JPS6338413Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a magnetic head for a video tape recorder (hereinafter simply referred to as "VTR"), and more specifically, a magnetic head that has a shield block in the center and an audio head and a control head on both sides. A block holder is provided in contact with the shield block, and the block holder is used as a reference surface for grinding the tape running surface, and as a mounting reference surface for attaching the audio head and control head. Improved the performance of the magnetic head by enabling accurate centering and improving azimuth, and made processing easier.
Regarding magnetic heads for VTRs.

The recent spread of VTRs has been extremely remarkable, and the recording system shown in Figure 1 is mainly used for the tapes used in small home VTRs. That is, as shown in the figure, a video signal track 2 is recorded diagonally at the center of the tape 1, an audio signal track 3 is recorded at its upper edge, and a control signal track 4 is recorded at its lower edge. ing. Of this recording method, in order to simultaneously record and reproduce audio signal track 3 and control signal track 4, see FIG.
A magnetic head such as the one shown in FIG. 2 (b) is used. In the figure, a magnetic head 11 includes a case 12 made of metal or the like, a shield block 13 made of ferrite, and an audio head 14 consisting of a front core, a back core, and a coil wound around the core, and a control panel. Head 1
It is composed of 5th grade. The magnetic head 11 has a shield block 13 and an audio head 1 in the case 12.
4. The control head 15 is inserted, and the space between these and the case 12 is filled with resin (not shown in FIG. 2).

Conventionally, when assembling and processing the magnetic head 11, the front cores of the audio head 14 and the control head 15 are bonded to both ends of the shield block 13 via ceramics, thin glass plates, etc., and these are mounted inside the case 12. After adhesive fixation, the tape running surface was ground.

However, this conventional method has the following drawbacks. That is, as mentioned above, the shield block 13 is made of an extremely hard and brittle material, and it is difficult to process the dimensions of each part extremely accurately. Control heads 15 often do not align their centers (in-line defects), and when grinding the tape running surface, variations in gap depth can occur, which has a very serious effect on the performance of magnetic head 11. magnetic head 1
There were variations in the performance of 1. Furthermore, due to the poor dimensional accuracy, it is difficult to automate the assembly process of the magnetic head 11 and requires a large number of man-hours, resulting in an increase in the cost of the magnetic head 11.

The present invention eliminates the drawbacks of the conventional VTR magnetic head mentioned above, and has stable performance and low cost.
Its purpose is to provide magnetic heads for VTRs.

The present invention was developed based on the fact that parts with extremely high dimensional accuracy can be easily obtained by die-casting materials such as zinc, aluminum, and copper alloys. A block holder having a rectangular plate-shaped main body, a rectangular parallelepiped block, and two core supports each consisting of two parallel bars is provided in contact with the shield block, and the core supports are connected to the audio head, This object is achieved by using the block as a reference for centering when installing the front core of the control head, and by using one surface of the block as a reference surface for grinding.

Embodiments of the present invention will be described below based on the drawings. FIG. 3 is a diagram showing the configuration of a magnetic head for a VTR according to the present invention, in which A is a plan view, B is a front view, and C is a cross-sectional view taken along the line H--H in FIG. As shown in the figure, a magnetic head 1 according to the present invention
1 has a case 12, a shield block 13, an audio head 14, a control head 15, etc., which is no different from the conventional example shown in FIG. However, in this example, a block holder 21 is provided in addition to these.
The audio head 14 and control head 15 are composed of a front core, a back core, and a coil wound around these cores.Furthermore, after inserting the shield block 13, audio head 14, control head 15, etc. into the case 12, Filling with resin is no different from the example described above, but for convenience of explanation, FIG.
Only 4A and 15A are shown (the situation in which the steps described later have been completed is shown).

