Magnetic memory device having a perfluro-polyether film coated on an inner surface of its housing for entrapping dust

• US 5,485,327 A
• Filed: 11/04/1994
• Issued: 01/16/1996
• Est. Priority Date: 01/31/1992
• Status: Expired due to Term

• Current Assignee: TDK Corporation
• Original Assignee: NEC Corporation
• Inventors: Yanagisawa, Masahiro
• Primary Examiner(s): Levy, Stuart S.
• Assistant Examiner(s): Renner, Craig A.
• Application Number:
  US08/334,805
• Time in Patent Office: 438 Days
• Field of Search: 360/97.02, 360/97.03, 360/97.04, 360/97.01, 360/137, 360/98.02, 360/134, 360/132, 360/133
• US Class Current: 360/97.02
• CPC Class Codes: G11B 25/043 using rotating discs
• CPC Class Codes: G11B 33/1446 Reducing contamination, e.g. by dust, debris

Abstract

Mechanical components including a magnetic head 3 and a magnetic disk medium 4 are contained in a housing 6 separating from outside atmosphere 5. A perfluoro-polyether film 9 is coated on the inner surface of said housing 6 and the upper surface of a base 2 provided with the housing 6. Floating dust in the housing 6 adheres on and is incorporated in said perfluoro-polyether film 9 so that dust is removed from the space in the housing 6 thereby the space in the housing 6 is maintained at a clean state free from dust. As a result, the head flotation is stabilized, abrasion of the medium and the head can be avoided and the occurrence of head-crush can be prevented.

Claims

1. A magnetic memory device comprising:

a housing means separating mechanical components means, including a magnetic medium means, from outside atmosphere, and

coating means comprising a prefluoro-polyether film coated on whole or a part of the inner surface of said housing means for trapping dust which may be contained within said housing means.

2. The magnetic memory device according to claim 1, wherein said magnetic medium means is a circular magnetic disk medium and said coating means comprising said perfluoro-polyether film is coated on a part of the inner surface of said housing means and is located at a position inside said housing means near a circumferential periphery of said magnetic disk medium.

3. The magnetic memory device according to claim 1, wherein said magnetic medium means is a hard disk means.

4. The magnetic memory device according to claim 1, wherein said magnetic medium means is a floppy disk means.

6. The magnetic memory device according to either claim 1 or claim 5, wherein said perfluoro-polyether film contains one of the repeating unit taken from a group consisting of:

--OCF₂ --, --OC₂ F₄ --, --OCF₂ CF(CF₃)--, and --OC₃ F₆.

7. The magnetic memory device according to either claim 1 or claim 5, wherein said perfluoro-polyether film is made of a material selected from the group consisting of:

F₃ C(OCF₂)_p (OC₂ F₄)_q OCF₂ OCF₃,

F(CF(CF₃)CF₂ O)_m C₂ F₅,

F(C₃ F₆ O)_r C₂ F₅,

GCF₂ (OCF₂)_p (OC₂ F₄)_q OCF₂ G,

F(CF(CF₃)CF₂ O)_m CF₂ G,

F(C₃ F₆ O)_r C₂ F₄ G,

F(CF(CF₃)CF₂ O)_m CF₂ JCF₂ (OCF₂ (CF₃)CF)_m F,

F(C₃ F₆ O)_r C₂ F₄ JC₂ F₄ (OC₃ F₆)_r F, and

{F(C₃ F₆ O)_r C₂ F₄ }₃ L,

where, p, q or r is either 1 or other positive integer;

m is either 3 or greater integer;

G is a functional group selected from the group of --COOH, --CH₂ OH, --COOR (R is either hydrocarbon, fluoro-hydrocarbon or aromatic hydrocarbon), --CONHC₆ H₃ (CH₃)NCO, --N═

N--NH₂, --SO₃ H, --CSOH, --COSH and ##STR2## J is a functional group selected from the group of --SO₂ NHCO--, --SO₂ NHCH₂ --, --CH₂ N(OH)CH₂ --, --CONHCO--, --CONHCH₂ -- and --CSNH--;

L is --CH₂ (N(NH)--)CH₂ --.

5. A magnetic disk drive comprising a closed housing means having a rotatable disk means therein, a slider means supported adjacent to and separated from said rotatable disk means by an air gap, a film means on an inside wall of said housing means at least adjacent a circumference of said disk means for collecting dust within said housing means, said film means being a perfluoro-polyetherfilm which collects said dust within said housing means.

8. The drive of claim 5 wherein substantially the entire inside wall of said housing means is covered with said film means.