Patent application number | Description | Published |
20090059741 | Servo Control Apparatus and Method, and Disk Recording or Playback Apparatus - There is provided a servo controller that can automatically set a filter intended for stabilizing a closed loop. The servo controller includes a repetitive controller. The repetitive controller implements repetitive control of a servo error signal (observation signal y(t)) by producing, by an adaptive line spectrum enhancer or adaptive linear prediction unit, a second error signal (including mainly a rotational sync signal) resulted from reduction of an irrotational sync component from a first error signal resulted from subtraction of the observation signal y(t) from a target signal r(t) and producing a third error signal obtained by sequentially updating the first error signal while making one-period delay of the second error signal. | 03-05-2009 |
20090067302 | OPTICAL PICKUP DEVICE, OPTICAL RECORDING/REPRODUCING APPARATUS AND GAP-CONTROL METHOD - An optical pickup device is provided. The optical pickup device includes a light source, a focusing optical system configured to irradiate an optical recording medium with near-field light, a light-detecting unit configured to detect a total-reflection return-light quantity from the optical recording medium, a control unit configured to generate a control signal in response to a detection signal supplied from the light-detecting unit, and a drive unit configured to drive the focusing optical system to a predetermined position above the optical recording medium. The control unit feeds forward a push-pull signal in a traveling direction of the drive unit relative to the optical recording medium to a gap-error signal supplied from the light-detecting unit to generate a gap-servo signal. The control unit includes a repetitive controller storing a predetermined number of the push-pull signals. | 03-12-2009 |
20090135712 | SOLID IMMERSION LENS AND FOCUSING LENS, OPTICAL PICKUP DEVICE, AND DATA RECORDING/REPRODUCING APPARATUS USING THE SAME - A solid immersion lens (SIL) is provided. The SIL includes a spherical part, a cone-shaped part, a tip part, and an edge part between the cone-shaped part and the tip part. The edge part includes a curved surface. | 05-28-2009 |
20090168633 | OPTICAL PICKUP APPARATUS, OPTICAL READ/WRITE APPARATUS, AND GAP CONTROL METHOD - An optical pickup apparatus includes a light source, focusing optics, a light detector, a controller, and a drive unit. The drive unit first drives the focusing optics to a specific position on an information recording medium. Light from the light source irradiates the information recording medium via the focusing optics as near-field light. Light reflected off the medium due to total internal reflection is then detected by the light detector, generating a gap error signal as a result. The controller then generates a gap servo signal by conducting a feed-forward control, whereby a push-pull signal in the direction orthogonal to the relative travel direction of the medium is applied to the gap error signal. In so doing, precise control of the gap size between the focusing optics and the information recording medium is achieved for near-field read/write operations. | 07-02-2009 |
20090290460 | INFORMATION RECORDING METHOD AND INFORMATION RECORDING APPARATUS - In an information recording method, information is recorded to semiconductor memory when at least a specified amount of free space exists in the semiconductor memory. Information is recorded to magnetic memory when the free space in the semiconductor memory is insufficient but at least a specified amount of free space exists in the magnetic memory. Information is recorded to optical memory when the free space in both the semiconductor memory and the magnetic memory is insufficient. When retrieving recorded information, an access count is incremented, and information with a comparatively high access count is moved to the semiconductor memory, while information with a comparatively low access count is moved to the optical memory. Information is thus recorded to a recording medium suitably selected from among semiconductor memory, magnetic memory, and optical memory, thereby making effective use of each memory type. | 11-26-2009 |
20100142339 | DISK DEVICE AND DISK DRIVE CONTROLLING METHOD - A disk device includes a main control unit controlling the operation of a controlled object on the basis of an error signal calculated from a target signal of the controlled object and an observation signal of the controlled object, a repetitive control unit sampling the error signal with a sampling clock pulse to obtain a repetitive signal component generated in synchronization with rotation of the disk medium from the sampled error signal, a sampling clock generation unit generating the sampling clock pulse and resetting a timing at which the sampling clock pulse is generated in accordance with a rotation detecting pulse and a sampling clock limit unit limiting generation of the sampling clock pulse at a timing immediately before generation of the rotation detecting pulse. | 06-10-2010 |
