Detecting media defects

Patent metadata

Field	Value
Publication number	US-10115430-B2
Application number	US-201715629629-A
Country	US
Kind code	B2
Filing date	Jun 21, 2017
Priority date	Oct 11, 2016
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. Moreover, the program instructions readable and/or executable by a processor to cause the processor to perform a method which includes: instructing, by the processor, a drive to detect a written signal burst on a magnetic tape; and searching, by the processor, a surface of the magnetic tape proximate to the written signal burst for a defect. A computer-implemented method, according to another embodiment, includes: moving a magnetic tape to an approximate location of a defect, detecting a written signal burst on the magnetic tape, and stopping movement of the magnetic tape in response to detecting the written signal burst. Other systems, methods, and computer program products are described in additional embodiments.

First claim

What is claimed is:

1. A computer program product comprising a computer readable storage medium having program instructions embodied therewith, wherein the computer readable storage medium is not a transitory signal per se, the program instructions readable and/or executable by a processor to cause the processor to perform a method comprising:
instructing, by the processor, a drive to detect a written signal burst on a magnetic tape; and
searching, by the processor, a surface of the magnetic tape proximate to the written signal burst for a defect.

2. The computer program product of claim 1 , wherein the program instructions are readable and/or executable by the processor to cause the processor to perform the method comprising: instructing, by the processor, the drive to move the magnetic tape to an approximate location of the defect based on linear position information previously stored in response to detecting the defect.

3. The computer program product of claim 1 , wherein the program instructions are readable and/or executable by the processor to cause the processor to perform the method comprising: determining, by the processor, an approximate lateral position of the defect on the magnetic tape.

4. The computer program product of claim 3 , wherein the approximate lateral position of the defect on the magnetic tape includes: identifying a detector structure that identified the defect.

5. The computer program product of claim 4 , wherein the approximate lateral position of the defect on the magnetic tape is determined using dark force microscopy of the detector structure that identified the defect for identifying a location of smeared material of the detector structure.

6. The computer program product of claim 4 , wherein determining the approximate lateral position of the defect on the magnetic tape includes: determining a location of material of a detector structure smeared by the defect; and measuring a distance in a cross track direction from the location of the smeared material to a projected lateral location of a datum.

7. The computer program product of claim 1 , wherein the program instructions are readable and/or executable by the processor to cause the processor to perform the method comprising: instructing, by the processor, the drive to stop movement of the magnetic tape in response to detecting the written signal burst.

8. A computer-implemented method, comprising:
moving a magnetic tape to an approximate location of a defect;
detecting a written signal burst on the magnetic tape; and
stopping movement of the magnetic tape in response to detecting the written signal burst.

9. The computer-implemented method of claim 8 , wherein moving the magnetic tape to the approximate location of the defect is based on linear position information previously stored in response to detecting the defect.

10. The computer-implemented method of claim 9 , comprising: determining an approximate lateral position of the defect on the magnetic tape, wherein the approximate lateral position of the defect on the magnetic tape includes identifying a detector structure that identified the defect.

11. The computer-implemented method of claim 8 , comprising:
monitoring a resistance value of each of a plurality of detector structures positioned in an array;
detecting a change in a resistance value of at least one of the detector structures, for identifying an approximate location of defect on a magnetic medium; and
causing a write transducer to write a signal burst on the magnetic medium in response to detecting the change in resistance value,
wherein each of the detector structures include a pair of conductive layers separated by an insulating material.

12. An apparatus, comprising:
a plurality of detector structures positioned in an array; and
a write transducer aligned with each of the detector structures; and
a controller configured to cause one of the write transducers to write a signal burst in response to the associated detector structure encountering a defect.

13. The apparatus of claim 12 , wherein the controller is configured to cause each write transducer to write a pattern that is specific to that write transducer.

14. The apparatus of claim 12 , wherein the controller is configured to cause a plurality of the other writer transducers to write a predefined pattern in response to the detector structure encountering a defect.

15. The apparatus of claim 12 , with a proviso that none of the detector structures include an operable reader for reading data from a magnetic medium.

16. The apparatus of claim 12 , wherein the controller is configured to monitor a resistance value of each of the detector structures; and, in response to detecting a change in a resistance value of one of the detector structures, cause the write transducer associated therewith to write a signal burst.

17. The apparatus as recited in claim 12 , comprising:
a servo reader,
wherein the controller is configured to use the servo reader to determine a position along a length of a magnetic medium that corresponds to an identified defect.

18. The apparatus as recited in claim 12 , comprising at least one electronic lapping guide.

Assignees

• IBM

Inventors

• Biskeborn Robert G

Classifications

• G11B20/1816 Primary

  Testing · CPC title

• G11B5/00813

  magnetic tapes · CPC title

• G11B2020/1823

  wherein a flag is set when errors are detected or qualified · CPC title

• G11B20/1886

  with tapes · CPC title

• G11B5/00817

  on longitudinal tracks only, e.g. for serpentine format recording · CPC title