摘要:
A disc player having a prepit detecting circuit which can correctly detect prepits even if phases or amplitude levels of a plurality of read signals read out from a recording disc are deviated from each other. A phase difference between a first read signal and a second read signal read out by first and second reading elements arranged in two regions divided along the direction of recording tracks of a recording disc is detected. A first phase correction read signal is obtained by adjusting the phase of the first read signal by an amount according to the phase difference. A differential value between the first phase correction read signal and the second read signal is outputted as a prepit detection signal.
摘要:
An information recording apparatus (S) records record information onto an optical disc (1), which corresponds to a CLV (Constant Linear Velocity) method to keep a linear velocity of the optical disc constant when reproducing the record information from the optical disc. The information recording apparatus is provided with: an optical pickup (14) having a laser (14a) for irradiating a light beam (B) from the laser onto a record track of the optical disc and for detecting a reflected light from the optical disc; a rotation controlling device (11, 17 to 20) for rotation-controlling the optical disc to keep a rotation angular velocity of the optical disc constant when recording the record information onto the optical disc; and a laser drive controlling device (11, 15, 16) for obtaining an optimum value of a laser driving amount for the optical pickup in correspondence with a linear velocity of the record track of the rotation-controlled optical disc with respect to the optical pickup and for drive-controlling the laser by use of the obtained optimum value of the laser driving amount.
摘要:
An optical pickup for reading information from a recording medium having a plurality of prepits or for recording information onto the recording medium is provided. The optical pickup includes: a light emitting device for emitting a light beam to the recording medium; a dividing device for dividing the light beam reflected by the recording medium into a first divided beam and a second divided beam; an astigmatism producing device for producing astigmatism in the first divided beam; a first light receiving device for receiving the first divided beam from the astigmatism producing device; and a second light receiving device for receiving the second divided beam from the dividing device.
摘要:
A disc type identifying system for efficiently identifying one optical disc type from others having different recording formats, though having the same size and shape, is provided. The disc type identifying system comprises driver for rotating a disc to be identified a predetermined number of rotations; frequency detector for detecting frequency of a playback signal from the disc to be identified; and identifier for identifying the disc type based on the frequency of the playback signal detected when the disc to be identified is rotated the predetermined number of rotations. The predetermined number of rotations is set at the lowest linear speed among linear speeds defined in the different recording formats. Because the disc type may be identified in the process of a startup operation of a combination unit by constructing as described above, the startup time may be shortened, thus enhancing the efficiency of the system.
摘要:
The light measurement apparatus according to the present invention includes: an integrating sphere; a reference calibration light source body holding unit that is arranged on the integrating sphere and to which a reference calibration light source body is attached; a test light source body holding unit that is arranged on the integrating sphere and to which a test light source body to be measured is attached; a light detection unit that is arranged on the integrating sphere and detects light from the reference calibration light source body and the test light source body; and a control unit that controls lighting of the reference calibration light source body and the test light source body, the light measurement apparatus being configured so that only either one of the reference calibration light source body and the test light source body is able to selectively emit light in the integrating sphere.
摘要:
When a medium selection button 101 is operated, an optical disc reproduction apparatus 1 recognizes which medium is selected according to inputted medium selection information, and then opens a tray 104. Next, when a medium selection button 101 is operated, the optical disc reproduction apparatus 1 determines the inputted medium selection information and closes the tray 104. Next, the optical disc reproduction apparatus 1 acquires a priority list 16 and modifies the priority list 16 such that the order of the selected medium in the priority list 16 is a first priority and the remaining orders of the other media are successively lowered. The optical disc reproduction apparatus 1 performs a medium check for each of the media in accordance with the orders of the modified priority list 16.
摘要:
A sufficient S/N ratio in reproduction of an optical disk is achieved without complexing a circuit structure even if a data recording speed relative to the optical disk is increased. When data is recorded into an optical disk (DK), in an information recording and reproduction device (RP), both a first light beam and a second light beam are emitted at the same time. A sub-actuator section (20) is provided in addition to a main actuator (15) for correcting the displacement of light collecting spots caused by the displacement between the optical axis of the first beam and the optical axis of the second beam. Only the optical axis of the second light beam is adjusted by the sub-actuator section (20).
摘要:
A tilt servo control device of an apparatus for recording information on and reproducing information from an optical recording medium set in the apparatus, the apparatus comprising an optical system for leading a laser beam emitted from a light source to a recording surface of the optical recording medium and a laser beam reflected by the recording surface of the recording medium to a photo detector and a read signal generator for generating a read signal in accordance with an output signal of the photo detector. The tilt servo control device determines a type of the optical recording medium, generates a tilt drive signal so as to reduce a tilt angle at a position of the laser beam irradiating the recording surface and an optical axis of the laser beam by a method for generating a tilt drive signal corresponding to the recording medium type, and drives a tilt angle adjuster for adjusting the tilt angle in accordance with the tilt drive signal.
摘要:
Linking gap detecting device and method in which a light beam is irradiated to an information recording track of an optical recording medium; a light detecting signal is generated by receiving reflected light of the light beam irradiated to the information recording track; a synchronous signal is detected from the light detecting signal; it is judged whether the existing interval of the synchronous signal lies outside a predetermined interval range or not; and the linking gap is detected on the basis of a result of the judgment.
摘要:
A tilt servo control device of an apparatus for recording information on and reproducing information from an optical recording medium set in the apparatus, the apparatus comprising an optical system for leading a laser beam emitted from a light source to a recording surface of the optical recording medium and a laser beam reflected by the recording surface of the recording medium to a photo detector and a read signal generator for generating a read signal in accordance with an output signal of the photo detector. The tilt servo control device determines a type of the optical recording medium, generates a tilt drive signal so as to reduce a tilt angle at a position of the laser beam irradiating the recording surface and an optical axis of the laser beam by a method for generating a tilt drive signal corresponding to the recording medium type, and drives a tilt angle adjuster for adjusting the tilt angle in accordance with the tilt drive signal.