Abstract: A tilt can be detected highly accurately by minimizing the tilt detection error. An optical head includes: an objective lens for converging a light beam from a light source onto an optical disc; a photodetector section receiving the beam, reflected from the disc, at divided areas on its photodetection plane and outputting light detection signals from those areas; and a tilt detecting section for detecting a relative tilt between the lens and disc based on the detection signals.

Abstract: The present invention relates to a setup for storing data in a holographic storage medium, comprising a spatial light modulator medium (18), a detector (20), a holographic storage medium (10), a first lens (22) between the spatial light modulator medium and the holographic storage medium, and a second lens (24) between the holographic storage medium and the detector, wherein the distance between a surface of the spatial light modulator medium and a principal plane of the first lens corresponds to the focal distance of the first lens, and the distance between the principal plane of the first lens and a reference plane through the holographic storage medium corresponds to the focal distance of the first lens, wherein the distance between the reference plane through the holographic storage medium and a principal plane of the second lens corresponds to the focal distance of the second lens, and the distance between the principal plane of the second lens and a sensitive surface of the detector corresponds to the f

Abstract: The present invention relates to an optical system for performing radial tracking on an optical record carrier (100). The optical system contains light dividing means, e.g. a grating, for separating a light beam into a main beam (52) for reading and/or recording information as readable effects on the carrier, and a plurality of auxiliary beams (52a, 52b) applicable for radial tracking. The carrier contains readable effects arranged in multiple tracks in one or more spiral (s), where the one or more spiral (s) are separated by one or more guard band(s) (5, 15) in that two guard bands enclose multiple tracks.

Abstract: A recording medium includes a substrate having a microscopic pattern, which includes a shape of continuous substance of approximately parallel grooves formed with a convex shaped section and a concave shaped section alternating on a surface of the substrate. A recording layer is formed on the microscopic pattern and a light transmitting layer has a thickness of 0.05 mm to 0.12 mm formed on the recording layer. The microscopic pattern satisfies a relation of P??/NA, wherein P is a pitch of the convex shaped section, ? is a wavelength of a reproducing light beam and NA is a numerical aperture of an objective lens. The microscopic pattern also includes modulated address information formed on both side walls of the convex shaped section viewed from the light transmitting layer as a wobble, both the side walls being parallel to each other, and furthermore wherein the address information is modulated by the phase-shift keying modulation system.

Abstract: A hologram recording and reproducing system for recording or reproducing information to or from a hologram record carrier that stores an optical interference pattern of a reference beam and a signal beam therein as a diffraction grating, includes: light producing means that generates a reference beam and a signal beam based on a coherent beam in which the coherent beam is modulated into the signal beam according to information to be recorded; interference means that allows one of the reference and signal beams to propagate axially on an optical axis as a central region light flux and allows the other of the reference and signal beams to propagate coaxially and annularly in section as an annular region light flux surrounding the one spatially separated from the other in a same direction and converges both the reference beam and the signal beam on different focal points in the optical axis respectively through an objective lens optical system to cause interference between the reference beam and the signal beam;

Abstract: Light emitted from a radiation light source 1 passes through a diffraction grating 3a and is separated into transmitted light a, +1st order diffracted light b, and ?1st order diffracted light c. The transmitted light a, +1st order diffracted light b, and ?1st order diffracted light c are collected through an objective lens 7 on tracks on the signal plane 8a of an optical disc 8 in a partially overlapped state. Light reflected by the tracks on the signal plane 8a passes through the objective lens 7 and is incident upon light diverging means 13a.

Abstract: In an information recording medium comprising at least a substrate, a recording layer, and a resin layer, the substrate is formed with at least a pit corresponding to a read only area 31 and a groove corresponding to a recording/reproducing area 32 without overlapping with each other. A reflectivity of the recording layer is specified to be more than 10%. The recording layer and the resin layer are continuously adhered over both the read only and recording/reproducing areas 31 and 32. The information recording medium is characterized in that both push-pull signal outputs T1 and T2, which are reproduced from the read only area 31 and the recording/reproducing area 32 respectively, are more than 0.1 and satisfy an inequality 1.5?T1/T2?0.5.

Abstract: The present invention provides a method and apparatus for editing program search information. The scene descriptive information of optical disc program is edited into a search information unit when the optical disc program is inscribed on an optical disc or optical disc program is off-line edited. Said scene descriptive information includes description of the scene elements. Then said search information unit is edited into a search information file for use in optical disc search. By means of this solution, searching of keyword information, descriptive information of the scene as well as descriptive information of scene element are unified together and directly used as information to be searched, thus the present invention, being different from the conventional search information file such as the playlist which has only the pointer information but not the descriptive information of the object to be searched, simplifies the process of enhanced search.

