Patent US6353489B1 successfully refreshed from Google Patents.
US6353489B1
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Optical retro-reflection device
Assignee: Hoya Corp
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Filing: 2000-11-24
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Granted: 2002-03-05
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Expires: 2020-11-24
Abstract
Abstract An optical retro-reflective apparatus for application to reconfigurable displays for highway signs and other applications is disclosed. In a first preferred embodiment, the apparatus includes a retro-reflector such as a corner cube prism, three orthogonally arranged planer reflectors, or a plurality of either arranged as an array, or an array of micro-spheres or micro-prisms arranged as a corner-cube. In one embodiment, a holographic diffraction element is placed between a source of radiation such as visible light and one or more of the retro-reflectors. The diffraction element is made up of one or more stacked holographic devices in which pre-determined holographs are stored, operative to diffract a particular wavelength band of radiation (e.g. red, blue and green visible light). The hologram devices can be stacked and selectively deactivated so that the desired wavelength band (or color) to be diffracted is selected. In this way, the retro-reflective apparatus can be made to reflect or re-transmit light of a certain color. In a second embodiment, the retro-reflectors are arranged orthogonally and include the diffraction elements. The diffraction elements for each retro-reflector are programmed to diffract (and therefore reflect) a different wavelength band of light. Thus, only the retro-reflector that is in an active state will reflect (by diffraction) a portion of the incident radiation, and that portion is preferably red, green or blue visible light.
Inventors
- 👤 Milan M. Popovich
- 👤 Antoine Yvon Messiou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:53
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/203; E; E01; E01F; E01F9/00; E01F9/60; E01F9/604; E01F9/615; G02B5/08; G02B5/09; G02B5/12; G02B5/122; G02B5/124; G02B5/126; G02B5/128; G02B5/32
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
126 words
An optical retro-reflection apparatus comprising: a retro-reflector operative to receive radiation incident thereon and to reflect and/or re-emit the received radiation from said device in a direction parallel to its direction of incidence; one or more holographic diffraction elements, each having one or more holographic devices, each of the devices operative to diffract a predetermined wavelength band of radiation incident on said apparatus and switchable between an active, diffracting state and an inactive, non-diffracting state; a control circuit couple to each of the devices of each of said one or more diffraction elements, said control circuit operative to switch said holographic devices between their active and inactive states; and wherein the radiation reflected or re-emitted by said retro-reflector is the radiation diffracted by said diffraction device.
Claim 2
Dependent Claim
126 words
An optical retro-reflection apparatus comprising: a retro-reflector operative to receive radiation incident thereon and to reflect and/or re-emit the received radiation from said device in a direction parallel to its direction of incidence; one or more holographic diffraction elements, each having one or more holographic devices, each of the devices operative to diffract a predetermined wavelength band of radiation incident on said apparatus and switchable between an active, diffracting state and an inactive, non-diffracting state; a control circuit couple to each of the devices of each of said one or more diffraction elements, said control circuit operative to switch said holographic devices between their active and inactive states; and wherein the radiation reflected or re-emitted by said retro-reflector is the radiation diffracted by said diffraction device.
Claim 3
Dependent Claim
45 words
The optical retro-reflection apparatus of claim 1 wherein the one or more holographic layers comprises a holographic recording medium that records a hologram, wherein the holographic recording medium comprises: a monomer dipentaerythritol hydroxypentaacrylate; a liquid crystal; a cross-linking monomer; a coinitiator; and a photoinitiator dye.
Claim 4
Dependent Claim
57 words
The optical retro-reflection apparatus of claim 1 wherein the one or more holographic devices comprises a hologram made by exposing an interference pattern inside a polymer-dispersed liquid crystal material, the polymer-dispersed liquid crystal material comprising, before exposure: (a) a polymerizable monomer; (b) a liquid crystal; (c) a cross-linking monomer; (d) a coinitiator; and (e) a photoinitiator dye.
Claim 5
Dependent Claim
32 words
The optical retro-reflection apparatus of claim 1 wherein said one or more holographic diffraction elements are disposed between a source of radiation and the retro-reflector, and is operating in the transmissive-type mode.
