Patent ID: 7940438
Filing Date: 2011-05-10
Classification: G03H,G11B

Abstract:
1. A hologram reading apparatus comprising: a holding unit that holds a hologram recording medium in which page data is recorded by irradiating as a single beam both reference light and signal light which are modulated by a spatial light modulator, wherein the spatial light modulator includes a first pixel area for modulating the reference light and a second pixel area for modulating the signal light based on the page data to be recorded, and a pitch of pixels in the first pixel area is different from that in the second pixel area; a Fourier transform lens that subjects reproduction light to a Fourier transformation, wherein the reproduction light is obtained by irradiating the reference light to the hologram recording medium and wherein the reproduction light includes the reference light and the signal light; a filter disposed on a Fourier transform plane of the reproduction light by the Fourier transform lens, wherein the filter shields the reference light at a first spatial frequency band and transmits the signal light at a second spatial frequency band, based on that the reference light and the signal light which are included in the reproduction light differ from each other in distance of image formation positions of a spatial frequency component thereof; and a reading unit that receives the reproduction light at the second spatial frequency band transmitted through the filter and reads the page data modulated to the signal light at the second spatial frequency band.