Method and apparatus for wobble-free data recovery from CD-rom or the like
AssigneeTEAC Corporation
InventorsHiroshi Tsuyuguchi, Mitsumasa Kubo
Life of this patent
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Abstract
A CD-ROM drive is disclosed which usually is put to use with CR-ROMs of varying qualities which may, or may not, wobble during rotation, possibly resulting in the vibration of the complete device. On being loaded into the device, therefore, each disk is rotated at increasing speed preparatory to reading. The speed of disk rotation at which vibration due to disk wobbling builds up to a prescribed limit is held as a maximum allowable speed until the disk is unloaded. The disk is subsequently read at no more than the maximum allowable speed.
Claims18
A method of data recovery from rotating data storage disks of varying physical qualities which may wobble during rotation, the method comprising:
- (a) rotating a data storage disk at increasing speed preparatory to data recovery therefrom;
- (b) concurrently with step (a), sensing the possible wobbling of the rotating data storage disk;
- (c) ascertaining if the wobbling of the disk has built up to a predetermined limit;
- (d) holding as a maximum allowable speed the rotational speed of the disk at which the disk wobbled to the predetermined limit;
- or
- (e) instead of step (d), holding as a maximum allowable speed a predetermined maximum speed of disk rotation in the case where the disk does not wobble to the predetermined limit even when rotated at the predetermined maximum speed;
- and
- (f) in data recovery, rotating the disk at a speed not exceeding the maximum allowable speed that has been determined for the disk at step (d) or (e);
- (g) whereby the disk is not to wobble beyond the predetermined limit during data recovery therefrom.
A method of data recovery from rotating data storage disks of varying physical qualities which may wobble during rotation, the method comprising:
- (a) predetermining a series of limits of allowable disk wobbling at a series of predetermined speeds of disk rotation;
- (b) rotating a data storage disk at increasing speed preparatory to data recovery therefrom;
- (c) concurrently with step (b), sensing the possible wobbling of the data storage disk rotating at increasing speed;
- (d) ascertaining, at each predetermined speed of disk rotation, if the wobbling of the disk builds up to the predetermined limit at that predetermined speed;
- (e) holding as a maximum allowable speed the rotational speed of the disk at the time the disk is found to wobble to the predetermined limit at any predetermined speed;
- or
- (f) instead of step (e), holding as a maximum allowable speed a predetermined maximum speed of disk rotation in the case where the disk is found not to wobble to the predetermined limit at the predetermined maximum speed;
- and
- (g) in data recovery, rotating the disk at a speed not exceeding the maximum allowable speed that has been determined for the disk at step (e) or (f);
- (h) whereby the disk is not to wobble beyond the predetermined limit at one of the predetermined speeds during data recovery therefrom.
An apparatus for data recovery from rotating data storage disks of varying physical qualities which may wobble during rotation, wherein the improvement resides in the combination comprising:
- (a) drive means for imparting rotation to a data storage disk;
- (b) wobbling sensor means for sensing the possible wobbling of the disk;
- (c) speed sensor means for sensing the speed of rotation of the disk;
- and
- (d) control means connected to the drive means and the wobbling sensor means and the speed sensor means for causing the drive means to rotate each loaded data storage disk at increasing speed preparatory to data recovery therefrom in order to detect the possible wobbling of the disk by the wobbling sensor means and to determine if the wobbling of the disk has built up to a predetermined limit, for holding as a maximum allowable speed either the rotational speed of the disk at which the disk wobbled to the predetermined limit, or a predetermined maximum speed of disk rotation in the case where the disk does not wobble to the predetermined limit even when rotated at the predetermined maximum speed, and, in data recovery, for causing the drive means to rotate the disk at a speed not exceeding the maximum allowable speed;
- (e) whereby the disk is not to wobble beyond the predetermined limit during data recovery therefrom.
An apparatus for data recovery from rotating data storage disks of varying physical qualities which may wobble during rotation, wherein the improvement resides in the combination comprising:
- (a) drive means for imparting rotation to a data storage disk;
- (b) speed sensor means for sensing the speed of rotation of the disk;
- (c) mode select means for providing a mode select signal indicative of wobble check mode or read mode;
- (d) speed command means connected between the mode select means and the drive means for causing the disk to be rotated at increasing speed when the mode select signal indicates the wobble check mode;
- (e) wobbling sensor means for sensing the possible wobbling of the disk;
- (f) comparison means connected to the wobbling sensor means for comparing the wobbling of the disk with a predetermined limit of allowable disk wobbling during wobble check mode operation;
- (g) holding means connected to the speed sensor means and the comparison means for holding as a maximum allowable speed either the speed of rotation of the disk at the time the wobbling of the disk is found to reach the predetermined limit by the comparison means, or a predetermined maximum speed of disk rotation if the wobbling of the disk does not reach the predetermined limit even when the disk is rotated at the predetermined maximum speed;
- (h) the speed command means being connected to the holding means for causing the disk to be rotated during read mode operation at a speed not exceeding the maximum allowable speed being held by the holding means;
- (i) whereby the disk is not to wobble beyond the predetermined limit during data recovery therefrom.
Dependencies are inferred from the claim text.