公开(公告)号：EP0221583A3

公开(公告)日：1987-05-27

申请号：EP86201661

申请日：1986-09-24

Applicant: N.V. Philips' Gloeilampenfabrieken

Inventor： Verbunt, Johannes Petrus Maria

IPC: G11B05/133 ,  G11B05/193 ,  G11B05/23

CPC classification number: G11B5/1335 ,  G11B5/193 ,  G11B5/232 ,  Y10T29/49048 ,  Y10T29/49055 ,  Y10T225/304

Abstract: A plurality of separate magnetic head cores (3) is cut from a one- piece ferrite core block. A winding aperture (6) is provided in each magnetic head core. A fracture (7) in the cross-section of the material of the head core is generated between the winding aperture and the future tape contact face during or after the winding aperture is provided. A non-magnetic material in a liquid form is provided between the fracture faces and is converted to the solid form.

公开(公告)号：EP0149509A3

公开(公告)日：1987-04-01

申请号：EP85300017

申请日：1985-01-02

Applicant: NGK INSULATORS, LTD.

Inventor： Matsuzawa, Soichiro

IPC: G11B05/133 ,  G11B05/193 ,  G11B05/23

CPC classification number: G11B5/232 ,  G11B5/133 ,  G11B5/193 ,  Y10T29/49048 ,  Y10T29/49057

Abstract: A magnetic head core consisting of plural ferrite core elements (2,4) bonded together into a generally annular core assembly which has a magnetic gap (10) defined by opposed portions of the core elements and further has at least one groove (24) which is formed in the gap-defining opposed portions in the direction of sliding movement of a recording medium so as to define at least one track (18) which slidably contacts the recording medium moving in the vicinity of the magnetic gap. To render manufacture easy and to achieve good alignment of the track parts on the respective core elements, the groove (24) is inclined in the direction from one of the opposed portions to the other such that a depth D thereof at the position of the magnetic gap (10) is greater than the depth (d) of the magnetic gap. The inclined groove (24) is cut after the two core elements (2, 4) are bonded into the integral core assembly. Two core integral core assemblies may be bonded together into an integral composite core structure, such that the inclined grooves in one of the two core elements are aligned with those in the other core element. The two integral core assemblies are bonded with glass when the inclined grooves are filled with molten glass.

公开(公告)号：EP0201255A3

公开(公告)日：1987-08-26

申请号：EP86303186

申请日：1986-04-28

Applicant: Matsushita Electric Industrial Co., Ltd.

Inventor： Ono, Mitsuaki ,  Ueda, Masataka ,  Miyazaki, Osamu

IPC: G11B05/23 ,  G11B05/193 ,  G11B05/127 ,  G11B05/187

CPC classification number: G11B5/1871 ,  Y10T29/49043 ,  Y10T29/49052 ,  Y10T29/49057 ,  Y10T29/49067

Abstract: n a magnetic head comprising a head gap and a magnetic core composed of both a high permeability ferrite and a magnetic alloy, said magnetic alloy being disposed in the vicinity of said head gap, the improvement comprising a corrugation provided at a junction portion between said ferrite and said magnetic alloy, a height of said corrugation being not less than a value of the longest wavelength of luminance signals and color signals recorded on a magnetic recording medium, a distance defined between adjacent two crests or bottoms of said corrugation being smaller than a width of a head track.

公开(公告)号：EP0148628A3

公开(公告)日：1987-01-07

申请号：EP84309011

申请日：1984-12-21

Applicant: NGK INSULATORS, LTD.

Inventor： Matsuzawa, Soichiro

IPC: G11B05/133 ,  G11B05/193 ,  G11B05/23

CPC classification number: G11B5/133 ,  G11B5/193 ,  G11B5/232 ,  Y10T29/49034 ,  Y10T29/49048 ,  Y10T29/49055 ,  Y10T29/49067

Abstract: A magnetic head core consisting of plural core elements (16, 18) of ferrite butted and bonded together through solid-solid reaction so as to form a generally annular magnetic circuit having a magnetic gap (22). At least opposed portions of the magnetic circuit which define the magnetic gap and provide magnetic-medium contacting surfaces are formed of a single crystal of ferrite. At least one (16) of the plural core elements is originally an at least partially monocrystalline block of ferrite including a monocrystalline portion (15) consisting of a ferrite single crystal, and at least one of the opposed portions defining the magnetic gap is monocrystallized as a result of growth of the ferrite single crystal of the monocrystalline portion toward the original ferrite polycrystal of the core elements.