INFORMATION REPRODUCTION DEVICE AND READ CLOCK MONITORING METHOD

摘要

It is possible to realize an information reproduction device capable of appropriately monitoring a read clock frequency as compared to the conventional device. The information reproduction device includes frequency difference detection means for detecting a frequency difference between the read clock obtained by subjecting the reproduction signal to PLL and a reference frequency; information processing means for subjecting the reproduction signal to signal processing and outputting processing state information indicating whether the signal processing is being executed normally; and frequency monitoring means for monitoring whether the read clock frequency is normal according to the frequency difference and the processing state information. When the processing state is normal, the frequency monitoring means enters an OK status indicating that the read clock frequency is normal. When the processing state information indicates an error and the frequency difference is not smaller than a first threshold value, the frequency monitoring means enters an NG status indicating that the reproduction signal frequency is abnormal. When the frequency difference is smaller than a second threshold value in the NG status, the OK status is reset.