Claim 6
Dependent Claim
41 words
The optical retro-reflection apparatus of claim 1 wherein said one or more holographic diffraction elements comprise at least three of the holographic devices, each of said holographic devices operative to diffract a different wavelength band of the source radiation incident thereon.
Claim 7
Dependent Claim
25 words
The optical retro-reflection apparatus of claim 5 wherein said at least three holographic devices are operative to diffract red, green and blue visible light, respectively.
Claim 8
Dependent Claim
15 words
The optical retro-reflection apparatus of claim 5 wherein said retro-reflector is a cube corner prism.
Claim 9
Dependent Claim
16 words
The optical retro-reflection apparatus of claim 5 wherein said retro-reflector is three orthogonally arranged plane reflectors.
Claim 10
Dependent Claim
22 words
The optical retro-reflection apparatus of claim 5 wherein said retro-reflector comprises a plurality of three orthogonally arranged reflectors organized into an array.
Claim 11
Dependent Claim
21 words
The optical retro-reflection apparatus of claim 5 wherein said retro-reflector comprises a plurality of cube corner prisms organized into an array.
Claim 12
Dependent Claim
26 words
The optical retro-reflection apparatus of claim 9 wherein each of the three orthogonally arranged reflectors of the array is associated with its own holographic diffraction element.
Claim 13
Dependent Claim
27 words
The optical retro-reflection apparatus of claim 9 wherein two or more of the three orthogonally arranged reflectors of the array are associated with one holographic diffraction element.
Claim 14
Dependent Claim
25 words
The optical retro-reflection apparatus of claim 10 wherein each of the cube corner prisms of the array is associated with its own holographic diffraction element.
Claim 15
Dependent Claim
26 words
The optical retro-reflection apparatus of claim 10 wherein two or more of the cube corner prisms of the array are associated with one holographic diffraction element.
Claim 16
Dependent Claim
19 words
The optical retro-reflection apparatus of claim 5 wherein said retro-reflector comprises a plurality of Micro-spheres organized into an array.
Claim 17
Dependent Claim
26 words
The optical retro-reflection apparatus of claim 5 wherein said retro-reflector comprises an array of micro-prisms each of which is in the form of a cube corner.
Claim 18
Dependent Claim
102 words
The optical retro-reflection apparatus of claim 1 comprises three of said retro-reflectors arranged substantially orthogonal to one another, each of said retro-reflectors further comprising: one of the one or more holographic diffraction elements; an interference pass-band filter coupled between said holographic diffraction element and any radiation incident upon said apparatus, said filter operative to pass only those wavelength bands that the one or more devices of said holographic diffraction elements is operative to diffract while in the active state; and a light absorbing element coupled to a surface of said holographic diffraction element opposite to that which is coupled to said filter.
Claim 19
Dependent Claim
50 words
The optical retro-reflection apparatus of claim 17 wherein said one or more holographic devices of said diffraction elements for each of said three retro-reflectors are reflective-type and reflect only those wavelength bands of incident radiation for which their respective holographic devices are operative to diffract when in the active state.
Claim 20
Dependent Claim
45 words
The optical retro-reflection apparatus of claim 18 wherein said one or more holographic devices of each of said diffraction elements are controlled using a common electrode, and thus are active at the same time, thereby combining their respective pass-bands to provide an expanded optical bandwidth.
Claim 21
Dependent Claim
28 words
The optical retro-reflection apparatus of claim 18 wherein each of said diffraction devices of the three retro-reflectors are operative to diffract red, green and blue wavelength bands respectively.
Claim 22
Dependent Claim
24 words
The optical retro-reflection apparatus of claim 18 wherein only one of said diffraction elements of the three retro-reflectors is active at any given time.
Claim 23
Dependent Claim
36 words
The optical retro-reflection apparatus of claim 18 wherein said three retro-reflectors are not substantially orthogonal, said apparatus further comprising a Fresnel prism or lens underlying said filter by which to compensate for the lack of orthogonality.
Claim 24
Dependent Claim
15 words
The optical retro-reflection apparatus of claim 18 wherein said interference filter is a dichroic filter.
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) | 2005-03-04 | 2005-09-03 | 2006-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-03-04 | 2009-09-03 | 2010-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-03-04 | 2013-09-03 | 2014-03-05 | $7700.00 | Window Closed / Lapsed |