Abstract: A light source driving device for driving a light source includes a power stage circuit, a transformer circuit, a control circuit, and a fault detecting circuit. The power stage circuit converts an external electrical signal to an alternating current (AC) signal. The transformer circuit is connected between the power stage circuit and the light source to convert the AC signal to a high voltage electrical signal adapted for driving the light source. The fault detecting circuit detects whether the light source is nonfunctional, and outputs a fault signal upon the condition that the light source is nonfunctional. The fault detecting circuit includes a voltage level comparison circuit and a variable-benchmark voltage circuit. The control circuit is connected between the fault detecting circuit and the power stage circuit to output a control signal to the power stage circuit based on the fault signal.

Abstract: A backlight module that includes a lamp and a single side driving inverter that is coupled to one end of the lamp. The single side driving inverter is configured to control an operating current of the lamp to be within 80% to 100% of a saturation luminance current. The lamp has a characteristic such that when the operating current is lower than the saturation luminance current, the lamp luminance increases as the operating current increases, and when the operating current is substantially equal to or higher than the saturation luminance current, the lamp luminance does not increase as the operating current increases.

Abstract: An automatic detecting device of land pre-pits signal is disclosed. The device adjusts gain of push-pull signals to raise the signal to noise ratio of the land pre-pits signal to the wobble signal. Digital logic computation is also utilized to recognize the practical position of the land pre-pits. The level automatic detection of the RC circuit and the fixed slice level compose an automatic slice level, which is the basis for detecting the land pre-pits. The disclosed device eliminates the drawback of not easy to obtain correct land pre-pits signal from written disks by the conventional of fixed land pre-pits slice level technology.

Abstract: An automatic detecting device of land pre-pits signal is disclosed. The device adjusts gain of push-pull signals to raise the signal to noise ratio of the land pre-pits signal to the wobble signal. Digital logic computation is also utilized to recognize the practical position of the land pre-pits. The level automatic detection of the RC circuit and the fixed slice level compose an automatic slice level, which is the basis for detecting the land pre-pits. The disclosed device eliminates the drawback of not easy to obtain correct land pre-pits signal from written disks by the conventional of fixed land pre-pits slice level technology.

Abstract: This specification discloses an automatic calibration method for the output power of a pickup head for an optical information recording apparatus, which avoids laser diode thermal effects using duty cycle control and obtains the correct conversion function between the output current of a front monitor diode and the output power of the pickup head by curve fitting. This method only needs to measure one set of front monitor diode output current and output power conversion function of the pickup head. The same conversion function is applicable to all pickup heads of the same type. The optical information recording apparatus automatically detects the corresponding parameter for the pickup head. Each optical information recording apparatus can also automatically detect the specific power control parameters for each set of power control channel to obtain the optimal recording characteristics.