GB2145271A - Magnetic head - Google Patents
Magnetic head Download PDFInfo
- Publication number
- GB2145271A GB2145271A GB08420437A GB8420437A GB2145271A GB 2145271 A GB2145271 A GB 2145271A GB 08420437 A GB08420437 A GB 08420437A GB 8420437 A GB8420437 A GB 8420437A GB 2145271 A GB2145271 A GB 2145271A
- Authority
- GB
- United Kingdom
- Prior art keywords
- magnetic
- upper drum
- magnets
- drum
- rotation detecting
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/52—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with simultaneous movement of head and record carrier, e.g. rotation of head
- G11B5/53—Disposition or mounting of heads on rotating support
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/52—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with simultaneous movement of head and record carrier, e.g. rotation of head
- G11B5/53—Disposition or mounting of heads on rotating support
- G11B5/531—Disposition of more than one recording or reproducing head on support rotating cyclically around an axis
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B15/00—Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function
- G11B15/18—Driving; Starting; Stopping; Arrangements for control or regulation thereof
- G11B15/46—Controlling, regulating, or indicating speed
- G11B15/467—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven
- G11B15/473—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the heads
- G11B15/4731—Controlling, regulating, or indicating speed in arrangements for recording or reproducing wherein both record carriers and heads are driven by controlling the speed of the heads control of headwheel rotation
Landscapes
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
Abstract
A rotating head cylinder includes a rotatable upper drum 2, a fixed lower drum 3 disposed opposite to the upper drum 2, a pair of magnetic heads 6, and a pair of rotation detecting magnets 8 cooperating with detection coils 11. The magnetic heads 6 and their respective magnets 8 are embedded in magnetic holders 5 to constitute respective integral units. <IMAGE>
Description
SPECIFICATION
Magnetic head
Field of the invention
The present invention relates to a magnetic head in a rotating head cylinder.
Background of the invention
A rotating head cylinder of the prior art is shown in
Figures 1 and 2, where the cylinder consists of an upper drum 2 rotating about a shaft 1 and a fixed lower drum 3. Magnetic heads 6 which are held to their respective magnetic holders 5 are mounted with screws 7 to the surface 4 of the upper drum 2 that is opposed to the lower drum 3. Magnets 8 for detecting rotation are mounted separately by molded members 9 close to their respective heads 6 and at positions that are spaced a certain angle 6 from their respective heads 6 about the shaft 1.
Another head 12 that acts to detect rotation and has a coil 11 is mounted to the surface 10 of the fixed lower drum 3 which is opposed to the upper drum 2.
The head 12 is placed so as to be able to face the magnets 8 on the upper drum 2.
The head cylinder is rotated in synchronism with a reference signal which is the vertical synchronizing signal of 60 Hz contained in a video signal during recording of video signals. The reference signal is the control signal recorded at the lower fringe of a tape during reproduction. The video head assembly is equipped with a pulse generator to measure the rotational frequency or detect the phase.
This prior art device is capable of detecting the rotation of the upper drum 2 by means of its head 12 that reads the magnetic flux signal produced from the two magnets 8 which are mounted to the surface 4 of the upper drum 2 so as to be spaced 180 apart from each other as shown in Figure 2, the head 12 being mounted to the surface 10 of the lower drum 3.
This device has the disadvantage that the positions at which the magnets 8 are mounted must be shifted corresponding to the installation positions of the magnetic heads 6, because the heads 6 are mounted to the upper drum 2 with the screws 7, and because the magnets 8 are separately mounted to the upper drum 2 with the molded members 9 at positions spaced the certain angle 6 from the heads 6. Further, it is difficult to determine the angle 6 in mounting the magnets 8 serving to detect the rotation. Accordingly, the device is not assembled in an efficient way.
Summary of the invention
In view of the foregoing difficulties associated with the prior art device, it is the main object of the present invention to provide a magnetic head in which magnets for detecting rotation can be always mounted at a given angle to their respective magnetic heads, and which dispenses with operations for adjusting the positions of the magnets after the components have been mounted.
The above object is achieved in accordance with the teachings of the present invention by providing a structure in which the magnetic heads and their respective rotation detecting magnets are imbedded in respectivei magnetic holders to constitute units.
Brief description of the drawings
Figure 1 is a side elevation of a conventional rotating head cylinder;
Figure 2 is a plan view taken along the surface 4 of the upper drum of Figure 1;
Figure 3 is a side elevation of a rotating head cylinder according to the present invention;
Figure 4 is a plan view taken along the surface 4 of the upper drum of Figure 3;
Figure 5 is an enlarged view of one magnetic holder shown in Figures 3 and 4; and
Figure 6 is a side elevation of the magnetic holder shown in Figure 5.
