Patent ID: 8060331
Filing Date: 2011-11-15
Classification: G11B

Abstract:
1. A controller of an optical disk device, the controller comprising: a first sub-controller for receiving an input signal from a controlled plant, the first sub-controller comprising a first lead-lag filter for filtering the inputted signal with a first phase lock loop to generate a first lead-lag filtered signal, and a first low pass filter in serial connection with the first lead-lag filter for passing low-frequency components of the first lead-lag filtered signal; a second sub-controller for receiving an output signal from the first sub-controller, the second sub-controller comprising a second lead-lag filter for filtering the output signal from the first sub-controller with a second phase lock loop to generate a second lead-lag filtered signal, and a second low pass filter in serial connection with the second lead-lag filter for passing low-frequency components of the second lead-lag filtered signal; and a third sub-controller for receiving the input signal from the controlled plant, the third sub-controller comprising a third lead-lag filter for filtering the input signal with a third phase lock loop to generate a third lead-lag filtered signal, a third low pass filter for passing low-frequency components in the third lead-lag filtered signal to generate a third low-pass filtered signal, and an fourth lead-lag filter for filtering the third low-pass filtered signal with an fourth phase lock loop.