JPH029042A - Device for grounding fixed drum - Google Patents

Abstract

PURPOSE:To reduce the fraction defective by providing an insertion hole on the end face of a drum, inserting an earth contact which can be deformed in the radial direction into this insertion hole and executing an earth. CONSTITUTION:An earth contact 31 is inserted into an insertion hole 46 formed in the lower drum 12, and bent so as to contract in the radial direction when the contact 31 is inserted into the lower drum 12 made of Al, and by its elastic restoring force, joint force can be obtained. In such a way, the earth of the drum 12 can be attained by inserting the earth contact 31, and by inserting the contact 31, a fall-off stop of a connector 45 and the earth of the fixed drum 12 can be attained simultaneously. Also, since i is unnecessary to execute soldering to the inside of the drum 12, no flux is generated, and the fraction defective can be lowered.

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to a grounding device for a fixed drum in a rotary head device. KSummary of the Invention 1 In an apparatus for connecting a fixed drum of a VTR and a head amplifier using a flexible printed circuit board, 1. An earth contact is planted in the terminal plate on the tip side of the flexible printed circuit board, and an earth contact insertion hole is formed on the lower surface of the fixed drum, and the earth contact is inserted into the insertion hole while being deformed in the radial direction. The terminal board is handled in such a way as to achieve a stop and grounding of the fixed drum. BACKGROUND OF THE INVENTION Generally, a VTR is equipped with a rotating head device, and this rotating head device is composed of a rotating drum and a fixed drum. A magnetic head is mounted facing the outer periphery of the rotating drum, and helical scanning is achieved by the magnetic head scanning the magnetic tape helically wound around the rotating drum and the fixed drum. ing. Between the rotating head bags of such a VTR, it is necessary to ground the head drum using a signal cable between the head drum and the head amplifier. Therefore, in the past, a relay board was attached to the lower surface of the fixed drum by screwing, and the ground was connected to this relay board.

[Problems to be solved by the invention]

