JPS5987620A - Magnetic head device - Google Patents

Abstract

PURPOSE:To attain the transfer of a signal with high quality by decreasing the gap at a place near the rubbing surface of a magnetic tape between two video heads set approximately in parallel to each other to prevent the drop of the tape into the gap between tapes and decreasing the region width of a standing wave to reduce the spacing loss. CONSTITUTION:A core 16 contains a projected bar 18 protruding partially at a place near the rubbing surface of a magnetic tape. A core 17 forms a video head 5 together with a core 11 and also contains a projected bar 19 opposite to the core 16. With such a head device, it is possible to obtain a gap 20 smaller than a gap 13 between video heads 4 and 5 by means of bars 18 and 19 of cores 16 and 17 respectively. Therefore the dropping quantity of a magnetic tape 2 can be reduced to the gap 20, and the region of a standing wave (m) is relatively reduced. This reduces the spacing loss of the head 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic head useful for a helical scan type magnetic recording/reproducing device equipped with a plurality of video heads and having a recording/reproducing function as well as a special reproduction function such as still reproduction. It is related to the device.

Conventional configurations and their problems In recent years, magnetic recording/reproducing devices (VTRs) have been equipped with special functions such as stay and slow search in addition to normal recording/playback functions. There is a trend to increase the number of video heads in addition to paired video heads. A magnetic head device installed in a conventional VTR will be explained below.

FIGS. 1 to 4 show conventional examples, each showing the radial arrangement and an enlarged portion of the head tape. In the figures, 1 is a head cylinder portion in which a magnetic tape 2 is wound at a predetermined angle.

3 and 4 are video heads that have different head gap inclinations and are extended to the separation side in approximately 1000 equal parts. 5 is the same video head, and is used for special playback of stills, etc., so it is different from the above video head 3. have the same bed gap slope. 6 is the head cylinder section 1
This is the head window installed in the head window. As shown in FIG. 4, the videos 3, 4.5 fixed at a predetermined position on the head base 7 fixed to the head cylinder part 1 face out through this window part 6, protrude by a predetermined amount, and come into contact with the magnetic tape 2. and perform recording or playback operations. 8.9 is a core constituting the video head 4; 1o is a coil wound around the cores 8 and 9; 11 and 12 are the cores of the video head 5 as well. Further, 14 is a head gap 16 provided between the cores 8 and 9 or between the cores 11 and 12.
It is a glass material that makes up the . These two heads 4 and 6 are arranged and fixed in parallel so that the distance 2 between them does not change even if the sliding surfaces of the magnetic tape 2 of the video heads 4 and 6 wear out. Reference numeral 13 indicates a gap between the video head 4 and the video head 4.

Problems with the conventional head device constructed by fixing the two video heads 4 and 6 to one Herad base 7 as described above will now be described.

1 As shown in FIG. 2, in the configuration of the conventional head device, when the head device rotates in the direction of the arrow, the contact between the magnetic tape 2 and the video heads 4 and 6 is as shown in FIG. When the magnetic tape 2 falls into the gap 13 between the magnetic tape 2 and the video head 4, a region of standing waves m is generated due to the etching and contact between the magnetic tape 2 and the video head 4. Since this area extends to the vicinity of the gap 15 of the video head 4, spacing occurs and signal exchange is obstructed, making it impossible to obtain a good reproduced signal. This is particularly noticeable at the beginning of contact between the magnetic tape 2 and the head unit.

11 As shown in FIG. 3, the above-mentioned gap 13 is 300 μm for winding the coil 10 around the video heads 4 and 5.
Although the winding state of the coil 10 is controlled to a certain degree, due to variations in the coil winding force, the coil 10 may be wound with a bulge. In this case, the swollen coil 10 protrudes close to the magnetic tape sliding surface of the gap 13, so that the magnetic tape 2 and the coil 1o may come into contact, causing the coil to break. As described above, the conventional device has many problems.

Purpose of the Invention The present invention solves the above-mentioned conventional problems.
A head device that reduces the area width of standing waves generated in the gap between video heads, reduces spacing loss, enables good signal transmission and reception, and prevents the coil from coming out near the magnetic tape sliding surface. The purpose is to provide

Structure of the Invention The present invention narrows the gap near the magnetic tape sliding surface of two video heads arranged in parallel to each other, prevents the magnetic tape from falling into the gap, and narrows the width of the standing wave. , which reduces spacing loss.

Description of examples An embodiment of the present invention will be described below with reference to FIG.

FIG. 6 is a plan view of essential parts of a di-air head device in one embodiment of the present invention.

Items 1 to 16 in FIG. 5 are the same as items 1 to 15 of the conventional example shown in FIG. In the figure, reference numeral 16 denotes a core that constitutes the video head 4 together with the core 8. This core 1
6 has a partially convex protrusion 18 formed near the magnetic tape sliding surface. 17 is also a video-\
This core constitutes Rad 6 together with core 11, and this core 17
Similarly, a convex protrusion 19 is provided at a position opposite to the core 16. 2o is the above core 16 and 17
This shows the gap between the convex protrusions 18 and 19, and the gap 13 is smaller and is set to about 150 μm.

According to the head device of this embodiment configured as described above, the convex protrusions 18 and 19 provided on the cores 16 and 17 create a gap 2o between the video heads 4 and 5 that is narrower than the gap 13. It becomes possible to do so. Therefore, since the gap 2o between the video heads 4 and 5 is small,
The amount of the magnetic tape 2 that falls into the gap 20 is reduced, the area of the standing wave m is relatively reduced, the spacing loss of the video head 4 is reduced, and good signal transmission and reception becomes possible. Furthermore, since the gap 2o is narrower than the gap 13, the coil 1o wound around the gap 13 does not protrude into the gap 2o.
No coil breakage occurs.

Effects of the Invention As described above, according to the present invention, it is possible to stably obtain a good reproduction signal, and it is also possible to greatly reduce the occurrence of coil breakage.

[Brief explanation of the drawing]

FIG. 1 is a head arrangement diagram of a conventional VTR head device, FIGS. 2 and 3 are enlarged views of the main parts of the same device, FIG. 4 is an explanatory diagram of the same device, and FIG. 6 is an embodiment of the present invention. FIG. 2 is an enlarged view of a main part of a magnetic head device of a VTR as an example. 1...Part of cylinder, 2...Magnetic tape, 3゜4.6...Video head, 6...
...Head window, 7...Head base, 8,9
, 11.12... Core 10... Coil, 13... Gap, 15... Head gap, 16.17... Core, 18.19...
...Convex shaped protrusion, 2o...Gap. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] When two magnetic heads are arranged parallel to each other on a head base with a gap provided, the two magnetic heads are formed in the vicinity of the sliding surface of the magnetic chip from the maximum gap between the two magnetic heads. A magnetic head device characterized in that the width of the gap between the heads is narrowed.