JPS57138002A - Permanent magnet erasing head - Google Patents

Permanent magnet erasing head

Info

Publication number
JPS57138002A
JPS57138002A JP2411281A JP2411281A JPS57138002A JP S57138002 A JPS57138002 A JP S57138002A JP 2411281 A JP2411281 A JP 2411281A JP 2411281 A JP2411281 A JP 2411281A JP S57138002 A JPS57138002 A JP S57138002A
Authority
JP
Japan
Prior art keywords
magnet
magnetic field
thickness
substance
nonmagnetic
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
JP2411281A
Other languages
Japanese (ja)
Other versions
JPS6313250B2 (en
Inventor
Norio Miyatake
Nobuo Kashimura
Keizo Ishiwatari
Noboru Koizumi
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 JP2411281A priority Critical patent/JPS57138002A/en
Publication of JPS57138002A publication Critical patent/JPS57138002A/en
Publication of JPS6313250B2 publication Critical patent/JPS6313250B2/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)

Abstract

PURPOSE:To obtain a permanent magnet erasing head of gradient magnetic field type with stable performance without dispersion in magnetic field strength distribution, by alternately laminating a plurality of permanent magnets and nonmagnetic substances with different thickness and making magnetization toward laminating direction of the magnet plates. CONSTITUTION:Magnet plates 9, 10, 11 with different thickness and nonmagnetic substances 12 with different thickness are combined alternately for lamination and a tape sliding surface 1 is shaped. The assembly is clipped with magnetizing magnet poles 13 from both sides and magnetization is made by applying a DC magnetic field. A leakage magnetic flux shown in broken lines 14 appears at the surface 1. The magnetic flux density distribution measured toward the sliding surface shows an inverted gradient magnetic field distribution, and the leakage magnetic flux density at larger size ratio T/L of the magnet plate is increased and decreased at smaller size ratio T/L. As the thickness of the nonmagnetic substance 12, thicker substance is used at thicker magnet thickness at both sides clipping the nonmagnetic substance and thinner substance is used at thin magnet thickness. Thus, without dispersion in the magnetic field strength distribution, stable performance can be achieved.
JP2411281A 1981-02-19 1981-02-19 Permanent magnet erasing head Granted JPS57138002A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2411281A JPS57138002A (en) 1981-02-19 1981-02-19 Permanent magnet erasing head

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2411281A JPS57138002A (en) 1981-02-19 1981-02-19 Permanent magnet erasing head

Publications (2)

Publication Number Publication Date
JPS57138002A true JPS57138002A (en) 1982-08-26
JPS6313250B2 JPS6313250B2 (en) 1988-03-24

Family

ID=12129240

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2411281A Granted JPS57138002A (en) 1981-02-19 1981-02-19 Permanent magnet erasing head

Country Status (1)

Country Link
JP (1) JPS57138002A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4023807Y1 (en) * 1964-01-22 1965-08-13
JPS4843617A (en) * 1971-10-04 1973-06-23
JPS50151216U (en) * 1974-05-30 1975-12-16
JPS5362517A (en) * 1976-11-16 1978-06-05 Toshiba Corp Multipolar magnetism erasing head
JPS5539548U (en) * 1978-09-04 1980-03-13

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5446794A (en) * 1977-09-22 1979-04-12 Nippon Nohyaku Co Ltd Thiadiazine and bactericidal agent containing the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4023807Y1 (en) * 1964-01-22 1965-08-13
JPS4843617A (en) * 1971-10-04 1973-06-23
JPS50151216U (en) * 1974-05-30 1975-12-16
JPS5362517A (en) * 1976-11-16 1978-06-05 Toshiba Corp Multipolar magnetism erasing head
JPS5539548U (en) * 1978-09-04 1980-03-13

Also Published As

Publication number Publication date
JPS6313250B2 (en) 1988-03-24

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