JPH02201702A - Rotary head device - Google Patents

Abstract

PURPOSE:To improve the coaxial accuracy of a rotary drum by providing the fixed side transformer of a cylindrical rotary transformer positioned concentrically with a fixed shaft and the stator side of a motor for a fixed drum, and providing the rotation side transformer of the cylindrical rotary transformer and the rotor side of the motor for a rotary drum. CONSTITUTION:A head assembly 38, a rotation side rotary transformer 39, a rotor assembly, etc., are attached to a rotary drum 32. The head assembly 38 consists of a head base 38a and a magnetic head 38b adhesively fixed to the tip of the base, is fixed to the bottom surface part of the rotary drum 32 with the use of a screw 40, and a head terminal is connected to a flexible printed circuit (FPC) provided at the bottom surface part of the rotary drum 32. Further coaxial type rotary transformes 34 and 39 are used, and for the rotation side rotary transformer 39, the external diameter at higher accuracy is fitted to the internal diameter of a cylinder having the central axis of the rotary drum 32. Thus the coaxial accuracy between the rotating side rotary transformer 39 and the rotary drum 32 can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the structure of a video tape recorder (hereinafter referred to as a VTR), and particularly to the structure of a rotary head device of a VTR.

(Prior Art) FIG. 3 is a sectional view of a rotary head device commonly used in conventional VTRs, and the following description will be made with reference to the same figure.

As shown in the figure, an upper ball bearing 2a and a lower ball bearing 2b are press-fitted into the fixed drum 1 from above and below, and a disk-shaped fixed-side rotary transformer is adhered thereto. Flywheel 5 with shaft 4 press-fitted
A rotary transformer 6 on the rotating side, which is separate from this, is glued to the shaft 4. The shaft 4 is lightly press-fitted into a ball bearing, and a collar 7 is fixed to the lower end by a set screw 8. With this structure, the flywheel 5 and collar 7 can freely rotate relative to the fixed drum 1.

A stator assembly 10 of a motor is fixed to the fixed drum 1 by screws 9, and a rotor assembly 12 of the motor is fixed to the collar 7 by screws 11. A head assembly 14 is fixed to the rotating drum 13 with a screw 15, and the relative height of this head can be adjusted with a set screw 16.

The rotating drum 13 is fitted with the flywheel assembly 5 and fixed with a screw 17.

Further, a relay pin 18 is soldered to the head assembly 14, and a relay ring 2 is soldered to the rotary transformer 6 on the rotary side via the substrate 19 on the rotating drum 13.
It is electrically coupled to 0.

(Problems to be Solved by the Present Invention) When attaching the rotating drum 13 to the flywheel 5 described above, first, the shaft 4 to which the fixed drum 1 is attached is attached.
At this time, in order to adjust the gap between the fixed side rotary transformer 3 and the rotating side rotary transformer 6 installed in advance on the flywheel 5, the upper ball bearing 2a must be pressed into place. This has been done by appropriately providing spacers A at the positions where the flywheel 5 and the flywheel 5 come into contact. Then, the rotating drum 13 is attached to the flywheel 5 with the gap adjusted, but at this time, depending on how pressurization is applied to the bearings 2a and 2b, the tape running reference groove (lead) formed on the surface of the fixed drum 1 is There was a problem in that the height up to the rotating drum mounting surface B formed on the flywheel 5 varied.

In order to eliminate this variation, the height was adjusted by cutting the rotary drum mounting surface B of the flywheel fixed to the shaft 14 in this state, but this made the assembly work very complicated and the workability was reduced. It was bad.

Further, there is a problem in that an error occurs in the fitting between the flywheel 5 and the rotary drum 13, and the coaxial precision with respect to the shaft 4 deteriorates, which causes the rotary drum 13 to run out on its outer periphery.

