# US 5,345,354 A · Magnetic read/write head having a reduced thickness closure core

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- Number: US 5,345,354 A
- Document ID: US5345354A
- Status: Granted
- Kind: A
- Application number: 08/045,109
- Filed: 1993-04-12
- Granted: 1994-09-06
- Earliest claimed: 1989-03-03
- Assignees: TDK Corporation
- Inventors: Tomio Ito; Hideyuki Miyazaki; Hideyuki Moriya; Kazuhito Wakabayashi
- Web page: https://patentgrep.com/patent/US5345354A

## CPC

- G11B 5/2452: {where the dimensions of the effective gap are controlled}
- G06K 7/084: {sensing magnetic material by relative movement detecting flux changes without altering its magnetised state}
- G11B 15/125: {conditioned by the operating function of the apparatus}
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS

## Abstract

This invention relates to a wide-write/narrow-read head having a pair of C-shaped cores one of which is used as a read core and the other of which is used as a write core, and a closure core which is provided between the two cores to shut off side magnetic circuits at the time of data reading. The closure is reduced in thickness at the tip end and is shaped to slope toward the read head so as to increase magnetic resistance from said closure core to said read core in order to prevent the magnetic flux extending between said write core and said closure core from leaking into said read core from said closure core.

## Claims

### Claim 1

A magnetic head comprising a closure core having a recessed portion at the center tip end thereof, a first and second C-shaped core provided on both sides of said closure core, said first C-shaped core having a projection at the center tip end thereof in a manner to be inserted into said recessed portion, magnetic gaps formed respectively between said closure core and said second C-shaped core and between said projection of said first C-shaped core tip end and second C-shaped core, and a first coil and a second coil wound on said first and second C-shaped cores respectively, wherein the magnetic head is further provided with an electrical short circuit of said closure core including an ON/OFF switch to selectively close said short circuit.

### Claim 2

A data recording/reproducing method by means of a magnetic head comprising a closure having a recessed portion at the center tip end thereof, a first and a second C-shaped core provided on both sides of said closure core, said first C-shaped core having a projection at the center tip end thereof in a manner to be inserted into said recessed portion, magnetic gaps formed respectively between said closure core and said second C-shaped core and between said projection of said first C-shaped core tip end and said second C-shaped core, a first coil and a second coil wound on said first and second C-shaped cores respectively, an electrical short circuit of said closure core, including an ON/OFF switch for selectively closing said short circuit, wherein said first C-shaped core and said first coil are used as a read core and a read coil while said second C-shaped core and second coil are used as a write core and a write coil, and said ON/OFF switch is turned off at the time of recording data while said switch is turned on at the time of reproducing the data.