Mediatek Corporation

Ying-Feng Huang

Chih-Ching Yu

Yu-Chun Lin

Ming-Tsang Wu

Pi-Hai Liu

Hao-Hui Yin

Ping-Tsai Tsai

Hung-Hsiang Chang

Kun-Yi Chan

Tzu-Ching Yang

Ya-Fang Nien

Chih-Yu Fan

Hua-Ting Chi

A method for controlling layer changes for an optical disk drive is provided, where a focus of a laserbeam emitted by a pickup head of the optical disk drive is moved from a current data layer of a disk to a target data layer of the disk. First, a position of a collimator lens of the pickup head is adjusted for spherical aberration correction. The objective lens is then lowered to a low position to move the focus of the laserbeam off the surface of the disk. The objective lens is then raised towards the disk. A focusing error signal is generated while the objective lens is being raised. Whether a target S-curve corresponding to the target data layer is present in the focusing error signal is then started to be detected. If the target S-curve is detected, the focus on operation on the target data layer of the disk is successful.

Method for controlling layer changes for an optical disk drive

The invention provides an optical disk drive. In one embodiment, the optical disk drive comprises a feeding device, a power driver, and a controller. The feeding device comprises a spherical aberration (SA) lens and a stepping motor, wherein the SA lens corrects spherical aberration of a light beam emitted by a pickup head, and the stepping motor moves the SA lens according to a plurality of control signals. The power driver generates the control signals to drive the stepping motor to move the SA lens. The controller directs the power driver to drive the stepping motor to move the SA lens with only stable steps when the SA lens is required to move, so that the stepping motor is in a stable state without inducing step errors after the stepping motor rotates with the stable steps.

Optical disk drive and method for driving a feeding device of an optical disk drive

The invention provides an optical disk drive. The optical disk drive comprises a pickup head, a seek control device, a lens vision characteristic decoder, and an anti lens shift device. The pickup head comprises a sled and a lens for projecting a beam on a disk. The seek control device moves the sled, and shifts the lens with a shift distance relative to an origin at a center of the sled. The equalizer derives a servo signal from a reflection of the beam. The lens vision characteristic decoder obtains a vision characteristic of the lens according to the servo signal and determines a track-on direction according to the vision characteristic. The anti lens shift device triggers the seek control device to perform a track-on process according to the track-on direction.

Optical disk drives and method for controlling track-seeking for optical disk drives

A method for improving readability of an optical disc includes: changing a first control parameter of an optical storage apparatus that accesses the optical disc and obtaining a plurality of associated values of an index corresponding to the readability of the optical disc for respective changed/unchanged values of the first control parameter; setting the first control parameter to be an optimal value out of the changed/unchanged values of the first control parameter according to the index; changing a second control parameter with the first parameter set to be the optimal value to obtaining a plurality of associated values of the index for respective changed/unchanged values of the second control parameter; and setting the second control parameter to be an optimal value according to the index. The control parameters having their individual optimal values are utilized for further control during decoding. In addition, an associated optical storage apparatus is further provided.

Method for improving readability of an optical disc, and associated optical storage apparatus

A data recording device. A random data generator randomly generates substitute data. A recording data generator receives original data and a recording address from a host, receives the substitute data, compares the recording address with a reference address, and outputs the substitute data according to the comparison result. An encoder generates a first data block according to the substitute data. A modulator modulates the first data block. An optical pickup records the modulated first data block on the optical recording medium according to the recording address.

Data recording devices and methods thereof

A signal gain control method and system for use in optical disc drives to prevent undesirable saturation occurrences in circuit operations. The method includes fetching a preset reading front monitor diode signal and a preset gain controlling signal for reading; generating a front monitor diode signal by a front monitor diode signal conversion circuit; calculating a gain controlling signal based on the preset gain controlling signal for reading, the preset reading front monitor diode signal, and the front monitor diode signal by a signal processor; adjusting a gain for detection signals according to the gain controlling signal by a gain adjustment unit; and generating control signals according to the adjusted detection signals by a pre-amp module.

Method and system for signal gain control in optical disc drives

A method for discriminating between different types of optical discs is intended to apply to an optical storage device with a pick-up head having three beams. A main beam push-pull signal and a sub-beam push-pull signal, both acquired by means of the photo-detector of the pick-up head, are superposed on each other to have an additive push-pull signal, whereas, on subtraction, the difference between the main beam push-pull signal and the sub-beam push-pull signal generates a differential push-pull signal. If the peak-to-peak voltage of the differential push-pull signal is greater than that of the additive push-pull signal, it is judged that the light spots derived from the sub-beams and the main beam of the three beams respectively fall on two contiguous lands and a groove therebetween on an optical disc inside the optical storage device. Also, if the peak-to-peak voltage of the differential push-pull signal is smaller than that of the additive push-pull signal, it is judged that the light spots derived from the sub-beams and the main beam separately fall on three contiguous grooves on the optical disc respectively.

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Chia-Yi Hsien, Taiwan

Ying-Feng Huang