Abstract: An optimal recording apparatus and method for optical recording media are disclosed which are capable of recording data on the optical recording medium under optimum conditions in an optical recording/reproducing apparatus. In accordance with the optimal recording apparatus and method, a reference power value recorded on an optical recording medium is first read out. Test data is then recorded onto a first field of a test data in the optical recording medium under a condition in which a recording power value is varied with reference to the read power value. The test data recorded on the first field is subsequently reproduced in order to determine an optimum recording power value from the reproduced characteristics. Based on the determined optimum recording power value, test data is recorded on a second field of the test area under a condition in which a format of recording signals is varied. The test data recorded on the second field is subsequently reproduced in order to determine an optimum write strategy.

Abstract: An optical scanning device (1) for scanning an information layer (2) includes a radiation source (6) for supplying a radiation beam (14), a lens system (7) having an optical axis (OO?), and a detection system 8) including: (i) an astigmatism generating element (9) for generating a first amount of astigmatism (W1) represented by a vector (Wo,1, ?1), so as to transform the radiation beam to a first astigmatic radiation beam (29); (ii) an astigmatism correcting element (27) for generating a second amount of astigmatism (W2) represented by a vector (Wo,2, ?2), so as to transform the first astigmatic radiation beam to a second astigmatic radiation beam (30) having a third amount of astigmatism (W3) represented by a vector (Wo,3, ?3), and (iii) a detector (28) for transforming the second astigmatic radiation beam to an electrical signal. According to the invention, W3 is adapted to the detector and that Wo,2 and ?2 comply substantially with the following equation: (Wo,1, 2?1)+(Wo,2, 2?2)=(Wo,3, 2?3).

Abstract: Disclosed is an optimal recording method for optical recording media which is capable of recording information about optimum recording conditions on an optical recording medium in order to allow a subsequent recording of data at an optimum recording power, based on the recorded optimum recording condition information. In this method, test data is recorded to allow derivation of an optimum power value based on reproduction characteristics of the test data. An intrinsic recorder ID information of an optical recording/reproducing apparatus, used to record data on the optical recording medium, and information about the record speed of the apparatus are recorded, along with the derived optimum power value, onto the count area of the optical recording medium or respective lead-in areas of sessions. The apparatus reads out the recorded optimum recording condition information when data is subsequently recorded onto the optical recording medium.

Abstract: The present invention writes location information on representative audio sections, each being specified within an audio track by a user, for audio tracks recorded in a high-capacity storage medium, and, if requested, reproduces representative audio sections only using the written location information, thereby helping a user find a desirable audio track easily and quickly among a lot of recorded audio tracks.

Abstract: An optical recording medium and an optical recording and reproduction device including the same, wherein the optical recording medium comprises a substrate, a reflective layer formed on the substrate, a recording layer formed on the reflective layer, a first protective layer formed on the recording layer and a transparent heat radiating layer formed on the first protective layer for promoting dispersion of heat from the recording layer, and light is focused on the recording layer from an optical system via a side at which the first protective layer is formed to prevent heat buildup, erasure of recorded signals and damage to the optical recording medium.

Abstract: An information recording medium reproducing system has an insertion opening, a recording medium storing portion and a medium carrying device. Photodetectors are provided for detecting passing of the recording medium and for producing a passing signal when the medium passes. A controller is provided for controlling operation of the medium carrying device. The controller applies a discharge signal to the medium carrying device when the passing signal is not produced within a predetermined time, whereby the medium carrying device is actuated in discharge operation.

Abstract: A data recorder for writing data to a recording medium that prevents buffer underrun errors. An optical head generates a laser beam at a high power level when writing data on the recording medium and at a low power level when reading data from the medium. The writing of data is interrupted when there is a possibility of a buffer underrun error. When restarting data writing from where the interruption occurred, the laser beam is shifted from the low power level to the high power level before reaching the location at which the interruption occurred. This guarantees that the laser beam has the required power level when writing is restarted.

Abstract: Improvements in the shape of three-dimensional features displayed in optical recording structures, particularly in such structures displaying features of differing dimensional characteristics. The shape improvements include reductions in berm height and width, dual level data marks and tracking guides, and land areas projecting above or into the surface of the recording structure.

Abstract: A storage apparatus comprises a storage medium (27) on which information can be stored in form of electronic charge. The storage medium (27) comprises a plurality of separated electrically conductive charge-storing elements (4) on its surface. The apparatus further comprises a read/write head (28) with which the information can be written to and/or read from the storage medium (27). Additionally, it contains driving means (29, 30, 31) which serves to move the read/write head (28) and the storage medium (27) relatively to each other. The read/write head (28) comprises cantilever means (2) with an electrically conductive read/write tip (1) which is connected to read/write means (24). For writing, a charge-, voltage or current source (33) that delivers the electronic charge is provided. For reading, measure means (36) which measures the electronic charge is provided.

Abstract: An optical disk for a sampled servo system is provided with a servo area having a synchronization pit serving as a synchronization reference of reproduction; and a data area having a plurality of data pits which records the digital data and a tracking pit which serves as a tracking reference of the reproduction. The data pits are provided with first data pits and second data pits; and the tracking pit is located between the first and the second data pits. The tracking pit is located at a predetermined position in the data area. A pit row of the plurality of data pits and the tracking pit has the identical pit period. A pit row of the plurality of data pits and the tracking pit has a reverse phase between adjoining two tracks.

