JPS59160812A - Head for vtr - Google Patents

Abstract

PURPOSE:To improve the contact state between a head and a tape and improve the picture quality of VTR by forming a tape run surface on a plane which runs through the center of the tape run surface and is perpendicular to the relative sliding direction of the head symmetrically about an axis which runs through the center of the tape run surface and is perpendicular to the tape run surface. CONSTITUTION:The shape of the tape run surface when cut by the plane 8 perpendicular to an (x) direction in the direction of the relative slide between the tape 5 and head 1 is shown by a solid line 9. The part of the tape run surface in the cut surface of the head shown by the solid line 9 is symmetrical about an (y) axis. The surface shape of the tape run surface 8 on the said plane 8 is symmetrical about the height-directional axis of the head 1 which crosses the (x) axis, i.e. (y) axis in standard video recording and reproduction mode. Therefore, pressing force which operates on the tape 5 on the tape run surface 3 is symmetrical about the (y) axis in an operation state and the magnetic tape 5 deforms symmetrically about the (x) axis near the tape run surface 3. Consequently, the contacting state between the tape run surface 2 and tape 5 is improved to improve the picture quality of VTR.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a VT with an improved shape of a magnetic tape running surface.
Regarding the R head.

FIG. 1 is a perspective view showing an example of a conventional VTR head. The head chip 1 includes a tape running surface 3 having a magnetic gap 2 . Further, the winding 4 is wound through the winding window 4a. The voltage change occurring in the winding 4 is converted into a magnetic change, and recording is performed on the magnetic tape.

By the way, as shown in a perspective view in FIG.
is its side 1a (see Figure 1),
The upper drum 6 is parallel to the circumferential direction of the upper drum 6.
installed on. The magnetic tape 5 is wound around an upper drum 6 and a lower drum 7 paired therewith. As is clear from FIG. 2, as the upper drum 6 rotates, the magnetic head 1 comes into contact with the tape 5 from below and exits upward. On the other hand, since the head chip 1 has its side surface 1a (see FIG. 1) parallel to the circumferential direction of the upper drum 6, the tape running surface 3 forms an angle with the longitudinal direction of the tape 5. It passes over the surface of the tape 5. This angle varies depending on the relative angle between the magnetic tape 5 and the head 1.

Now, in the case of standard recording/playback mode, a plane 1b (
Please refer to FIG. )think of.

This plane 1b is schematically shown as a symbol 1i19 in FIG. 3, and the shape of the portion of the tape running surface 3 is symmetrical with respect to the center of the tape running surface 3.

On the other hand, a plane 8 indicated by a broken line in FIG. 3 is a plane perpendicular to the relative sliding direction (x axis) between the magnetic tape 5 and the head 1. As can be seen from FIG. 1, the tape running surface 3 has a three-dimensional shape with the maximum height at its center, so the cross-sectional shape of the head 1 when cut along this plane 8 is the third This is shown by the broken line in the figure. Therefore, magnetic tape 5
It is no longer symmetrical with respect to the y-axis in the height direction passing through the X-axis, which is the relative sliding direction between the head 1 and the head 1. Therefore, the deformed state of the tape 5 is no longer symmetrical about the X axis. Therefore, the pressing force of the head 1 acting on the magnetic tape 5 is no longer symmetrical about the x-axis, and if the rigidity of the magnetic tape 5 is taken into account, there is a possibility that the contact state between the head 1 and the tape 5 is no longer symmetrical about the x-axis. be. As a result, the contact state between the tape running surface 3 and the magnetic tape 5 changes, resulting in a disadvantage that the image quality of the VTR deteriorates.

The present invention solves the above-described drawbacks of the conventional VTR head, and aims to improve the state of contact with the magnetic tape during running.

In summary, this invention provides that, on a plane passing through the center of the tape running surface and perpendicular to the direction of relative sliding between the tape and the head, the shape of the tape running surface is aligned with an axis passing through the center of the tape running surface and perpendicular to the tape running surface. Symmetrical with respect to.

This is a VTR head characterized by certain features.

Other features of the invention will become apparent from the following detailed description with reference to the drawings.

The feature of this invention lies in the shape of the tape running surface 3. That is, in FIG. 3, the shape of the tape running surface when cut along a plane 8 perpendicular to the relative sliding direction x of the tape and the head is a solid line 9 in FIG. As is clear from FIG. 3, the tape running surface portion of the cut surface of the head indicated by the solid line 9 is symmetrical with respect to the y-axis. Other points are similar to the conventional head 1 shown in FIG. Therefore, the following description will be made by using the same reference numerals for the same parts.

As mentioned above, in the standard recording/playback mode, the plane 8 perpendicular to the X-axis in the relative sliding direction between the head 1 and the magnetic tape 5
When considering this, the surface shape of the tape running surface 3 on this plane 8 is symmetrical with respect to the height direction axis of the head 1, that is, the y-axis passing through the X-axis. Therefore, in operating condition,
The pressing force acting on the tape 5 on the tape running surface 3 is symmetrical about the y-axis, and the magnetic tape 5 is deformed symmetrically about the x-axis near the tape running surface 3. Therefore, the contact state between the tape running surface 2 and the tape 5 is significantly improved compared to the conventional magnetic head 1, and as a result, it is possible to improve the image quality of the VTR.

As described above, according to the present invention, the shape of the tape running surface in a plane passing through the center of the tape running surface and perpendicular to the direction of relative sliding between the tape and the head is set to a plane passing through the center of the tape running surface and perpendicular to the tape running surface. Since it is symmetrical about the axis, the contact between the head and the tape is improved, making it possible to improve the image quality of the VTR.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional VTR head. FIG. 2 is a perspective view for explaining the operation of the VTR head shown in FIG. 1. FIG. 3 is a diagram for explaining the invention in detail. In the figure, 1 is a head, 31 is a tape running surface, and 8 is a plane passing through the center of the tape running surface and perpendicular to the direction of relative sliding between the tape and the head. Agent: Kuzuno d - (1 other person) Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] The shape of the tape running surface on a plane passing through the center of the magnetic tape running surface and perpendicular to the direction of relative sliding between the magnetic tape and the head is symmetrical with respect to an axis passing through the center of the tape running surface and perpendicular to the tape running surface. A VTR head featuring: