[go: up one dir, main page]

JPS57113401A - Permanent magnet erasing head - Google Patents

Permanent magnet erasing head

Info

Publication number
JPS57113401A
JPS57113401A JP86481A JP86481A JPS57113401A JP S57113401 A JPS57113401 A JP S57113401A JP 86481 A JP86481 A JP 86481A JP 86481 A JP86481 A JP 86481A JP S57113401 A JPS57113401 A JP S57113401A
Authority
JP
Japan
Prior art keywords
magnetic
permanent magnet
magnetic field
magnet powder
degression
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP86481A
Other languages
Japanese (ja)
Other versions
JPH0127482B2 (en
Inventor
Norio Miyatake
Keizo Ishiwatari
Noboru Koizumi
Nobuo Kashimura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP86481A priority Critical patent/JPS57113401A/en
Publication of JPS57113401A publication Critical patent/JPS57113401A/en
Publication of JPH0127482B2 publication Critical patent/JPH0127482B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/325—Erasing heads using permanent magnets

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Magnetic Heads (AREA)
  • Paints Or Removers (AREA)

Abstract

PURPOSE:To facilitate the stabilization of characteristics by obtaining an inverted degression magnetic field by performing magnetization once, by laminating several kinds of permanent magnet plates having anisotropy in the lamination direction and nonmagnetic materials by turns. CONSTITUTION:To provide permanent magnet plates with different magnetic characteristics, Sr ferrite magnet powder is kneaded with a etylene-vinyl acetate copolymer and the mixture is formed in a magnetic field and demagnetized while the content of the magnet powder is made different. Those magnet plates 9-11 and nonmagnetic materials 12 are laminated by turns, and the external shape is determined. As the nonmagnetic material 12, a resin plate of an ethylene-vinyl acetate polymer which does not contain magnet powder is used. This lamination is sandwiched in between magnetic poles 13 for magnetization and then applied with a DC magnetic field, so that magnetic flux appears on a magnetic-tape sliding surface 1 as shown by a broken line 14 while having inverted degression distribution of magnetic intensity in the sliding direction. Therefore, the variance of the magnetic-fiels intensity distribution is eliminated to facilitate the stabilization of characteristics.
JP86481A 1981-01-06 1981-01-06 Permanent magnet erasing head Granted JPS57113401A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP86481A JPS57113401A (en) 1981-01-06 1981-01-06 Permanent magnet erasing head

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP86481A JPS57113401A (en) 1981-01-06 1981-01-06 Permanent magnet erasing head

Publications (2)

Publication Number Publication Date
JPS57113401A true JPS57113401A (en) 1982-07-14
JPH0127482B2 JPH0127482B2 (en) 1989-05-29

Family

ID=11485531

Family Applications (1)

Application Number Title Priority Date Filing Date
JP86481A Granted JPS57113401A (en) 1981-01-06 1981-01-06 Permanent magnet erasing head

Country Status (1)

Country Link
JP (1) JPS57113401A (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4023807Y1 (en) * 1964-01-22 1965-08-13
JPS4917218A (en) * 1972-06-02 1974-02-15
JPS5178213A (en) * 1974-12-27 1976-07-07 Matsushita Electric Ind Co Ltd SHOKYO HETSUDO

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4023807Y1 (en) * 1964-01-22 1965-08-13
JPS4917218A (en) * 1972-06-02 1974-02-15
JPS5178213A (en) * 1974-12-27 1976-07-07 Matsushita Electric Ind Co Ltd SHOKYO HETSUDO

Also Published As

Publication number Publication date
JPH0127482B2 (en) 1989-05-29

Similar Documents

Publication Publication Date Title
US3257586A (en) Flexible permanent magnet and composition
JPS5616932A (en) Recording and reproducing head for vertical magnetic recording and manufacture of this recording and reproducing head and recording and reproducing unit using this recording and reproducing head
JPS5613513A (en) Magnetic head and its manufacture
GB1196228A (en) Improvements in or relating to Magnets
JPS5488110A (en) Vertical magnetization recorder-reproducer
JPS57113401A (en) Permanent magnet erasing head
JPS5256510A (en) Magnetic recording material
JPS54128719A (en) Vertical magnetization recorder
JPS5577025A (en) Erasing head
JPS55133509A (en) Electromagnet device
JPS5687217A (en) Vertical magnetization type magnetic head and its manufacture
JPS55120109A (en) Magnetic tape for attraction
JPS5323608A (en) Magnet ic recording medium
JPS5782208A (en) Permanent magnet erasing head
JPS578905A (en) Permanent magnet erasing head
JPS5687220A (en) Vertical magnetization type magnetic head
JPS55117729A (en) Magnetic head
JPS55146609A (en) Recording and reproducing device for magnetic card of lamination of temperature sensing magnetic material
JPS57127917A (en) Magnetic head device
JPS5589906A (en) Magnetic head for erase
JPS5471396A (en) Preparation of roll magnet
JPS57183615A (en) Vertical magnetic recording and reproducing device
JPS5597020A (en) Thin-film magnetic head
JPS5774823A (en) Magnetic recording and reproducing head
GB1373390A (en) Manganese-zinc ferrites for magnetic heads