公开(公告)号：CA2046704A1

公开(公告)日：1992-03-29

申请号：CA2046704

申请日：1991-07-10

Applicant: IBM

Inventor： FENNEMA ALAN A ,  FINKELSTEIN BLAIR I ,  TAYEFEH MOROVAT ,  YARDY RAYMOND

IPC: G11B7/00 ,  G11B7/004 ,  G11B7/0045 ,  G11B7/085 ,  G11B7/09 ,  G11B7/125 ,  G11B11/10 ,  G11B11/105 ,  G11B19/12

公开(公告)号：CA2046696A1

公开(公告)日：1992-03-29

申请号：CA2046696

申请日：1991-07-10

Applicant: IBM

Inventor： FENNEMA ALAN A

IPC: G11B7/085 ,  G11B7/09 ,  G11B7/095

Abstract: TU9-90-033 ANTI-SKATING CONTROL OF A POSITIONING SERVO SYSTEM A servo positioning system, such as used in an optical disk or other types of disk drives includes focus and positioning servo circuits. When a focus error is detected, then it is desired to stop the operation of the positioning system. Similarly, when a positioning error is detected, such as excessive speed or a non-zero velocity at the end of a seek or positioning motion, the head carriage should also be stopped. The stopping of the head carriage is by dynamic braking through use of a power amplifier which is switched from a transconductance mode used during normal servo positioning operations to a voltage amplifying mode which is set to a zero input for dynamically braking the servo positioning system to a safe speed and thence to a stop condition whereupon further error recovery procedures may be employed.

公开(公告)号：CA2012800C

公开(公告)日：1995-01-17

申请号：CA2012800

申请日：1990-03-22

Applicant: IBM

Inventor： CHOW WILLIAM W ,  FENNEMA ALAN A ,  FIORINO BENJAMIN C ,  HENDERSON IAN E ,  KADLEC RONALD J ,  ROBERTS SPENCER D

IPC: G05D3/12 ,  G11B7/085 ,  G11B11/105 ,  G11B21/08 ,  G11B7/00

Abstract: A track-seeking apparatus of a disk recorder employs a track-crossing sensor to produce track-crossing signals. An oscillator is slaved to the sensor for supplying substitute track-crossing pulses in the absence of the sensor providing such pulses or when the radial velocity exceeds a threshold velocity. A velocity profile means alters the oscillator frequency so that the oscillator produces track-crossing pulses in accordance with the profile. TU988001

公开(公告)号：CA1309497C

公开(公告)日：1992-10-27

申请号：CA577711

申请日：1988-09-16

Applicant: IBM

Inventor： FENNEMA ALAN A

IPC: G11B7/09 ,  G11B7/085 ,  G11B21/08 ,  G11B7/08

Abstract: An optical disk recorder includes a position servo control loop for causing a beam of radiation to faithfully follow a track on the disk, jump from a current track to an adjacent track or to a small number of tracks away from the current track. Operation of the position servo loop is altered by selectively reversing the phase of a differentiated position error signal and integrating the differentiated position error signal for comparison with a sawtooth signal for moving the beam of radiation from the current track to an immediately adjacent track under continuous position servo control. Upon reaching the adjacent track, the sawtooth signal returns to a reference potential for initiating track following. The servo error between the integrated differentiated position error signal and the sawtooth signal is sufficiently small such that relaxation of the sawtooth signal does not cause any significant perturbations in the positioning servo loop operation. A velocity long seek servo can be substituted for the position servo loop for more rapid long seeks. TU987004

公开(公告)号：CA2046721A1

公开(公告)日：1992-03-29

申请号：CA2046721

申请日：1991-07-10

Applicant: IBM

Inventor： FENNEMA ALAN A ,  HANCOCK REED A

IPC: G11B5/55 ,  G11B7/085 ,  G11B11/105 ,  G11B21/08 ,  G11B7/12

Abstract: TU9-90-031 CONTROLLING HEAD SEEKING SPEED IN DISK STORAGE UNITS BY LIMITING DISPLECEMENT OF HEAD WITH RESPECT TO ITS SUPPORTING HEADARM In a "piggy-back" head support system, a fine actuator which carries the head (lens or transducer) is controlled to move the head. A coarse actuator or headarm movably supports the fine actuator and is mounted on a frame for movement radially of the signal storage disk. The head scans tracks on the disk. A servo actuates the coarse actuator to follow the movements of the fine actuator. In a seek, the fine coarse actuator may not be able to follow the fine actuator resulting in the fine actuator hitting a safety stop. When this happens, seek errors occur. According to the invention, the relative displacement of the fine actuator with respect to the coarse actuator is limited during predetermined portions of a seek operation, i.e., the high speed accelerate and decelerate portions.

