JPS6032252B2 - Direct drive cylinder device for videotape recorder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder device that is directly driven by a helical scan type video tape recorder.

There is an apparatus in which the cylinder for the magnetic head of a video tape recorder is directly driven by a prior art flat plate electric motor.

This flat plate electric motor is roughly constructed as follows.
An annular permanent magnet is fixed to a rotor disc fixed to a rotating shaft, and a plurality of drive coils are fixed to a stator yoke formed from a disc part and a cylindrical part, and these drive coils are connected to the above permanent magnets. The rotor disks are opposed to each other in all directions of the axis with an air gap in between, and a large number of teeth are provided on the outer circumference of the rotor disk.

A detection element facing this tooth portion in the axial direction with an air gap in between is attached to the stator yoke side. This detection element uses a magnetically sensitive element (for example, a Hall element), which detects the position and speed of the rotor by changes in magnetic flux, and uses this signal to control the supply voltage and current and apply them to each drive coil. is rotated in a predetermined direction and speed. The flat plate electric motor constructed in this way is built into a fixed cylinder, and the upper cylinder above the fixed cylinder is fixed to the upper end side of the rotating shaft and is driven to rotate. A magnetic head for recording and reproducing magnetic tape is attached to the upper cylinder. By the way, a compact cylinder with a built-in flat plate electric motor is equipped with a rotating transformer that sends and receives signals from the magnetic head of the rotating upper cylinder to the fixed cylinder side, and a connecting wire drawn out from this fixed side coil to the outside. Is required. In addition, there are many connection wires for multiple detection elements and wiring for multiple drive coils to be drawn out to the outside, but it is difficult to wire many connection wires and draw them out to the outside in a narrow cylinder device. The workability was poor and the external size was large. Furthermore, magnetic tape runs on half of the outer circumference of the cylindrical portion of the cylinder, making it difficult to draw out a large number of wiring terminals. In this invention, a connection wire that connects the stationary coil of a rotary transformer and leads it out to the outside, a connection wire that connects the detection element and leads it out to the outside, and a connection wire that connects the drive coil and leads it out to the outside are each formed using a printed wiring board. , a notch is provided in a part of the cylindrical portion of the fixed cylinder on the side where the magnetic head does not contact, and the wiring terminal portion of each of the printed wiring boards is exposed to the outside through the notch;
A video tape recorder that does not interfere with the running of the magnetic tape, has a compact cylinder section, and improves the workability of wiring connections.
The purpose of the present invention is to provide a direct drive cylinder device for the

FIG. 1 is a longitudinal cross-sectional view of a main part of a cylinder device incorporating a flat plate type electric motor, showing one embodiment of the present invention.

1 is a thin flat plate electric motor, which is constructed as follows.

Reference numeral 2 denotes a rotating shaft, which is rotatably supported by a fixed cylinder 4 via a bearing 3.

This fixed cylinder 4 has a cylindrical portion 4a and is made of a non-magnetic material. Reference numeral 5 denotes a rotor disk made of magnetic material, which is attached to a post 6 fixed to the rotating shaft 2. A large number of teeth 5a are provided on the outer circumference, and the position of the rotor can be adjusted by changes in magnetic flux. The speed is being detected.

Reference numeral 7 denotes an annular permanent magnet fixed on the rotor disk 5, and is magnetized alternately to N and S poles in the circumferential direction.

A stator yoke 8 is made of a magnetic material, and is composed of a disk portion 8a and a cylindrical portion 8b extending downward from the outer circumferential side of the disk portion 8a.

9 is a plurality of drive coils fixed in the disk portion 8a; 1;
Kawama is a plurality of detection elements arranged on the toothed portion 5a of the rotor disk 5 with small air gaps in all axial directions, and consists of a magnetic sensing element, such as a Hall element, The position and speed of the rotor are detected by changes in the magnetic flux, and the voltage and current supplied to each drive coil 9 are controlled by this signal, giving a predetermined rotation to the rotor disk 5.

Next, reference numeral 11 denotes an annular holding member, which has elasticity and is made of a synthetic resin material, etc., and is fixed to the disc portion 8a of the stator yoke 8, and is attached to each detection element at multiple locations in the circumferential direction. It supports 10.

Reference numeral 12 designates a second printed wiring board for the detection elements, which has an annular shape and is fixed to the holding member 11 on the inner circumferential side of the stator yoke 8, and has a printed wiring board as a connection line drawn out from each detection element 10 to the outside. is provided, and the wiring terminal portion 12a is connected to the cutout portion 8c of the cylindrical portion 8b of the stator yoke and the cylindrical portion 4a of the fixed cylinder 4.
It passes through the notch 4c and is exposed to the outside.

A perspective view of the cylinder device is shown in FIG.
A guide groove 14d is formed on the outer circumferential surface of the cylindrical portion 4a for feeding the magnetic tape 30 in oblique contact with the upper cylinder 20.
At the same time, the outer diameter is reduced by 4 mm.

Reference numeral 32 indicates a support plate, and 33 and 34 indicate guide rods on the support side and the winding side.

The cutout portion 4c of the fixed cylinder 4 is provided with the magnetic tape 10.
The wiring terminal portion 12a is provided on the opposite side of the contact surface 4e so that the wiring terminal portion 12a can be exposed without interfering with the running of the tape. Returning to FIG. 1, reference numeral 16 denotes a first printed wiring board for the drive coil, which has an annular shape and is fixed between the disk portion 8a of the stator iron 8 and the drive coil 9, and connects these drive coils. Printed wiring is provided as a connection wiring to be connected and drawn out to the outside, and the wiring terminal portion 16a is connected to the above-mentioned notch portions 8c and 4.
It is sent out through c.

