JPH10198905A - Rotary drum device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to adjust rotary balance of a rotary drum unit by a simple method. SOLUTION: To a rotary drum 1, video heads 2 forming an angle of 180 degrees to each other and recording and reproducing a video signal on a magnetic tape, a rotary transformer 5 transmitting/receiving an electrical signal to/from the video head 2, and a relay board 6 electrically connecting the rotary transformer 5 and the video head 2, are respectively attached. In this case, the relay board 6 is provided with a plurality of machine screw holes 10 for rotary balance adjustment ranging in a ring shape centering a center of rotation of the drum 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drum device such as a helical scan type video tape recorder for recording and reproducing signals by a rotary head, and more particularly to a rotary balance of a rotary drum unit which is a rotary portion of the rotary drum device. Of the correction means.

[0002]

2. Description of the Related Art A conventional rotation balance correction of a rotary drum unit will be described with reference to FIGS.

FIG. 3 is a plan view of a rotating drum unit, which is a rotating portion of a conventional magnetic head device, viewed from a stator. In FIG. 3, reference numeral 1 denotes a rotating drum, and 2 denotes a video head for recording and reproducing a video signal. Reference numeral 3 denotes a rotary erasing head for erasing a video signal recorded on a magnetic tape as the rotary drum 1 rotates. A dummy head 4 having a weight substantially equal to that of the erasing head 3 is attached to the rotary drum 1 at a position at an angle of 180 degrees with the erasing head 3. 5 is a rotary transformer, and 6 is a relay board for electrically connecting the rotary transformer 5 to the video head 2 and the erasing head 3 via a relay terminal 7.
Each is attached to the rotating drum 1. Reference numeral 8 denotes a copper foil portion on which solder can be freely attached to the outer periphery of the relay board 6. The rotating drum unit configured as described above rotates around the rotating shaft 9.

A magnetic tape (not shown) wound at approximately 180 degrees is brought into pressure contact with the rotary drum unit, and the rotary drum unit is rotated by a rotary drum motor (not shown) to record a signal.

[0005] However, when the rotary drum unit having the above structure is rotated, the weight difference between the video heads 2 arranged at positions 180 degrees apart from each other, the rotation erasing head 3 and the dummy heads arranged at positions 180 degrees apart from each other are obtained. 4
And the weight variation of the solder provided for electrical connection, the center of gravity of the rotation of the rotary drum unit is located at a position distant from the rotary shaft 9, and the rotary drum unit is rotated in this state. In this case, not only vibrations and abnormal noises are generated, but also reproduced images having a lot of jitters.

In order to prevent this, the unbalance amount of the balance and the position where the unbalance occurs are measured in the state of the rotating drum unit, and as shown in FIG. The balance was corrected so that a suitable amount of solder 10 was piled up or an unbalanced position was directly removed by a suitable amount by machining so that the center of gravity of the rotation of the rotary drum unit came close to the rotation shaft 9.

[0007]

However, in the above-described method for correcting the balance by soldering, during the soldering operation, due to the scattering of the flux and the scattering of the solder, precision parts such as the head do not function or the rotation is poor. Had the problem of getting lost. On the other hand, in the balance correction by machining, there is a problem that man-hours are increased due to scattering of chips, washing for removing chips, and the like.

[0008]

According to the present invention, there is provided a rotary drum device comprising: a rotary drum; a video head for recording and reproducing a video signal on a magnetic tape at an angle of 180 degrees; and an electrical signal to the video head. In a rotary drum device on which a rotary transformer for transmitting and receiving, and a relay board for electrically connecting the rotary transformer and the video head are respectively mounted, a rotation balance connected to the relay board in an annular shape around a rotation center of the rotary drum. A plurality of adjustment screw holes are formed.

According to the present invention, it is possible to provide a rotary drum device capable of adjusting the rotational balance by a simple method when the rotational balance of the rotary drum unit is lost.

