Information storage device and computer product
View Patent ↗According to one embodiment, an information storage device includes a recording/reproducing head, a positioning controller, a position detector, a storage module, and a position error detector. The position detector detects the position of the recording/reproducing head. The storage module stores servo control filters. The position error detector generates a new position error signal from a target position and the position of the recording/reproducing head when the positioning controller performs positioning control with control current obtained from a position error signal having passed through each servo control filter. Upon occurrence of a recording/reproducing error, learning to calculate a vibration amount from the position of the recording/reproducing head is sequentially performed for the servo control filters for a predetermined time. The positioning controller performs the positioning control with control current obtained from the position error signal having passed through one of the servo control filters where the vibration amount is smallest.
1. An information storage device, comprising:
a recording-reproducing head configured to record data on a recording medium and reproduce the data on the recording medium;
a positioning controller configured to position the recording-reproducing head;
a position detector configured to detect a position of the recording-reproducing head based on a servo signal on the recording medium;
a storage module configured to store a plurality of servo control filters; and
a position error detector configured to generate a new position error signal from a target position and the position of the recording-reproducing head detected by the position detector when the positioning controller performs positioning control for the recording-reproducing head with control current obtained by causing a position error signal to pass through each of the servo control filters, wherein,
learning to calculate a vibration amount is sequentially performed with respect to each of the servo control filters for a predetermined time when the positioning controller performs the positioning control upon occurrence of a recording error or a reproducing error, the vibration amount being calculated from the position of the recording-reproducing head detected by the position detector,
the positioning controller is configured to perform the positioning control with one of the servo control filters where the vibration amount is smallest,
the vibration amount calculated with respect to each of the servo control filters is stored in the storage module in association with the servo control filter, and
upon occurrence of the recording error or the reproducing error, among the servo control filters each associated with the vibration amount stored in the storage module, the vibration amount is sequentially calculated with respect to the servo control filters in ascending order of the vibration amount stored in the storage module.
2. The information storage device of claim 1 , wherein, when a difference between the vibration amount stored in the storage module in association with each of the servo control filters and a vibration amount calculated upon occurrence of a recording error or a reproducing error is equal to or larger than a predetermined value, the vibration amount stored in the storage module is initialized.
3. The information storage device of claim 1 , wherein, when the vibration amount calculated with respect to each of the servo control filters exceeds a predetermined value during a retry performed upon occurrence of a recording error or a reproducing error, the learning is performed.
4. The information storage device of claim 1 , wherein, when a retry rate exceeds a predetermined value, the learning is performed.
5. A computer program product embodied on a non-transitory computer-readable medium and comprising code that, when executed, causing a computer to perform:
reading a plurality of servo control filters from a storage module;
sequentially performing learning to calculate a vibration amount with respect to each of the servo control filters for a predetermined time when, upon occurrence of a recording error or a reproducing error, positioning control is performed for a recording-reproducing head with control current obtained by causing a position error signal to pass through the each of the servo control filters, the vibration amount being calculated from the position of the recording-reproducing head
generating a new position error signal from a target position and a position of the recording-reproducing head when the positioning control is performed with one of the servo control filters where the vibration amount is smallest;
storing the vibration amount calculated with respect to each of the servo control filters in the storage module in association with the servo control filter; and
upon occurrence of the recording error or the reproducing error, among the servo control filters each associated with the vibration amount stored in the storage module, sequentially calculating the vibration amount with respect to the servo control filters in ascending order of the vibration amount stored in the storage module.
6. A method performed by an information storage device comprising a recording-reproducing head, the method comprising:
reading a plurality of servo control filters from a storage module;
sequentially performing learning to calculate a vibration amount with respect to each of the servo control filters for a predetermined time when, upon occurrence of a recording error or a reproducing error, positioning control is performed for a recording-reproducing head with control current obtained by causing a position error signal to pass through the each of the servo control filters, the vibration amount being calculated from the position of the recording-reproducing head;
generating a new position error signal from a target position and a position of the recording-reproducing head when the positioning control is performed with one of the servo control filters where the vibration amount is smallest;
storing the vibration amount calculated with respect to each of the servo control filters in the storage module in association with the servo control filters; and
upon occurrence of the recording error or the reproducing error, among the servo control filters each associated with the vibration amount stored in the storage module, sequentially calculating the vibration amount with respect to the servo control filters in ascending order of the vibration amount stored in the storage module.
7. The method of claim 6 , wherein, when a difference between the vibration amount stored in the storage module in association with each of the servo control filters and a vibration amount calculated upon occurrence of a recording error or a reproducing error is equal to or larger than a predetermined value, the vibration amount stored in the storage module is initialized.
8. The method of claim 6 , wherein, when the vibration amount calculated with respect to each of the servo control filters exceeds a predetermined value during a retry performed upon occurrence of a recording error or a reproducing error, the learning is performed.
9. The method of claim 6 , wherein, when a retry rate exceeds a predetermined value, the learning is performed.