Patent US4840444A successfully refreshed from Google Patents.
US4840444A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite holographic elements
Assignee: Individual
•
Filing: 1987-08-17
•
Granted: 1989-06-20
•
Expires: 2007-08-17
Abstract
Abstract A composite holographic element (10) comprises a substrate (11) having on one surface (12) a relief pattern providing a holographic image when viewed in reflection, a partially reflective layer (14) facing the said surface, and a thin optically absorbent layer (13) adjacent the substrate.
Inventors
- 👤 Brian Hewitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:31
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/02; G03H1/0252; G02; G02C; G02C7/00; G03H1/024; G03H1/0244; G03H1/22; G03H1/2202; G03H2001/2223; G03H2001/2231; G03H2250/00; G03H2250/36
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
56 words
A composite optical element comprising a substrate having on one surface a surface relief pattern capable of providing a holographic image when viewed in reflection, a partially reflective layer facing the said surface of the substrate, and at least one thin optically absorbent layer adjacent the substrate to provide absorption of light incident on the substrate.
Claim 2
Dependent Claim
56 words
A composite optical element comprising a substrate having on one surface a surface relief pattern capable of providing a holographic image when viewed in reflection, a partially reflective layer facing the said surface of the substrate, and at least one thin optically absorbent layer adjacent the substrate to provide absorption of light incident on the substrate.
Claim 3
Dependent Claim
25 words
An element according to claim 1 in which the absorbent layer is disposed between the said surface of the substrate and the said reflective layer.
Claim 4
Dependent Claim
24 words
An element according to claim 1 in which the absorbent layer is on the surface of the substrate opposite that bearing the relief pattern.
Claim 5
Dependent Claim
44 words
An element according to claim 1 in which a first absorbent layer is disposed between the said surface of the substrate and the said reflective layer and a second absorbent layer is on the surface of the substrate opposite that bearing the relief pattern.
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) | 1992-06-19 | 1992-12-19 | 1993-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-19 | 1996-12-19 | 1997-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-19 | 2000-12-19 | 2001-06-20 | $7700.00 | Window Closed / Lapsed |