Dynamic magnetic information storage or retrieval – Automatic control of a recorder mechanism
Reexamination Certificate
1998-11-13
2001-10-16
Faber, Alan T. (Department: 2651)
Dynamic magnetic information storage or retrieval
Automatic control of a recorder mechanism
C360S078110, C360S077030, C360S077040, C324S212000
Reexamination Certificate
active
06304404
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a recording medium driving device for driving a recording medium on which are formed plural tracks substantially parallel to one another, and to a tracking method for tracking a head with respect to the tracks formed on the recording medium substantially parallel to one another.
2. Description of the Related Art
Among conventional recording/reproducing apparatus for recording/reproducing 3.5 inch flexible magnetic discs, there is known an apparatus of the specifications in which a flexible magnetic disc is run in rotation at an rpm of the order of 300 to 600 rpm for recording/reproduction. These specifications are referred to hereinafter as the lower-order specifications. The flexible magnetic disc, recorded or reproduced on this recording/reproducing apparatus of the lower-order specifications, has a post-formatting recording capacity of approximately 1.44 Mbyte.
In recording/reproducing information signals on this recording/reproducing apparatus of the lower-order specifications, a stepping motor is used to effect tracking of the magnetic head with respect to each data track. That is, when recording/reproducing information signals for a recording medium of the lower-order specifications, the magnetic head is moved stepwise by the stepping motor along the radius of the magnetic disc for positioning the magnetic head on each data track.
On the other hand, it is required of the flexible magnetic disc to be of such specifications in which the recording density is higher than that of a disc of lower-order specifications and in which the rotational velocity is of the order of approximately 1200 to 3600 rpm for recording/reproduction to improve its recording density or data transfer rate. These specifications are referred to hereinafter as the upper-order specifications. It is required of the flexible magnetic disc used in the upper-order specifications to be of a reduced track width to increase the recording capacity to the order of 150 to 650 Mbyte.
Recently, attempts are being made to develop a recording/reproducing apparatus capable of recording/reproducing both the flexible magnetic discs of the widely used lower-order specifications and those of the upper-order specifications.
On the flexible magnetic discs of the upper-order specifications, there are pre-recorded the position information specifying the positions of the data tracks and the tracking information. With the recording/reproducing apparatus, the magnetic head can be tracked onto the respective data tracks by detecting this position information. In the recording/reproducing apparatus configured for recording/reproducing the flexible magnetic disc of the above-mentioned upper-order specifications, the magnetic head is moved radially of the recording medium, using a voice coil motor, in order to secure followup characteristics. Thus, with the recording/reproducing apparatus of the upper-order specifications, the magnetic head can be tracked onto the targeted data track to effect recording/reproduction by detecting the position information and applying tracking servo to the voice coil motor even though the track pitch is reduced as compared to that of the above-mentioned recording medium of the lower-order specifications.
However, with the recording/reproducing apparatus for recording/reproduction for both the flexible magnetic discs of the lower-order specifications and those of the upper-order specifications, the position information cannot be detected in the same manner as when recording/reproducing the flexible magnetic disc of the upper-order specifications because the position information is not recorded on the above-mentioned flexible magnetic disc of the lower-order specifications.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a recording/reproducing method and apparatus having the function of permitting tracking of a magnetic head on data tracks formed on the lower-order specifications and the upper-order specifications.
In one aspect, the present invention provides a recording medium driving apparatus for driving a recording medium having a plurality of tracks formed thereon for extending substantially parallel to one another, including a head, movement means for causing movement of the head in a direction perpendicular to the tracks, sine wave detection means for detecting sine wave signals representing a substantially sinusoidal wave which completes its one period each time the head is moved by one track pitch when the head is moved by the movement means, the sine wave signals, storage means for storing the table information, calibration control means for sequentially storing, during calibration, a maximum value and a minimum value of the signal level of the sine wave signal obtained for each track as the table information in the storage means, as the head is moved by the movement means and tracking control means for reading out from the storage means the locally maximum and locally minimum values associated with the target track, generating the target sine wave level information based on the read-out locally maximum and locally minimum values and for tracking the head to the target track by the head movement means based on the generated targeted sine wave level information.
Preferably, the tracking control means controls the head movement means so that the head will be positioned at a position such that the signal level of the sine wave signal detected by the sine wave detection means is a signal level indicated by the targeted sine wave level information.
Preferably, the targeted sine wave level information is a mean value of the read-out locally maximum and locally minimum values.
Preferably, the sine wave detection means is an optical scale.
Preferably, the recording medium driving apparatus further includes loading means for detachably loading one of a first recording medium having tracks formed thereon at a first track pitch and a second recording medium having tracks formed thereon at a second track pitch narrower than the first track pitch, and discriminating means for discriminating the type of the recording medium loaded on the load means. The tracking control means performs tracking control based on the table information when the discriminating means is found to be the first recording medium.
Preferably, the recording medium is a disc-shaped recording medium.
Also preferably, the movement means is a voice coil motor.
In another aspect, the present invention provides a tracking method for tracking a head to each of a plurality of tracks formed substantially parallel to one another on a recording medium, including the steps of generating a sine wave signal representing a substantially sinusoidal wave which completes its period from track to track as the head is moved in a direction perpendicular to the plural tracks, the sine wave signal, sequentially storing a locally maximum value and a locally minimum value of the signal level of the sine wave signal as the table information in storage means, reading out the locally maximum value and the locally minimum value associated with a targeted track, generating the target sine wave level information based on the read-out locally maximum and locally minimum values and tracking the head to the target track based on the generated target sine wave level information.
According to the present invention, a sine wave signal, representing a substantially sinusoidal wave whose one cycle is competed every track, is generated at the time of calibration as the head is moved in a direction perpendicular to the plural tracks by head movement means, and the locally maximum and locally minimum values of the signal level of the sine wave signal are sequentially stored as the table information on the storage means. During tracking, the locally maximum and minimum values associated with the targeted track are read out from the storage means, and the targeted sine wave level information is generated on the basis of the generated targeted sine wave level
Faber Alan T.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Sony Corporation
LandOfFree
Recording medium driving apparatus and tracking method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Recording medium driving apparatus and tracking method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Recording medium driving apparatus and tracking method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2590115