US3728117A
Expired / Lapsed
US
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Optical diffraction grid
Assignee: FA HEIDENHAIN J DT
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Filing: 1968-12-18
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Granted: 1973-04-17
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Expires: 1988-12-18
Abstract
Abstract A METHOD OF PRODUCING OPTICAL DIFFRACTION GRIDS HAVING A PREDETERMINED ASYMMETRIC GROOVE PROFILE WHICH COMPRISES THE STEPS OF EXPOSING A LIGHT SENSITIVE LAYER TO AT LEAST ONE SYSTEM OF FRINGES OF LIGHT AND POSITIONING THE LIGHT SENSITIVE LAYER RELATIVE TO THE FRINGE SYSTEM IN SUCH A MANNER THAT THE LOCALLY RESULTING EXPOSURE IS AN ASYMMETRIC FUNCTION WITH RESPECT TO A NORMAL TO THE SURFACE OF THE LIGHT SENSITIVE LAYER, AND SUBSEQUENTLY DEVELOPING THE LIGHT SENSITIVE LAYER. D R A W I N G
Inventors
- 👤 J Heidenhain
- 👤 H Burkhardt
- 👤 H Kraus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:39
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/18; G02B5/1847; G02B5/1857; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |