Patent US3603668A successfully refreshed from Google Patents.
US3603668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite diffraction grating formed from superimposed aligned gratings
Assignee: US Philips Corp
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Filing: 1970-01-29
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Granted: 1971-09-07
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Expires: 1990-01-29
Abstract
Abstract A device for reconstructing a hologram using white light, by providing in the optical path before or after the hologram a dispersion-compensating element. A preferred embodiment employs a diffraction grating. A relatively efficient and inexpensive transmission diffraction grating is obtained by a pile of aligned, superimposed replicas having the same spacing.
Inventors
- 👤 Dominick John Debitetto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:30
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/22; G03H1/24; G02; G02B; G02B5/00; G02B5/18; G02B5/1814
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
38 words
An inexpensive transmission grating exhibiting improved efficiency comprising a pile of superimposed, aligned, nonblazed thin transmission diffraction gratings having straight grooves, said gratings having the same grating line density and arranged with their grooves parallel to one another.
Claim 2
Dependent Claim
38 words
An inexpensive transmission grating exhibiting improved efficiency comprising a pile of superimposed, aligned, nonblazed thin transmission diffraction gratings having straight grooves, said gratings having the same grating line density and arranged with their grooves parallel to one another.
Claim 3
Dependent Claim
19 words
A grating as set forth in claim 1 wherein each of the grating layers is a thin plastic replica.
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) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |