Photostorage and retrieval of multiple images by diffraction processes with cross-talk suppression

Claim 3

A method as defined by claim 1 wherein said medium stores information as a density image and wherein said minimization is achieved by processing said medium to about gamma -2.

Claim 4

A method as defined by claim 1 wherein said minimization is achieved by forming said periodic carrier functions with duty cycles substantially less than one-half.

Claim 5

A method as defined by claim 3 wherein said duty cycle of said carrier functions is between about 10 percent and about 20 percent.

Claim 6

A process for making a photostorage record comprising: making a plurality of image exposures on the same recording area of photostorage medium, each exposure being made through a light modulating device imparting to the exposure a spatially-distributed periodic modulation with a unique characteristic so arranged relative to the characteristics of the other exposures that if, after processing the record, it is illuminated with light which is at least partially coherent at said record, diffraction orders of said modulations each convolved with a spectrum of the associated image will be erected spatially separated in a transform plane; and processing said medium to develop said plurality of images in a transparency having an amplitude transmittance which is substantially linearly proportional to the input intensity by which said exposures were made, said medium being processed to a substantially constant gamma of substantially minus two.

Claim 7

A process for making a photostorage record comprising: making a plurality of image exposures on the same recording area of photostorage medium, each exposure being made through a light modulating device imparting to the exposure a spatially-distributed periodic modulation with a unique characteristic so arranged relative to the characteristics of the other exposures that if, after processing the record, it is illuminated with light which is at least partially coherent at said record, diffraction orders of said modulations each convolved with a spectrum of the associated image will be erected spatially separated in a transform plane; and processing said medium to develop said plurality of images in a transparency having an amplitude transmittance which is substantially linearly proportional to the input intensity by which said exposures were made, said medium being processed to a substantially constant gamma of substantially minus two.

Claim 8

A photostorage process comprising: consecutively making a plurality of image exposures of a single area on a photostorage mediuM through an amplitude diffraction grating with the grating having different angular orientations for each exposure to obtain a latent composite image; processing said medium to a gamma of about minus two to obtain a transparency having an amplitude transmission which is linearly proportional to the input intensity when illuminated with light of uniform amplitude; placing said medium in a coherent optical system so as to form the spectrum of said composite image in a transform plane; and positioning a spatial filter in said transform plane so as to separate an image corresponding to one of said plurality of exposures by selectively passing a diffraction order greater than zero of said grating as it was oriented during said one of said plurality of exposures along with the image spectrum centered in said order.

Claim 9

A photostorage process comprising: consecutively making a plurality of image exposures of a single area on a photostorage mediuM through an amplitude diffraction grating with the grating having different angular orientations for each exposure to obtain a latent composite image; processing said medium to a gamma of about minus two to obtain a transparency having an amplitude transmission which is linearly proportional to the input intensity when illuminated with light of uniform amplitude; placing said medium in a coherent optical system so as to form the spectrum of said composite image in a transform plane; and positioning a spatial filter in said transform plane so as to separate an image corresponding to one of said plurality of exposures by selectively passing a diffraction order greater than zero of said grating as it was oriented during said one of said plurality of exposures along with the image spectrum centered in said order.

Claim 10

A photostorage and retrieval process, comprising: making a plurality of image exposures of a single area on a photostorage medium through an amplitude diffraction grating with the grating having different angular orientations for each exposure to obtain a latent composite image; processing said medium to a gamma of about minus two to obtain a transparency having an amplitude transmission which is linearly proportional to the input intensity when illuminated with light of uniform amplitude; placing said medium in a coherent optical system so as to form the spectrum of said composite image in a transform plane; and positioning a spatial filter in said transform plane so as to separate an image corresponding to one of said plurality of exposures by selectively passing a diffraction order greater than zero of said grating as it was oriented during said one of said plurality of exposures along with the image spectrum centered in said order, said constant gamma of minus two being obtained by exposing a second photosensitive material to said medium, said material and said medium having gammas that will multiply to a gamma of minus two as a result of double negative processing, and wherein said process further comprises controlling each exposure so as to remain on the linear portions of the H and D curves for both the medium and the material.

Claim 11

A photostorage and retrieval process, comprising: making a plurality of image exposures of a single area on a photostorage medium through an amplitude diffraction grating with the grating having different angular orientations for each exposure to obtain a latent composite image; processing said medium to a gamma of about minus two to obtain a transparency having an amplitude transmission which is linearly proportional to the input intensity when illuminated with light of uniform amplitude; placing said medium in a coherent optical system so as to form the spectrum of said composite image in a transform plane; and positioning a spatial filter in said transform plane so as to separate an image corresponding to one of said plurality of exposures by selectively passing a diffraction order greater than zero of said grating as it was oriented during said one of said plurality of exposures along with the image spectrum centered in said order, said constant gamma of minus two being obtained by exposing a second photosensitive material to said medium, said material and said medium having gammas that will multiply to a gamma of minus two as a result of double negative processing, and wherein said process further comprises controlling each exposure so as to remain on the linear portions of the H and D curves for both the medium and the material.

Claim 12

A photostorage and retrieval process comprising: making a plurality of image exposures of a single area on a photostorage medium through an amplitude diffraction grating with the grating having different angular orientations for each exposure to obtain a latent composite image; processing said medium to a gamma of about minus two to obtain a transparency having an amplitude transmission which is linearly proportional to the input intensity when illuminated with light of uniform amplitude; placing said medium in a coherent optical system so as to form the spectrum of said composite image in a transform plane; and positioning a spatial filter in said transform plane so as to separate an image corresponding to one of said plurality of exposures by selectively passing a diffraction order greater than zero of said grating as it was oriented during said one of said plurality of exposures along with the image spectrum centered in said order, said constant gamma of minus two being obtained using a photostorage medium that will reversal process to a gamma of minus two, said process further comprising preexposing said medium with a weak exposure sufficient to cover the nonlinear ''''foot'''' of the H and D curve of the medium, limiting said exposures so that the maximum exposure in any one spot does not exceed the linear portion of the H and D curve for the medium and reversal processing said medium to obtain a gamma of minus two.

Claim 13

A photostorage and retrieval process comprising: making a plurality of image exposures of a single area on a photostorage medium through an amplitude diffraction grating with the grating having different angular orientations for each exposure to obtain a latent composite image; processing said medium to a gamma of about minus two to obtain a transparency having an amplitude transmission which is linearly proportional to the input intensity when illuminated with light of uniform amplitude; placing said medium in a coherent optical system so as to form the spectrum of said composite image in a transform plane; and positioning a spatial filter in said transform plane so as to separate an image corresponding to one of said plurality of exposures by selectively passing a diffraction order greater than zero of said grating as it was oriented during said one of said plurality of exposures along with the image spectrum centered in said order, said constant gamma of minus two being obtained using a photostorage medium that will reversal process to a gamma of minus two, said process further comprising preexposing said medium with a weak exposure sufficient to cover the nonlinear ''''foot'''' of the H and D curve of the medium, limiting said exposures so that the maximum exposure in any one spot does not exceed the linear portion of the H and D curve for the medium and reversal processing said medium to obtain a gamma of minus two.