Abstract A double-sided, holographic replica comprises a web of transparent, thermoplastic, sheet material having a separate series of off-axis-recorded, phase-modulated holograms pressed into each of the opposite surfaces, respectively, of the web. Oppositely disposed (front and rear) holograms are such as to provide angularly displaced reconstructed images, respectively, when a monochromatic read-out beam is transmitted through the web. The double-sided holographic replica is made by first pressing the web and a first holographic master between a first pair of heated calender rollers to form one replica on one surface of the web, and then pressing the web, while thermoplastically adhered to the first master, and a second holographic master between a second pair of heated calender rollers to form another replica on the other surface of the web. The first and second masters are subsequently cooled and separated from the web.
An information recording medium consisting of substantially homogeneous transparent sheet material having formed in each of the opposite surfaces thereof a separate relief pattern, each of said separate relief patterns comprising a tilted off-axis recorded transmission hologram formed by object and reference beams which define a plane oblique to the longitudinal axis of the hologram, said oppositely disposed relief patterns providing angularly displaced reconstructed images when a monochromatic read-out beam is transmitted through the sheet material.
Claim 2
Dependent Claim
76 words
An information recording medium consisting of substantially homogeneous transparent sheet material having formed in each of the opposite surfaces thereof a separate relief pattern, each of said separate relief patterns comprising a tilted off-axis recorded transmission hologram formed by object and reference beams which define a plane oblique to the longitudinal axis of the hologram, said oppositely disposed relief patterns providing angularly displaced reconstructed images when a monochromatic read-out beam is transmitted through the sheet material.
Claim 3
Dependent Claim
19 words
An information recording medium as described in claim 1, wherein said sheet material is a web of thermoplastic material.
Claim 4
Dependent Claim
23 words
An infoRmation recording medium as described in claim 1, wherein said relief patterns having a depth in the range between 5 and 2,000A.
Claim 5
Dependent Claim
33 words
An information recording medium as described in claim 1, wherein said sheet material has a thickness of between about 1 and 6 mils, and said holograms have a resolution of about one micron.
Claim 6
Dependent Claim
32 words
An information recording medium as described in claim 1, wherein said sheet material is cast vinyl, and said holograms formed in said opposite surfaces of said sheet material are opposite each other.
Claim 7
Dependent Claim
30 words
An information recording medium as described in claim 5, wherein said cast vinyl sheet material has an elongation befure rupture of less than, or equal to, 5 percent at 25*C.