US 7,244,532 B2 · Holographic recording medium

Abstract

A holographic recording medium includes a holographic recording carrier including a first light transmittable substrate, a second light transmittable substrate and a holographic recording layer sandwiched therebetween, a first antireflection film formed on the surface of the first light transmittable substrate and a second antireflection film formed on the surface of the second light transmittable substrate, and optical characteristics of the first antireflection film and those of the second antireflection film are determined to be different from each other the thus constituted holographic recording medium can achieves improved data recording characteristics and data reproducing characteristics using an object beam and a reference beam, and concurrently enables desired positioning of an object beam and a reference beam, or only the reference beam, and detection of the address of the region in which data are being recorded or from which data are being reproduced using a position control beam.

Claims17

Dependent claims

A holographic recording medium comprising a holographic recording carrier in which data can be holographically recorded, a first inorganic antireflection film formed on one surface of the holographic recording carrier and a second inorganic antireflection film formed on the other surface of the holographic recording carrier, optical characteristics of the first inorganic antireflection film and those of the second inorganic antireflection film being different from each other,

wherein the holographic recording carrier includes a first light transmittable substrate, a second light transmittable substrate and a holographic recording layer sandwiched therebetween, and
wherein the holographic recording carrier is constituted so that data can be recorded therein and data can be reproduced therefrom by projecting a first laser beam, and a concavo-convex pattern is formed on the second light transmittable substrate and covered by the second inorganic antireflection film so that the first laser beam can be positioned and an address of a region in which data are being recorded or from which data are being reproduced by projecting a second laser beam onto the concavo-convex pattern.

A holographic recording medium comprising:

a holographic recording carrier in which data can be holographically recorded wherein the holographic recording carrier includes a first light transmittable substrate, a second light transmittable substrate and a holographic recording layer sandwiched therebetween;
a first inorganic antireflection film formed on one surface of the holographic recording carrier;
a second inorganic antireflection film formed on the other surface of the holographic recording carrier, reflection characteristics of the first inorganic antireflection film and those of the second inorganic antireflection film being different from each other, the holographic recording carrier being constituted so that data can be recorded therein and data can be reproduced therefrom by projecting a first laser beam;
and
a concavo-convex pattern formed on the second light transmittable substrate and covered by the second inorganic antireflection film so that the first laser beam can be positioned and an address of a region in which data are being recorded or from which data are being reproduced can be detected by projecting a second laser beam whose wavelength is longer than that of the first laser beam onto the concavo-convex pattern, the second inorganic antireflection film being formed so that a reflection coefficient thereof with respect to the second laser beam is higher than that with respect to the first laser beam thereof.

2 more elements

Dependencies are inferred from the claim text.

Holographic recording medium

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Holographic recording medium

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Abstract

Claims17