Abstract: According to one embodiment, a focus position control method includes irradiating a beam to an optical disc via an objective lens, receiving reflected light and outputting a signal, generating a focus error signal, detecting an amplitude of a signal high-pass-filtering the signal, detecting an intensity of a signal low-pass-filtering the signal, supplying a driving voltage corresponding to the focus error signal to a drive coil configured to move the objective lens to an optical axis direction of the beam when the amplitude is larger than the first value, or when the amplitude is not larger than the first value and the intensity is smaller than the second value, and supplying a driving voltage having a constant voltage value to the drive coil when the amplitude is not larger than the first value and the intensity is not smaller than the second value.

Abstract: According to one embodiment, when a focus servo goes off and the distance between an objective lens and a recording layer of an optical disc does not coincide with a focal length of the objective lens, a control voltage or current corresponding to an optical disc wobble stored in a memory is superimposed on a control voltage or current supplied to a driving mechanism to move an objective lens along an optical axis for re-focusing, and the superimposed voltage or current is supplied to the driving mechanism. Therefore, pull-in of a focus servo for re-focusing is possible in a short time.

Abstract: According to one embodiment, an optical disc apparatus includes a pickup which receives reflected light from an optical disc, a tracking error detecting section which detects a tracking error from an output signal of the pickup, a reproducing section which reproduces data in a phase lock state of a data phase, the data lock state being detected by a phase lock loop based on the output signal of the pickup, and a control section which renders a tracking servo of the pickup for the optical disc valid when a residual component of an error detection signal from the tracking error detecting section in a tracking servo-on state falls within a predetermined allowable range, and renders the tracking servo of the pickup invalid with release of the phase lock state.

Abstract: According to one embodiment, the invention provides an optical disk device having an irradiation section which applies a laser beam to an optical disk, a detection section which receives a reflected light emitted from the irradiation section and reflected from the optical disk to output a detection signal, and a discrimination section which performs focus search using the irradiation section and the detection section and determines whether the optical disk is a triple layer optical disk on the basis of the detection signal upon performing focus search.

Abstract: An area unused for recording the information is detected in an information recording layer that is the layer jump destination of an optical disk having a plurality of information recording layers. In the current information recording layer, a laser beam is temporarily moved to a position corresponding to the area unused for information recording, and thereafter, a layer jump operation is carried out.

Abstract: According to one embodiment, a focus position control method includes irradiating a beam to an optical disc via an objective lens, receiving reflected light and outputting a signal, generating a focus error signal, detecting an amplitude of a signal high-pass-filtering the signal, detecting an intensity of a signal low-pass-filtering the signal, supplying a driving voltage corresponding to the focus error signal to a drive coil configured to move the objective lens to an optical axis direction of the beam when the amplitude is larger than the first value, or when the amplitude is not larger than the first value and the intensity is smaller than the second value, and supplying a driving voltage having a constant voltage value to the drive coil when the amplitude is not larger than the first value and the intensity is not smaller than the second value.

Abstract: According to one embodiment, a device which identifies the types of recording media different in recording density including, a light source which outputs light at a predetermined wavelength, a photodetector which detects reflected light from one information recording layer of a recording medium having at least two information recording layers provided with a first recording density or a second recording density higher than the first recording density, a lens which condenses the light from the light source to present a minimum spot on one of the information recording layers of the recording medium, and a signal processing circuit which acquires a component containing characteristics peculiar to the information recording layer of the recording medium having the second recording density out of the reflected light detected by the photodetector.

Abstract: According to one embodiment, an optical disc apparatus includes a calculation unit that calculates a tilt of a disc, a determining unit that determines whether or not the tilt of the disc calculated by the calculation unit is larger than a preset predetermined reference value, and a correction unit that corrects the tilt of the disc calculated by the calculation unit.

Abstract: According to one embodiment, here is provided an optical disk apparatus including: a reading unit configured to read an address corresponding to a position of beam spot; a calculating unit configured to calculate, from the address corresponding to the position of beam spot, a seeking amount in making an access to a burst cutting area formed on a disk; and a movement unit configured to move the position of beam spot in accordance with the seeking amount calculated by the calculating unit.

Abstract: An optical disc apparatus includes a pickup unit, a pickup control unit, a data reading circuit, a PLL control circuit, a CPU, a RAM, a ROM, an LED drive circuit, an LED display unit, and an interface circuit. The CPU functions as at least a CD/DVD determining unit, a type-of-disc determining unit, a thread motor drive unit, a focusing servo executing unit, an obtaining unit, a threshold calculating unit, a number-of-peaks calculating unit, and a checking unit.

Abstract: An optical disc apparatus includes an optical pickup which irradiates a first laser beam for reproducing a first DVD medium, or a second laser beam for reproducing a second DVD medium onto a installed optical disc, and receives the reflected light from the installed optical disc, a controller determines that the installed optical disc is the second DVD medium when a value by normalizing the amplitude of a RF signal generated from the reflected light with a coefficient is larger than first threshold value and smaller than a second threshold value, and the controller determines that the installed optical disc is the first DVD medium when the value is not larger than first threshold value and smaller than a second threshold value.

Abstract: An optical disc apparatus comprises a focus error detector which detects a focus error, a focus adjusting unit which adjusts a focus of a light beam at either of recordable layers based on an output from the focus error detector, a wobble signal detector which detects a wobbled groove and outputs a wobble signal, and a controller which holds an output of the focus error detector when a level of the wobble signal detected by the wobble signal detector is lower than a threshold level.

Abstract: An area unused for recording the information is detected in an information recording layer that is the layer jump destination of an optical disk having a plurality of information recording layers. In the current information recording layer, a laser beam is temporarily moved to a position corresponding to the area unused for information recording, and thereafter, a layer jump operation is carried out.