公开(公告)号：CA2046697A1

公开(公告)日：1992-03-28

申请号：CA2046697

申请日：1991-07-10

Applicant: IBM

Inventor： BACA FRANCISCO A ,  FENNEMA ALAN A ,  HANCOCK REED A ,  JAQUETTE GLEN A ,  TIPTON LAWRENCE D ,  WINARSKI DANIEL J

IPC: G11B7/00 ,  G11B7/0037 ,  G11B7/004 ,  G11B7/09 ,  G11B7/125 ,  G11B11/105 ,  G11B19/04 ,  G11B19/28 ,  G11B27/36 ,  G11B33/10

Abstract: TU9-90-006 CALIBRATING OPTICAL DISK RECORDERS TO SOME PARAMETERS DURING DISK SPIN UP WHILE DEFERRING CALIBRATION OF OTHER PARAMETERS This disclosure deals with an optical disk recorder/player (drive) of the type that receives a removable disk for signal exchanging operations. Once a disk is inserted into the drive, the rotation of the disk begins a period of accelerating rotational speed called spin up. During spin up, the focus and tracking systems of the drive are calibrated. Once the disks reach a desired operating rotational speed, a menu is provided for determining when to calibrate a laser in the drive for recording operations. Such writing or recording calibration of the laser occurs at different times in accordance with the types of signal processing functions to be performed with respect to the particular disk. Description includes a media library in which a plurality of optical disk drives are controlled in a manner for minimizing access times to any optical disk within the media library.

公开(公告)号：BR9102191A

公开(公告)日：1991-12-24

申请号：BR9102191

申请日：1991-05-29

Applicant: IBM

Inventor： CHILDERS EDWIN RALPH ,  FENNEMA ALAN A ,  MCREYNOLDS DAVID P

IPC: G11B5/596 ,  G11B7/08 ,  G11B7/09 ,  G11B21/00 ,  G11B33/08 ,  G02B7/02

Abstract: The present invention relates to a rotatable work tool assembly comprising a rotatable body (13), a fixed holder for the body, a work tool (22) mounted on the body, a pivot pin (21) extending from the holder, and a recess (20A) within the body adapted to receive the pivot pin so that the body can rotate about the pivot pin relative to the holder and the work tool can move into a selected work position. According to the invention the assembly is characterized in that it comprises biasing means for applying a biasing force to the body in a direction along a line extending from the axis of the pivot pin to the work tool for all positions of the body as it rotates so as to tend to prevent any movement of the body relative to the pivot pin along the line due to spacing between the outer surface of the pivot pin and the inner surface of the recess.

公开(公告)号：CA2039351A1

公开(公告)日：1991-12-05

申请号：CA2039351

申请日：1991-03-28

Applicant: IBM

Inventor： CHILDERS EDWIN R ,  FENNEMA ALAN A ,  MCREYNOLDS DAVID P

IPC: G11B5/596 ,  G11B7/08 ,  G11B7/09 ,  G11B21/00 ,  G11B33/08

Abstract: The present invention relates to a rotatable work tool assembly comprising a rotatable body (13), a fixed holder for the body, a work tool (22) mounted on the body, a pivot pin (21) extending from the holder, and a recess (20A) within the body adapted to receive the pivot pin so that the body can rotate about the pivot pin relative to the holder and the work tool can move into a selected work position. According to the invention the assembly is characterized in that it comprises biasing means for applying a biasing force to the body in a direction along a line extending from the axis of the pivot pin to the work tool for all positions of the body as it rotates so as to tend to prevent any movement of the body relative to the pivot pin along the line due to spacing between the outer surface of the pivot pin and the inner surface of the recess.