HOLOGRAM RECORDING METHOD AND RECORDING REPLAYING DEVICE

摘要

The information light which is emitted from a coherent light source (151) and includes information to be recorded interferes with the reference light having the same wavelength as the information light, so that displacement of a hologram recording medium (130) to which the information is recorded as a hologram is detected, and a displacement signal is generated. Next, the displacement signal is sampled per constant time period, a plurality of ranges formed by dividing at a constant interval respectively define ranks, a frequency is assigned to a rank relevant to the sampled value of the displacement signal so as to calculate the frequency distribution information of the sampled values. Next, an allowable displacement range which is an amplitude range of the displacement of the displacement signals is determined from the frequency distribution information, and if the sampled value of the displacement signal is within the allowable displacement range when recording of information to the hologram recording medium (130) is started, recording of the information to the hologram recording medium (130) is performed, and if the sampled value of the displacement signal is out of the allowable displacement range, exposure control is performed for at least one of the information light and the reference light so that the light is faded or blocked to have a light intensity at which the information is not recorded to the hologram recording medium (130).