axis of the beam source to reflect the coherent light beam onto the first prism at said angle.
Claim 7
Dependent Claim
32 words
The apparatus according to claim 1, in which the downstream faces of the first and second prisms are orientated at an equal angle to the opposite sides of the semi-transparent reflecting means.
Claim 8
Dependent Claim
19 words
The apparatus according to claim 6, in which the first and second prisms have the same index of refraction.
Claim 9
Dependent Claim
23 words
The apparatus according to claim 1, in which the transmittance and reflectance of the semi-transparent reflecting means are equal at said predetermined angle.
Claim 10
Dependent Claim
19 words
The apparatus according to claim 1, in which the first prism has a triangular cross-section with equal face angles.
Claim 11
Dependent Claim
17 words
The apparatus according to claim 1, in which the first prism has a truncated triangular cross section.
Claim 12
Dependent Claim
15 words
The apparatus according to claim 1, in which the first and second prisms are identical.
Claim 13
Dependent Claim
171 words
Apparatus for producing an interference pattern of continuously variable fringe spacing, comprising: a coherent light beam source; a plane beam splitter, the beam source being arranged to radiate a coherent light beam onto the beam splitter at a predetermined angle thereto, the beam splitter splitting the beam into first and second beam components; first and second beam deflecting means, the first and second beam components from the splitter being incident on the first and second beam deflecting means respectively, the first and second beam deflecting means deflecting the first and second beam components into first and second beam paths respectively parallel to the beam splitter; beam converging means to converge the first and second beam components deflected by the first and second beam deflecting means respectively to overlap and produce an interference pattern; the beam source being fixed parallel to the beam splitter, the apparatus further comprising third beam deflecting means movable along the axis of the beam source to deflect the beam onto the beam splitter at the predetermined angle.
Claim 14
Dependent Claim
171 words
Apparatus for producing an interference pattern of continuously variable fringe spacing, comprising: a coherent light beam source; a plane beam splitter, the beam source being arranged to radiate a coherent light beam onto the beam splitter at a predetermined angle thereto, the beam splitter splitting the beam into first and second beam components; first and second beam deflecting means, the first and second beam components from the splitter being incident on the first and second beam deflecting means respectively, the first and second beam deflecting means deflecting the first and second beam components into first and second beam paths respectively parallel to the beam splitter; beam converging means to converge the first and second beam components deflected by the first and second beam deflecting means respectively to overlap and produce an interference pattern; the beam source being fixed parallel to the beam splitter, the apparatus further comprising third beam deflecting means movable along the axis of the beam source to deflect the beam onto the beam splitter at the predetermined angle.
Claim 15
Dependent Claim
172 words
Apparatus for producing an interference pattern of continuously variable fringe spacing, comprising: a coherent light beam source; a plane beam splitter, the beam source being arranged to radiate a coherent light beam onto the beam splitter at a predetermined angle thereto, the beam splitter splitting the beam into first and second beam components; first and second beam deflecting means, the first and second beam components from the beam splitter being incident on the first and second beam deflecting means respectively, the first and second beam deflecting means deflecting the first and second beam components into first and second beam paths respectively parallel to the beam splitter; beam converging means to converge the first and second beam components deflected by the first and second beam deflecting means respectively to overlap and produce an interference pattern; the beam source being fixed perpendicular to the beam splitter, the apparatus further comprising third beam deflecting means movable along the axis of the beam source to deflect the beam onto the beam splitter at the predetermined angle.
Claim 16
Dependent Claim
172 words
Apparatus for producing an interference pattern of continuously variable fringe spacing, comprising: a coherent light beam source; a plane beam splitter, the beam source being arranged to radiate a coherent light beam onto the beam splitter at a predetermined angle thereto, the beam splitter splitting the beam into first and second beam components; first and second beam deflecting means, the first and second beam components from the beam splitter being incident on the first and second beam deflecting means respectively, the first and second beam deflecting means deflecting the first and second beam components into first and second beam paths respectively parallel to the beam splitter; beam converging means to converge the first and second beam components deflected by the first and second beam deflecting means respectively to overlap and produce an interference pattern; the beam source being fixed perpendicular to the beam splitter, the apparatus further comprising third beam deflecting means movable along the axis of the beam source to deflect the beam onto the beam splitter at the predetermined angle.
Claim 17
Dependent Claim
186 words
Apparatus for producing an interference pattern of continuously variable fringe spacing, comprising: a coherent light beam source; a plane semi-transparent mirror; first and second plane mirrors arranged at an equal angle to the opposite faces of the semi-transparent mirror, the beam source being arranged to radiate a coherent light beam onto the semi-transparent mirror at a predetermined angle thereto, the semi-transparent mirror splitting the beam into first and second beam components, the first beam component being reflected by the semi-transparent mirror onto the first plane mirror and the second beam component passing through the semi-transparent mirror onto the second plane mirror, the first and second beam component being reflected by the first and second plane mirrors respectively parallel to the semi-transparent mirror; and beam converging means to converge the first and second beam components to overlap and produce an interference pattern, the beam source being operative to displace the coherent light beam relative to the semi-transparent mirror in such a manner that the spacing between the first and second beam paths of the first and second beam components and thereby the fringe spacing are continuously variable.
Claim 18
Dependent Claim
186 words
Apparatus for producing an interference pattern of continuously variable fringe spacing, comprising: a coherent light beam source; a plane semi-transparent mirror; first and second plane mirrors arranged at an equal angle to the opposite faces of the semi-transparent mirror, the beam source being arranged to radiate a coherent light beam onto the semi-transparent mirror at a predetermined angle thereto, the semi-transparent mirror splitting the beam into first and second beam components, the first beam component being reflected by the semi-transparent mirror onto the first plane mirror and the second beam component passing through the semi-transparent mirror onto the second plane mirror, the first and second beam component being reflected by the first and second plane mirrors respectively parallel to the semi-transparent mirror; and beam converging means to converge the first and second beam components to overlap and produce an interference pattern, the beam source being operative to displace the coherent light beam relative to the semi-transparent mirror in such a manner that the spacing between the first and second beam paths of the first and second beam components and thereby the fringe spacing are continuously variable.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-29 | 1980-08-30 | 1981-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-29 | 1984-08-30 | 1985-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-29 | 1988-08-30 | 1989-03-01 | $7700.00 | Window Closed / Lapsed |