Abstract: Test writing is executed while skipping areas where deviations are present on an optical disk to thereby improve accuracy and reliability of an optimum recording condition to be derived. A deviation detecting unit detects the deviations of a guide groove on the optical disk on the basis of a fluctuation amount of a focus error signal or a tracking error signal, and registers information of the detected deviations onto a memory. A test writing processing unit refers to the memory, and records and reproduces a test signal while skipping the areas where the deviations are detected.

Abstract: In a method for adjusting a focus position for an optical disc, onto/from which in formation is recorded or reproduced, while adjusting the focus position of an optical reproducing means, upon a recording surface of an optical information recording medium having an area where information of the optical information recording medium is recorded in advance, comprising the following steps of: memorizing plural numbers of information relating to focus positions determined appropriately, which can be obtained from the area where the information of the optical information recording medium is recorded in advance; and adjusting the focus position for the optical disc loaded into an apparatus, from at lease one (1) signal relating to the focus position, which can be obtained from the optical disc, with utilizing a relationship between the plural numbers of information relating to the focus positions determined appropriately, memorized in advance, when reproduction of the information is impossible when the optical disc

Abstract: Disclosed is an optical disc apparatus that sets a plurality of virtual zones, which correspond to a plurality of zones that are arranged in the radial direction of an optical disc, for a plurality of recording layers of the optical disc. When a servo signal distortion is detected in a virtual zone to change the rotation speed of the optical disc to a low speed in the virtual zone during an information recording or reproduction operation relative to a first recording layer, the optical disc apparatus stores the change information. When a recording or reproducing operation is to be performed in a virtual zone of a second recording layer, which is in the same disc radial position as the virtual zone of the first layer, the optical disc apparatus changes the rotation speed of the optical disc for the virtual zone to a low speed in accordance with the change information.

Abstract: An optical disc apparatus, as a learning operation before a recording or reproducing operation, rotates an optical disc at a first speed to read PID information, discriminates between lands and grooves of the optical disc, detects switching positions between lands and grooves, sets a rotation angle position of tracking pull-in of an objective lens of a time length that allows the PID information to be stably read, with respect to the switching position, and stores the set position information of tracking pull-in as learning result information. During recording or reproducing, the optical disc apparatus rotates the optical disk at a second speed higher than the first speed, pulls in the objective lens for tracking based on the stored position information of tracking pull-in, reads PID information, and performs the recording or reproducing operation while discriminating between lands and grooves and detecting switching positions between lands and grooves.

Abstract: In an optical disc device employing a CLV method, executing pickup return processing when focus drop occurs during recording poses problems of increased waiting time for rotation and increased focus servo recovery processing time. When defocusing occurs and focus pull-in cannot be achieved by retry, a first rotation frequency at a radial position thereof is calculated. Next, a second rotation frequency at the innermost circumferential position at the current speed is calculated. Next, a third rotation frequency at a radial position where recording is restarted after focus servo recovery is calculated. Next, a fourth rotation frequency at pickup return position at a different speed is calculated.

Abstract: In a method for adjusting a focus position for an optical disc, onto/from which in formation is recorded or reproduced, while adjusting the focus position of an optical reproducing means, upon a recording surface of an optical information recording medium having an area where information of the optical information recording medium is recorded in advance, comprising the following steps of: memorizing plural numbers of information relating to focus positions determined appropriately, which can be obtained from the area where the information of the optical information recording medium is recorded in advance; and adjusting the focus position for the optical disc loaded into an apparatus, from at lease one (1) signal relating to the focus position, which can be obtained from the optical disc, with utilizing a relationship between the plural numbers of information relating to the focus positions determined appropriately, memorized in advance, when reproduction of the information is impossible when the optical disc

Abstract: An optical disc apparatus is designed to perform focus control of an objective lens of an optical pickup by generating a first focus error signal of an astigmatism method from a signal based on 0-order light of a reflected laser beam, as well as generating a second focus error signal of a differential astigmatism method from the signal based on the 0-order light and from a signal based on ±1-order light. The focus control of the objective lens is performed by the second focus error signal during recording or reproducing operation within a recording layer of an optical disc. The focus control is performed by the first focus error signal when a focus jump is performed in response to switching of the recording layer of the optical disc.

