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US 6,307,817 B1Granted
Magnetic recording medium thermal stability measuring method and thermal stability measuring apparatus
AssigneeNEC Corporation
InventorShinzo Tsuboi
Life of this patent
Estimating the term…
Abstract
A thermal stability measuring method for a magnetic recording medium includes heating the magnetic recording medium, reproducing an information recorded on the magnetic recording medium, and measuring a thermal stability according to a reproduction output during the heating.
Claims7
A thermal stability measuring method for a magnetic recording medium, said method comprising steps of:
- contact-free heating said magnetic recording medium from a location spaced apart from the medium;
- reproducing an information recorded on said magnetic recording medium;
- measuring a thermal stability according to a reproduction output during said heating;
- and
- calculating a reproduction output during heating in relation to a reproduction output during non-heating so as to determine an attenuation amount.
2 more elements
A thermal stability measuring method for a magnetic recording medium, said method comprising steps of:
- contact-free heating said magnetic recording medium from a location spaced apart from the medium;
- reproducing an information recorded on said magnetic recording medium;
- and
- measuring a thermal stability according to a reproduction output during said heating, wherein
- said magnetic recording medium is heated by a predetermined magneto-optical head laser radiation, and
- an information is reproduced from said magnetic recording medium heated, by a predetermined reproduction head, and wherein
- heating is carried out while said magneto-optical head is shifted in a radial direction of said magnetic recording medium;
- an information is reproduced while said reproduction head is shifted in a radial direction of said magnetic recording medium, said reproduction head having a width smaller than a recording track width of said magnetic recording medium and equal to or smaller than said laser spot diameter;
- and
- according to said reproduction output, a thermal stability of said magnetic recording medium is determined.
7 more elements
A thermal stability measuring method for a magnetic recording medium, said method comprising steps of:
- contact-free heating said magnetic recording medium from a location spaced apart from the medium;
- reproducing an information recorded on said magnetic recording medium;
- and
- measuring a thermal stability according to a reproduction output during said heating, wherein
- said magnetic recording medium is heated by a predetermined magneto-optical head laser radiation, and
- an information is reproduced from said magnetic recording medium heated, by a predetermined reproduction head, and wherein
- a predetermined area of said magnetic recording medium is locally heated by laser radiation of said magneto-optical head so as to change magnetization state thereof;
- an information recorded on said magnetic recording medium is reproduced by a predetermined reproduction head;
- and
- upon detection of a fluctuation of said reproduction output, shifting of said reproduction head is terminated, thus positioning said reproduction head in relation to said magneto-optical head.
7 more elements
A thermal stability measuring apparatus for a magnetic recording medium, said apparatus comprising:
- a heater whose position over a magnetic recording medium can be controlled so as to non-contactingly heat the magnetic recording medium from a position spaced apart the magnetic recording medium;
- a reproduction head whose position over a magnetic recording medium can be controlled;
- and
- an analyzer for determining a reproduction output from said reproduction head so as to analyze a thermal stability, wherein said analyzer determines the thermal stability according to an attenuation amount of a reproduction output during heating in relation to a reproduction output during non-heating.
1 more element
A thermal stability measuring apparatus for a magnetic recording medium, said apparatus comprising:
- a heater whose position over a magnetic recording medium can be controlled so as to non-contactingly heat the magnetic recording medium from a position spaced apart the magnetic recording medium;
- a reproduction head whose position over a magnetic recording medium can be controlled;
- and
- an analyzer for determining a reproduction output from said reproduction head so as to analyze a thermal stability, wherein
- said heater is a magneto-optical head radiating a laser beam, and
- said magneto-optical head is shifted in a radial direction of said magnetic recording medium while carrying out heating;
- said reproduction head is shifted in a radial direction of said magnetic recording medium while reproducing an information, said reproduction head having a width smaller than a recording track width of said magnetic recording medium and equal to or smaller than said laser beam spot diameter;
- and
- said reproduction output is used to determine a thermal stability of said recording medium.
6 more elements
Dependencies are inferred from the claim text.