US4605606A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gaussian laser beam filter
Assignee: NCR Voyix Corp
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Filing: 1985-02-28
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Granted: 1986-08-12
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Expires: 2005-02-28
Abstract
Abstract A method for constructing an optical filter for use in a holographic scanner includes exposing a photographic film to a laser, developing the film and reinserting the developed film into the unexpanded output beam of the laser to provide a uniform illumination of the outputted beam. The filter is positioned in the reference beam in the construction of a hologram used in the holographic scanner.
Inventors
- 👤 Ronald A. Ferrante
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:37
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/09; G02B27/0927; G02B26/00; G02B26/08; G02B26/10; G02B26/106; G02B27/0938; G02B27/0944; G02B5/00; G02B5/20; G02B5/205; G02B5/32
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
179 words
A method for the construction of a hologram for use in a scanning system comprising the steps of; providing a source of coherent light having an intensity which varies from point to point over its cross-sectional area in accordance with a predetermined Gaussian function; splitting the light beam into first and second unexpanded light beams; focusing the first unexpanded light beam onto an object through a first spatial filter for expanding the light beam as it strikes the object; positioning a photographic film in the second unexpanded light beam at a predetermined distance from the source of coherent light; developing the exposed photographing film for a predetermined time period; reinserting the developed film in the second unexpanded light beam at said predeveloped distance from the source to cause said unexpanded coherent light beam to have a uniform intensity when emerging from the film; focusing the uniform intensity second light beam through a second spatial filter onto a collimating lens which emits a collimated light beam; and directing the collimated light beam onto a recording medium located adjacent the object.
Claim 2
Independent Claim
179 words
A method for the construction of a hologram for use in a scanning system comprising the steps of; providing a source of coherent light having an intensity which varies from point to point over its cross-sectional area in accordance with a predetermined Gaussian function; splitting the light beam into first and second unexpanded light beams; focusing the first unexpanded light beam onto an object through a first spatial filter for expanding the light beam as it strikes the object; positioning a photographic film in the second unexpanded light beam at a predetermined distance from the source of coherent light; developing the exposed photographing film for a predetermined time period; reinserting the developed film in the second unexpanded light beam at said predeveloped distance from the source to cause said unexpanded coherent light beam to have a uniform intensity when emerging from the film; focusing the uniform intensity second light beam through a second spatial filter onto a collimating lens which emits a collimated light beam; and directing the collimated light beam onto a recording medium located adjacent the object.
Claim 3
Dependent Claim
23 words
The method of claim 1 in which the filter comprises Kodak 649F photographic film exposed for 0.163 seconds to the source of light.
Claim 4
Dependent Claim
22 words
The method of claim 1 in which the first and second light beams are each focused through a pin hole spatial filter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-08-11 | 1990-02-10 | 1990-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-08-11 | 1994-02-10 | 1994-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-08-11 | 1998-02-10 | 1998-08-12 | $7700.00 | Window Closed / Lapsed |