Mediatek Corporation

Mediatek Incorporation

Hao-Cheng Chen

Wen-Yi Wu

Shung-Yunn Wang

Chun-Nan Chen

Chin-Huo Chu

A method for counting a number of tracks of an optical disc in an optical disc system. The optical disc system includes an optical pickup, a light source, and a plurality of optical sensors. The method includes emitting a light beam to the optical disc from the light source, detecting light reflected from the optical disc by the optical sensors, and generating a tracking error signal according to detected signals of the optical sensors while the optical pickup moves along a radial direction of the optical disc. The method further includes generating a tracking error zero crossing signal according to the tracking error signal, generating a peak detecting signal according to the tracking error signal, generating a pseudo radio frequency zero crossing signal according to the peak detecting signal, and generating a track count signal according to the pseudo frequency crossing signal.

Track count method for an optical disc in an optical disc system

An apparatus for detecting position of blank areas for an optical disc in an optical disc drive according to a wobble signal and a blank signal includes an address decoder for generating a physical address value according to the wobble signal; a counting device coupled to the address decoder for generating a count value according to the wobble signal; and a decision circuit coupled to the counting device for determining whether the count value is within a predetermined range when the edge of the blank signal occurs. If the count value is within the predetermined range when the blank edge occurs, the decision circuit generates a position value corresponding to a blank area of the optical disc.

Method and apparatus for detecting position of blank area of optical disc

An ADIP demodulation method and apparatus, which are used in an optical disk driver to generate the ADIP information according to a wobble signal. The apparatus includes a slicing unit for receiving the wobble signal and generating a wobble pulse, a phase locked loop for generating a reference wobble signal with the same frequency and phase as the wobble pulse and a reference clock with frequency higher than the wobble pulse, a channel bit generator for generating a channel bit signal according to the reference wobble signal and the wobble pulse, and a decoder for decoding to ADIP information according to the channel bit signal. The channel bit generator generates a difference signal between the wobble pulse and the reference wobble signal, and outputs the channel bit signal according to the difference signal.

ADIP demodulation method and apparatus

A pre-pit signal decoder includes a shift register, a pattern comparator, a counting unit, an in-sync signal generating unit and a protection unit. The register receives serial pre-pit bits and converts them into a parallel pre-pit byte. The comparator generates an odd sync bit, an even sync bit, a low bit, and a high bit according to the pre-pit byte and receives a disable signal to operate when the disable signal is not enabled. The counting unit generates a counting value, which marks oddness/evenness of frames of the pre-pit bits and sequence of wobble signals in the frames, according to the odd sync, even sync, low and high bits. The signal generating unit generates an in-sync signal according to the odd sync, even sync, low, and high bits. The protection unit receives the counting value and the in-sync signal to thereby enable the disable signal at positions where the pre-pit bits impossibly exist according to the counting value. The decoder controls operations of the pattern comparator according to the disable signal of the protection unit so as to reduce the error rate.

Pre-pit signal decoder

An optical storage disc stores storage information and includes track information. A method for performing a target search on the optical storage disc includes: generating a first intermediate signal according to a readout signal generated by an optical storage device reading the storage information; generating a second intermediate signal according to the track information carried within the readout signal; generating a hybrid address signal according to the first intermediate signal and the second intermediate signal; and performing the target search on the optical storage disc according to the hybrid address signal and a target address set by the optical storage device.

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Taipei Hsien, Taiwan

Hao-Cheng Chen