US3735374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hologram identification system
Assignee: Thales SA
•
Filing: 1970-06-25
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Granted: 1973-05-22
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Expires: 1990-06-25
Abstract
Abstract An identification arrangement comprises light sources and photodetectors arranged in accordance with a predetermined correspondence code. An appropriate key hologram produces, in respect of each of these sources, respective real images on the above photo-detector. Threshold circuits are connected to these photo-detectors and an assembly of coincidence circuits produces a signal when signals of predetermined levels are simultaneously applied to the outputs of all the photo-detectors.
Inventors
- 👤 M Rembault
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:24
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/04; G03H1/0402; G03H1/041; G06; G06V; G06V10/00; G06V10/88
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
168 words
A hologram identification system, for identifying objects carrying at least one hologram key means storing a pattern of interference fringes constructed from light beams respectively emitted by m point reference sources and focused on n luminous object points; the locations of said point sources and said object points in relation to said hologram key means being characteristic of a predetermined correspondence code ; said identification system comprising: m point light sources and n point photo-detectors located in respective predetermined locations determined by said correspondence code, m and n being positive integers higher than one; means for positioning said hologram key means in a location where said hologram key means actually focuses said sources onto said photo-detectors ; logic circuit means connected to said photo-detectors and having an output for supplying a first control signal when, upon insertion of said hologram key means in said location, said n photodetectors simultaneously supply respective signals ; and supply mans for supplying electrical energy to said sources and said logic circuit means.
Claim 2
Dependent Claim
168 words
A hologram identification system, for identifying objects carrying at least one hologram key means storing a pattern of interference fringes constructed from light beams respectively emitted by m point reference sources and focused on n luminous object points; the locations of said point sources and said object points in relation to said hologram key means being characteristic of a predetermined correspondence code ; said identification system comprising: m point light sources and n point photo-detectors located in respective predetermined locations determined by said correspondence code, m and n being positive integers higher than one; means for positioning said hologram key means in a location where said hologram key means actually focuses said sources onto said photo-detectors ; logic circuit means connected to said photo-detectors and having an output for supplying a first control signal when, upon insertion of said hologram key means in said location, said n photodetectors simultaneously supply respective signals ; and supply mans for supplying electrical energy to said sources and said logic circuit means.
Claim 3
Dependent Claim
36 words
A system as claimed in claim 1 , wherein said logic circuit means comprise threshold circuits for said control signal to be supplied if said photo-detector signals have respective amplitudes simultaneously higher than respective predetermined thresholds.
Claim 4
Dependent Claim
103 words
A system as claimed in claim 2 , wherein said logic circuit means comprise : n variable threshold circuits connected respectively to said photo-detectors and having each a threshold level control input; m evaluating circuits, coupled respectively to said light sources and having outputs respectively connected to said control inputs of said threshold circuits which are connected to said photo-detectors corresponding respectively to said sources, for evaluating the light intensities respectively supplied by said sources and for supplying threshold control signals; and coincidence circuit means having n inputs respectively connected to said threshold circuits and an output for supplying said first control signal.
Claim 5
Dependent Claim
54 words
A system as claimed in claim 3 , wherein said inserting means comprise means for inserting a plurality of key holograms in series, at least the first of which operates by transmission, the real point images supplied by one of said holograms serving as point light sources for the next one of said holograms.
Claim 6
Dependent Claim
43 words
A system as claimed in claim 3 , wherein said key hologram is an hologram operating by reflection, said sources are white light sources and said photo-detectors are selected for being sensitive to the wavelengths of the light radiations reflected by said hologram.
Claim 7
Dependent Claim
41 words
A system as claimed in claim 3 , wherein said evaluating circuits comprise each an auxiliary photo-detector and said key hologram forms an extra real image of the corresponding light source on a predetermined location where said auxiliary photo-detector is located.
Claim 8
Dependent Claim
35 words
A system as claimed in claim 1 , wherein said logic circuit means further comprise an alarm arrangement for signalling that the illumination of said photo-detectors is different from the illumination according to said code.
Claim 9
Dependent Claim
24 words
A system as claimed in claim 7 , wherein said arrangement comprises an alarm circuit and an extra photo-detector connected to said alarm circuit.
Claim 10
Dependent Claim
33 words
A system as claimed in claim 8 , wherein said arrangement further comprises an inverter, connected to said output of said logic circuit means and having an output connected to said alarm circuit.
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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) | 1976-05-21 | 1976-11-20 | 1977-05-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-21 | 1980-11-20 | 1981-05-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-21 | 1984-11-20 | 1985-05-22 | $7700.00 | Window Closed / Lapsed |