Abstract: Disclosed herein is a misjudgment correction circuit, including, an edge detection section configured to detect, in a binarized full addition signal obtained by adding first and second signals of the same or opposite polarity, edges at which the logic value of the binarized signal changes, a push-pull signal acquisition section configured to acquire a binarized push-pull signal obtained by subtracting the second signal from the first signal, a majority decision calculation section configured to acquire, in chronologic order, a plurality of logic values of the push-pull signal between the two adjacent edges so as to determine, by a majority decision, the more numerous of the two logic values, and a wave correction section configured to correct the push-pull signal between the edges to the more numerous logic value determined by the majority decision calculation section.

Abstract: In electronic devices such as combination CD-ROM and MP3 recorder/players power is conserved by buffering audio or visual data in a solid state memory, preferably of the FLASH or DRAM type, before writing the data to a rotating hard disk. Alternatively, audio and/or visual data, including musical works and still pictures and video, read from a rotating hard disk may be buffered in the same solid state memory while being played. By rotating the hard disk drive only for transfer of audio-visual data, which is normally compressed, in blocks, the hard drive may be stopped both during relative lengthy accumulation, and/or use, of this data, and energy conserved.

Abstract: An apparatus comprising a center error creation circuit and a center error offset injection circuit. The center error creation circuit may be configured to generate a center error signal in response to light from a main laser reflected from a surface of an optical disc. The center error offset injection circuit may be configured to (i) determine a value of the center error signal when a lens in a sled housing is at a mechanical center and (ii) generate an offset signal based upon the value. The center error offset injection circuit generally measures an average value of the center error signal over a predetermined amount of time when a lens suspension which holds the lens in place is in a mechanical equilibrium state.

Abstract: In an information recording medium comprising at least a substrate, a recording layer, and a resin layer, the substrate is formed with at least a pit corresponding to a read only area 31 and a groove corresponding to a recording/reproducing area 32 without overlapping with each other. A reflectivity of the recording layer is specified to be more than 10%. The recording layer and the resin layer are continuously adhered over both the read only and recording/reproducing areas 31 and 32. The information recording medium is characterized in that both push-pull signal outputs T1 and T2, which are reproduced from the read only area 31 and the recording/reproducing area 32 respectively, are more than 0.1 and satisfy an inequality 1.5?T1/T2?0.5.

Abstract: The present invention relates to a method of calibrating a radial offset of an optical recorder after a recordable record carrier is inserted (1000), the method comprising the steps of: determining wobble signal amplitudes at different radial offset values of a radial control loop (102), finding an optimal radial offset value at which the wobble signal amplitude is substantially maximal (104), and recording the data on at least one wobbled recording track (T1, T2, T3, . . . Tn) of the recordable record carrier using the optimal radial offset value (106). This is useful for all optical recording devices.

Abstract: A method of reducing power dissipation in a variable-gain photo-detector circuit is described. The variable-gain photo-detector circuit has an output to output a main spot signal and at least one side spot signal. The main spot (M) and the side spot (Si or S2) are formed by separating a light beam into a main beam and at least one side beam and focusing the main beam on the main spot (M) and the side beam on at least one side spot (Si or S2) on an optical record carrier The method processes the main spot signal with a first averaging circuit having a first cut-off frequency. The side spot signal is processed with a second averaging circuit having a second cut-off frequency. The second cut-off frequency is lower than the first cut-off frequency. The above technique reduces power dissipation in the variable-gain photo-detector circuit and is useful for all optical devices.

Abstract: A pickup head transmitting mechanism of a disc drive is provided. The pickup head transmitting mechanism has at least a guide rod, a thread rod, and a transmitting unit. The guide rod is utilized for supporting the pickup head of the disc drive. The thread rod is utilized for driving the pickup head along the guide rod. The transmitting unit is assembled between the pickup head and the thread rod and has a seat and a movable element. Wherein, the seat is fixed on the pickup head and has at least a sliding way extending toward the thread rod, and the movable element is slidably assembled in the sliding way and has a rack located on a surface thereof facing the thread rod. The rack is engaged with the thread rod.

