Abstract: A method for recording information and information recording/reproducing apparatus wherein information of a plurality of sectors is recorded as one recording unit into an optical information recording medium, a recording area of which is constructed with a plurality of zones, each being different in a sector number per one round of track. Information is recorded per one recording unit into the optical information recording medium and a verify control is conducted after the recording of information, wherein a number of recording units for conducting the verify control for each of the zones is changed upon basis of a number of sectors per one round of track and a number of sectors for turning back by the one round of track.

Abstract: Given a CD-ROM drive having a plurality of speed ranges selectable in n-fold graduation and having linearly reduced rotational speeds within each speed range respectively between outer and inner sector and having the prescription that a reduction of the rotational speed automatically ensues given a negative read result, control means are provided that effective switching into a lower speed range when a predetermined noise level is upwardly transgressed and/or when vibrations occur.

Abstract: Usable in an optical disk player, a servo device and a servo method for an optical disk using a plurality of beams prevent a servo error due to a defect of the optical disk by forming two beam spots on a single track of the optical disk and selectively switching to perform a servo controlling in accordance with a lagging beam spot when a defect of the disk is detected during the servo controlling in accordance with a leading beam spot.

Abstract: When a deviated gravity disc is reproduced at a higher rate with the disc reproducing apparatus, an excessive vibration is generated and this vibration gives adverse effect on the disc reproducing apparatus and peripheral components/apparatuses, and/or may represent an annoyance to a user. A vibration information detector for detecting vibration of the disc reproducing apparatus or a deviated gravity information detector for detecting amount of gravity deviation of disc is provided, and as a result of such detection of an imbalance (i.e., excessive vibration or mass eccentricity), and a reproducing rate switching control controls sets and limits the reproducing rate of the disc reproducing apparatus to a substitute speed which is lower or higher than a normal reproducing speed.

Abstract: The invention provides an optical disk medium having a recording spiral formed by connecting groove tracks and land tracks alternately, and permitting detection of a connecting point between a groove track and a land track reliably is provided, and a method of tracking the optical disk medium and an optical disk drive apparatus for driving the optical disk medium. One part of an identification signal area is shifted by a predetermined distance in one radial direction from the center of a groove, while another part of the identification signal area is shifted by the same distance in the opposite radial direction from the center of the groove. A land/groove polarity of a sector is determined by the polarity of a tracking error signal and the order of the polarities during reproduction of an identification signal.

Abstract: In order to correct the change in the offset and amplitude of a tracking error signal because of the change in the position of an object lens from the center of an optical pickup, the offset amount and amplitude value of the tracking error signal with respect to the displacement amount of the object lens from the center of the optical pickup are checked beforehand, and the displacement amount of the object lens is estimated on the basis of a tracking correction signal by using an object lens displacement observer.

Abstract: An optical information storage unit optically stores information on a disk shaped recording medium by irradiating a laser beam on the recording medium. The optical information storage unit is provided with a section which controls a laser power of the laser beam irradiated on the recording medium depending on a rotary angle of the recording medium.

Abstract: In a CD drive 100, a tracking subsystem comprising tracking detector 330, a control processor 310 and tracking actuator assembly 340, is coupled to photodiodes A-F, to have the lens assembly 200 track a data track 140 on a disc 105. A vibration detector subsystem comprising a vibration detector 350, the control processor 310, and the speed setting function 315, is also coupled to photodiodes A-F, and the vibration detector subsystem disables the tracking subsystem and detects vibration of the lens assembly 200 at a resonant speed.

Abstract: An apparatus for reading an optical data carrier (1) in accordance with the invention, comprises a transducer (5) for optically reading an optically readable pattern recorded in substantially parallel data tracks of the data carrier (1). The transducer (5) generates a read signal (S0(t)) which is an indication of the optically readable pattern. The apparatus further includes unit for realizing a relative movement of the transducer (5) with respect to the data carrier (1). The apparatus also has correction unit (16, 17, 18) for reducing tangential tilt (IT) and error, signal generating unit (20) for generating an error signal (SE(t) for the correction unit. The apparatus characterized in that the error signal generating unit (20) are adapted to derive the error signal (SE(t)) from a temporal asymmetry of the response of the read signal (S0(t)) to the optically readable pattern.

Abstract: An aberration compensation device includes: a phase difference generator for receiving an input signal and for generating a phase difference used for compensating for an aberration induced in a light beam; a temperature detector for detecting a temperature of the phase difference generator; and a corrector for controlling the input signal to be inputted to the phase difference generator based on the temperature detected by the temperature detector thereby to correct a variation of a characteristic of the phase difference generator resulting from a temperature variation.

Abstract: A method for recording data on an optical disk, capable of detecting an abnormal state which may occur in the middle of data recording, preventing the abnormal state from damaging the optical disk, and recording data continuously from the position wherein the abnormal state happened after the abnormal state terminates. The method of the present invention comprises the steps of (a) examining if an abnormal recording state is encountered while recording data on the optical disk, (b) suspending data recording if an abnormal recording state is detected in step (a), (c) requesting retransmission of the data received in step (a) and receiving said data after said abnormal recording state terminates, and (d) recording said retransmitted data in a selected area on the optical disk.

