Patent application number | Description | Published |
20090086592 | OPTICAL DISC APPARATUS SWITCHING FOCUS POINT BETWEEN LAYERS - A focus jump technique enables focus control on recording layers of a disc in such a manner that its effect is not absorbed by disturbance or a variation in the movement speed of an objective lens. The technique involves monitoring level of a focus error signal and rejecting noise from the error signal. A speed sensor detects movement speed of an objective lens; and a speed control circuit generates a voltage for controlling the objective lens, based on the detected movement speed. Movement speed of the objective lens is detected during focus jump, a corresponding lens drive signal is generated, and an end position is determined from behavior of the error signal immediately before the end of the jump. A focus control is pulled, from a focus point corresponding to one recording layer, into a focus point corresponding to another recording layer forcibly in a stable manner. | 04-02-2009 |
20090135684 | Defocus Detection Device, Defocus Detection Method and Optical Disk Unit Using the Same - Defocus detection device and method capable of detecting a defocus accurately during recording of information to an optical disk having a plurality of recording layers and an optical disk unit using the device and method are provided. A temporal restriction is imposed on defocus detection and besides, in comparison with a level for detection of a first change of a focus error signal developing during a defocus, a level for detection of a successively occurring second change of a polarity inverse to that of the first change is made to be smaller. When the first level is exceeded and thereafter the second level is exceeded within a restricted time, a defocus is detected. | 05-28-2009 |
20090296544 | OPTICAL DISK DEVICE - There is a need to prevent a possible erroneous detection of an off-track condition during recording to an optical disk. The above need can be addressed by, for example, determining an off-track condition has occurred when a light spot is located at least half-way from the track being recorded toward another track adjacent the track being recorded, and stopping a recording operation. In another example, the above need can be addressed by determining that off-track has occurred based on an output of a first off-track detector which detects that the light spot is off the track based on a wobble signal, an output of a second off-track detector which detects that the light spot is off the track based on a tracking error signal, and an output of a zero-cross detector which detects that the tracking error signal crosses zero based on an output of the tracking error signal. | 12-03-2009 |
20090303847 | OPTICAL DISC APPARATUS THEREFOR - There is a need to accurately lock focus of a laser beam onto a target data layer of a multilayer optical disc. The above need can be addressed by, for example, performing a focus lock operation after a spherical aberration correction amount is set in such a way as to make smaller the ratio of the focus error signal waveform amplitude at the data layer adjacent to a target data layer through which a laser beam passes earlier than through the target data layer to the focus error signal waveform amplitude at the target data layer than that when the spherical aberration correction amount is set so as to be optimal for the target data layer. | 12-10-2009 |
20100118670 | SERVO CONTROL SIGNAL GENERATION DEVICE AND AN OPTICAL DISK DEVICE USING THE SAME - A servo control signal generation device for discriminating a kind of an optical disk, changing over between top and bottom envelope signals of an RF signal, and generating a defect signal and a mirror signal includes an RF generator for generating the RF signal from reflected light of an optical disk, a disk discriminator for discriminating a kind of the optical disk from the RF signal, and a top envelope generator and a bottom envelope generator respectively for generating the top and bottom envelope signals of the RF signal. If the disk has reflectance after recording which is lower than that before recording, the defect and mirror signals are generated respectively from the top and bottom envelope signals. If the disk has reflectance after recording which is higher than that before recording, the defect and mirror signals are generated respectively from the bottom and top envelope signals. | 05-13-2010 |