Abstract: The invention provides an optical scanning apparatus for appliances for recording or reproducing information using an optical recording medium, said scanning apparatus automatically matching itself to the curvature of a curved recording medium or of a recording medium with axial runout without there being different wire diameters for the resilient support of the lens holder (LH) or other additional damping means or an additional control loop for this purpose. This object is achieved by virtue of an arrangement comprising coils and magnets being provided which has an asymmetrical magnetic field distribution which is provided for matching the orientation of a lens (L) in the optical scanning device to a curved recording medium or to any axial runout in the recording medium.

Abstract: An acceleration pulse waveform adjusting circuit (10) and a deceleration pulse waveform adjusting circuit (11) change the amplitude of a track jump pulse in accordance to linear velocity, so as to stably carry out track jump over a wide range of linear velocities. In case tracking gain is to be changed according to the linear velocity, the acceleration pulse waveform adjusting circuit (10) and the deceleration pulse waveform adjusting circuit (11) make the amplitude of acceleration pulse larger and the amplitude of deceleration pulse smaller, respectively, when the tracking gain is high, so as to stably carry out track jump operation with the given tracking gain.

Abstract: A focus error signal is generated by a first-order diffracted light diffracted by regions 23b, 24b on a hologram plane 2a, and an offset of a tracking error signal is canceled by first-order diffracted light diffracted by regions 21a, 22a, 23a, 24a on the hologram plane 2a. Consequently, even when there is an error in the substrate thicknesses of optical discs, jitter of a reproduction signal at a focus control point can be reduced by decreasing the distance between the focus control point and the point where the jitter is minimized.

Abstract: A base of an optical pickup includes a first bearing portion through which one of two guide shafts disposed in parallel to each other is inserted and a second bearing portion through which the other guide shaft is inserted, and is slidable along the two guide shafts. Under the first guide shaft that is inserted through the first bearing portion, a nut hold portion for holding a nut that connects a member of a drive mechanism for driving the base and the base to each other is disposed on the base. The nut hold portion includes an insertion opening that allows the nut to be inserted along a direction substantially parallel to a longitudinal direction of the first guide shaft.

Abstract: An optical pickup for irradiating an information recording medium, such as a DVD, with a laser beam when an information signal is recorded or reproduced, and information equipment provided with the optical pickup.

Abstract: The optical information recording/reproducing unit distinguishes an unrecorded area of a set optical disc (step A100). Thereafter, recording is performed in the unrecorded area under a plurality of recording conditions wherein the recording power is changed with a bias power being constant, to select a recording power providing an optimum reproduced-signal quality (step B100). Subsequently, recording is performed using the selected recording power under a plurality of recording conditions wherein the recording power is fixed onto the selected recording power and the bias power is changed, to select a bias power providing an optimum reproduced-signal quality (step C100). The selected recording power and the selected bias power are set as the recording-use optical irradiation power and bias power, respectively (step D100).

Abstract: A method for calibrating a recording condition in an information recording unit includes: heating a recorded data pattern recorded on the information recording medium; reproducing the recorded data pattern after the heating, to measure a reproduced-signal quality; and determining a recording condition based on the measured reproduced-signal quality.

Abstract: An information recording medium (100) comprising (i) a first recording layer (layer L0) in which a first part of record data can be recorded and which has such a characteristic that the number of times of possibly rewriting the record data per unit area corresponds to a first number of times; and (ii) a second recording layer (layer L1) in which a second part of the record data can be recorded by use of a laser beam having passed through the first recording layer and which has such a characteristic that the number of times of possibly rewriting the record data per unit area corresponds to a second number of times; wherein frequently rewritten information (FS1), which is relatively frequently rewritten, can be recorded at least in the second recording layer

Abstract: An object of the invention is to provide an optical element for use in an optical information recording and reproducing device or a like device for recording or reproducing information with respect to an information recording medium using laser light, wherein the optical element is a resin optical element capable of suppressing lowering in transmittance due to deterioration by irradiation of light having a high energy density, and maintaining a high transmittance for a long time. To realize the above object, used is an optical element made of a silicon resin cured material obtained by subjecting a silicon resin composition containing a silsesquioxane compound to a curing treatment.

Abstract: Magnetic recording media conventionally require a time-consuming and cost-increasing task of recording servo pits on each individual disk. Disclosed are a magneto-optical recording medium and a recording and reproducing method for the magneto-optical recording medium. The magneto-optical recording medium has the structure in which at least a recording layer magnetized in a direction perpendicular to the plane is formed on a disk substrate, and allows a format signal to be formed thereon by changing the magnetization direction or the magnetic anisotropy of the recording layer or by oxidizing the recording layer to form pits. This structure significantly improves the disk productivity and reduces the disk cost and also enables the magnetic recording medium to have good characteristics including stable servo characteristics.