Abstract: An apparatus in accordance with the invention for reading and/or writing information from/onto an optical data carrier (1) has a transducer (5) for generating a detection signal (S0) in response to a signal (x) recorded on the data carrier. The apparatus has correction unit (16, 17, 18) for reducing errors in the detection signal (S0) as a result of radial tilt. The apparatus further has error signal generating unit (20) for generating an error signal (Se) for the correction unit (16, 17, 18). The error signal generating unit (20) calculate the error signal (Se) from correlations between a first auxiliary signal (S1) and a second auxiliary signal (S2) and from correlations between the first auxiliary signal (S1) and a third auxiliary signal (S3), which auxiliary signals are derived from the detection signal (S0). The second (S2) and the third auxiliary signal (S3) are estimates of the recorded signal (x).

Abstract: Vibrations transferred to the outside are lessened and high performance against external vibrations and impact is maintained. Further, data is recorded and reproduced satisfactorily. A CD-ROM drive device is provided which is capable of reproducing data at a standard speed, a quadruple speed and a sextuple speed. When a disk is mounted to the CD-ROM drive device, TOC information is read in a playback state at the standard speed (ST1). Next, the disk is placed in a playback state at the sextuple speed and is set to a state held at a predetermined address position (ST2). It is distinguished using a tracking error signal, a control signal for a spindle motor, etc. whether the disk is either an eccentric disk or an unbalance disk (ST3). When the disk is found not to be either the eccentric disk or the unbalance disk, a playback speed is set to the sextuple speed. On the other hand, when the disk is found to be either the eccentric disk or the unbalance disk, the playback speed is set to the quadruple speed.

Abstract: A method of manufacturing an optical disc master from a glass substrate includes coating the substrate with a layer of photoresist, and applying an alkali-gel layer atop the photoresist. The coated substrate is then placed in an environment with a higher than normal humidity. The surface of the coated glass is selectively exposed to a beam of a writing laser, the exposure being controlled by digital information to be recorded on the disc. Exposed portions of the coated substrate experience a chemical reaction between the photoresist and the alkali material in the humid environment. Exposed portions are then developed and ablated thereby creating the pits and lands.

Abstract: Given a CD-ROM drive having a plurality of speed ranges selectable in n-fold graduation and having linearly reduced rotational speeds within each speed range respectively between outer and inner sector and having the prescription that a reduction of the rotational speed automatically ensues given a negative read result, control means are provided that effective switching into a lower speed range when a predetermined noise level is upwardly transgressed and/or when vibrations occur.

Abstract: A data recording method and device for an optical memory card which is adapted to prevent a recording error due to step-out during a data recording operation, and minimize a decrease in the recording capacity of an optical memory card. While data are recorded, an output from an SYNC mark detection circuit (2) and an output from an internal synchronization signal generation circuit (3) are compared with each other in a comparator circuit (4). When step-out occurs, a write signal generation circuit (5) is stopped and the data recording operation is interrupted, and a re-recording operation is started at a frame adjacent to the frame in which a recording error occurred, on the basis of the value in a write cycle counter, whereby a decrease in the recording capacity of the optical memory card is minimized.

Abstract: An optical recording and reproducing apparatus for adjusting a tilt of an optical pickup in accordance with an amount of jitter of a reproduction signal, a tilt adjusting method therefor, and a recording control method. The optical recording and reproducing apparatus includes an optical pickup having an object lens, a tilt adjusting unit for adjusting a tilt angle of the object lens, a jitter detecting unit for detecting an amount of jitter of a reproducing signal generated by the optical pickup from a disk, and a tilt controlling unit for minimizing the amount of jitter by feeding the amount of jitter detected by the jitter detecting unit back to the tilt adjusting unit. According to the optical recording and reproducing apparatus, there is no need for a space in which a displacement sensor detecting the tilt angle of the optical pickup faces the disk.

Abstract: Apparatus and method for automatically and non-invasively detecting and recording random and/or intermittent errors made during play by digital disc players without supervision, without need for invasive player component testing or disassembly, and without need for analyzing complex waveforms, or use of high level processors. Intermittent errors are found in an actual playback audio signal derived from the output of a digital disc player. A test digital disc prerecorded with a test tone comprising an expected audio signal is played, while an analyzer reads the actual playback audio signal produced, and detects deviations of the actual playback audio signal from the expected audio signal. To detect deviations of the actual playback audio signal from the expected audio signal, the analyzer can comprise an amplitude detection circuit, a phase detection circuit, and a noise detention circuit, each optionally generating character signals that simplify processing.

Abstract: A signal compensating apparatus is an apparatus for compensating a control signal which is generated on the basis of a light beam reflected by an optical recording medium and which includes information with respect to a relationship between a spot of the light beam and a track of the optical recording medium. The signal compensating apparatus has: a detecting device for detecting a damaged part of the control signal, which is caused by a defect of the optical recording medium or an obstruction existing on an optical path of the light beam or on the optical recording medium; a replacing signal generating device for generating a replacing signal whose level gradually varies so as to connect a level of a first normal part of the control signal immediately before the damaged part with a level of a second normal part of the control signal immediately after the damage part; and a replacing device for replacing the damaged part by the replacing signal.

Abstract: The demodulated signal from the optical disk, containing a plurality of addresses is supplied to the address decoder which sets error detection flags when address decoding fails. If all addresses fail to decode, an address interpolator performs address interpolation up to a stored maximum number of iterations, thereby allowing data to be continuously read out from the demodulated signal. The maximum number is stored in memory. If at least one address is decoded, the address interpolator selectively updates the stored maximum number to achieve higher performance in reproducing data items from the optical disk.

Abstract: The method and apparatus for testing the quality of an optical disk medium records test data in the outer area of an optical disk. This outer area of the optical disk is not used when manufacturing a prerecorded disk, and is also not used by users of write-once optical disks. The quality of the optical disk is judged based on the test signal produced from reproducing the test data in the outer area of the optical disk.