GB1267434A - Apparatus and method of testing a magnetic recording medium - Google Patents

Apparatus and method of testing a magnetic recording medium

Info

Publication number
GB1267434A
GB1267434A GB5028569A GB5028569A GB1267434A GB 1267434 A GB1267434 A GB 1267434A GB 5028569 A GB5028569 A GB 5028569A GB 5028569 A GB5028569 A GB 5028569A GB 1267434 A GB1267434 A GB 1267434A
Authority
GB
United Kingdom
Prior art keywords
head
magnetic
flux pattern
winding
resulting
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.)
Expired
Application number
GB5028569A
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.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
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 International Business Machines Corp filed Critical International Business Machines Corp
Publication of GB1267434A publication Critical patent/GB1267434A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/12—Measuring magnetic properties of articles or specimens of solids or fluids
    • G01R33/1207—Testing individual magnetic storage devices, e.g. records carriers or digital storage elements

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Abstract

1,267,434. Magnetic flaw testing. INTERNATIONAL BUSINESS MACHINES CORP. Oct.14, 1969 [Oct.16, 1968], No.50285/69. Heading G1N. Magnetic recording tape is tested for flaws by saturating it in one direction, then magnetizing it below saturation in the opposite direction, and detecting any inconsistencies in the resulting recorded flux pattern. As shown in Fig.9, head 120 produces a magnetic field which decreases in the thickness of the magnetic coating 112 of the tape so that the resulting flux pattern varies as shown by arrows VWXYZ. Pick-up head 124 detects any inconsistency in the resulting flux pattern due to a hole, Fig. 15D, or a bump, Fig. 16D. The detector winding 128, which may be centre-tapped to give a differential output, is preferably connected to an integrator having a frequency/gain characteristic complementary to that of the detector head so that the overall response is linear. In an alternative arrangement, Figs.1-8 (not shown), a common winding (34) Fig.4 (not shown) may serve as a bias and sense winding, means (40) being provided to adjust the bias field.
GB5028569A 1968-10-16 1969-10-14 Apparatus and method of testing a magnetic recording medium Expired GB1267434A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US76809268A 1968-10-16 1968-10-16
US76801468A 1968-10-16 1968-10-16

Publications (1)

Publication Number Publication Date
GB1267434A true GB1267434A (en) 1972-03-22

Family

ID=27117998

Family Applications (1)

Application Number Title Priority Date Filing Date
GB5028569A Expired GB1267434A (en) 1968-10-16 1969-10-14 Apparatus and method of testing a magnetic recording medium

Country Status (1)

Country Link
GB (1) GB1267434A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2000295A (en) * 1977-06-10 1979-01-04 Basf Ag Method and device for determining the homogeneity of a magnetic dispersion and method of manufacturing a magnetic recording medium from such a dispersion
WO1987005112A1 (en) * 1986-02-17 1987-08-27 Julius Hartai Method and apparatus for non-destructive materials testing and magnetostructural materials investigations
EP0297922A2 (en) * 1987-07-02 1989-01-04 Seagate Technology, Inc. Non-destructive method for magnetic measurements of recording disc members

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2000295A (en) * 1977-06-10 1979-01-04 Basf Ag Method and device for determining the homogeneity of a magnetic dispersion and method of manufacturing a magnetic recording medium from such a dispersion
GB2000295B (en) * 1977-06-10 1982-03-10 Basf Ag Method and device for determining the homogeneity of a magnetic dispersion and method of manufacturing a magnetic recording medium from such a dispersion
WO1987005112A1 (en) * 1986-02-17 1987-08-27 Julius Hartai Method and apparatus for non-destructive materials testing and magnetostructural materials investigations
US4931730A (en) * 1986-02-17 1990-06-05 Dam Patent A/S Method and apparatus for non-destructive materials testing and magnetostructural materials investigations
EP0297922A2 (en) * 1987-07-02 1989-01-04 Seagate Technology, Inc. Non-destructive method for magnetic measurements of recording disc members
EP0297922A3 (en) * 1987-07-02 1990-10-10 Seagate Technology, Inc. Non-destructive method for magnetic measurements of recording disc members

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