The light energy necessary for the precure process is held by the RFID at
the holographic memory. The controller acquires the light energy
corresponding to the temperature of the recording position detected by
the temperature sensor out of the precure information acquired by the
RFID reader. The exposure time (light emitting time of LED) Te in the
precure process is calculated based on the calculating equation Te
(sec)=En (joule)/Pd (watt) from the energy En and the intensity Pd of
light irradiated onto the recording position detected by the light
detector.