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公开(公告)号：DE68906047T2
公开(公告)日：1993-10-28
申请号：DE68906047
申请日：1989-02-07
Applicant: IBM
Inventor： DIMATTEO JOSEPH HOWARD , FIORINO BENJAMIN C , FENNEMA ALAN AUGUST , LEWKOWICZ JULIAN
Abstract: A focus acquire circuit for use in optical systems, such as optical data recorders and players, uses up to three parameter signals to indicate an in-focus condition. The zero crossing of a focus error signal is combined with a signal indicating that the focus error signal has approached a peak value and with a signal indicating a change in laser drive signal amplitude to indicate an in-focus condition. Various circuit details are illustrated showing how the three parameters can be combined together for indicating an in-focus condition.
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公开(公告)号：CA2039351C
公开(公告)日：1995-09-26
申请号：CA2039351
申请日：1991-03-28
Applicant: IBM
Inventor： CHILDERS EDWIN RALPH , FENNEMA ALAN AUGUST , MCREYNOLDS DAVID PAUL
Abstract: An optical disk recorder, or other apparatus, use a rotary actuator for supporting a work tool, such as an objective lens which is pivotable or rotatable about a pivot pin. Rotation causing or tracking coils on the rotary actuator are disposed adjacent to permanent magnets to selectively effect rotation of the rotary actuator about the pivot pin. A bias electrical current is supplied to these coils to generate magnetic fields which are in opposite rotational senses; such fields force the rotary actuator against the pin in such a manner that the point of contact between the rotary actuator and the pin follows the rotation of the actuator about the pin.
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公开(公告)号：DE69114434D1
公开(公告)日：1995-12-14
申请号：DE69114434
申请日：1991-09-24
Applicant: IBM
Inventor： FENNEMA ALAN AUGUST , HANCOCK REED ALAN
IPC: G11B5/55 , G11B7/085 , G11B11/105 , G11B21/08
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Patent Agency Ranking
公开(公告)号：DE69016269T2
公开(公告)日：1995-07-13
申请号：DE69016269
申请日：1990-05-03
Applicant: IBM
Inventor： CHOW WILLIAM WAI-CHUNG , FENNEMA ALAN AUGUST , FIORINO BENJAIN CARMEL , HENDERSON IAN EDWARD , KADLEC RONALD JAMES , ROBERTS SPENCER DONALD
IPC: G05D3/12 , G11B7/085 , G11B11/105 , G11B21/08
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公开(公告)号：DE69121478T2
公开(公告)日：1997-02-13
申请号：DE69121478
申请日：1991-05-29
Applicant: IBM
Inventor： FENNEMA ALAN AUGUST , ROBERTS SPENCER DONALD
Abstract: The present invention relates to a focusing system for a moveable lens comprising a moveable lens (10), moving means (15,16) for moving the lens, and a control system (20, 21, 22, 23) for supplying position control signals 24) to the moving means and for detecting when the lens is in an in-focus position. According to the invention the focusing system is characterised in that the control system comprises means for supplying a ramp position control signal to the moving means to move the lens into an in-focus position, and modulating means for modulating the ramp position control signal so that it becomes a series of pulses.
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公开(公告)号：DE69121478D1
公开(公告)日：1996-09-26
申请号：DE69121478
申请日：1991-05-29
Applicant: IBM
Inventor： FENNEMA ALAN AUGUST , ROBERTS SPENCER DONALD
Abstract: The present invention relates to a focusing system for a moveable lens comprising a moveable lens (10), moving means (15,16) for moving the lens, and a control system (20, 21, 22, 23) for supplying position control signals 24) to the moving means and for detecting when the lens is in an in-focus position. According to the invention the focusing system is characterised in that the control system comprises means for supplying a ramp position control signal to the moving means to move the lens into an in-focus position, and modulating means for modulating the ramp position control signal so that it becomes a series of pulses.
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公开(公告)号：DE69114434T2
公开(公告)日：1996-06-20
申请号：DE69114434
申请日：1991-09-24
Applicant: IBM
Inventor： FENNEMA ALAN AUGUST , HANCOCK REED ALAN
IPC: G11B5/55 , G11B7/085 , G11B11/105 , G11B21/08
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公开(公告)号：DE69020926T2
公开(公告)日：1996-03-14
申请号：DE69020926
申请日：1990-03-05
Applicant: IBM
IPC: G11B21/10 , G05B19/23 , G05B19/39 , G05D3/12 , G11B7/085 , G11B7/09 , G11B11/105 , G11B21/08 , G11B7/08
Abstract: A position servo system has a position loop and a velocity loop. The position loop controls the stop-lock condition and provides for movement control within a range about the stop-lock position. The velocity circuit is employed for movements outside of the range of the position servo circuit. When the velocity servo's loop is being used, a compare circuit compares the servo drive signal from the velocity circuit with a signal generated by the position servo loop which is tracking the velocity servo loop. When the compare means finds that the servo drive signals have equal amplitudes, then the velocity servo loop is disconnected from an actuator with the position servo loop then connected to the activation for completing the movement to a desired or target stop-lock position. The above-indicated servo system controls a topping or fine actuator carried on a carriage moved by a coarse actuator. The fine and coarse actuators move along the same axis and transverse to movement of any work element, such as a record storage disk. The coarse actuator is continuously slaved to the positioning of the topping or fine actuator. A relative position sensor disposed intermediate the fine and coarse actuators supplies a position error signal for enabling the coarse actuator to continuously follow the fine actuator. Feed forward signals are supplied from the fine actuator to the coarse actuator. A preferred embodiment is shown using an optical disk environment.
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