Detailed description of the invention
Referring to Figures 3-6, there is shown a rotating head cylinder embodying the concept of the present invention. Those components of this head cylinder which are indicated by reference numerals 1 through 12 are the same as those of the aforementioned conventional device indicated by the same numerals. In the conventional device, as shown in Figure 2, the magnetic heads 6 are supported by their respective magnetic holders 5 and are mounted to the upper drum 2 with the screws 7. The magnets 8 for detecting rotation are mounted with the molded members 9 at positions spaced a certain angle 6 from their respective heads 6. The heads 6 and the magnets 8 are separately mounted to the upper drum 2.In the novel device, as shown in Figures 3 and 5, a magnetic head 6 and a rotation detecting magnet 8 spaced a certain angle 6 from the head 6 are imbedded in a magnetic holder 5 to constitute a unit, which is mounted to the upper drum 2 with a screw 7. Another unit constructed in the same way as the above unit is also mounted to the upper drum 2 with a screw 7.
As thus far described, in the novel device, the magnetic heads 6 and the respective rotation detecting magnets 8 are spaced the certain angle 6 from each other, and are imbedded in their respective magnetic holders 5, forming units, as shown in
Figures 4 and 5. Therefore, it is possible to mount the magnetic heads 6 and the respective magnets 8 to the upper drum 2 while keeping the angular distance between them at the certain angle 6, irrespective of the positions at which the heads 6 are mounted.
In general, when magnetic heads such as the magnetic heads 6 are mounted, the opposed positions, the height, etc. are required to be determined with very high accuracy. In the present invention, the relative positional relation between the magnetic heads 6 and their respective rotation detecting magnets 8 is established during manufacture of the device. After these components are mounted to the upper drum 2, adjustment of positions including fine adjustment operations are dispensed with.
The operation for mounting the detecting magnets 8 can be effected simultaneously with the mounting of the magnetic heads 6 and hence no separate step is required for mounting the magnets 8. Further, since accurate assembly operations are performed only on the side of the upper drum 2, the number of assembly steps can be reduced.
In the device according to the invention, magnetic heads and their respective rotation detecting magnets are imbedded in their respective magnetic holders to constitute units and, accordingly, the magnetic heads and the magnets can be always mounted in an angularly spaced relation to each other. Further, after mounting these components, operations for adjusting the detecting magnets are not necessary. Consequently, the invention permits a magnetic head to be manufactured economically and with high accuracy.
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit and scope of the following claims.
Claims (3)
1. In a magnetic head assembly having:
an upper drum rotating about a shaft,
a fixed lower drum disposed opposite to the upper drum, magnetic heads and their respective rotation detecting magnets which are supported on the surface of the upper drum that is opposed to the lower drum, and
a rotation detecting head disposed on the surface of the lower drum that is opposed to the upper drum, the rotation detecting head having a coil,
the improvement wherein the magnetic heads and their respective rotation detecting magnets are imbedded in respective magnetic holders to constitute respective integral units.
2. A magnetic head assembly as set forth in claim 1, wherein said units are secured to the upper drum by their respective screws.
3. A magnetic head assembly substantially as hereinbefore described, with reference to Figures 3 to 6 of the accompanying drawings.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1983126851U JPS6035317U (en) | 1983-08-18 | 1983-08-18 | magnetic head |
Publications (3)
Publication Number | Publication Date |
---|---|
GB8420437D0 GB8420437D0 (en) | 1984-09-12 |
GB2145271A true GB2145271A (en) | 1985-03-20 |
GB2145271B GB2145271B (en) | 1988-06-15 |
Family
ID=14945419
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB08420437A Expired GB2145271B (en) | 1983-08-18 | 1984-08-10 | Magnetic head assembly |
Country Status (4)
Country | Link |
---|---|
JP (1) | JPS6035317U (en) |
KR (1) | KR890005696Y1 (en) |
DE (1) | DE3430317A1 (en) |
GB (1) | GB2145271B (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0203420A1 (en) * | 1985-05-14 | 1986-12-03 | Deutsche Thomson-Brandt GmbH | Apparatus, especially a video recorder |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3606091A1 (en) * | 1986-02-26 | 1987-08-27 | Thomson Brandt Gmbh | DEVICE, ESPECIALLY VIDEO RECORDER |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54102445A (en) * | 1978-01-27 | 1979-08-11 | Matsushita Electric Ind Co Ltd | Fluid bearing revolving apparatus |
-
1983
- 1983-08-18 JP JP1983126851U patent/JPS6035317U/en active Pending
-
1984
- 1984-06-25 KR KR2019840005997U patent/KR890005696Y1/en not_active IP Right Cessation
- 1984-08-10 GB GB08420437A patent/GB2145271B/en not_active Expired
- 1984-08-17 DE DE19843430317 patent/DE3430317A1/en active Granted
Non-Patent Citations (1)
Title |
---|
NONE * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0203420A1 (en) * | 1985-05-14 | 1986-12-03 | Deutsche Thomson-Brandt GmbH | Apparatus, especially a video recorder |
Also Published As
Publication number | Publication date |
---|---|
KR890005696Y1 (en) | 1989-08-25 |
DE3430317C2 (en) | 1987-04-23 |
JPS6035317U (en) | 1985-03-11 |
GB2145271B (en) | 1988-06-15 |
KR850009670U (en) | 1985-12-05 |
GB8420437D0 (en) | 1984-09-12 |
DE3430317A1 (en) | 1985-03-07 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PCNP | Patent ceased through non-payment of renewal fee |