Magnetic recording medium substrate and manufacturing method...

Glass manufacturing – Processes – With chemically reactive treatment of glass preform

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C428S846900, C428S848600, C501S123000

Reexamination Certificate

active

07624594

ABSTRACT:
The present invention is a magnetic recording medium substrate made of amorphous glass of B2O3—Al2O3—SiO2—Li2O type, wherein a chamfer is formed between an edge face at an outer circumference side or an inner circumference side of the substrate and a principal plane of the substrate, and a content of sodium and potassium at a surface area of the inner or outer circumference side edge face and a surface area of the chamfer is greater than a mean content of sodium and potassium of the magnetic recording medium substrate. With the present invention, it is possible to prevent generation of projections on a magnetic film, a protective film or the like due to movement of lithium ions in a magnetic recording medium substrate made of amorphous glass which includes lithium.

REFERENCES:
patent: 6554615 (2003-04-01), Brodkin et al.
patent: 2001/0014573 (2001-08-01), Shimoi et al.
patent: 2001/0051585 (2001-12-01), Ryu et al.
patent: 2002/0041138 (2002-04-01), Nishikawa
patent: 2002/0055017 (2002-05-01), Fukushima et al.
patent: 2002/0169063 (2002-11-01), Terashi et al.
patent: 2002/0197437 (2002-12-01), Hashimoto et al.
patent: 2003/0164005 (2003-09-01), Saito et al.
patent: 2003/0172677 (2003-09-01), Miyamoto et al.
patent: 2004/0232576 (2004-11-01), Brodkin et al.
patent: 11-191212 (1999-07-01), None
patent: 2000-076652 (2000-03-01), None
patent: 2001-023155 (2001-01-01), None
patent: 2001-056929 (2001-02-01), None
patent: 2001-180969 (2001-07-01), None
patent: 2002-362944 (2002-12-01), None
patent: 2003-277102 (2003-10-01), None
Translation JA 11-191212.
Translation JA 2001-180969.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Magnetic recording medium substrate and manufacturing method... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Magnetic recording medium substrate and manufacturing method..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic recording medium substrate and manufacturing method... will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-4139875

All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.