Patent ID: 8121010

Claim:
A hologram device comprising: a light source that applies light to a hologram recording medium having a recording layer in which information recording is performed by interference fringes between signal light and reference light; a spatial modulation unit that generates the signal light in a signal light area and/or the reference light in a reference light area with a gap area in between the signal light area and the reference light area for isolating the areas, and generates a marker light in a predetermined position within the gap area of an incident surface of the light from the light source by performing spatial light modulation on the light from the light source; a light applying unit that applies the light subjected to spatial light modulation by the spatial light modulation unit to the hologram recording medium via an objective lens; a light receiving unit that receives the light applied via the objective lens through the hologram recording medium; and a tilt detection unit that obtains a tilt error signal representing an error from an ideal angle of a tilt angle as an incident angle of the applied light via the objective lens to an information recording surface of the hologram recording medium based on a result of detection of an error between an ideal light reception position of the marker light in the light receiving unit and a real light reception position of the marker light by the light receiving unit.