Electromagnetic transducer head

• US 4,246,619 A
• Filed: 01/11/1979
• Issued: 01/20/1981
• Est. Priority Date: 01/13/1978
• Status: Expired due to Term

• Current Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation)
• Inventors: Nei, Atsushi, Sakai, Kunihide, Hirai, Shiro
• Primary Examiner(s): Wolff, John H.
• Application Number:
  US06/002,564
• Time in Patent Office: 740 Days
• Field of Search: 360/119, 360/122, 360/125, 360/126-127, 428/611, 428/928, 148/12 EA, 148/100-101, 29/603
• US Class Current: 360/125.01
• CPC Class Codes: G11B 5/133 with cores composed of particles, e.g. with dust cores, with ferrite cores with cores composed of isolated magnetic particles in thin films G11B5/31
• CPC Class Codes: G11B 5/193 the pole pieces being ferrite or other magnetic particles G11B5/1871 takes precedence; in thin film G11B5/31
• CPC Class Codes: Y10T 29/49034 Treating to affect magnetic properties
• CPC Class Codes: Y10T 29/49048 Machining magnetic material [e.g., grinding, etching, polishing]
• CPC Class Codes: Y10T 29/49055 with bond/laminating preformed parts, at least two magnetic

Abstract

An electromagnetic transducer head for a tape recording and reproducing system comprises a pair of generally U-shaped single crystalline ferrite cores having their first legs secured together and their second legs spaced from each other to form a magnetic gap in which a wafer of glossy material is provided. Each of the ferrite cores has crystal planes (211), (110) and (111). The magnetic gap is aligned to the crystal plane (111) and the second legs of the cores are shaped to provide a tape contact surface which is parallel with the crystal plane (211). The crystal plane (110) is at right angles to the planes (211) and (111) and forms a passage for magnetic flux. The crystallographic axis <110> of each core extends at an angle to the magnetic gap so as to meet the axis <110> of the other core at a point aligned with the tape contact face.

Claims

1. An electromagnetic transducer head comprising a pair of single-crystalline ferrite half core elements each having crystal planes (211), (111) and (110) which are at right angles to each other, said core elements being secured together to form a magnetic circuit with a magnetic gap therein, said magnetic gap lying in a plane which is substantially parallel with said crystal plane (111), said core elements forming a tape contact face which is parallel with said crystal plane (211) and intersecting the plane of said magnetic gap at right angles, said core elements forming a common surface substantially parallel with said crystal plane (110), each of said core elements having a crystallographic axis <

110>

extending at an angle to the plane of said magnetic gap to intersect the crystallogrphic axis <

110>

of the other core element at a point lying in said tape contact face, and a coil wound on said magnetic circuit.

2. An electromagnetic transducer head as claimed in claim 1, wherein each of said core elements comprises a generally U-shaped ferrite core, the first leg of the U-shape of each core being secured to the first leg of the U shape of the other core and the second leg of each core being spaced from the second leg of the other core to form said magnetic gap, said first and second legs of each core forming a common surface which is flush with the common surface formed by the other core, said common surfaces being parallel with said crystal plane (110).

3. An electromagnetic transducer head as claimed in claim 1 or claim 2, wherein, a line perpendicular to the plane of said gap is inclined at an angle less than 10°

to said common surface.

4. An electromagnetic transducer head as claimed in claim 1, wherein said angle is approximately 55°

.

5. An electromagnetic transducer head as claimed in any one of claims 1, 2 or 4, further comprising a spacer of fused material provided in said magnetic gap.

6. An electromagnetic transducer head as claimed in any one of claims 1, 2 or 4, wherein said half core elements have a positive magnetic anisotropic constant K₁.