US6753989B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recording surface relief microstructure
Assignee: De la Rue International Ltd
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Filing: 2002-07-24
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Granted: 2004-06-22
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Expires: 2022-07-24
Abstract
Abstract A method of recording a surface relief microstructure in a record medium includes: i) causing a coherent reconstruction or replay beam to impinge on a holographic optical element assembly, the holographic optical element assembly including a holographic optical element (HOE), the assembly causing selected portions of the beam to interfere at a focal region after diffraction by the holographic optical element so as to reconstruct a real image of an aperture previously used to construct the HOE; ii) locating a record medium at the focal region so that the real image is recorded; and, iii) causing relative movement between the record medium and the interfering beam portions and repeating steps i) and ii) so that the real image is recorded at a plurality of locations or pixels on the record medium.
Inventors
- 👤 Brian William Holmes
- 👤 John David Wiltshire
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:58
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/04; G03H1/0402; G03H1/0404; G03H2001/0439; G03H1/0465; G03H2001/0473; G03H1/0476; G03H2001/0482; G03H1/0493; G03H2001/0497; G03H2210/00; G03H2210/50; G03H2210/55; G03H2223/00; G03H2223/12; G03H2225/00; G03H2225/30; G03H2225/31; G03H2230/00; G03H2230/10
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
154 words
A method of recording a surface relief microstructure in a record medium, the method comprising: i) causing a coherent reconstruction or replay beam to impinge on a holographic optical element assembly, the holographic optical element assembly including a holographic optical element (HOE), the assembly causing selected portions of the beam to interfere at a focal region after diffraction by the holographic optical element so as to reconstruct a real image of an aperture previously used to construct the HOE; ii) locating a record medium at the focal region so that the real image is recorded; and, iii) causing relative movement between the record medium and the interfering beam portions and repeating steps i) and ii) so that the real image is recorded at a plurality of locations or pixels on the record medium; wherein the holographic optical element assembly further includes an aperture mask for selecting the beam portions by defining suitable selecting apertures.
Claim 2
Independent Claim
154 words
A method of recording a surface relief microstructure in a record medium, the method comprising: i) causing a coherent reconstruction or replay beam to impinge on a holographic optical element assembly, the holographic optical element assembly including a holographic optical element (HOE), the assembly causing selected portions of the beam to interfere at a focal region after diffraction by the holographic optical element so as to reconstruct a real image of an aperture previously used to construct the HOE; ii) locating a record medium at the focal region so that the real image is recorded; and, iii) causing relative movement between the record medium and the interfering beam portions and repeating steps i) and ii) so that the real image is recorded at a plurality of locations or pixels on the record medium; wherein the holographic optical element assembly further includes an aperture mask for selecting the beam portions by defining suitable selecting apertures.
Claim 3
Dependent Claim
28 words
A method according to claim 1 , wherein the holographic optical element is constructed so as to generate a real image of an aperture having a non-circular shape.
Claim 4
Dependent Claim
20 words
A method according to claim 2 , wherein the aperture is in the shape of a polygon or an indicium.
Claim 5
Dependent Claim
13 words
A method according to claim 1 , wherein the aperture is a pinhole.
Claim 6
Dependent Claim
39 words
A method according to claim 1 , wherein the holographic optical element is constructed and illuminated such that the beam portions impinge on the record medium at angles on the same side of a normal to the record medium.
Claim 7
Dependent Claim
22 words
A method according to claim 1 , wherein the aperture mask is a spatial light modulator such as a liquid crystal display.
Claim 8
Dependent Claim
37 words
A method according to claim 1 , wherein the holographic optical element assembly further includes a diffraction grating and a screen arranged so that only first order diffracted beams from the diffraction grating pass through the HOE.
Claim 9
Dependent Claim
34 words
A method according to claim 1 , wherein only two portions of the beam impinge on the record medium, the portions lying in a plane substantially orthogonal to the plane of the record medium.
Claim 10
Dependent Claim
55 words
A method according to claim 1 , wherein only two portions of the beam impinge on the record medium, the portions lying in a plane which is rotated relative to the record medium for different locations such that resulting interference fringes are recorded in a range of directions of rotation relative to the record medium.
Claim 11
Dependent Claim
20 words
A method according to claim 1 , wherein more than two portions of the beam impinge on the record medium.
Claim 12
Dependent Claim
28 words
A method according to claim 10 , wherein, for a set of locations, a common reference beam portion is caused to interfere with respective different “object” beam portions.
Claim 13
Dependent Claim
71 words
A method according to claim 9 , wherein only two portions of the beam impinge on the record medium, the portions lying in a plane which is rotated relative to the record medium for different locations such that resulting interference fringes are recorded in a range of directions of rotation relative to the record medium, wherein the “object” beam portions originate from positions on the HOE around a reference beam position.
Claim 14
Dependent Claim
14 words
A method according to claim 1 , wherein the beam portions have different intensities.
Claim 15
Dependent Claim
25 words
A method according to claim 1 , further comprising recording a 3D holographic image into the record medium in register with the real image pixels.
References Cited (Backward Citations)
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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) | 2007-06-22 | 2007-12-22 | 2008-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-06-22 | 2011-12-22 | 2012-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-06-22 | 2015-12-22 | 2016-06-22 | $7700.00 | Window Closed / Lapsed |