METHOD FOR RENEWALLING RECORD HOLOGRAMDATA IN VOLUME HOLOGRAPHIC DIGITAL STORAGE/REPRODUCING SYSTEM

摘要

PURPOSE: A method for updating recording data in a volume holographic digital storage/reproducing system is provided to update relevant hologram data recorded in case that a degree of a degradation exceeds a threshold setup by detecting the degree of the degradation in case that the hologram data recorded in storage media are reproduced. CONSTITUTION: In case that a reproducing mode is executed, a shutter is opened, and a shutter is closed(202,204). A standard light diverged through a reflecting mirror is measured in storage media(206). Hologram data stored in the storage media are reproduced(208). An output data processing block checks whether a reproducing output detected is reached to a threshold(210). The output data processing block converts the hologram data reproduced and restored into an original signal in prior to a modulation(212). A system control block opens two shutters(214). Hologram data updated are recorded in the storage media(216). The system control block clears reproduction angle information(218). The system control block checks whether recording hologram data to be reproduced exists(220). A present recording mode is switched to a reproducing mode(222).