Abstract: An apparatus for judging an optical disc includes a gain controller, an amplitude detecting unit and an amplitude comparing unit. The gain controller is used for receiving a radio frequency signal from an optical pickup head; and processing the radio frequency signal into an amplified radio frequency signal with a target amplitude according to an amplitude feedback signal. The amplitude detecting unit is used for receiving the amplified radio frequency signal, generating the amplitude feedback signal to the gain controller, and outputting a top envelope amplitude according to an top envelope signal of the amplified radio frequency signal. The amplitude comparing unit is used for comparing the top envelope amplitude with a threshold value to generate a resulting signal, and judging whether the laser beams emitted from the optical pickup head are irradiated on a blank area or a data-recorded area according to the resulting signal.

Abstract: A method and a device of distinguishing blank area from non-blank area in an optical disc are provided. An input signal such as a DPD TE signal or RF ripple signal is first filtered to obtain a filtered signal. A subtracting operation of the input signal and the filtered signal is then performed to obtain a first signal. According to a peak value and a bottom value of the first signal, the first signal is processed into a second signal. By comparing the second signal with a reference signal, whether the currently read area is blank area or non-blank area can be discriminated. An indicating signal is outputted at a first value to indicate the blank area while the indicating signal is outputted at a second value to indicate the non-blank area.

Abstract: An apparatus for judging an optical disc includes a gain controller, an amplitude detecting unit and an amplitude comparing unit. The gain controller is used for receiving a radio frequency signal from an optical pickup head; and processing the radio frequency signal into an amplified radio frequency signal with a target amplitude according to an amplitude feedback signal. The amplitude detecting unit is used for receiving the amplified radio frequency signal, generating the amplitude feedback signal to the gain controller, and outputting a top envelope amplitude according to an top envelope signal of the amplified radio frequency signal. The amplitude comparing unit is used for comparing the top envelope amplitude with a threshold value to generate a resulting signal, and judging whether the laser beams emitted from the optical pickup head are irradiated on a blank area or a data-recorded area according to the resulting signal.

Abstract: A motor rotational speed control device for controlling a direct current (DC) brush motor is provided, which includes a motor driver, a detection unit and a central processing unit (CPU). The motor driver is coupled to a first control terminal and a second control terminal of the DC brush motor. The detection unit detects a back electromotive force (EMF) of the DC brush motor through the first control terminal and the second control terminal when the motor driver is set to a disable state, and accordingly generates back EMF information. The CPU determines whether the direct current brush motor has stopped rotating according to the back EMF information, and determines whether to generate a brake control signal according to a determination result. The motor driver reduces a rotation speed of the DC brush motor according to the brake control signal when the motor driver is set to an enable state.

Abstract: A method and a device of distinguishing blank area from non-blank area in an optical disc are provided. An input signal such as a DPD TE signal or RF ripple signal is first filtered to obtain a filtered signal. A subtracting operation of the input signal and the filtered signal is then performed to obtain a first signal. According to a peak value and a bottom value of the first signal, the first signal is processed into a second signal. By comparing the second signal with a reference signal, whether the currently read area is blank area or non-blank area can be discriminated. An indicating signal is outputted at a first value to indicate the blank area while the indicating signal is outputted at a second value to indicate the non-blank area.