US4225211A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Random phase plate for holography and process for manufacturing same
Assignee: Ricoh Co Ltd
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Filing: 1978-08-28
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Granted: 1980-09-30
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Expires: 1998-08-28
Abstract
Abstract A coating material such as a solution of polyvinyl butyral resin in benzene is applied to a transparent base in such a manner that the thickness thereof varies in a continuous and random manner so that concentration of light in the central area of a hologram produced using the plate is below a predetermined tolerable value.
Inventors
- 👤 Michiharu Abe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:41
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/04; G03H1/16; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
153 words
A process for producing a random phase holographic plate coated with polyvinyl butyral resin in which the thickness H of the resin varies in a continuous and random manner over the said plate relative to light of a wavelength λ such that exp -4π.sup.2 (n-n.sub.o).sup.2 σh.sup.2 /λ.sup.2 ≦0.10 where h m is a mean value of H, h=H-h m ; σh is a standard deviation of h; n is a refractive index of the solidified coating material for light of the wavelength λ; n o is a refractive index of air for light of the wavelength λ; and exp indicates exponentiation, comprising the steps of: (a) applying a 17.5% by weight solution of polyvinyl butyral resin in benzene to the upper surface of a transparent substrate, and (b) solidifying the solution by rotating the substrate about a perpendicular rotary axis at a rate of from 200 to 1500 rpm to evaporate the solvent.
Claim 2
Dependent Claim
153 words
A process for producing a random phase holographic plate coated with polyvinyl butyral resin in which the thickness H of the resin varies in a continuous and random manner over the said plate relative to light of a wavelength λ such that exp -4π.sup.2 (n-n.sub.o).sup.2 σh.sup.2 /λ.sup.2 ≦0.10 where h m is a mean value of H, h=H-h m ; σh is a standard deviation of h; n is a refractive index of the solidified coating material for light of the wavelength λ; n o is a refractive index of air for light of the wavelength λ; and exp indicates exponentiation, comprising the steps of: (a) applying a 17.5% by weight solution of polyvinyl butyral resin in benzene to the upper surface of a transparent substrate, and (b) solidifying the solution by rotating the substrate about a perpendicular rotary axis at a rate of from 200 to 1500 rpm to evaporate the solvent.
Claim 3
Dependent Claim
14 words
The process according to claim 1 in which the substrate is a glass plate.
Claim 4
Dependent Claim
106 words
A random phase holographic plate, comprising a transparent substrate and a transparent polyvinyl butyral coating on the substrate in which the thickness H of the coating varies in a continuous and random manner over the random phase plate relative to light of a wavelength λ such that exp -4π.sup.2 (n-n.sub.o).sup.2 σ.sub.h.sup.2 /λ.sup.2 ≦0.10 where h m is a mean value of H, h=H-h m ; σ h is a standard deviation of h; n is a refractive index of the coating material for light of the wavelength λ; n o is a refractive index of air for light for the wavelength λ; and exp indicates exponentiation.
Claim 5
Dependent Claim
106 words
A random phase holographic plate, comprising a transparent substrate and a transparent polyvinyl butyral coating on the substrate in which the thickness H of the coating varies in a continuous and random manner over the random phase plate relative to light of a wavelength λ such that exp -4π.sup.2 (n-n.sub.o).sup.2 σ.sub.h.sup.2 /λ.sup.2 ≦0.10 where h m is a mean value of H, h=H-h m ; σ h is a standard deviation of h; n is a refractive index of the coating material for light of the wavelength λ; n o is a refractive index of air for light for the wavelength λ; and exp indicates exponentiation.
Claim 6
Dependent Claim
15 words
The plate according to claim 3, in which the transparent substrate comprises a glass plate.
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) | 1983-09-30 | 1984-03-31 | 1984-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-30 | 1988-03-31 | 1988-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-30 | 1992-03-31 | 1992-09-30 | $7700.00 | Window Closed / Lapsed |