JPS647449Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is a video tape recorder (hereinafter referred to as VTR).
It is abbreviated as. ) This is a rotary head device suitable for use in the rotary head device, in particular, the rotary side can be well grounded, and the reproduced signal from the rotary head can be extracted satisfactorily through the rotary transformer.

A rotary head device as shown in FIG. 1 is generally used as a rotating head device for a VTR. That is, in FIG. 1, 1 is a rotating shaft, 2 and 3 are bearings that rotatably support the rotating shaft 1, 4 is a bearing housing, 5 is a lower fixed drum located below, and 6
is an upper fixed drum located on the upper side, 7 is a rotating flange attached to the rotating shaft 1, and 8 is a rotating flange 7
9 is a rotating disk mounted on the rotary disk 8.
10 is a drum support member for fixing the lower fixed drum 5 and the upper fixed drum 6, and 11 is a positioning screw.
Further, 12 is the rotor of the rotating transformer T mounted on the rotating flange 7, 13 is the stator of the rotating transformer T mounted on the lower fixed drum 5, 14 is a bearing nut for preload adjustment, and 15 is the end of the lower fixed drum 5. 16 is the rotary shaft 1 of the motor mounted on the stator.
This is a rotor of a motor provided at one end of the motor in correspondence with the stator 15. In such a rotary head device, a reproduced signal reproduced by the rotary magnetic head 9 is taken out via a rotary transformer T.
In this case, a semiconductor amplifier circuit may be provided in the rotating disk 8, and the reproduced signal reproduced by the rotating magnetic head 9 may be amplified by the semiconductor amplifier circuit and then taken out via the rotating transformer T.

In this rotating head device, the rotating magnetic head 9, the rotor 12 of the rotating transformer T, etc. are grounded through the rotating shaft 1. In this case, it is conceivable to do this through the bearings 2 and 3, but this is not sufficient, and the free end of the plate spring 18 is fixed at one end to a motor holder, for example, via the spacer 17. It was made to come into elastic contact with the.

However, even with the configuration of the grounding on the rotating side of the rotary head device as shown in FIG. 1, the resistance value due to contact resistance is about 0.1Ω, which is relatively large, and when the rotating shaft 1 is eccentric, the plate The spring 18 vibrates vertically and is not sufficiently grounded, which adversely affects the reproduced signal obtained through the rotary transformer T, resulting in deterioration of the characteristics of the reproduced signal.

In view of this point, the present invention is designed to ensure that the rotating side of the rotating head device is sufficiently grounded, and the rotating transformer T
This is intended to improve the characteristics of the reproduced signal obtained through the .

Hereinafter, one embodiment of the rotary head device of the present invention will be described with reference to FIGS. 2 and 3. In FIGS. 2 and 3, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In this example, as shown in FIG. 3, one end 1a of the rotating shaft 1 is provided with a screw hole 1b having an opening on its end face and a screw groove on its inner wall. It has a through hole 19a for a small-diameter conducting wire, has a holding hole 19b for a ground terminal 20 (described later) having an opening on its other end, and is made of a male spiral-shaped good conductor, such as phosphor bronze, with a spiral groove on its outer wall surface. Earth terminal holder 1
Screw together 9. A ground terminal 20 made of a good conductor, such as phosphor bronze, is pushed out and held in the holding hole 19b of the ground terminal holder 19 by a compression coil spring 21, and the tip of the ground terminal 20 is held with a good conductor fixed to a motor holder, for example. For example, it is pressed against a piece of phosphor bronze 22. Further, in this example, one end of the conducting wire 23 is soldered to the other end of the ground terminal 20, and the other end of the conducting wire 23 is connected to the through hole 19a.
Through the ground terminal holder 19, one end of the ground terminal holder 19 is soldered to the outside. The rest of the structure is the same as in FIG.

In this embodiment as well, the reproduced signal from the rotating magnetic head 9 can be taken out via the rotating transformer T, as in FIG. In this case, the ground on the rotating side is a phosphor bronze piece 22 fixed to the motor holder which directly connects the ground terminal 20 to the ground by means of the compression coil spring 21.
This ground terminal 20 is electrically connected to the ground terminal holder 19 with a conductor 23,
Since this ground terminal holder 19 is screwed onto the rotating shaft 1, this ground terminal 20 is almost directly connected to the rotating shaft 1, and this contact resistance can be kept extremely small, for example, at a resistance value of 0.01Ω or less. did it.

Therefore, according to the present invention, the resistance value due to the contact resistance of the ground on the rotating side can be kept extremely low and stable, and the characteristics of the reproduced signal when the reproduced signal from the rotating magnetic head 9 is extracted via the rotary transformer T can be I was able to improve it.

It goes without saying that the present invention is not limited to the above-described embodiments, and that various other configurations may be adopted without departing from the gist of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example of a conventional rotary head device, Fig. 2 is a cross-sectional view showing an embodiment of the rotary head device of the present invention, and Fig. 3 is a partially enlarged view showing an example of the main parts of the present invention. FIG. 1 is a rotating shaft, 1b is a screw hole, 9 is a rotating magnetic head, 19 is a ground terminal holder, 20 is a ground terminal, 21 is a compression coil spring, 22 is a good conductor piece,
23 is a conducting wire.

Claims (1)

[Scope of utility model registration request] In a rotary head device in which the reproduction signal from the rotary head is taken out through a rotary transformer and the rotary side is grounded through the rotary shaft, a screw hole is provided at one end of the rotary shaft, and a screw hole is provided at one end of the rotary shaft. A ground terminal holder made of a good conductor, which holds a ground terminal made of a good conductor through a spring, is screwed into the screw hole,
A rotary head device characterized in that one end of the ground terminal is electrically connected to the ground terminal holder via a conductive wire, and the other end of the ground terminal is brought into contact with a fixed piece of good conductor.