Patent ID: 7869106
Filing Date: 2011-01-11
Classification: G03H,G11B

Abstract:
1. A holographic recording method for recording information in an angle multiplex fashion as a hologram, comprising: branching out signal light and reference light from a laser light source; crossing either one of the signal light and the reference light to the other in a recording layer of an optical recording medium at a predetermined incidence angle; changing the incidence angle at a predetermined angular pitch in a first format; and changing the incidence angle in a second format of higher angular selectivity for another optical recording medium, wherein the incidence angle when recording information in the second format of higher angular selectivity is adjusted to cover the predetermined incidence angle and an incidence angle that satisfies the Bragg's condition when recording in the first format, and an angular pitch of the second format during recording is set to Δθ/n (n is an integer not smaller than 2), where Δθ is an angular pitch of the first format during recording, and substantially identical information is recorded in a multiplex fashion at two incidence angles near to both sides of an incidence angle common to the second format and the first format.