As shown in the figure, in this example, a block holder 21 is provided in contact with the surface of the shield block 13 opposite to the surface facing the tape running surface 11A. FIG. 4 is a detailed view of this block holder 21, in which A is a plan view, B is a front view, C is a bottom view, D is a left side view, and E is a cross section of the block holder 21 in the direction of the arrow. This is a diagram. In the figure, the block holder 21 has a square plate shape, and one surface 2 of the block holder 21 has a square plate shape.
A main body 22 in which 2A is a contact surface of the shield block 13, a rectangular block 23 provided in contact with the other surface 22B of the main body 22, and a main body 22.
It consists of two core supports 24 extending from both ends of the core support 24, each consisting of two parallel rods. Furthermore, a gap 24A is formed between the two side surfaces of the core support 24 and the end surface of the main body 22. This block holder 21 is usually integrally molded by die-casting of zinc (Zn), aluminum (Al), copper (Cu), or copper alloy, but it is not necessarily limited to these materials, and may be formed by machined metal material. It is also possible to effectively use a material made of plastic material or molded from plastic material.

The VTR magnetic head according to the present invention described above is manufactured through the following assembly process.

The shield block 13 is fixed to one surface 22A of the block holder main body 22 with adhesive or the like.

The front core 14A of the audio head and the front core 15A of the control head are inserted into the two gaps 24A of the block holder 21, respectively, and one of the three surfaces forming the gaps 24A is inserted.
Each front core is fixed to the block holder 21 using an adhesive or the like using the front cores 2 to 2 as a reference.

The block holder 21 is inserted into the case 12 and temporarily fixed with adhesive or the like.

Surface 23A of block 23 opposite to main body 22
Tape running surface 1 with (see Figure 4) as the reference plane.
Grind 1A.

A coil is inserted into the front cores 14A and 15A of each head, and then a back core is attached to each head.

A resin is filled into the gap between the case 12, the block holder 21, the audio head 14, the control head 15, etc., and dried and solidified.

The block holder 21 used in the magnetic head for VTR according to the present invention is a die-cast product or the like and has extremely high dimensional accuracy.
4. The control head 15, etc. are all mounted and fixed with reference to this block holder 21, and the tape running surface 11A is also attached to the block holder 21.
Grinding is performed using No. 1 as a reference surface. Therefore, in the magnetic head for VTR according to the present invention, the centering of each part is extremely accurate, there is no fear of misalignment (in-line failure) between the audio head 14 and the control head 15, and the gap depth of each head is very accurate. It is extremely accurate and can eliminate variations, improving the azimuth of the magnetic head, etc.
You can get extremely high quality products. Furthermore, since the block holder 21 provides a reference surface for accurate centering and a mounting surface for the machine, automation of the assembly process is extremely easy.

In summary, the present invention improves the quality and performance of magnetic heads for VTRs, eliminates variations in quality and performance, and furthermore has extremely excellent effects such as greatly reducing the cost by automating assembly processing. is clear.

[Brief explanation of the drawing]

Figure 1 shows the tape recording system used in small household VTRs, and Figure 2 shows the conventional tape recording system for audio signal tracks and control signal tracks.
Figure 3 shows the magnetic head for VTR according to the present invention, where A is a plan view, B is a front view, and Figure 3 is a diagram showing a magnetic head for VTR according to the present invention, A is a plan view, B is a front view, and C is a bottom view. Figure 4 of the cross section of Ha-Ha seen in the direction of the arrow.
The figures show the details of the block holder, and A is a plan view, B is a front view, C is a bottom view, D is a left side view, and E is a view of the cross section of the block holder in the direction of the arrow. 1...Tape, 2...Video signal track, 3...
...Audio signal track, 4...Control signal track, 11...Magnetic head, 11A...Tape running surface, 12...Case, 13...Shield block, 14...Audio head, 14A...Front core, 15... ...Control head, 15A...
Front core, 21...Block holder, 22...
...Main body, 23...Block, 23A...Reference surface,
24...Core support, 24A...Void.

Claims (1)

[Scope of Claim for Utility Model Registration] A magnetic head for a video tape recorder comprising a shield block, an audio head, and a control head placed in a case and filled with resin, in which the magnetic head contacts the shield block and performs the following (a). ~(c)
A magnetic head for a video tape recorder, characterized in that it is provided with an integrally molded block holder consisting of the following elements. (a) A main body in the shape of a square plate, one surface of which serves as the contact surface of the shield block. (b) A rectangular block on the other side of the body. (c) Two core supports, each consisting of two mutually parallel bars, extending from each end of the body.