Furthermore, since the rotating side rotary transformer 6 was attached to the flywheel 5 and the head assembly 14 was attached to the rotating drum 13 which was separate from the flywheel 5, the low retrans and head assembly 14
cannot be directly electrically connected to relay pin 18.
, the board 19, the relay ring 20, and other components, which leads to problems such as a complicated structure and an increase in the number of components.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and consists of a fixed drum and a rotating drum equipped with a magnetic head, and a motor connects the rotating drum to the fixed drum. In the rotary head device, the rotary head device rotates against the fixed drum, and the rotary drum is located on the fixed drum and is rotatably attached to the fixed shaft via a ball bearing. The fixed drum is provided with a fixed side transformer of a cylindrical rotary transformer located concentrically with the fixed shaft and the stator side of the motor, and the rotating drum is provided with a rotation side of the cylindrical rotary transformer. A rotary head device characterized in that a side transformer and a rotor side of the motor are provided, and the magnetic head and the rotary transformer are electrically connected via a substrate provided on the back side of the rotary drum. This is what we are trying to provide.

(Example) FIG. 1 is a longitudinal sectional view of a rotary head device 30 according to the present invention, and FIG. 2 is a back view of the rotary drum shown in FIG. 1. Roughly speaking, the rotating head device 30 includes a fixed drum 31 and a rotating drum 32.

First, each component disposed on the fixed drum 31 will be explained. A fixed shaft 33 is press-fitted into the fixed drum 31 and has a structure in which it stands upright with respect to the fixed drum. A fixed rotary transformer 34 and a stator assembly 35 of the motor section are attached to the fixed drum 31. The fixed rotary transformer 34 has a cylindrical magnetic core, and coils (not shown) corresponding to the number of magnetic heads described later are wound around an annular groove formed on the outer periphery. In addition, each coil is fixed to a drum 31 at the lower end.
A terminal (not shown) leading to the outside is provided. This fixed side rotary transformer 34 is attached to a cylindrical shaft 36 formed on the fixed drum 31 and fixed by adhesive.

Further, the stator assembly 35 constitutes a motor in cooperation with a rotor assembly 37, which will be described later, and rotates the rotating drum 32.

Note that the terminal for leading out to the outside of the fixed drum 31 is soldered to a board (not shown) disposed at the bottom of the fixed drum 31, and is connected to the inside of the magnetic recording/reproducing device via a lead pattern formed on this board. It is configured to be connected to the electrical circuit of

Next, the components arranged in the rotating drum 32 will be explained. A head assembly 38 is attached to the rotating drum 32.
, rotating side low retrans 39, rotor assembly 3
7 etc. is installed.

The head assembly 38 consists of a helad base 38a and a magnetic head 38b adhesively fixed to the tip thereof, and is fixed to the bottom of the rotating drum 32 using a screw 40, and its head terminal is provided on the bottom of the rotating drum 32. Connected to a flexible printed circuit (FPC). The rotating rotary transformer 39 has a cylindrical magnetic core similar to the fixed rotary transformer 34, and a plurality of coils are wound around an annular groove formed on the inner circumference. Further, the end wire portion of each coil is connected to a terminal provided on the rotary side low retransformer 39, and the
It is electrically connected to each head assembly via a PC. In the assembled state, the fixed side rotary transformer 34 is disposed opposite to the inside of the rotating side rotary transformer 39,
Send and receive signals without contact.

This rotating side rotary transformer 39 is fixed to the rotating drum 32 with adhesive.

As mentioned above, the rotary transformers 34 and 39 use coaxial types, and the outer diameter of the rotary transformer 39 on the rotating side can be fitted to the inner diameter of the cylinder having the central axis of the rotating drum 32 with higher precision. Therefore, the coaxial accuracy of the rotating side rotary transformer 39 and the rotating drum 32 can be achieved without using a jig. Rotor assembly 37
The annular magnet 37a is provided inside a bottomed annular yoke, and this annular magnet 37a is attached to the stator assembly 35.
The coil 35a is installed so as to face the coil 35a provided therein. These assemblies 35 and 39 work together to constitute a motor, and the rotor assembly 39 rotates when power is supplied to the coil 39a, thereby rotating the rotary drum 3.
2 also rotates.