The first and second printed wiring boards 16 and 12 are shown in a bottom view in FIG.

A plurality of printed wirings 13 are provided on both sides of the second printed wiring board 12, and each detection element 10 is connected and supported by soldering with its lead terminal piece 15, and a plurality of wirings are provided on the wiring terminal portion 12a. Terminals 14 are formed, and external connection wires (not shown) are soldered and connected. First printed wiring board 1
6, a plurality of wiring terminals 17 are provided on one side, and a wiring terminal 18 is formed in the wiring terminal portion 16a, to which an external connection power distribution line is connected.

Each drive coil 9 is connected by connecting the lead wire 19 to the printed wiring 17 by soldering. Returning to Figure 1,
Reference numeral 19 denotes a magnetic shield inserted inside the cylindrical part and the bottom of the fixed cylinder 4, which is made of a thin magnetic material and has a cutout part in a part of the cylindrical part, and the above-mentioned wiring. Pass the terminal portions 12a and 16a through.

The upper cylinder 20 is made of a non-magnetic material, is attached to a boss 21 fixed to the upper end of the rotating shaft 2 with a slight clearance from the fixed cylinder 4, and is rotated.

A pair of magnetic heads 31 (shown in FIG. 4) are attached to the lower part of the upper cylinder 20 at symmetrical positions for recording and reproducing the magnetic tape running around the outer circumference of the cylindrical portion. There is. Reference numeral 22 denotes a rotating transformer, which consists of a rotating coil 23 fixed to the upper cylinder 20 side, and a stationary coil 24 fixed to the stator yoke 8 with an air gap axially separated from this coil. It sends and receives signals from the magnetic head 31.

A third printed circuit board 25 is fixed on the disk portion 8a of the stator yoke 8 and connects the fixed coil, and is drawn out from the fixed coil 24 as shown in a plan view in FIG. A printed wiring 26 is provided as a connection line, and a lead wire 28 of the fixed side coil 24 is connected by soldering.

The wiring terminal portion 25a of this printed wiring board 25 passes through the cutout portion 4c of the fixed cylinder 4 and is taken out to the outside, and the wiring terminal 27
is formed. In this way, each electric element within the cylinder is connected by each printed wiring board, and the printed terminal portion of each printed wiring board is connected to the notch 4c provided on the side of the cylindrical portion 4a of the fixed cylinder 4 that does not contact the magnetic tape 30. is passed through and taken out to the outside so that external connection wires can be easily connected.

As described above, according to the present invention, each drive coil is connected by the first printed wiring board, the detection element is connected by the second printed wiring board, and the fixed side coil of the rotary transformer is connected by the third printed wiring board. Each printed wiring board is arranged parallel to the bottom of the fixed cylinder,
The printed terminals are passed through the notches on the cylindrical part of the fixed cylinder on the side that does not come in contact with the magnetic tape and are exposed to the outside, so wiring can be done easily in a narrow space without interfering with the running of the magnetic tape. First, the cylinder part is shaped into a 4-shape, which improves the workability of wiring contact.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the main parts of a direct drive cylinder device for a video tape recorder according to an embodiment of the present invention;
The figure is a bottom view of the first and second printed wiring board parts in FIG.
Figure 3 is a plan view of the third printed wiring board section in Figure 1;
This figure is a perspective view showing a state in which a tape is applied to the cylinder portion of FIG. 1. 1...Flat type electric motor, 2...Rotating shaft,
4... Fixed cylinder, 4a... Cylindrical part, 4
c... Notch, 5... Rotor disk, 7...
...Permanent magnet, 8...Stator yoke, 8. a・
... Disc part, 9 ... Drive coil, 10.
...Detection element, 12...Second printed wiring board, 12a...Wiring terminal section, 13...
・Printed wiring, 16...First printed wiring board, 1
6a...Wiring terminal section, 17...Printed wiring, 201...Upper cylinder, 22...Rotating transformer, 23...Rotating side coil , 24...
... Fixed side coil, 25 ... Third printed wiring board, 25a ... Wiring terminal section, 26 ...
...Printed wiring, 30...Magnetic tape, 31...
...magnetic head. Figure 4 Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 A permanent magnet is fixed to the rotor disk fixed to the rotating shaft,
A plurality of drive coils facing this permanent magnet with an air gap in the axial direction are fixed to the stator yoke side, the movement of the rotor disk is detected by a detection element, and the supplied power is detected by the signal of this detection element. A flat plate electric motor which controls and applies a voltage to the drive coil to rotate the rotor disc, a fixed cylinder housing the electric motor, and a fixed cylinder arranged above the fixed cylinder and fixed to the upper end of the rotating shaft. In a cylinder device for a helical scan video tape recorder, the upper cylinder is rotatable and has a magnetic head attached to its cylindrical portion. A first printed circuit board is provided with a notch, and is fixed to the inner side of the disc part of the stator yoke and connects each of the drive coils, and is attached to the inner circumferential side of the cylindrical part of the stator yoke. A second printed wiring board to which the detection element is connected is connected to a fixed side coil fixed to the stator yoke side of the rotary transformer which transmits and receives signals from the magnetic head, and the stator yoke is and a third printed wiring board fixed to the upper side of the disk part, each of the printed wiring boards being arranged parallel to the bottom of the fixed cylinder, and each wiring terminal part being connected to the notch part of the fixed cylinder. A direct drive cylinder device for a video tape recorder, characterized in that the cylinder is delivered to the outside through a cylinder.