Abstract: A method for detecting a mechanical shock affecting on optical disc drive based on using the Focus Error (FE) and/or the Tracking Error (TE) servo-loop signals. An shock detection signal is generated as weighted time-integral of the servo loop signal, for example by using the integral signal of the PID controller of the servo loop, or a low pass filter, or digital integration by a Digital Signal Processor (DSP). A shock is considered to be detected if the shock detection signal exceeds a threshold value. A method for recording data onto an optical disc and the corresponding optical disc drive are also disclosed. The shock signal is monitored real time and the recording is interrupted if a shock is detected. The recording is resumed by linking from the last recorded area when the shock signal becomes low again.

Abstract: An object of the invention is to increase a transfer rate in data recording or data reproduction. A beam spot 10 is cyclically moved in a track set with a predetermined pattern. The track set is constituted of adjacent tracks of a predetermined number. In recording, the power of a laser beam is impulsively controlled with a predetermined intensity when the beam spot 10 crosses the middle of each of tracks 11, 12, and 13 to record data in the track set constituted of the tracks 11, 12, and 13. In reproduction, the data recorded in the track set constituted of the tracks 11, 12, and 13 is reproduced by sampling a reproduction signal to be generated in receiving reflected light of the light beam when the beam spot 10 crosses the middle of each of the tracks 11, 12, and 13.

Abstract: An optical pickup is opposed to an inner-radius portion of an optical disc that is set, and pits (a modulation signal) are read by applying laser light for a DVD to the inner-radius portion. The read-out modulation signal is decoded by inputting it to a CD decoder. If decoded disc information includes particular verification data, the optical disc is judged to be a legitimate optical disc of a particular type and formation of a visible image on the label surface is permitted.

Abstract: An information recording/reproducing device includes a radiation light source 1 such as a semiconductor laser, a spatial modulation element 6 that splits laser light 2 emitted from the radiation light source 1 into a large number of diffracted light rays, and an objective lens 7 that converges the large number of diffracted light rays onto different points. The laser light 2 emitted from the radiation light source 1 is split into a large number of diffracted light rays by the spatial modulation element 6, the large number of diffracted light rays are converged onto different points in the photosensitive layer 8b of the information recording medium 8 by the objective lens 7, and information is recorded in the photosensitive layer 8b of the information recording medium 8, using an assembly of these converging points. Accordingly, it is possible to provide an information recording device capable of realizing high-contrast recording in which stray light or diffraction has no influence during signal recording.

Abstract: A pre-recording region (13) and a post-recording region (14) are formed on a recording disk (1). In the pre-recording region (13), reproduction sequence control data (21) is unrewritably recorded. In the post-recording region (14), a reproduction data unit can be additionally written. The post-recording region (14) is divided into a plurality of unit regions (24). The reproduction sequence control data (21) is made to have a control data unit (23) corresponding with the unit region (24) by 1:1 relationship. The control data unit (23) is made to have information defining the recording position and the length of the corresponding unit region (24).

Abstract: An optical rotating plate has an optical rotating material layer. A phase plate is provided on a first surface side of the optical rotating plate and has at least one birefringent material layer. The first surface side is disposed toward an emitting side of an optical path, thereby giving different phase differences to a first linearly polarized light group containing at least a linearly polarized light having a first wavelength and a second linearly polarized light group containing at least a linearly polarized light having a second wavelength which is different from the first wavelength.

Abstract: An optical disk drive includes drive current generation unit for supplying a mark forming semiconductor laser drive current and a space forming semiconductor laser drive current; first high-frequency superimposition unit for superimposing a high-frequency component on the space forming semiconductor laser drive current; and high-frequency superimposition control unit for controlling the first high-frequency superimposition unit to stop the superimposition of the high-frequency component for a predetermined duration prior to a timing at which to switch from the space forming semiconductor laser drive current to the mark forming semiconductor laser drive current, eliminating positional variations on the disk of the mark leading and trailing edges due to the high frequency superimposition.

Abstract: An information recording medium for enabling quick finalization and efficient data recording/reproducing, and a recording/reproducing apparatus and method are provided. The information storage medium includes a finalization area of which both of an in-groove pre-pit and a land pre-pit are formed in at least a part, while the information storage medium is manufactured.

