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 reverse pattern is formed in a track adjacent to a specified track on an optical recording medium with a predetermined light beam capable of writing large recording marks. Thereafter, a normal pattern is formed in an area, of an adjacent track, which is adjacent to the reverse pattern in the specified track with recording light beams of various strengths, the adjacent track being adjacent to the specified track. The specified track is read to detect a plurality of re-out signals according to individual light beam conditions. The adjacent track is read to detect a plurality of read-out signals according to individual light beam conditions. An optimum recording condition is determined for the specified track from the plurality of light beam condition and the read-out signals from the specified track and the adjacent track, and information is recorded in the specified track according to the optimum recording condition.

Abstract: A boundary position search method and an information recording apparatus are provided for rapidly transferring a recording/reproducing head to a boundary position between a recorded region and an unrecorded region of a recording disc when new information data is recorded on the recording disc. In response to a recording start instruction, the recording/reproducing head is first forcedly transferred in a radial direction of the disc, while confirmation is made as to the presence or absence of an RF signal carrying an information signal in a read signal. A slider unit is controlled to stop a transfer operation of the recording/reproducing head when a transition is detected from a state in which an RF signal exists to a state in which no RF signal exists.

Abstract: An optical pickup apparatus includes a photodetector for receiving a diffracted light reflected from the recording medium; and a tilt detector for detecting a tilt amount of the recording medium on the basis of a light intensity within an interference region of a 0th-order diffraction light and at least one diffraction light other than the 0th-order diffraction light of the reflected light received by the photodetector.

Abstract: A method and system for correcting tracking errors in an optical storage medium having multiple tracks arranged in different layers of the optical storage medium, directs a reading spot that is nominally focused on to a track in the optical storage medium, and continually moves the reading spot in axial and radial directions so as to receive a signal having an amplitude which varies according to respective offsets from the track in radial and axial directions. The received signal is used to determine a direction of a respective offset from the track in radial and axial directions, and a location of the reading spot is adjusted accordingly.

Abstract: An optical disk drive unit performing write power calibration which performs recording on a given test area of an optical disk by changing a write power and sets an optimum write power based on characteristic values obtained from reproduced signals from the given test area includes average calculation means for dividing the given test area into a plurality of areas, performing recording on the areas by changing the write power equally, and calculating averages of characteristic values obtained from reproduced signals from the areas, and optimum write power setting means for setting the optimum write power based on the averages of the characteristic values calculated by the average calculation means. Thereby, with the averages of the characteristic values obtained from the areas of the optical disk which areas are in angularly different positions, the effects of the periodic variation of the optical disk can be reduced and the optimum write power can be set with good accuracy.

Abstract: An information recording medium has a plurality of stacked recording layers. Each recording layer has a spiral track which defines a plurality of rounds, and at least one index header aligned in the radial direction of the disk to partially intercept the spiral track. The index header has address data of each round of the spiral track, which is formed by embossed pits, and some or all of the index headers of the first and second recording layers are laid out to overlap each other when viewed from the predetermined surface.

Abstract: To correct a bit shift of binary data read from a medium and further enable correction of a bit error caused by mis-correction of the bit shift, a data recovery apparatus according to the present invention comprises: circuits for respectively correcting time at an intersection of a read signal and a slice signal; and a circuit for generating gray bits representing a time cell including an intersection, the time of the intersection being uncorrected and a time cell adjacent to the time cell, positioned in the direction of the intersection being shifted for correction.

Abstract: An optical head 2 and a matrix circuit 3 cooperate, generating a signal form the light reflected from an optical disk 1. An evaluation-function generating circuit 5 generates an evaluation function from the signal reproduced from the optical disk 1. A controller 6 sets an initial focus value at a point where the evaluation function is minimal. The initial focus value is set in a servo circuit 7. The controller 6 sets an observation point deviating from the point at which it has set the initial focus value. The controller 6 corrects the initial focus value set in the servo circuit 7.

Abstract: An optical pickup is provided which includes a light source, an optical system for converging a laser beam emitted from the light source, and an optical element having a function of increasing a numerical aperture of the optical system, wherein recording and/or reproducing information on a recording medium is performed by using the laser beam from the light source while the optical element is brought in contact with or in close to the recording medium, and the optical element has a contamination-preventing structure.

Abstract: An object of this invention is to provide a recording apparatus, reproducing apparatus, recording method and reproducing method for recording or reproducing data in/from a recording medium while the recording medium is rotating by inertia after a rotation thereof by driving is stopped.

Abstract: There is an optical pickup apparatus 200 using a semiconductor laser element 50 having a first light emission part 36 and a second light emission part 40, wherein it is constructed so that in case that the first light emission part 36 is placed in a position in which an image height does not occur and the second light emission part 40 is placed in a position in which an image height occurs, when the first light emission part 36 is driven, the same focus driving currents are supplied from a focus driving part 120 and when the second light emission part 40 is driven, an objective lens 54b is driven in a focus direction with the objective lens inclined by generating an offset value having a predetermined value from an offset generation part 126 and varying one of the focus driving currents of the focus driving part 120.

