Mediatek Corporation

Mediatek Incorporation

Hung-Hsiang Chang

Chih-Ching Yu

Ping-Tsai Tsai

Ying-Feng Huang

Te-Wang Tseng

Fu-Shan Wang

Chih-Yu Fan

The invention relates to recording on a medium, and in particular, to laser control during recording data on an optical medium. A laser control method for dynamically adjusting laser power during recording data onto an optical disc comprises: recording normal data onto the optical disc according to an initial laser power; stopping recording when a trigger is generated; reading back the recorded normal data and generating a first recording quality index; recording a test pattern at a test pattern starting point according to a selected laser power; reading back the test pattern and generating a second recording quality index; and determining an adaptive laser power to continually record the normal data according to the first recording quality index and the second recording quality index.

Method and apparatus for laser control during recording

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 used in an optical storage device having a pickup head. The pickup head includes an object lens, a first and a second light source. The object lens focuses the laser light generated by the first or the second light source onto a first or a second focal point. A driving control effort is used to change the location of the object lens. The method includes the following steps: providing the driving control effort to move the object lens; measuring a first parameter when the first focal point passes through a predetermined layer of an optical disc; measuring a second parameter when the second focal point passes through the predetermined layer of the optical disc; and (d) determining the relationship between the difference of object lens location and the driving control effort according to the predetermined distance, the first parameter, and the second parameter.

Method for determining relationship between difference of object lens location and driving control effort in optical storage device and apparatus thereof

A method for controlling long seeking operation in an optical disc drive is provided. The optical disc drive includes a sled actuator, a pickup head installed on the sled actuator for reading and/or writing data in an optical disc, and a controller for controlling the sled actuator to move together with the pickup head. The method includes the steps of (a) receiving remaining tracks information indicating a number of tracks remained to be crossed by the sled actuator and/or the pickup head; (b) receiving velocity information indicating a velocity of the sled actuator and/or the pickup head; (c) receiving acceleration information indicating an acceleration of the sled actuator and/or the pickup head; (d) driving the sled actuator to move according to the remaining tracks information, the velocity information, and the acceleration information.

Growing community of inventors

Hsinchu County, Taiwan

Hung-Hsiang Chang