Abstract: An optical storage medium can be provided by which illegal usage of the optical storage medium involving an infringement on the copyright can be prevented effectively without impairment of the functions for reproducing physical format information and optical storage medium manufacturing information. The optical storage medium includes a main information region in which encrypted data information is recorded as a pit row that is capable of being read out by means of light and a control data region. In the control data region, key information for decoding the encryption of the data information, the physical format information and the optical storage medium manufacturing information are recorded by wobbling a groove.

Abstract: An optical information recording medium 1 is constructed by sequentially layering a reflective layer 11, a protective layer 12, a recording layer 13, a protective layer 14, and a light transmissive protective layer 15 on a substrate 10. As the recording layer 13, a recording layer containing ZnS, SiO2, and Sb as principal components, or preferably, a recording layer expressed by a compositional formula [(ZnS)x(SiO2)1-x]y(SbzX1-z)1-y (where 0<x?1.0, 0.3?y?0.7, and 0.8<z?1.0 are met and X denotes at least one element selected from a group of Ga, Te, V, Si, Zn, Ta, and Tb) is adopted.

Abstract: A last optimum parameter value control method is disclosed, with a laser parameter value being adjusted in a predetermined sequence at an ADIP/ATIP frame of an optical recording medium. Jitter is measured at each ADIP/ATIP frame in order to obtain an average jitter value for that particular frame, and hence parameter value.

Abstract: An optical pickup in which constituting components are arranged so that a dead space can be reduced and aberrations can also be reduced at a low manufacturing cost is provided. In an outward path for projecting a laser beam onto a recording surface 12 of an optical disc 11, the laser beam emitted from a laser diode 2 is reflected on a polarization mirror 3, polarized by a quarter wavelength plate 4, and then passed through an objective lens 5 so that the laser beam is focused on the recording surface 12 of the optical disc 11. In a returning path for receiving the laser beam reflected on the recording surface 12, the laser beam reflected on the recording surface 12 and passed through the objective lens 5 is polarized by the quarter wavelength plate 4, transmitted through the polarization mirror 3, reflected on a total reflective film 61 of the quarter wavelength plate 6, and then reflected on the polarization mirror 3 so that the laser beam is received by a photodiode 7.

Abstract: According to one embodiment, a pit having a shape wherein the shapes of the top of a recording mark (recording start position) and the end of the recording mark (recording end position) are symmetrical can be formed on a stamper master with high reproducibility. As a result, the noise level/jitter degree of the reproduction signal obtained by reproduction from an optical disc as a final product can be reduced, thereby manufacturing at low cost the optical disc from which a signal can be stably reproduced.

Abstract: A method of recording data optically to an optical disk having a plurality of sectors, in which each sector has a region to be recorded with data, the data is recorded in units of blocks, and the block includes a predetermined number of sectors and is a data unit including error correction codes. In recording data related to a content by dividing and recording the data in a plurality of sectors continuously, dummy data to be used for extracting a clock in phase lock loop (PLL) for data reproduction is recorded on a region adjacent before a sector from which data recording is started. The data related to the contents is recorded on sectors following the region recorded with the dummy data.

Abstract: An optical storage medium can be provided by which illegal usage of the optical storage medium involving an infringement on the copyright can be prevented effectively without impairment of the functions for reproducing physical format information and optical storage medium manufacturing information. The optical storage medium includes a main information region in which encrypted data information is recorded as a pit row that is capable of being read out by means of light and a control data region. In the control data region, key information for decoding the encryption of the data information, the physical format information and the optical storage medium manufacturing information are recorded by wobbling a groove.

Abstract: [Problems] To effectively perform optimal tilt adjustment. [Means for Solving the Problems] A tilt adjusting method adjusts a tilt angle of an actual incident light and reflected light with respect to an incident light and a reflected light under optimal tilt when recording and reproducing data onto/from an information recording medium. Two or more output signals having a balance between a signal component and a noise component changing with respect to a parameter of a correction object are extracted from the reproduction signal of the information recording medium and the signal component and the noise component are evaluated for performing signal correction, thereby calculating a first and a second coefficient. When the first coefficient is out of a set reference range, the tilt adjustment is performed by the first coefficient and when the first coefficient in the set reference range, the tilt adjustment is performed by the second coefficient.

