Abstract: An optical disc device of the present invention has a carriage opposed to an optical disc medium and capable of moving in a radial direction of the optical disc medium; a first driving section for driving the carriage; an object lens mounted in the carriage for focusing laser light on the optical disc medium; a second driving section mounted in the carriage for displacing the object lens in the radial direction of the object lens; a lens-position detecting section fixed to the carriage for detecting positional information on the object lens; an eccentricity removing section for generating a position detecting signal by removing an eccentric component of the optical disc medium from the positional information on the object lens; and a displacement detecting section for determining, using the position detecting signal, whether or not the carriage should be driven and for providing an instruction to begin driving the carriage, to the first driving section, based on a result of the determination.

Abstract: In a distributed processing management apparatus, server 3 has a node table 5, a job management table 6 and a job class table 7 in order to manage the resource status such as the CPU operating ratio of each node in every predetermined time period. When the operating ratio of the CPU and other elements of a node rises after the input of a job and the speed of executing the input job falls, the server 3 re-inputs the job from the current node 2a to some other node 2b. With this arrangement, it is possible to improve the overall TAT and effectively exploit computer resources in grid computer environment.

Abstract: An optical disk apparatus includes a carriage actuator that drives the carriage with a two-phase stepping motor. The carriage is provided with an objective lens that condenses a laser beam onto an optical disk and a lens actuator that moves the objective lens. A system controller drives the two-phase stepping motor in a first conduction mode of supplying current only to A-phase exciting coil and a second conduction mode of supplying current only to B-phase exciting coil in one-phase excitation drive mode, and detects a travel distance of the carriage based on a relative displacement of the objective lens with respect to the carriage, thus to control the current conduction to the A-phase exciting coil and the B-phase exciting coil based on the detection result, such that the travel distance of the carriage in the first and the second conduction mode becomes substantially the same.

Abstract: The present invention relates to optical disc drives including a carriage which is movable radially of an optical disc and an objective lens which is supported on the carriage movably in radial directions of the disc for formation and placement of a beam spot on the disc. The invention aims at reducing minute vibration of the objective lens during a seek control stably and reliably. According to the present invention, the minute vibration of an objective lens (104) is reduced by moving the objective lens (104) at a relative speed of zero with respect to a carriage (101) during the seek operation, based on a TZC signal which indicates that the beam spot has crossed over a track in an optical disc (2). In this control, a position of the objective lens (104) in the carriage (101) right before starting the seek operation is detected and stored in a memory (802). Then, a position of the objective lens (53) in the carriage (101) is detected during the seek operation.

Abstract: A reference-position learning unit measures a current of one rotation of a medium in a state in which the focus of an objective lens is pulled-in by a focus pull-in control unit at a predetermined point in the radial direction of the medium upon insertion of the medium, calculates a mean current value thereof, and stores the calculated mean current value in the memory as a reference current value for positioning the objective lens at a reference position at which focus pull-in control is started. In focus pull-in performed after a learning process, a reference-position control unit positions the objective lens at a reference position obtained through a learning process in accordance with the reference current, and then, causes the focus pull-in control unit to perform focus pull-in.

Abstract: An optical disc device of the present invention has a carriage opposed to an optical disc medium and capable of moving in a radial direction of the optical disc medium; a first driving section for driving the carriage; an object lens mounted in the carriage for focusing laser light on the optical disc medium; a second driving section mounted in the carriage for displacing the object lens in the radial direction of the object lens; a lens-position detecting section fixed to the carriage for detecting positional information on the object lens; an eccentricity removing section for generating a position detecting signal by removing an eccentric component of the optical disc medium from the positional information on the object lens; and a displacement detecting section for determining, using the position detecting signal, whether or not the carriage should be driven and for providing an instruction to begin driving the carriage, to the first driving section, based on a result of the determination.

Abstract: A reference-position learning unit measures a current of one rotation of a medium in a state in which the focus of an objective lens is pulled-in by a focus pull-in control unit at a predetermined point in the radial direction of the medium upon insertion of the medium, calculates a mean current value there of, and stores the calculated mean current value in the memory as a reference current value for positioning the objective lens at a reference position at which focus pull-in control is started. In focus pull-in performed after a learning process, a reference-position control unit positions the objective lens at a reference position obtained through a learning process in accordance with the reference current, and then, causes the focus pull-in control unit to perform focus pull-in.