20100149937 | MULTI-LAYERED OPTICAL DISK AND OPTICAL DISK DEVICE - There are provided a multi-layered optical disk and an optical disk device capable of swiftly reproducing control information recorded into a predetermined recording layer in advance. The object can be accomplished by employing the following configuration: When the optical disk device performs a focus lead-in operation into the multi-layered optical disk, the device positions its optical pickup at a BCA radius position, and takes advantage of a signal which is generated such that an influence exerted on the signal by BCA is avoided. Also, the object can be accomplished by employing the following configuration: An angle index unit for indicating a rotation reference position is provided in the multi-layered optical disk, and a partial area of the BCA is selected as an unrecording area. The optical disk device starts the focus lead-in operation in synchronization with rotation angle information created from the rotation reference position. | 06-17-2010 |
20100226239 | MULTILAYER OPTICAL DISC - A multilayer optical disc which has three or more recording layers and enables easy positioning of a focused beam spot onto a particular recording layer in which a BCA is disposed. An inter-layer distance between a particular recording layer and a recording layer adjacent to the particular recording layer is larger than the other inter-layer distances in which, at the focused beam spot positioning, the focused beam spot traverses the said adjacent recording layer earlier than the other recording layer adjacent to the particular recording layer. | 09-09-2010 |
20100260026 | MULTILAYER OPTICAL DISC - In a multi-layer optical disc, having three ( | 10-14-2010 |
20110044144 | OPTICAL DISC APPARATUS SWITCHING FOCUS POINT BETWEEN LAYERS - A focus jump technique enables focus control on recording layers of a disc in such a manner that its effect is not absorbed by disturbance or a variation in the movement speed of an objective lens. The technique involves monitoring level of a focus error signal and rejecting noise from the error signal. A speed sensor detects movement speed of an objective lens; and a speed control circuit generates a voltage for controlling the objective lens, based on the detected movement speed. Movement speed of the objective lens is detected during focus jump, a corresponding lens drive signal is generated, and an end position is determined from behavior of the error signal immediately before the end of the jump. A focus control is pulled, from a focus point corresponding to one recording layer, into a focus point corresponding to another recording layer forcibly in a stable manner. | 02-24-2011 |
20110051575 | FOCUS JUMP METHOD AND OPTICAL DISC APPARATUS - An optical disc apparatus includes a multilayer optical disc having a reproduction-only recording layer and a recording layer of the recordable area, on the disc, to record and reproduce the disc by the same wavelength laser light, so that a seek operation is performed rapidly, and a generation method tracking error signal (TE) is switched over by using a DPD method and push-pull method in response to a target layer to which a focus jump is applied, for a time period during which a tracking servo loop is opened in association with a focus jump. | 03-03-2011 |
20110051589 | Optical Disc, Optical Disc Reproducing Apparatus, Optical Disc Apparatus, Reproducing Method and Recording Method - Where a hybrid disc has different types of media, the light spot moves among recording layers of the different media, after loading the disc into an optical disc apparatus, there is a problem that information on a media type of each recording layer should be recorded in DI etc. of the optical disc. Detailed information on the hybrid disc is stored in DI, by changing a disc layer type identifier or a disc structure in DI such as BCA or PIC on the optical disc. | 03-03-2011 |
20110134731 | OPTICAL DISC APPARATUS AND DEFOCUS CORRECTING METHOD - An optical disc apparatus in which a bias of a focusing error signal is changed to a value according to a recording power at timing corresponding to a predetermined address position before starting the recording and a defocus of an opposite polarity is preliminarily caused so as to set off a defocus which occurs at the start of the recording. | 06-09-2011 |
20110299374 | MULTILAYER OPTICAL DISC - A multilayer optical disc which has three or more recording layers and enables easy positioning of a focused beam spot onto a particular recording layer in which a BCA is disposed. An inter-layer distance between a particular recording layer and a recording layer adjacent to the particular recording layer is larger than the other inter-layer distances in which, at the focused beam spot positioning, the focused beam spot traverses the said adjacent recording layer earlier than the other recording layer adjacent to the particular recording layer. | 12-08-2011 |
20120106307 | OPTICAL DISC APPARATUS AND DEFOCUS CORRECTING METHOD - An optical disc apparatus in which a bias of a focusing error signal is changed to a value according to a recording power at timing corresponding to a predetermined address position before starting the recording and a defocus of an opposite polarity is preliminarily caused so as to set off a defocus which occurs at the start of the recording. | 05-03-2012 |