Abstract: Test writing is executed while skipping areas where deviations are present on an optical disk to thereby improve accuracy and reliability of an optimum recording condition to be derived. A deviation detecting unit detects the deviations of a guide groove on the optical disk on the basis of a fluctuation amount of a focus error signal or a tracking error signal, and registers information of the detected deviations onto a memory. A test writing processing unit refers to the memory, and records and reproduces a test signal while skipping the areas where the deviations are detected.

Abstract: In an optical disc device employing a CLV method, executing pickup return processing when focus drop occurs during recording poses problems of increased waiting time for rotation and increased focus servo recovery processing time. When defocusing occurs and focus pull-in cannot be achieved by retry, a first rotation frequency at a radial position thereof is calculated. Next, a second rotation frequency at the innermost circumferential position at the current speed is calculated. Next, a third rotation frequency at a radial position where recording is restarted after focus servo recovery is calculated. Next, a fourth rotation frequency at pickup return position at a different speed is calculated.

Abstract: Disclosed is a method of reproducing optical information by applying laser light to the medium while rotating a recording medium having concentric information tracks or a spiral information track so that the linear velocity of the medium is constant, and thereby reproducing the information recorded on the recording medium by the reflected light. In this method, in moving a reproduction radial position to a second radial position different from the current position, a laser power is changed to second laser power, which is different from current laser power, and then the light spot is moved to the second radial position. This method can prevent degradation of a medium in reproduction light resistance caused by substantially high power reproduction, and erasing or destruction of already recorded data that may be caused, in high-speed recording of a rewritable-type or write-once-type optical disc, when the linear velocity at the time of reproduction becomes slow, e.g.

Abstract: Disclosed is an optical disc apparatus that sets a plurality of virtual zones, which correspond to a plurality of zones that are arranged in the radial direction of an optical disc, for a plurality of recording layers of the optical disc. When a servo signal distortion is detected in a virtual zone to change the rotation speed of the optical disc to a low speed in the virtual zone during an information recording or reproduction operation relative to a first recording layer, the optical disc apparatus stores the change information. When a recording or reproducing operation is to be performed in a virtual zone of a second recording layer, which is in the same disc radial position as the virtual zone of the first layer, the optical disc apparatus changes the rotation speed of the optical disc for the virtual zone to a low speed in accordance with the change information.

Abstract: Within a seek control method for moving an optical spot onto an arbitrary track, by moving the optical spot into a radial direction of an optical information recording medium, which is formed with lands and grooves, spirally, on an information recording surface thereof, calculation is made on time from staring of seek operation up to completion of pulling the optical spot onto a target track, calculating is made an amount of rotation of the optical information recording medium within that time, which is calculated in the above, determination is made on whether the pulling operation can be conducted or not within a pull-in escape region on a land/groove exchange portion of a tack on the information recording surface of the optical information recording medium, upon the amount of rotation which is calculated in the above, and a starting position of the pulling operation is changed so that the pulling operation can be executed escaping from said pulling escape region, upon basis of result of the determination, t

Abstract: An optical disc apparatus, as a learning operation before a recording or reproducing operation, rotates an optical disc at a first speed to read PID information, discriminates between lands and grooves of the optical disc, detects switching positions between lands and grooves, sets a rotation angle position of tracking pull-in of an objective lens of a time length that allows the PID information to be stably read, with respect to the switching position, and stores the set position information of tracking pull-in as learning result information. During recording or reproducing, the optical disc apparatus rotates the optical disk at a second speed higher than the first speed, pulls in the objective lens for tracking based on the stored position information of tracking pull-in, reads PID information, and performs the recording or reproducing operation while discriminating between lands and grooves and detecting switching positions between lands and grooves.