Filter circuit with phase adjusting function, phase demodulating circuit and optical disk device



PROBLEM TO BE SOLVED: To provide a filter circuit with the phase adjusting function capable of exactly specifying the position on media by adjusting not only the frequency characteristic but also the phase characteristic in accordance with an input signal frequency. SOLUTION: In the state that the filter circuit 16 having the frequency and phase characteristics being variable with a signal from the outside is set to the desirable frequency characteristic by a 1st control signal from a frequency control circuit 17, the device is arranged so that the phase with the high sensitivity for the change with respect to the frequency is also correctable in accordance with the frequency of an input signal by adjusting the phase characteristic by a 2nd control signal from a phase adjustment circuit 20 so as to keep the phase difference constant between the input signal and the output signal of the filter circuit 16 detected by a phase detecting circuit 19. Thus, the phase generated by the filter circuit 16 or the peripheral circuits is removed, and the phase difference between the input signal and the output signal is kept to be constant independently of the frequency.
(57)【要約】 【課題】 周波数特性だけでなく、位相特性も入力信号 周波数に応じて調整することで、メディア上の位置を正 確に特定できる位相調整機能付フィルタ回路を提供す る。 【解決手段】 外部からの信号により周波数特性及び位 相特性が可変なフィルタ回路16を周波数制御回路17 からの第1の制御信号により所望の周波数特性に設定し た状態で、フィルタ回路16の入力信号と出力信号との 位相検出回路19により検出される位相差を一定に保つ ように位相調整回路20からの第2の制御信号によって 位相特性を調整することで、周波数に対する変化感度の 高い位相まわりについても入力信号周波数に応じて補正 できるようにした。これにより、フィルタ回路16やそ の周辺回路によって発生する位相まわりを除去し、入力 信号と出力信号との位相差を周波数に依らず一定に保つ ことができる。




Download Full PDF Version (Non-Commercial Use)

Patent Citations (0)

    Publication numberPublication dateAssigneeTitle

NO-Patent Citations (0)


Cited By (3)

    Publication numberPublication dateAssigneeTitle
    JP-2009296482-ADecember 17, 2009Alps Electric Co Ltd, アルプス電気株式会社ダイバーシチ受信装置
    US-7224652-B2May 29, 2007Ricoh Company, Ltd.Optical disc apparatus, information recording method, adjustment apparatus, adjustment method and fabrication method for optical disc apparatus, and method and apparatus for adjusting phase shift amount
    WO-2005024801-A1March 17, 2005Ricoh Company, Ltd.Dispositif de disque optique, procede d'enregistrement d'information, dispositif de reglage d'un dispositif de disque optique, procede de reglage, procede de fabrication, procede de reglage de la quantite de deplacement de phase et dispositif de reglage