发明名称 |
Generating a quadrature seek signal from a discrete-time tracking error signal and a discrete-time RF data signal in an optical storage device |
摘要 |
In an optical disk storage device wherein user data is demodulated from a light beam reflecting off data pits in tracks of an optical disk storage medium, a quadrature seek signal is generated indicative of the light beam crossing tracks of the optical disk during a seek operation. The quadrature seek signal is generated from a discrete-time tracking error signal (TES) and a discrete-time RF baseband signal. The discrete-time TES is generated according to the mode of operation, compact disk (CD) or digital video disk (DVD). In CD mode the TES is generated as the difference between E and F tracking photodiodes, and in DVD mode the TES is generated using a discrete-time differential phase detector (DPD). To generate the discrete-time RF baseband signal, the RF data signal (generated as the sum A+B+C+D of a four quadrant photodiode) is sampled at the channel rate and the RF data samples passed through a discrete-time envelope detector. The envelope detector extracts a discrete-time RF baseband signal which represents the light beam's location with respect to a track centerline. The discrete-time TES and baseband signals are synchronized and converted into binary square waves which form a quadrature seek signal (four transitions per track) for counting track crossings and for determining the radial seek direction.
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申请公布号 |
US5914922(A) |
申请公布日期 |
1999.06.22 |
申请号 |
US19970989272 |
申请日期 |
1997.12.12 |
申请人 |
CIRRUS LOGIC, INC. |
发明人 |
SUPINO, LOUIS;GRABA, JIM;ZHU, SHUANGXIA;ROMANO, PAUL M. |
分类号 |
G11B21/08;G11B7/085;G11B7/09;G11B21/10;(IPC1-7):G11B7/09 |
主分类号 |
G11B21/08 |
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