Abstract: Briefly, in accordance with one or more embodiments, a harmonic of a clock signal is determined that is expected to provide interference with an input of a radio-frequency (RF) receiver based at least in part on a frequency of the clock signal and one or more frequencies of operation of the RF receiver. A duty cycle of the clock signal at which the harmonic will be attenuated is calculated, and the duty cycle of the clock signal is set to the calculated value as a base duty cycle in order to mitigate RF interference (RFI) at the RF receiver due to the harmonic of the clock signal. In one or more embodiments, the power level of the harmonic may be measured as the duty cycle may be swept over a range near the base duty cycle, and the duty cycle may be set to a value in the range at which the harmonic is minimized or reduced below a threshold value.

Abstract: Methods and apparatus are provided for reducing cross-talk and jitter caused by track offsets in multi-beam optical disks. The method and apparatus involve using split detectors and cross-talk cancellation algorithms in the multi-element photodetector of the multi-beam optical disks. The cross-talk cancellation algorithms are applied according to the value of the track offset as a function of the track pitch.

Abstract: Methods and apparatus are provided for reducing cross-talk and jitter caused by track offsets in multi-beam optical disks. The method and apparatus involve using split detectors and cross-talk cancellation algorithms in the multi-element photodetector of the multi-beam optical disks. The cross-talk cancellation algorithms are applied according to the value of the track offset as a function of the track pitch.

Abstract: The present invention provides digital read channel circuitry for an optical disk reader. An RF signal corresponding to a track on the optical disk is sampled to provide digital samples corresponding to the RF signal. The samples are taken at a rate that may differ from the channel bit rate of the RF signal. The digital samples are then processed to provide data at the channel bit rate. Multiple digital read channels may be used to read multiple tracks of an optical disk simultaneously. The multiple RF signals may be sampled based on a sample clock common to the multiple digital read channels.

Abstract: In a CD-ROM reader system wherein five adjacent tracks of a CD-ROM are separately illuminated by five light beams of an optical pickup, a recorded data readout system simultaneously reads the recorded data of the separate tracks by detecting the received light outputs of the returned beams, and outputs the data in the sequence in which it was recorded. For example, if one light beam becomes unreadable by the recorded data readout system, the system will read the recorded data using the remaining four light beams. This readout is performed in recurring operations in which data is read for approximately one revolution of the CD-ROM; then, after there are no longer any gaps in the combined data, the pickup is track-jumped forward by approximately two tracks. At this point the recorded data is again read for one revolution, and the process repeats.