When a relay board for grounding is screwed to a fixed drum, the drum deforms and the board material becomes loose due to creep. This deteriorates tracking accuracy and
Problems such as image distortion will occur. The present invention has been made in view of these problems, and it is an object of the present invention to provide a grounding device for a fixed drum that reliably achieves grounding without having to install a screw on the fixed drum. This is the purpose. Means for Solving Problem K] The present invention provides a rotating drum comprising a rotating drum having a head and a stationary drum rotatably supporting the rotating drum and whose outer peripheral surface forms a guide surface for a tape-shaped recording medium. In the head device, an insertion hole is provided at the end of the fixed drum, and a radially deformable earth contact is inserted into the insertion hole to perform earthing. Therefore, the grounding of the stationary drum is achieved by inserting a radially deformable earth contact into a bottle insertion hole formed at the end of the stationary drum.
Eliminates the need to use screws for fixed drums. K Embodiment FIG. 4 shows the overall structure of a head drum device according to an embodiment of the present invention, and this device has a magnetic head 1.
0 and a fixed drum 12 disposed coaxially below the rotating drum 11. The magnetic head 10 is attached to the tip of a helad base 13, and the head base 13 is connected to the rotating drum 1 by screws 14.
It is fixed to the bottom surface of 1. A contactor 16 attached to the terminal plate 15 is connected to the magnetic head 1.
0 and the rotor 18 of the low retransformer 17 are connected. The rotary transformer 17 is for transmitting and receiving signals between the rotating side and the fixed side, and its rotor 18 is attached to the head drum 11 side, and the lower stator 19 is attached to the fixed drum 12 side. They face each other with a tiny air gap in between. A rotating drum 11 having a magnetic head 10 is attached to a boss 22. Rotating drum 11 is screw 2
3 to the boss 22. And boss 22
is supported by a pair of upper and lower ball bearings 24 and 25.
It is rotatably supported by 26. The lower end portion of this support shaft 26 is press-fitted into a hole 27 formed in the center of the fixed drum 12. Further, a flexible printed circuit board 28 is attached to the lower side of the fixed drum 12, and a pin 30 and a ground contact 31 are embedded in two terminal plates attached to the ends of this printed circuit board 28. The leading end of the printed circuit board 28 is attached to the lower surface of the lower stationary drum 12 via. The connection between the terminal plate 29 of the flexible substrate 28 and the lower drum 12 is particularly made as shown in FIG. A pin 30 and a ground contact 3 are attached to the terminal plate 29 attached to the tip of the flexible curtain plate 28.
1 are planted respectively. On the other hand, a connector 45 and a ground contact insertion hole 46 are provided on the lower drum 12 side.
and is provided. Note that the earth contact 45 is the second
As shown in the figure, a plate made of a conductive material is bent into a circular shape, and leads 47 provided at the bottom of the plate are passed through the terminal plate 29 and the flexible board 28, and the flexible board 28 is connected to the terminal board 29 by soldering. It is designed to be connected by soldering to the pattern. The vial 30 and the ground contact 31 are inserted into a connector 45 and a ground contact insertion hole 46, respectively. Connection between the head drum 12 side and the head amplifier is achieved by the connector 45 and the pin 30, and the ground contact insertion hole 46
The fixed drum 12 is grounded by a ground contact 31 inserted into the ground contact 31 . A motor 34 is disposed inside the rotating drum 11 as shown in FIG. 4, and the motor 34 drives the rotating drum 11 to rotate. That is, the stator yoke 35 is connected to the rotating drum 11 by the screws 36.
At the same time, a magnet 37 is attached to the yoke 35.
is fixed. The magnet 37 faces a coil formed on a printed circuit board 38 placed above it. The printed circuit board 38 is fixed to a boss 39 fixed to the upper end of the support shaft 26 via screws 40. A terminal plate 42 attached to the tip of the flexible board 41 is attached to the boss 39.
is fixed to the flexible substrate 41.
The coil of the printed circuit board 38 is energized through the coil. In the above configuration, magnetic tape is helically wound around the outer circumferential surfaces of the rotating drum 11 and fixed drum 12, which are arranged coaxially above and below, and in this state, the rotating drum is 11 is driven to rotate. Then, the magnetic head 10 supported by the drum 11 via the base 13 scans the surface of the magnetic tape obliquely, resulting in a helical scan. Therefore, a signal supplied from the fixed side via the rotary transformer 17 is applied to the magnetic head 10.
The signal is recorded on the magnetic chip. Alternatively, the magnetic head 10 reads the signal on the magnetic tape and supplies this signal to the fixed side through the rotary transformer 17. As a result, predetermined recording and/or reproduction will be performed. Furthermore, in this VTR, a flexible printed circuit board 28 is used as a signal cable for connection between the fixed drum 12 and the head amplifier, and a flexible printed circuit board 28 is used as a signal cable to connect the fixed drum 12 and the head amplifier. In some cases, a ground contact 31 is provided on the terminal plate 29 to prevent the connector 45 from falling off and to ground the drum body 12 at the same time. The earth contact 31 is inserted into the insertion hole 4 formed in the lower drum 12.
As shown in Fig. 3, when the contacts 31 are inserted into the aluminum lower drum 12, they are bent to contract in the radial direction, and their elastic restoring force causes them to bend. It becomes possible to obtain fastening force. With this structure, it is possible to ground the drum 12 by inserting the ground contact 31, and by inserting the contact 31, it is possible to simultaneously prevent the connector 45 from being removed and ground the fixed drum 12. becomes possible. Further, since there is no need to solder the inside of the fixed drum 12, flux does not enter, and the defective rate is reduced. Further, since there is no need to screw the lower drum 12, problems such as poor tracking accuracy and image distortion are eliminated. Effects of the Invention 1 As described above, in the present invention, a bottle insertion hole is provided in the end face of a fixed drum, and a radially deformable earth contact is inserted into the insertion hole to perform earthing. Earthing of the stationary drum is thus achieved only by inserting a ground contact, without the use of screws.

[Brief explanation of the drawing]

Fig. 1 is a #I sectional view showing the connection operation of the terminal plate for grounding the lower drum according to an embodiment of the invention, Fig. 2 is an external perspective view of the earth contact, and Fig. 3 is the earth contact. FIG. 4 is an enlarged cross-sectional view of the main part showing the inserted state, and FIG. 4 is a vertical cross-sectional view of the entire assembled head drum device. The names of the main parts in the drawings are as follows. 10...Magnetic head 11...Rotating drum 12...Fixed drum 28...Flexible printed circuit board 29...Terminal board 30...Bin 31...Earth contact 45...Connector 46...・Earth contact insertion hole

Claims (1)

[Claims] 1. A rotary head device comprising a rotary drum having a head and a fixed drum that rotatably supports the rotary drum and whose outer circumferential surface forms a guide surface for a tape-shaped recording medium, in which an insertion hole is provided in an end surface of the fixed drum. 1. A grounding device for a fixed drum, characterized in that a radially deformable grounding contact is inserted into the insertion hole to perform grounding.