Tape media kiss-contact read verification

Patent metadata

Field	Value
Publication number	US-8964319-B1
Application number	US-201414198198-A
Country	US
Kind code	B1
Filing date	Mar 5, 2014
Priority date	Mar 5, 2014
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

A supplemental module that includes one or more read elements periodically engages a magnetic recording medium, and the read elements generate an electrical signal corresponding to transitions written to the magnetic recording medium by a write element. A computer receives information representative of the electrical signal and determines if a quality metric of the magnetic recording medium derived from the electrical signal is within a defined range. If the quality metric is not within the defined range, a defined action is performed by the computer.

First claim

What is claimed is:

1. An apparatus comprising:
a supplemental module that periodically engages a magnetic tape recording medium;
at least one read element in the supplemental module that generates an electrical signal corresponding to transitions written to the magnetic tape by a write element, the read element disposed a distance away from the magnetic tape when the supplemental module engages the magnetic tape, such that a signal resolution measurement value is approximately a minimum acceptable value when the magnetic tape is a reference tape;
a computer that receives information representative of the electrical signal and determines if a quality metric of the magnetic tape recording medium derived from the electrical signal is within a defined range; and
in response to determining that the quality metric is not within the defined range, performing a defined action.

2. An apparatus in accordance with claim 1 , further comprising a servo coupled to the supplemental module, wherein activating the servo physically engages or disengages the supplemental module from the magnetic recording medium.

3. An apparatus in accordance with claim 1 , further comprising a tape roller or guide coupled to a servo, wherein activating the servo causes the tape roller or guide to physically engage or disengage the magnetic tape from the supplemental module.

4. An apparatus in accordance with claim 1 , wherein the quality metric is one or more of: transition magnetic field strength at one or more bit densities, signal-to-noise ratio (SNR), transition parameter, PW-50 pulse width, bit error rate (BER), degree of overwrite.

5. An apparatus in accordance with claim 1 , wherein the supplemental module includes a coating disposed over the read element having a thickness sufficient to cause the read element to be disposed the distance away from the magnetic tape when the supplemental module engages the magnetic tape.

6. An apparatus in accordance with claim 1 , wherein the read element is recessed from a magnetic tape bearing surface of the supplemental module sufficient to cause the read element to be disposed the distance away from the magnetic tape when the supplemental module engages the tape.

7. An apparatus in accordance with claim 1 , wherein the distance away from the magnetic tape is approximately between 5 and 50 nm.

8. An apparatus in accordance with claim 1 , wherein and the supplemental module periodically engages the magnetic tape one or more of: once per a defined number of wraps of the tape around a supply reel or take up reel, after a defined elapsed tape recording appliance operation time, after a defined tape length that moves across the tape head module, when a tape is loaded to the tape recording appliance, when a BER exceeds a threshold value.

9. An apparatus in accordance with claim 1 , wherein the supplemental module periodically engages the magnetic recording medium sufficient for the supplemental module to read a defined number of data blocks from the magnetic recording medium.

10. An apparatus in accordance with claim 1 , wherein the defined action is one or more of: transmitting a message signal indicating that the quality metric is not within the defined range, and disabling write operations by the write head.

11. A method comprising:
periodically engaging a supplemental tape head module, that includes one or more read elements, to a magnetic tape recording medium, wherein the supplemental tape head module periodically engages the magnetic recording medium one or more of: once per a defined number of wraps of the tape around a supply reel or take up reel, after a defined elapsed tape recording appliance operation time, after a defined tape length that moves across the tape head module, when a tape is loaded to the tape recording appliance, when a BER exceeds a threshold value;
receiving, by a computer, information representative of an electrical signal from at least one of the read elements corresponding to transitions written to the magnetic tape recording medium by a write element;
determining, by the computer, if a quality metric of the magnetic tape recording medium derived from the electrical signal is within a defined range; and
in response to determining that the characteristic of the quality metric is not within the defined range, performing, by the computer, a defined action.

12. A method in accordance with claim 11 , wherein the quality metric is one or more of: transition magnetic field strength at one or more bit densities, signal-to-noise ratio (SNR), transition parameter, PW-50 pulse width, bit error rate (BER), degree of overwrite.

13. A method in accordance with claim 11 , wherein the defined action is one or more of: transmitting a message signal indicating that the quality metric is not within the defined range, and disabling write operations by the write head.

Assignees

• IBM

Inventors

• Biskeborn Robert G
• Lo Calvin S
• Wong Tak H
• Yan Xu

Classifications

• G11B5/455

  Arrangements for functional testing of heads; Measuring arrangements for heads · CPC title

• G11B27/36

  Monitoring, i.e. supervising the progress of recording or reproducing {(for digital recording G11B20/00 and s.gr.; for monitoring, testing or measuring of TV recorders of the type covered by H04N5/76 and subgroups, see H04N17/06)} · CPC title

• G11B20/10472

  derived from statistics of other quality measures, e.g. their mean, variance or skew · CPC title

• G11B20/10305

  signal quality assessment · CPC title

• G11B5/00813

  magnetic tapes · CPC title