-
公开(公告)号：JPH04134682A
公开(公告)日：1992-05-08
申请号：JP25546590
申请日：1990-09-27
Applicant: IBM
Inventor： KAGAMI NAOYUKI , KUBO HIROAKI , TAKEKOSHI MAKOTO
Abstract: PURPOSE: To surely recover a track follow-up operation in a short time by carrying out a seek operation in which a track separated by a prescribed distance is made a target track, in response to a failed detection of the track follow-up operation. CONSTITUTION: With a track follow-up operation failing, the amplitude of a tracking error signal(TES) expands, with a TES error generated and guided to a controller 200, so that the failure of the track follow-up operation is detected. In this case, a seek operation is carried out by setting a target position at five tracks away towards the inside if the present position is near the outer side of an optical disk, and at five tracks away towards the outside if near the inner side. With the seek operation performed, the moving speed of a beam is controlled along a speed profile and, as a result, the beam gains such a speed as capable of being transferred to a follow-up operation at the point of time after moving five tracks. Thus, since a servo control is not turned off after the detection of the failure of the track follow-up operation, its recovery is surely performed.
-
公开(公告)号：JPH04146531A
公开(公告)日：1992-05-20
申请号：JP26398190
申请日：1990-10-03
Applicant: IBM
Inventor： KAGAMI NAOYUKI , KUBO HIROAKI , OKADA KEIICHI , TAKEKOSHI MAKOTO
Abstract: PURPOSE: To prevent a failure in shifting from a seek operation to a track following operation and also a failure of the seek operation by correcting a variation in a feedback amt. at the time of speed control or a variation of a driving signal. CONSTITUTION: A prescribed value is set in a speed profile generator 88 by a controller 200, and a seek in the direction outside a prescribed number of tracks is started. At this time, a timer 400 is simultaneously started to judge whether contents of a track counter 84 is reduced by 100 tracks, and when the 100 tracks are reduced, its required time is measured by the timer 400. In this case, an outside seek TES gain correcting value is evaluated by a prescribed calculating expression to obtain the positive TES gain correcting value if a seek time is shorter than a target time, i.e., a prescribed reference value, and the negative correcting value if larger. By this method, no shifting failure from the seek operation to the track following operation and no failure in the seek operation can be ensured.
-
公开(公告)号：JPH06150335A
公开(公告)日：1994-05-31
申请号：JP28269092
申请日：1992-10-21
Applicant: IBM
Inventor： KAGAMI NAOYUKI , TAKEKOSHI MAKOTO
Abstract: PURPOSE: To surely set a focus by gradually attenuate an offset value at a prescribed level added to a focus error signal in response to the closing of the loop of a focus servo so as to control the focus servo so that an objective lens may always exist in the neighborhoed of a focal position. CONSTITUTION: A disk 100 is rotated by a spindle motor 102 and an optical head 108 is provided with the objective lens 104 and a focus actuator 106 for driving this in a direction vertical to the face of the disk, namely in a focusing direction. The focus error signal is obtained by a focus error signal generator 110 through the use of a astigmatizing method and this error signal is made a so to speak S-curve characteristic near the focal position of the lens 104. A focus servo circuit based on the focus error signal consists of a signal generator 110, a phase compensation circuit 120 and a focus actuator driver 122 and when the loop is closed, the lens 104 is driven vertically to insert the disk surface within the focal depth of the lens 104.
-
公开(公告)号：JPH0460973A
公开(公告)日：1992-02-26
申请号：JP17039890
申请日：1990-06-29
Applicant: IBM
Inventor： TAKEKOSHI MAKOTO , ROORENSU DEII TEIPUTON
Abstract: PURPOSE: To allow an optical head to arrive at a target position in a short period of time by previously storing a relation between the distance to this target position and an index relating to the movement of the optical head heading toward the target position and calculating the number of the track cross signals to be counted during the seek operation when the target position is given. CONSTITUTION: This driving device is provided with a memory means 45 for storing the relation between the distance to the target position and the index relating to the movement of the optical head 11 heading toward the target position and a control means 41 for calculating the number of the track cross signals to be counted during the seek operation by utilizing this relation when the target position is given and generating a control signal for seeking the optical head 11 in accordance with the calculated number of the track cross signals. The counting of the number of the track cross signals to be counted before at least the head arrives at the target position is made possible even if the seek operation is actually not executed. As a result, the need for the reseek operation is eliminated and the completion of the seek operation in the short period of time is made possible.
-
-
-
Search Results
4
records
(took 0.017 seconds)