Furthermore, since each assembly 35, 39 is built into each drum 31, 32 in the assembled state, the drum unit can be made thinner.

Next, the structure of the rotating drum 32 itself will be described.

The rotary drum 32 according to the present invention does not have a hole for fitting a flywheel, which was formed in a rotary drum with a conventional structure, but instead has two ball bearings 41a for receiving the fixed shaft 22. .

41b is directly embedded from above and below, respectively, and has a fixed structure.

In other words, it has a structure in which the conventional flywheel and rotating drum are integrated.

The rotating drum 32 configured in this way is similar to the fixed drum 31.
The fixed shaft 32 established in the ball bearing 41a
, 41b, and the collar 42 is fixed to the upper end with a set screw 43.

This structure allows the rotating drum 32 to rotate freely relative to the fixed drum 31.

With the above-mentioned configuration, it is possible to completely eliminate the installation errors that conventionally occur when fitting the rotary drum to the flywheel, and there is no need to adjust the outer circumference runout. Furthermore, since there is no flywheel involved, there is less variation in the height from the reed provided on the fixed drum to the magnetic head, unlike in the past, and there is no need for machining and cutting after assembly. Moreover, it is of course possible to use a spacer for height adjustment if necessary.

(Effects of the Invention) As described above, according to the present invention, in a rotating head device that includes a fixed drum and a rotating drum on which a magnetic head is mounted, and in which the rotating drum is rotated relative to the fixed drum by a motor, the fixed shaft and the rotary drum, which is located on the fixed drum and is rotatably attached to the fixed shaft via a ball bearing, and the fixed drum has the above-mentioned A fixed side transformer of a cylindrical rotary transformer located concentrically with the fixed shaft and a stator side of the motor are provided, and a rotating side transformer of the cylindrical rotary transformer and a rotor side of the motor are provided on the rotating drum, In addition, since the magnetic head and the rotary transformer are electrically connected through the substrate provided on the back side of the rotary drum, there is no installation error that conventionally occurred when the rotary drum was attached to the flywheel. The coaxial precision of the rotating drum with respect to the fixed shaft is improved, the occurrence of peripheral runout is suppressed, smooth rotation of the rotating drum can be realized, and a VTR with excellent image quality can be provided. In addition, the magnetic head and the rotating transformer of the rotary transformer can be directly connected, eliminating the need for extra parts and, in addition, eliminating the need for the flywheel as an independent component as described above. The number of parts can be reduced, and the number of processing steps and assembly steps can be reduced, resulting in a corresponding reduction in cost, making it possible to provide a cost-effective VTR.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a rotary head device 30 according to the present invention, FIG. 2 is a rear view of the rotary drum shown in FIG. 1, and FIG. 3 is a rotary head generally used in conventional VTRs. FIG. 2 is a cross-sectional view of the device. 30...Rotating head device, 31...-fixed drum, 3
2... Rotating drum, 33... Fixed shaft, 34...
... Fixed side rotary transformer, 35 ... Stator assembly, 36 ... Cylindrical shaft,
37... Rotor assembly, 38... Head assembly 39... Rotating side rotary transformer, 40... Screws 41a, 41b... Ball bearing, 42... Collar, 43... Set screw FPC. ...Flexible printed circuit.

Claims (1)

[Claims] A rotary head device consisting of a fixed drum and a rotating drum on which a magnetic head is mounted, and in which the rotating drum is rotated relative to the fixed drum by a motor, the fixed drum having a fixed shaft mounted thereon, and the rotating drum located on the fixed drum. The rotating drum is rotatably attached to the fixed shaft via a ball bearing, and the fixed drum has a fixed side of a cylindrical rotary transformer located concentrically with the fixed shaft. A transformer and a stator side of the motor are provided, and the rotating drum is provided with a rotating side transformer of the cylindrical rotary transformer and a rotor side of the motor. A rotary head device characterized in that the magnetic head and the rotary transformer are electrically connected.