Back to results
US 5,162,927 AGranted
High efficiency holograms by multiple-layer holography
AssigneeHughes Aircraft Company
InventorsGaylord E. Moss, John E. Wreede, Edward T. Knobbe, Darrell F. Hatch
Life of this patent
Estimating the term…
Abstract
A method is disclosed for forming a multi-layer holographic device 22. A first hologram is formed on a major surface of a substrate 14. The first hologram is desensitized to prevent interaction with a second subsequently formed hologram. The second hologram is formed conterminous with said first hologram.
Claims15
A method of forming a holographic device, said method comprising the steps of:
- (a) forming a first hologram on a major surface of a substrate with following steps:
- (i) first, providing a photo-sensitive layer comprising photoreactive material and photosensitive material,
- (ii) second, drying said photosensitive layer to a predetermined moisture content,
- (iii) third, exposing said photo-sensitive layer to create a latent image, and
- (b) desensitizing by removing said photoreactive material from said photosensitive material from said first hologram to prevent interaction with a second subsequently formed hologram;
- (c) forming the second subsequently formed hologram conterminous with said first hologram, with the following steps:
- (i) first, providing a photosensitive layer on said first hologram,
- (ii) second, drying said photosensitive layer to a predetermined moisture content,
- (iii) third, exposing said photosensitive layer to create a latent image, and
- (d) processing together said first and second holograms to fully develop the holographic image and to achieve a predetermined fringe configuration in the first and second holograms, so that the holograms of said device are bonded together absent an adhesive layer between said first and second holograms.
7 more elements
A method of forming a holographic device, said method comprising the steps of:
- (a) forming a first hologram on a major surface of a substrate with the following steps:
- (i) first, providing a photosensitive layer comprising photoreactive material and photosensitive material,
- (ii) second, drying said photosensitive layer to a predetermined moisture content,
- (iii) third, exposing said photosensitive layer to create a latent image, and
- (b) desensitizing by removing said photoreactive material from said photosensitive material from said first hologram to prevent interaction with a second subsequently formed hologram;
- (c) forming the second subsequently formed hologram conterminous with the first hologram, with the following steps:
- (i) first, providing a photosensitive layer on said first hologram,
- (ii) second, drying said photosensitive layer to a predetermined moisture content,
- (iii) third, exposing said photosensitive layer to create a latent image, and
- (d) desensitizing by removing said photoreactive material from said photosensitive material from said second hologram to prevent interaction with a third subsequently formed hologram;
- (e) forming the third subsequently formed hologram conterminous with the second hologram, with the following steps:
- (i) first, providing a photosensitive layer on said second hologram,
- (ii) second, drying said photosensitive layer to a predetermined moisture content,
- (iii) third, exposing said photosensitive layer to create a latent image, and
- (f) processing together said first, second and third holograms to fully develop the holographic image and to achieve a predetermined fringe configuration in the holograms,
- so that the holograms of said device are bonded together absent an adhesive layer between the respective holograms.
13 more elements
A method of forming a holographic device, said method comprising the steps of:
- (a) forming a first hologram on a major surface of a substrate with the following steps:
- (i) first, providing a photo-sensitive layer, comprising photoreactive material and photosensitive material,
- (ii) second, drying said photosensitive layer to a predetermined moisture content,
- (iii) third, exposing said photosensitive layer to create a latent image, and
- (b) desensitizing by removing said photoreactive material from said photosensitive material from said first hologram to prevent interaction with an adjacent subsequently formed holgram;
- and
- (c) forming a plurality of subsequently formed holograms conterminous with the first hologram, with the following steps:
- (i) first, providing a photosensitive layer on a last prior hologram,
- (ii) second, drying said photosensitive layer to a predetermined moisture content,
- (iii) third, exposing said photosensitive layer to create a latent image, and
- (d) desensitizing each hologram by removing said photoreactive material from said photosensitive material from said hologram to prevent interaction with the next adjacent subsequently formed hologram;
- (e) processing together all holograms to fully develop the holographic image and to achieve a predetermined fringe configuration in the holograms,
- so that the holograms of said device are bonded together absent an adhesive layer between the respective holograms.
10 more elements
A method of forming a multi-layer holographic device, said method comprising the steps of:
- (a) coating a major surface of a substrate with a first photosensitive gelatin layer;
- (b) drying said first photosensitive-gelatin layer to a predetermined moisture content;
- (c) exposing said first photosensitive layer to form a first hologram having a first holographic fringe configuration formed therein;
- (d) removing ammonium dichromate from said first gelatin layer so as to desensitize said layer;
- (e) partially dehydrating said first gelatin layer in an alcohol bath to partially develop the first holographic image;
- (f) heating said first gelatin layer for a predetermined amount of time so as to form within the hologram a desired fringe spacing which reflects light at a peak wavelength for which light diffraction is sought, and to surface harden said first gelatin layer;
- (g) coating at a temperature of less than about 50.degree. C., a major surface of said first gelatin layer with a second photosensitive layer so that the light-diffracting effects of the first hologram are substantially erased;
- (h) exposing said second photosensitive layer to form a second hologram having a second holographic fringe configuration formed therein;
- and
- (i) processing together said first and second layers to fully develop the holographic image and to achieve a predetermined fringe configuration in the first and second holograms.
7 more elements
Dependencies are inferred from the claim text.