Abstract: An optical head is provided with a light source for emitting a first laser beam having a first wavelength shorter than 430 nm, a two-wavelength light source for emitting a second laser beam having a second wavelength equal to or longer than 430 nm, a flat beam splitter in the form of a single plate for reflecting the first laser beam emitted from the light source, a wedge prism in the form of a single plate for reflecting the first laser beam reflected by the flat beam splitter and transmitting the second laser beam emitted from the two-wavelength light source, and an objective lens for focusing the first laser beam reflected by the wedge prism on an information recording surface of a BD. The light source is arranged such that the optical axis of the first laser beam emitted from the light source is inclined with respect to that of the second laser beam emitted from the two-wavelength light source. By this construction, the miniaturization of the optical head can be realized.

Abstract: An optical disk device is provided to carry out a stable operation of a reflection-type photo sensor which detects a position of an optical pickup unit and to simplify an assembly process.

Abstract: A hologram recording apparatus (300) records record information into a hologram recording medium (100) on which a hologram recording layer (11) and a position information recording layer (13). The hologram recording apparatus is provided with: a first recording device (101) for recording the record information into the hologram recording layer; and a second recording device (121) for setting an area portion of the position information recording layer in a recorded state, the area portion of the position information recording layer corresponding to an area portion of the hologram recording layer in which the record information is recorded.

Abstract: The invention relates to an optical drive for recording information on an optical carrier or disk (1). The optical drive has a radiation source (4) controllable by control means (50, 22) having calibrated values for a threshold current (I_THR_O) and a change current (I_delta_O). The control means (50, 22) is adapted for: 1) re-calibrating the change current (I_delta_O) using the corresponding threshold current (I_THR_O) to a re-calibrated change current (I_delta—1) by application of a power difference (delta_P), and 2) applying the re-calibrated change current (I_DEL—1) together with the calibrated threshold current (I_THR_O). The re-calibration is performed by refining or re-adapting the change current during operation of the optical drive. It is a distinct advantage of the present invention that the re-calibration of the change current can be performed with no or very little time consumption.

Abstract: An apparatus for assembling a lens module, is provided. The lens module includes a lens and a lens holder for receiving the lens. The lens holder has a through hole and a retainer formed in the through hole. The apparatus includes a base for supporting the lens holder, and a supporter formed on the base, for extending through the through hole of the lens holder and supporting the lens thereon. A height of the supporter is greater than a depth of the through hole of the lens holder. The supporter is movable relative to and away from the lens holder so as to place the lens on the retainer in the through hole of the base.

Abstract: A method and apparatus for determining the parameters for disc recording is provided. For those discs that haven't pre-stored recording information or have pre-stored recording information not meeting the quality requirement, according to the method of the present invention, set the initial values of record strategy parameters firstly, then perform disc recording test with a group of parameters that have close relevancy among each other according to the method designed in the experiment, and finally determine the relationship between each optimal parameters and the optical disc recording quality, so that optimal parameters value corresponding to each parameter can be obtained for disc recording. According to the present invention, the optimal disc recording parameters can be determined within the limited time and limited space of disc recording test.

Abstract: Provided is an optical disk device installed in a personal computer, including: an information creation unit that creates identification information for identifying the type of the personal computer based on a command transmitted from the personal computer; and a parameter selection unit that conducts switching, for parameter selection, concerning a parameter indicating an amount of unbalance of an optical disk, which has previously been determined depending on the type of the personal computer, in accordance with the identification information created by the information creation unit.

Abstract: A device for detecting wobbles on an optical disc is provided, where the device is utilized for generating a wobble signal according to a plurality of detection signals. The device includes an analog signal processing circuit, a pair of analog-to-digital converters (ADCs), and a digital signal processing circuit. The analog signal processing circuit is arranged to perform analog signal processing on the detection signals to generate a plurality of output signals. In addition, the pair of ADCs are arranged to digitalize the output signals to generate a plurality of digital values. Additionally, the digital signal processing circuit is arranged to perform digital signal processing on the digital values and generate an arithmetic output, where the arithmetic output is utilized for generating the wobble signal or utilized as the wobble signal. An associated method for detecting wobbles on an optical disc is further provided.

Abstract: A threshold voltage generating circuit detects the amplitude ?V of the wobble signal included in the push-pull signal, and generates a threshold voltage Vth based upon the amplitude ?V of the wobble signal thus detected. A first filter removes the high-frequency components from the push-pull signal, thereby extracting the wobble signal. A peak hold circuit holds the peak value of the wobble signal thus extracted by the first filter. A second filter extracts a DC signal which is the DC component of the push-pull signal. An amplifier amplifies the difference ?V between the output of the peak hold circuit and the output of the second filter, i.e., the amplitude of the wobble signal.