Abstract: Both of one audio information and another audio information are recorded on a same information record medium. An audio information reproducing apparatus is provided with: a detecting device for detecting said one audio information and said another audio information from the information record medium and also detecting a time period required for one beat of the detected another audio information; and an accumulating device for accumulating said one audio information detected from the information record medium to thereby continue reproducing and outputting said one audio information through the accumulating device. The audio information reproducing apparatus is also provided with a controlling device for controlling the detecting device to detect said another audio information and the time period required for one beat, within a time duration that the accumulated one audio information is being reproduced and outputted through the accumulating device.

Abstract: When an error requiring a retry operation has occurred, information concerning the error requiring a retry operation is stored every time. The information includes a sector number (or beginning sector number and number of sectors), the content of the command; a write or read designation, and the number of the times of error occurrence in the sector (or number of the times of retry operation), for example. In case of recording information, like the prior art, information to be written which is stored in a buffer memory is held as it is. Since the information concerning an error requiring a retry operation is stored, even though an error requiring a retry operation occurs repeatedly, a write and/or read operation of the next executable command to another track is executed without immediately switching to the retry operation. Thus, other commands are executed between the occurrence of the error requiring a retry operation and actual execution of the retry operation.

Abstract: A DVD playback apparatus accurately discriminates a hybrid disc, to prevent a recordable CD installed therein from being damaged by a laser beam for a DVD/MMCD. The hybrid disc includes a label printed surface formed on a substrate, a CD recording surface formed below the label printed surface, having identification information expressing a disc type, and a DVD recording surface formed below the CD recording surface. The DVD playback apparatus irradiates a CD laser beam on an optical disk installed therein. If data is readable from the optical disc, it is checked whether the identification information is recorded in the predetermined recording area. The DVD playback apparatus recognizes the optical disc as the hybrid disc, if the identification information is recorded in the predetermined recording area.

Abstract: An optical recording medium comprises a superresolution film which has a light transmittance varying in accordance with the intensity of incident light and which has a superresolution function for optically masking part of incident light to form an optical aperture having a smaller size than a spot size of incident light, the superresolution film including at least two kinds of superresolution films having different response times until the superresolution function occurs after being irradiated with light. Thus, it is possible to easily and surely reduce the light spot size to greatly enhance the recording density. In addition, it is possible to extend the operating wavelength range by providing at least two kinds of superresolution films having different operating wavelengths causing the superresolution function.

Abstract: In a CIRC encoder for carrying out error correction coding processing with a CIRC, a first interleaver and a second interleaver are provided which have different delay parameters, and these interleavers are switched in accordance with the recording density of an optical disc for recording data. Also, in a CIRC decoder, a first deinterleaver corresponding to the first interleaver and a second deinterleaver corresponding to the second interleaver are provided, and these deinterleavers are switched in accordance with the recording density of an optical disc for reproducing data. A recording/reproducing system is realized which is capable of carrying out appropriate recording and reproduction of data to and from an optical disc having a higher recording density can be carried out and is also capable of handling an optical disc of an existing format.

Abstract: A driving device for an optical storage medium, includes: an optical pickup for reading out information from an information track on the optical storage medium; a tracking error signal generator for generating a tracking error signal from the information read out by the optical pickup; a tracking controller for controlling the optical pickup to follow the information track on the optical storage medium based on the tracking error signal generated by the tracking error signal generator; a disturbance detector for detecting a magnitude of a disturbance of the tracking error signal caused by impediments existing on the optical storage medium; a correction signal generator for generating a correction signal corresponding to the magnitude of the disturbance of the tracking error signal detected by the disturbance detector; and a limiting unit for limiting an operation of the tracking controller in accordance with the correction signal generated by the correction signal generator.

Abstract: A disturbance compensation module using learning control generates a control input to compensate for track position errors due to a periodic disturbance occurring in an optical recording medium in an optical recording medium drive servo system of an optical recording/reproducing apparatus. The module includes a first filter to filter the track position errors and a memory to store control inputs to compensate for a track control cycle in a corresponding address. A second filter filters the control inputs stored in the memory. An adder adds the filtered track position errors from the first filter to the filtered control inputs from the second filter and outputs a result to the memory, updating the control inputs to compensate for the track position errors.

Abstract: An optical system including an objective lens applies five light beams (31 to 35) generated by an optical pickup to a plurality of adjacent tracks on a signal plane of a CD-ROM. Light beams reflected from the signal plane are detected with photodetectors (PD1, to PD6), and in accordance with the detection outputs of the photodetectors (PD1 to PD5), a record data read system reads at the same time data recorded on respective tracks applied with the light beams (31 to 35), and outputs to read data in the record order of CD-ROM by preventing the read data from being duplicated or omitted. Prior to reading record data, a system controller performs an offset bias adjustment of a focus servo system.