Abstract: The present invention provides a method for detecting disk defects of a blank optical disk in a recording and reproducing system when a data-recording operation is performed. In the embodiment, an ATIP and the carrier signal of the ATIP signal, ATFM signals, are compared to obtain a difference between these two signals. A wobble defect flag signal is set if the difference keeps higher than a predetermined threshold for a predetermined time interval. On the contrary, the wobble defect flag signal is cleared if the difference keeps lower than the predetermined threshold for the predetermined time interval.

Abstract: The apparatus of detecting defects of the present invention includes: a photodetector, detecting a intensity of reflective laser beam and generating a reflective signal; a sample/hold circuit, coupling to the photodetector circuit, sampling and holding the reflective signal; a comparator, coupling to the sample/hold circuit, comparing the sampling and holding result with a default range; and a defect flag generating circuit, coupling to the comparator, generating a defect flag signal. The method of detecting defects of the present invention includes: monitoring a reflective signal (WRF signal) when recording an optical disk; determining if the static region of WRF signal is within a predetermined range; if no, the region is regarded as a defect region, and a defect flag is set.

Abstract: The method of detecting defect signals includes: setting a default pit length range; inputting a data signal including a plurality of pits with different pit lengths; transferring the data signal into NRZ signal and counting the pit length of each pit; accumulating the number of the pits whose pit length are within the default pit length range, and accumulating the number of the pits whose pit lengths are outside the default pit length range but within the corresponding ranges; changing the logic state of a defect flag signal when one of the accumulative value reaches a corresponding threshold. The present invention also provides an apparatus for detecting defect signals.

Abstract: A method for determining the position of an optic pick-up head and the device of the same are disclosed. The number of frames in certain section of the disk are used to determine the position of the optic pick-up head. The number of frames in inner section of the compact disk is smaller than that in the outer section. The disk is virtually divided into a plurality of sections, and number of frames within each section is defined. As a result, when the optic pick-up head is at a certain frame, the position of the optic pick-up head can be determined the number of frames in the section.

Abstract: A defect protecting circuit and a method for data slicer in an optical drive is disclosed. As a defect occurs in a disk, the gain of the data slicer is switched to a high gain. After the defect does not occur further, the gain is switched back to a normal gain. Therefore the slicing level can return back to a correct slicing level for reducing incorrect data after the defect terminates, and the jitter in the output data is also reduced.

Abstract: A method for controlling the burst cutting area (BCA) clock in reading BCA data and a circuit of the same functions to allow BCA data to be read correctly. A BCA clock extractor is used for reading the BCA data correctly. A proper clock modulation is performed through this BCA clock extractor so as to read BCA data correctly.

Abstract: A focusing controller and the method thereof for an optical disk drive. The focusing controller includes a filter, a coupler and a focus compensator. The filter filters out a high-frequency component of the track error signal and derives an adjusted signal, while the coupler eliminates the adjustment signal from the focusing error signal so as to generate a coupled signal. The focus compensator generates a focus control signal used for controlling a position of the pick up head of the optical disk drive according to the coupled signal during a focusing operation.

Abstract: A method and a device for adjusting control parameters of a servo system of an optical disk drive. A first sinusoidal signal is introduced into a control loop of the servo system, while a band-pass filter is used to extract a second sinusoidal signal. Gain and/or phase variations of the control loop are derived by comparing signal parameters of both the first and second sinusoidal signals. A compensator is then employed to adjust the derived gain and/or phase variations of the control loop so as to overcome the disadvantage of system instability after a long-term working.

Abstract: Method and device for generating a stable power control signal in a CD recorder. The power control signal for controlling a laser diode may be a read level, an erase level and a write level. A pickup device outputs a feedback control signal to a read control circuit, and a read power control voltage is thus obtained. Then, the read power control voltage is inputted to a write control circuit, which generates first and second write power control voltages. The read level equals a reference voltage added by the read power control voltage, the erase level equals the read level added by the first write power control voltage, and the write level equals the erase level added by the second write power control voltage, so the read power control voltage and thus the read, erase and write levels are automatically and dynamically adjusted as the feedback control signal varies.

Abstract: The disclosed invention provides a tracking method of an optical storage. When proceeding with tracking, the optical pickup head can be moved constantly and the TE signal can be detected. Then differentiation of the TE signal is obtained. If the differentiation is less than 0, then the TE signal is masked; otherwise, the TE signal is not masked. Therefore, the TE Hysteresis signal can be determined by the TE signal and its differentiation. The TE Hysteresis signal of 0 represents that the laser beam is in the Pit, and then the tracking procedure is finished. Otherwise, the aforementioned steps are repeated until the end of the tracking procedure.

Abstract: A method for obtaining an optimum focusing point of an optical pickup unit and a servo system of an optical disk drive using this method is disclosed. An optical pickup drive circuit controls a position of an optical pickup unit according to an optical pickup control signal. A compensator receives an input signal and thus generates the optical pickup control signal. By varying levels of the input signal may enable the optical pickup unit to move to different positions. The optical pickup control signal enables the optical pickup unit to move to an optimum focusing point when the input signal activates the optical pickup unit to achieve the situation that an average difference between a peak envelop and a bottom envelop of the optical pickup control signal is minimized, or that an amplitude and a level of the tracking error signal are maximized in accompanied with minimum distortion range.

