Lite-On It Corporation

Yu-Hung Sun

Chih-Hao Chang

An apparatus and a method for determining the type of an optical disk are provided. Firstly, an RF signal of the optical disk in an optical disk drive is read out. Next, a bandpass signal is extracted from the RF signal by a bandpass filter whose central frequency is a wobble frequency. Then, whether the bandpass signal corresponds to a wobble signal is determined. If so, the optical disk is a recordable optical disk; otherwise, the optical disk is a read-only optical disk.

Apparatus and method for determining type of an optical disk

A method for discriminating an optical disk is disclosed. Peak values and trough values of focus error signal and RF level signal are detected by an operation of focus search. Threshold levels for detecting each material layer of the optical disk are determined according to the peak values and the trough values. Thereafter another focus search for the optical disk is executed to calculate a thickness of the substrate and a distance between the first and the second recording layer of the optical disk according to the threshold levels. Thus the type of the optical disk can be discriminated.

Disk discrimination method

A method is disclosed for jumping tracks on a double-layer optical disk from a first address A on a first data layer to a target address D on a second data layer. According to the method, the first address A where the optical head is currently positioned is read. Then, after jumping to the second data layer, a relative second address B on the second data layer that corresponds to the first address A on the first data layer is read. If the second address B on the second data layer is smaller than the first address A on the first data layer, then the address of the second address B on the second data layer is shifted and a new target address is obtained on the second data layer based on this address shift. A calculation function is performed based on the first address A and the new target address, and then the optical head is moved to the new target address on the second data layer. On the other hand, if the second address B on the second data layer is larger than the first address A on the first data layer, then a calculation function is calculated based on the second address B and the target address D, and then the optical head is moved to the target address D on the second data layer.

Track jump method for dual-layered optical disk reading device

A method of increasing data extraction compatibility for an optical disc drive is disclosed. The method first provides extraction parameter sets, wherein the extraction parameter sets comprise a first extraction parameter set and a second extraction parameter set. The optical disc drive then uses the first extraction parameter set to extract data from an optical disc. Finally, the optical disc drive uses the second extraction parameter set to extract data from the optical disc if a data extraction error occurs.

Data extraction for an optical disc drive

A fuzzy-neuro method uses a neuro network to discriminate optical disk type. The fuzzy-neuro method establishes a plurality of characteristic signal sets corresponding to the optical disks of various formats; and uses the neuro network to match the optical disk under question to the characteristic signal sets for finding the type thereof.

Fuzzy-neuro method for discriminating optical disk type

The present invention proposes a method of detecting reverse rotation of a DC motor by using the back EMF, wherein the back EMF of the DC motor is detected to judge whether the brakeage of the motor is finished. A simple electronic circuit is exploited to accomplish this work effectively. No additional sensors are required so that the cost can be reduced.

Growing community of inventors

Taipei, Taiwan

Yu-Hung Sun