US4085429A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic head having optimum spacer thickness disposed between dummy and write-in core segments
Assignee: Canon Inc
•
Filing: 1976-06-03
•
Granted: 1978-04-18
•
Expires: 1996-06-03
Abstract
Abstract In a magnetic head comprising a write-in excitation core and a read-out excitation core having a narrower track width than that of the write-in excitation core and forming a closed magnetic circuit with a gap interposed between the two cores, a non-magnetic spacer having thickness 1.5 to 5 times as great as the width of the gap is disposed at one or each end of the read-out excitation core with respect to the widthwise direction of the track thereof, and a dummy core is disposed adjacent to the read-out excitation core with the non-magnetic spacer interposed therebetween to form a closed magnetic circuit with the gap interposed between the dummy core and the write-in excitation core.
Inventors
- 👤 Tachio Hasegawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:17
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G11B5/09; G11B5/127; G11B5/187; G11B5/245; G11B5/2452
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
199 words
A magnetic head comprising: a write-in excitation core; a write-in coil wound around said write-in excitation core; a read-out excitation core having narrower track width than that of said write-in excitation core for forming a closed magnetic loop circuit with a gap interposed between said read-out excitation core and said write-in excitation core; a read-out coil wound around said read-out excitation core; a non-magnetic spacer having thickness 1.5 to 5 times as great as the width of said gap and disposed at at least one end of said read-out excitation core with respect to the width direction of the track of said read-out excitation core; and a dummy core disposed adjacent to said read-out excitation core with said non-magnetic spacer interposed therebetween for forming a closed magnetic loop circuit with a dummy gap interposed between said dummy core and said write-in excitation core, the dummy gap having the same width as said first mentioned gap, said dummy core comprising a plurality of divided dummy core segments, and additional non-magnetic spacers each of which has thickness 1.5 to 5 times as great as the width of said first mentioned gap and interposed among respective ones of said dummy core segments.
Claim 2
Dependent Claim
199 words
A magnetic head comprising: a write-in excitation core; a write-in coil wound around said write-in excitation core; a read-out excitation core having narrower track width than that of said write-in excitation core for forming a closed magnetic loop circuit with a gap interposed between said read-out excitation core and said write-in excitation core; a read-out coil wound around said read-out excitation core; a non-magnetic spacer having thickness 1.5 to 5 times as great as the width of said gap and disposed at at least one end of said read-out excitation core with respect to the width direction of the track of said read-out excitation core; and a dummy core disposed adjacent to said read-out excitation core with said non-magnetic spacer interposed therebetween for forming a closed magnetic loop circuit with a dummy gap interposed between said dummy core and said write-in excitation core, the dummy gap having the same width as said first mentioned gap, said dummy core comprising a plurality of divided dummy core segments, and additional non-magnetic spacers each of which has thickness 1.5 to 5 times as great as the width of said first mentioned gap and interposed among respective ones of said dummy core segments.
Claim 3
Dependent Claim
188 words
A magnetic head comprising: a read-out excitation core; a read-out coil wound around said read-out excitation core; a write-in excitation core having wider track width than that of said read-out excitation core for forming a closed magnetic loop circuit with a gap interposed between said read-out excitation core and said write-in excitation core, said write-in excitation core comprises a plurality of divided write-in excitation core segments, and non-magnetic spacers each of which has thickness 1.5 to 5 times as great as the width of said gap and interposed among respective ones of said write-in excitation core segments; a write-in coil wound around said write-in excitation core; an additional non-magnetic spacer having thickness 1.5 to 5 times as great as the width of said gap and disposed at at least one end of said read-out excitation core with respect to the width direction of the track of said read-out excitation core; and a dummy core disposed adjacent to said read-out excitation core with said additional non-magnetic spacer interposed therebetween for forming a closed magnetic loop circuit with the gap interposed between said dummy core and said write-in excitation core.
Claim 4
Dependent Claim
188 words
A magnetic head comprising: a read-out excitation core; a read-out coil wound around said read-out excitation core; a write-in excitation core having wider track width than that of said read-out excitation core for forming a closed magnetic loop circuit with a gap interposed between said read-out excitation core and said write-in excitation core, said write-in excitation core comprises a plurality of divided write-in excitation core segments, and non-magnetic spacers each of which has thickness 1.5 to 5 times as great as the width of said gap and interposed among respective ones of said write-in excitation core segments; a write-in coil wound around said write-in excitation core; an additional non-magnetic spacer having thickness 1.5 to 5 times as great as the width of said gap and disposed at at least one end of said read-out excitation core with respect to the width direction of the track of said read-out excitation core; and a dummy core disposed adjacent to said read-out excitation core with said additional non-magnetic spacer interposed therebetween for forming a closed magnetic loop circuit with the gap interposed between said dummy core and said write-in excitation core.
Claim 5
Dependent Claim
51 words
A magnetic head according to claim 2, wherein said dummy core comprises a plurality of divided dummy core segments, and further additional non-magnetic spacers each of which has thickness 1.5 to 5 times as great as the width of said gap and interposed among respective ones of said dummy core segments.
References Cited (Backward Citations)
US3167618A
Cited
US3353168A
Cited
US3562443A
Cited
US3662122A
Cited
US3668332A
Cited
US3827083A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-17 | 1981-10-17 | 1982-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-17 | 1985-10-17 | 1986-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-17 | 1989-10-17 | 1990-04-18 | $7700.00 | Window Closed / Lapsed |