Abstract: A track servo control perform follow-up control of an optical beam to a track of an optical disk, and control the vibration of the optical beam due to the ID pit noise of the optical disk. The control system is comprised of a feedback control block for feedback-controlling the actuator by the track error signal from the actuator and the learning control block. Since the optical disk ID pit noise is periodic noise, the learning control block learns this, inputs the learning result to the feedback control system. The learning result is subtracted from the learning input, and the signal after subtraction is learned in order to converge the learning. Therefore even if the periodic ID pit noise is applied, this noise can be removed from the control loop and the vibration of the actuator due to periodic noise can be decreased, making a stable track follow-up operation possible.

Abstract: There is provided an optical recording medium processing apparatus comprising: a carriage including a lens to guide a light beam to a recording medium for moving in a direction extending across tracks on the recording medium; a detector for detecting a TES; and a controller for moving the carriage across the tracks from an innermost circumferential position of the medium or its vicinity, for counting the number of tracks in accordance with a TZC pulse generated by the TES having a predetermined level or higher detected by the detector, and after the carriage has been moved for a predetermined period of time, for positioning the light beam spot on a target track in accordance with the counted number of the tracks. Therefore, the initial seek control process, whereby the carriage is moved from the innermost circumferential position of the medium or its vicinity to the center, can be performed without a position sensor.

Abstract: A track servo control perform follow-up control of an optical beam to a track of an optical disk, and control the vibration of the optical beam due to the ID pit noise of the optical disk. The control system is comprised of a feedback control block for feedback-controlling the actuator by the track error signal from the actuator and the learning control block. Since the optical disk ID pit noise is periodic noise, the learning control block learns this, inputs the learning result to the feedback control system. The learning result is subtracted from the learning input, and the signal after subtraction is learned in order to converge the learning. Therefore even if the periodic ID pit noise is applied, this noise can be removed from the control loop and the vibration of the actuator due to periodic noise can be decreased, making a stable track follow-up operation possible.

Abstract: In a low speed seek control unit, when it is judged by an error detection judging unit that a zero-cross error detection has occurred during a seeking operation, a speed prediction calculating unit predictively calculates a correct speed on the basis of the last track zero-cross interval free from any error detection and supplies the predicted speed in place of a detected speed to a speed control unit for the execution of a speed control, while a counter modification unit returns a track counter so as to have a value before the error detection. In a high speed seek control unit, when it is judged by an error detection judging unit that a zero-cross error detection has occurred, a speed prediction calculating unit predictively calculates a correct speed and supplies the predicted speed in place of a detected speed to a speed control unit for the execution of a speed control, while a counter modification unit modifies a track counter so as to have a correct value.

Abstract: When an access of a 1-track seek is instructed from an upper apparatus, a 1-track seek period is divided into a predetermined accelerating period and decelerating period. A decelerating current is determined in accordance with a difference between sample points before and after a zero-cross point of a tracking error signal E2, namely, a beam velocity with respect to the decelerating period and is supplied. With regard to a fine seek as well, the decelerating current is determined from the beam velocity obtained from the difference between the sample points before and after the zero-cross point just before a target track and is supplied.

Abstract: When an access of a 1-track seek is instructed from an upper apparatus, a 1-track seek period is divided into predetermined accelerating period and decelerating period. A decelerating current is determined in accordance with a difference between sample points before and after a zero-cross point of a tracking error signal E2, namely, a beam velocity with respect to the decelerating period and is supplied. With regard to a fine seek as well, the decelerating current is determined from the beam velocity obtained from the difference between the sample points before and after the zero-cross point just before a target track and is supplied.

Abstract: When an access of a 1-track seek is instructed from an upper apparatus, a 1-track seek period is divided into predetermined accelerating period and decelerating period. A decelerating current is determined in accordance with a difference between sample points before and after a zero-cross point of a tracking error signal E2, namely, a beam velocity with respect to the decelerating period and is supplied. With regard to a fine seek as well, the decelerating current is determined from the beam velocity obtained from the difference between the sample points before and after the zero-cross point just before a target track and is supplied.

Abstract: When an access of a 1-track seek is instructed from an upper apparatus, a 1-track seek period is divided into predetermined accelerating period and decelerating period. A decelerating current is determined in accordance with a difference between sample points before and after a zero-cross point of a tracking error signal E2, namely, a beam velocity with respect to the decelerating period and is supplied. With regard to a fine seek as well, the decelerating current is determined from the beam velocity obtained from the difference between the sample points before and after the zero-cross point just before a target track and is supplied.