US4304459A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reflective holographic scanning system insensitive to spinner wobble effects
Assignee: Xerox Corp
•
Filing: 1979-07-02
•
Granted: 1981-12-08
•
Expires: 1999-07-02
Abstract
Abstract A holographic scanning system includes a reflective type holographic spinner having a plurality of diffraction gratings on its surface. A reconstruction wavefront incident on a non-grating surface of the spinner is reflected into a corrective optical element which displaces and redirects the wavefront so that it is incident at the grating at an angle corrected for the effects of spinner wobble.
Inventors
- 👤 Charles J. Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:54
CPC Classifications
G; G02; G02B; G02B26/00; G02B26/08; G02B26/10; G02B26/106
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
152 words
A holographic scanning system including a reflection holographic spinner having on its surface at least one holographic facet; a source of coherent light which directs a reconstruction light wavefront, onto a portion of said spinner surface adjacent said facet at a first angle of incidence, θ i said reconstruction wavefront being reflected from said surface; an optical element disposed in the path of said reflected wavefront, said element acting to condition said wavefront and redirect it onto said holographic facet at a second angle of incidence, said facet diffracting said wavefront at a first order diffraction angle θ d , means for rotating said spinner so that said facet is rotated across said reconstruction wavefront producing a corresponding translation of the diffracted wavefront, and means for focusing said diffracted wavefront, whereby a scan line is generated at an image plane which is substantially invariant to the presence of spinner wobble during rotation.
Claim 2
Dependent Claim
152 words
A holographic scanning system including a reflection holographic spinner having on its surface at least one holographic facet; a source of coherent light which directs a reconstruction light wavefront, onto a portion of said spinner surface adjacent said facet at a first angle of incidence, θ i said reconstruction wavefront being reflected from said surface; an optical element disposed in the path of said reflected wavefront, said element acting to condition said wavefront and redirect it onto said holographic facet at a second angle of incidence, said facet diffracting said wavefront at a first order diffraction angle θ d , means for rotating said spinner so that said facet is rotated across said reconstruction wavefront producing a corresponding translation of the diffracted wavefront, and means for focusing said diffracted wavefront, whereby a scan line is generated at an image plane which is substantially invariant to the presence of spinner wobble during rotation.
Claim 3
Dependent Claim
16 words
A holographic scanning system as defined in claim 1 wherein said optical element is a retroreflector.
Claim 4
Dependent Claim
18 words
A holographic scanning system as defined in claim 2 wherein said optical element is a corner cube reflector.
Claim 5
Dependent Claim
17 words
A holographic scanning system as defined in claim 2 wherein said optical element is a porro prism.
Claim 6
Dependent Claim
17 words
A holographic scanning system as defined in claim 2 wherein said optical element is a catseye retroreflector.
Claim 7
Dependent Claim
27 words
A holographic scanning system as defined in claim 5 wherein said facets are plane diffraction gratings and wherein said retroreflector forms part of a prescan focusing element.
Claim 8
Dependent Claim
30 words
A holographic scanning system as defined in claim 1 wherein said optical element is a feedback device which introduces a multiplier factor x into the redirected wavefront such that ##EQU9##
Claim 9
Dependent Claim
79 words
A holographic scanning system as defined in claim 7 wherein said optical element is a retroreflector including a prism located so that said reflected wavefront strikes a first surface of said prism at an angle θ 1 , is refracted at said first surface at an angle θ 1 ' strikes the second surface at an angle θ 2 ' and is refracted at said second surface at an angle θ 2 , the multiplier factor x being ##EQU10##
Claim 10
Dependent Claim
54 words
A holographic scanning system as defined in claim 1 wherein said optical element includes a grating, said reflected wavefront incident on said grating at an angle θ i ' and diffracted by said grating at an angle θ d ' , the feedback multiplier X of the element being given by the equation ##EQU11##
Claim 11
Dependent Claim
63 words
A holographic scanning system as defined in claim 1 wherein said first angle of incidence is equal to said diffraction angle and further including a beamsplitter positioned in the path of the redirected wavefront and adapted to pass a portion of the redirected wavefront through to the facet surface while subsequently reflecting a portion of said diffraction wavefront to generate the scan line.
Claim 12
Dependent Claim
31 words
A holographic scanning system as defined in claim 1 wherein said facets are zone-type lenses which diffract said redirected incident wavefront to reconstruct a spot light for scanning an image plane.
Claim 13
Dependent Claim
28 words
A holographic scanning system as defined in claim 1 wherein said facets are plane diffraction gratings which diffract an incident reconstruction wavefront into zeroth and first order components.
Claim 14
Dependent Claim
26 words
A holographic scanning system as defined in claim 12 further including means for focusing said first order component as a scanning spot on an image plane.
References Cited (Backward Citations)
US3614193A
Cited
US3721487A
Cited
US3897132A
Cited
US3953105A
Cited
US4094576A
Cited
US4067639A
Cited
US4239326A
Cited
GB2000321A
Cited
US4243293A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-07 | 1985-06-08 | 1985-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-07 | 1989-06-08 | 1989-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-07 | 1993-06-08 | 1993-12-08 | $7700.00 | Window Closed / Lapsed |