Abstract: A method for adjusting a control parameter is adopted in an optical disc drive server system, which has a compensator, a control loop and a parameter regulator. The control loop includes an optical pickup and outputs a first tracking error signal/focus error signal. The compensator adjusts the first tracking error signal/focus error signal to obtain a compensated signal for driving the optical pickup to read/write the optical disc. The parameter regulator generates a first sinusoidal signal to be inputted to the control loop, which amplifies the first sinusoidal signal to obtain a second sinusoidal signal. The parameter regulator filters the second sinusoidal signal and calculates a relationship between the first sinusoidal signal and the second sinusoidal signal to obtain a control parameter. The parameter regulator adjusts the compensator to output the compensated signal according to the control parameter.

Abstract: A circuit for generating tracking error signal using differential phase detection, comprising a quadrant photodetector for receiving optical signal and inducting splitting signal A, splitting signal B, splitting signal C and splitting signal D, two adders for generating group signal (A+C) and group signal (B+D). A plurality of equalizers for receiving, equalizing and amplifying splitting signal A, splitting signal B, splitting signal C, splitting signal D, group signal (A+C) and group signal (B+D). A plurality of phase detectors for receiving the output of equalizers and comparing phase difference of splitting signal A and group signal (A+C), group signal (A+C) and splitting signal B, splitting signal C and group signal (B+D), and group signal (B+D) and splitting signal D, and outputting a plurality of adjustment signals respectively. A circuit for eliminating the phase difference by adding and subtracting some adjustment signals with same phase difference.

Abstract: An apparatus and method for controlling an operation of recording data employed in an optical storage system is disclosed. The apparatus has a sampling-and-holding circuit, an operational amplifier, a plurality of gain amplifiers, and a plurality of switches. The apparatus operates under a short-term open mode, a long-term open mode, and a closed-loop mode sequentially in response to control signals and close/open statuses of the switches. A write-control signal is initialized by using a virtual ground effect within the short-term mode. In the long-term mode, the write-control signal is charged to a voltage level suitable for recording data onto a compact disk, while the charged write-control signal is employed to record data on the compact disk within the closed-loop mode.

Abstract: A method and related apparatus for feedback control of laser power provided by a pick-up head of an optical disk drive. The pick-up head can adjust a cross-voltage of a laser generator according to a signal level of a control signal such that the laser power is changed correspondingly. The method includes updating the signal level of the control signal according to feedback of the cross-voltage or the control signal, such that the laser power is adjusted accordingly.

Abstract: An apparatus and related operating method for generating slice levels adapted to an optical system is disclosed. The apparatus basically encompasses a multiplexer, a low-pass filter, a digital signal processor (DSP), a digital-to-analog converter, and a comparator. In the beginning of the track-crossing operation, the optical system will enter the first DAC mode that a pre-stored slice level derived from a calibration process is accessed and converted by the digital-to-analog converter before being referred as the slice level in the first DAC mode. When the low-pass filter can follow the RFRP signal variations, the low-pass filter is used to receive the RFRP signal and derive the slice level in the low-pass-filter mode. When a track-on command is given, the optical system will enter the second DAC mode and find an average value of the last peak-hold and bottom-hold values derived at the end of the low-pass-filter mode.

Abstract: The invention provides a method of adjusting a tracking location in an optical storage device. The method is illustrated as follows. Firstly, the optical pickup head reaches the first tracking location according to a tracking error (TE) signal. Secondly, the optical pickup head is finely moved to an adjusted tracking location where the value of the amplitude of RFRP signal is maximum. The method can avoid wrong tracking location by simply based on the TE signal, then enable the optical pickup head to reach the correct track center and improve the quality of data reading.

Abstract: A multiplier for obtaining the product of elements in a Galois Field. The multiplier performs the multiplication of two n-bit elements, A(an-1, an-2, . . . , a3, a2, a1, a0) and B(bn-1, bn-2, . . . , b3, b2, b1, b0) in the Galois Field to yield the product C(cn-1, cn-2, . . . , c3, c2, c1, c0), wherein n≧1 ai(i=0˜n-1), bj(j=0˜n-1), and ck(k=O˜n-1) are all binary bits. The multiplier includes: an AND planer, for performing an AND logic operation of every bit ai in A(an-1, an-2, . . . , a3, a2, a1, a0) and every bit bj in B(bn-1, bn-2, . . . , b3, b2, b1, b0) to obtain (an-1bn-1, an-1bn-2, . . . , an-1b0, an-2bn-1, an-2bn-2, . . . , an-2b0, a0bn-1, a0bn-2, . . . , a0b0); and an XOR planer, for performing an XOR logic operation of the output from the AND planer to obtain C(cn-1, cn-2, . . . , c3, c2, c1, c0).

Abstract: A reference clock generating circuit of a disk data burst cutting area is disclosed. Thereby, the BCA reference clock is generated by dividing the reference clock of a spindle control circuit for further capturing the BCA clock and the BCA data so that the BCA data and BCA clock are stably generated even if the rotary speed of the motor is changed.

Abstract: A method for protecting a phase lock loop (PLL) in an optical system is disclosed. The disclosed method will determine whether the currently reading data is erroneous and then maintain the frequency currently locked by the PLL circuit when the waveform lengths of the EFM signal in a detecting window contain at least one waveform length longer than 11T and at least one waveform length shorter than 3T. Otherwise, the PLL circuit will adjust the locked frequency according to the waveform length of the detected EFM signal so that the system clock frequency can be adjusted based on the locked one. In addition, when the optical system seeks tracks for reading required data under a constant angular velocity (CAV) modulation mode, the PLL circuit will increase the locked frequency gradually as the pick-up head moves towards the outer tracks of the optical disc, and decrease the locked frequency gradually as the pick-up head moves towards the inner tracks of the optical disc.