20100157756 | OPTICAL DISC APPARATUS AND OPTICAL DISC DRIVE CONTROL METHOD - A movement speed of a lens included in an optical pickup is calculated by differentiating a total reflection return light quantity that is detected by emitting laser light and near-field light onto a signal recording surface of a rotationally driven optical disc. On the basis of the calculated movement speed, processing for driving the optical pickup or the lens included in the optical pickup is controlled. For example, in a case where the calculated movement speed exceeds a permissible speed set in advance, retreat processing is performed for moving the optical pickup or the lens included in the optical pickup apart from a surface of the optical disc. | 06-24-2010 |
20110019513 | SHORT-PULSE LIGHT SOURCE, LASER LIGHT EMISSION METHOD, OPTICAL DEVICE, OPTICAL DISC DEVICE, AND OPTICAL PICKUP - Directed to freely adjusting an emission period of a semiconductor laser. | 01-27-2011 |
20110134729 | RECORDING APPARATUS AND CONTROL METHOD - A recording apparatus for performing information recording using formation of marks by focusing a first light with an objective lens at a given position in a recording layer included in an optical disc recording medium, includes: a rotation driving unit; a focus servo control unit for condensing a second light on a reflection film and for controlling a position of the objective lens; a recording position setting unit for setting an information recording position of the first light in a focus direction; a tracking servo control unit for controlling a position of the objective lens; an eccentricity amount estimating unit for estimating an eccentricity amount of the optical disc recording medium; and an eccentricity estimation amount acquisition control unit for acquiring an eccentricity estimation amount for each rotation angle within one revolution of the disc. | 06-09-2011 |
20110134730 | RECORDING APPARATUS AND CONTROL METHOD - A recording apparatus for performing information recording using formation of marks by focusing a first light with an objective lens at a given position in a recording layer included in an optical disc recording medium, includes: a rotation driving unit for rotating the optical disc recording medium; a focus servo control unit for condensing a second light which is different from the first light on a reflection film, and for controlling a position of the objective lens so that a focal position of the second light follows the reflection film; a recording position setting unit for setting an information recording position of the first light in a focus direction by changing the collimation of the first light; a surface wobbling amount estimating unit; and a surface wobbling estimation amount acquisition control unit for acquiring a surface wobbling estimation amount for each rotation angle within one revolution of the disc. | 06-09-2011 |
20110170388 | OPTICAL DRIVE DEVICE AND FOCUS SERVO CONTROL METHOD - An optical drive device includes first and second light sources, an objective lens configured to receive a first light emitted from the first light source and a second light emitted from the second light source and to irradiate both the first light and the second light to an optical disc recording medium, a first focus mechanism configured to drive the objective lens in a focus direction, a second focus mechanism configured to change collimation of the second light incident to the objective lens and changing the focusing position of the second light independently of the first light, a first focus servo control unit configured to drive the first focus mechanism, an error signal subtraction unit configured to subtract the first focus error signal from a second focus error signal, and a second focus servo control unit configured to drive the second focus mechanism. | 07-14-2011 |
20110305127 | RECORDING DEVICE AND RECORDING METHOD - A recording device includes: a rotation driving unit that rotates an optical medium having a reference face and a recording layer, at a constant velocity; a light irradiating unit that irradiates the optical recording medium with first and second light through a common object lens; an infocus position adjusting unit that performs adjustment to focus; a light receiving unit that receives reflection light from the reference face; a reproducing clock generating unit that generates a reproducing clock on the basis of a light reception signal; a radial position detecting unit that detects the radial positional information on the basis of the light reception signal and the reproducing clock positional information; a frequency adjusting unit that changes a frequency of an input reference signal; and a recording unit that performs mark recording on the recording layer using the signal obtained by the frequency adjusting unit as a recording clock. | 12-15-2011 |