Abstract: A polarizing beam splitter for separating an upstream beam from a downstream beam according to the polarization of an incident beam is provided between first and second light sources emitting laser beams at respective wavelength and an objective lens. A phase plate for providing a phase difference to a beam incident on the polarizing beam splitter is provided between the polarizing beam splitter and the light sources. A portion of the laser beam incident on the polarizing beam splitter is reflected by the polarizing beam splitter and caused to be incident on a photo-detecting unit, so as to prevent an unnecessary portion of the laser beam is incident on the photo-detecting unit. According to the invention, the laser beam is used efficiently and the cost of fabricating an optical disk apparatus is reduced by eliminating a need for a gain controlling circuit in the photo-detecting unit.

Abstract: Disclosed is a method and apparatus for controlling the record and reproduction of optical record medium in which plural non-record regions having different phase are arranged between recordable data regions for the distinction in the shape of the data region. The method and apparatus performs the servo using focus error signal and tracking error signal averaged by the low pass filter at the header region of the optical disc. Especially, the tracking servo is performed by holding a fixed DC off-set value at the header region existing on the L/G switching or holding the tracking error value of the previous same track region. As a result, the exact header region is detected, the track sliding phenomenon is removed, and the tracking servo is stabilized, resulting in preventing the degeneration of the record and reproduction characteristics.

Abstract: A record carrier (1) has a servo track (4) indicating an information track (9) intended for recording information blocks represented by marks, the servo track (4) having a periodic variation of a physical parameter at a first frequency and modulated parts for encoding record carrier information. The modulated parts have a bit synchronization element constituted by a phase modulation of the periodic variation and a data part having data bits of the record carrier information encoded by direct digital modulation. Alternatively, the modulated parts include a second frequency, which is substantially different from the first frequency, for encoding data bits of the record carrier information, the second frequency being a integral multiple N of the first frequency. A recording and/or playback device has a device for recording/reading the information blocks and for reading the record carrier information.

Abstract: Signal quality evaluation is performed using a predetermined reproduction signal, a first pattern corresponding to a signal waveform pattern of the reproduction signal, and a given pattern corresponding to the signal waveform pattern of the reproduction signal and being different from the first pattern.

Abstract: First and second laser beam sources generate first and second laser beams of different wavelengths, respectively. A first collimating lens diverges the first laser beam at a predetermined angle so as to permit a fracture surface aberration of the first laser beam to fall below a predetermined value when the first laser beam generated from the first laser beam source is collected on the signal layer of the optical disk. A light receiving lens collects the laser beam reflected from the signal layer of the optical disk on a photo diode in the form of an optical spot of a predetermined size. A holographic lens has a pattern by which the first laser beam is converted into parallel rays so that the size of a spot of the first laser beam becomes identical with the size of a spot of the second laser beam as projected on the detecting section.

Abstract: A tuned circuit is used to detect wobble clock inversions. The tuned circuit reacts to a wobble inversion with a change in amplitude that may be detected by a threshold detector. A bandpass tuned circuit is used to detect wobble clock inversions. The output of the bandpass tuned circuit is input to a saturating high-gain amplifier such as a comparator. The output of the saturating high-gain amplifier reacts to wobble inversions with a half-cycle that has an increased duration as compared to half-cycles without wobble inversions.

Abstract: There is disclosed a small lightweight optical information storage apparatus which can obtain a sufficient writing light quantity, and an optical device which can realize the optical information storage apparatus. The optical device for use in the optical information storage apparatus has a splitting surface constituted of a part of a cylindrical surface. A light emitted from a light source is passed via the optical device and directed to an optical information storage medium, and a signal light is split from a return light from the optical information storage medium by the optical device.

Abstract: A recording apparatus for holographic recording medium having an alignment mark and designed to irradiate a recording light beam onto a recording region of holographic recording medium to record information as a hologram. This apparatus comprises a recording laser recording the hologram onto the medium, an alignment laser irradiating an alignment light beam onto the medium, the alignment light beam being less absorbed than the recording light beam by the medium, and being reflected by the medium, a first lens converging the recording light beam and directing it toward the medium, a second lens converging the alignment light beam and directing it toward the medium, a photodetector detecting a light intensity of the alignment light beam reflected from the medium to recognize the alignment mark, and a driving mechanism adjusting a region to be irradiated with the recording light beam relative to the medium based on the alignment mark.

Abstract: A method of recording additional information of a disk name of an optical disk, title information of a recorded program, etc., on the optical disk. Communication data containing edit data entered through a portable electronic machine capable of conducting wireless communications with an optical disk recording apparatus is transmitted by the portable electronic machine to the optical disk recording apparatus using the wireless communications and the edit data is recorded on the optical disk as additional information.

Abstract: An optical disc drive usable with discs to which data is continuously recorded and discs having a sector format can quickly resume playback signal output after passing imperfection causing potential reading errors, and plays disc with few read errors. A detection signal generator detects DC level fluctuation in the playback signal read from the disc and generates a detection signal tracking the DC level fluctuation. A selector selects a detection signal or a null signal without valid polarity based on the detection signal generated by the detection signal generator and input to the selector. A clamping unit performs a clamping process to suppress DC level fluctuation in the playback signal based on the detection signal when the selection unit selects the detection signal, and does not perform the clamping process when the selection unit selects the null signal. A signal processor performs specific signal processes based on clamping unit output.