[0010]

DETAILED DESCRIPTION OF THE INVENTION A rotary drum device according to claim 1 of the present invention comprises a video head for recording and reproducing a video signal on a magnetic tape at an angle of 180 degrees with respect to the rotary drum, and the video head. A rotary transformer for transmitting and receiving an electric signal to and from a rotary drum device, each of which is provided with a relay board for electrically connecting the rotary transformer and the video head, wherein the relay board has an annular shape around a rotation center of the rotary drum. A plurality of screw holes for adjusting the rotational balance connected to the head are formed, so that precision components such as a head do not function due to the rotational balance adjustment, and rotation failure does not occur. In addition, since the rotation balance can be easily adjusted by replacing the weight with the screw, the workability is improved.

(Embodiment 1) An embodiment of the invention described in claim 1 will be described below with reference to FIGS. Note that the same components as those of the conventional example are denoted by the same reference numerals and description thereof is omitted.

As shown in FIG. 1, reference numeral 2 denotes a video head for recording and reproducing a video signal on a magnetic tape.
Mounted at a 0 degree angle. Reference numeral 3 denotes an erasing head for erasing a video signal recorded on the magnetic tape, 4 denotes a dummy head attached to the erasing head 3 at an angle of 180 degrees to each other, 5 denotes the video head 2 and the erasing head 3 A rotary transformer 6 for transmitting and receiving an electric signal to and from the relay transformer 6 for electrically connecting the rotary transformer 5 and the video head 2 with a relay terminal 7; A large number of screw holes 10 for adjusting the rotational balance are formed in an annular shape around the rotating shaft 9 on the outer periphery of the relay board 6.

In the rotary drum unit configured as described above, adjustment of the rotational balance of the rotary drum unit will be described. The video head 2 or the rotation erasing head 3 and the dummy head 4 are mounted so that they are at 180 degrees to each other with respect to the rotation axis 9. When the rotation is performed about the rotation axis 9, the rotation is performed due to the mounting accuracy or a slight weight balance between each other. The rotation balance of the drum unit is lost. Therefore, a balance measuring device (not shown) is used to determine in which direction the rotating drum unit is out of balance by how much weight. By doing so, the unbalance amount and phase of the rotating drum unit are detected.

A plurality of screws 11 having different weights and different lengths and materials are prepared, and as shown in FIG.
The screw hole 10 at the phase position measured by the balance measuring device is selected from among the screws, and the screw 11 corresponding to the unbalance amount measured by the balance measuring device is selected and inserted into the selected screw hole 10. I do. In this operation, screws 11 having different weights depending on length, material, etc. are selected and the screws 11 are inserted into a large number of screw holes 10 formed in the relay board 6 until the unbalance amount falls within a predetermined standard. By doing so, the accuracy of the rotational balance adjustment is improved.

[0015]

According to the rotary drum device of the present invention, the use of a screw makes it possible to easily adjust the rotational balance of the rotary drum unit, thereby improving workability.
It is possible to prevent the scattering of the solder, the failure of precision components such as the head to function, and the occurrence of poor rotation.

[Brief description of the drawings]

FIG. 1 is a plan view of a rotary drum unit of a rotary drum device according to an embodiment of the present invention as viewed from a stator side.

FIG. 2 is a sectional view of a main part of the rotary drum unit with screws inserted into screw holes.

FIG. 3 is a plan view of a conventional rotating drum unit viewed from a stator side.

FIG. 4 is a sectional view showing a state in which the rotational balance of the conventional rotary drum unit is adjusted by soldering.

[Explanation of symbols]

 Reference Signs List 1 rotating drum 2 video head 3 erasing head 4 dummy head 5 rotary transformer 6 relay board 7 relay terminal 9 rotating shaft 10 screw hole 11 screw

Claims (1)

[Claims] 1. A video head that records and reproduces a video signal on a magnetic tape at an angle of 180 degrees with respect to a rotating drum, a rotary transformer that transmits and receives an electrical signal to and from the video head, the rotary transformer and the video In a rotary drum device to which a relay board for electrically connecting the head is mounted, a plurality of screw holes for adjusting a rotational balance that are annularly connected around the rotation center of the rotary drum are formed in the relay board. Characterized rotary drum device.