JPH09231529A - Head drum assembly for digital video cassette recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep proper contact with a video tape and to prevent occurrence of noise at the driving time by fitting plural heads to a rotary member to be positioned in a gap between an upper drum and a lower drum. SOLUTION: The upper drum 110 is fixed to an upper end part of a fixing shaft 150, and its lower surface is provided with a stator transformer 175. The lower drum 120 is fixed to a lower end part of the fixing shaft, and a motor stator 165 is arranged on its upper surface. The drums 110 and 120 are arranged so as to keep a predetermined gap between them. A pair of heads 130 fitted to the rotary member 140 are positioned in the gap between the drums 110 and 120. When the rotary member 140 and the one pair of heads 130 are rotated around the fixing shaft 150 at the time of driving the head drum assembly 200, the drums 110 and 120 are not rotated, and both drums acts as the fixed drums in the assembly.

Description

Detailed Description of the Invention

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital video cassette recorder (DVCR), and more particularly to a DVCR.
The present invention relates to a head drum assembly for a DVCR capable of maintaining proper contact with a video tape so that noise or distortion does not occur during driving of the.

[0003]

As is well known, a head drum assembly for a DVCR includes a plurality of movable parts such as a rotating member and a fixed part such as a fixed drum. Generally, the video tape inserted in the DVCR is DV
Although the video signal information is recorded or reproduced by traveling along a predetermined route provided on the deck of the CR, the head drum assembly for the DVCR has a small diameter and rotates at a high speed. It is difficult to maintain proper contact between the tape and the head drum, which causes noise and distortion. To prevent such problems, there is a need for a method of ensuring proper pressure contact between the head drum assembly and the video tape.

FIG. 1 is a schematic view of a conventional DVCR head drum assembly 100. The head drum assembly 100 includes a fixed shaft 50 provided with a pair of bearings 80, 85 and a motor stator 65, an upper drum 10 provided with a motor rotor 60 and a pair of heads 30, a lower drum 20 provided with a stator transformer 75, and It includes a rotating member 40 provided with a rotor transformer 70.

The upper drum 10 has a rotary member 40,
It is rotatably fitted around the fixed shaft 50,
The motor rotor 60 is on its upper surface, and the head 30 is on its lower surface.
Pairs are provided.

The lower drum 20 is fitted and fixed to the lower portion of the fixed shaft 50, and the stator transformer 75 is arranged on the upper surface thereof. These upper and lower drums 1
0 and 20 are arranged so as to maintain a predetermined gap therebetween. The pair of heads 30 provided on the upper drum 10 is located in the gap between the upper drum 10 and the lower drum 20.

The rotating member 40 is mounted between the upper drum 10 and the lower drum 20 so as to be attached to the lower side of the pair of the upper drum 10 and the head 30, and is fixed when the head drum assembly 100 is driven. The fixed shaft 50 is mounted via a pair of bearings 80, 85 so as to rotate about the shaft 50.
Is fitted.

Since the upper drum 10 is physically connected to the pair of the rotating member 40 and the head 30, the upper drum 10 is rotated about the fixed shaft 50 when the head drum assembly 100 is driven. Rotated with 30 pairs, it functions as a rotating drum in head drum assembly 100. On the other hand, the lower drum 20 has a fixed shaft 50.
Therefore, even if the upper drum 10 is rotated when the head drum assembly 100 is driven, it does not rotate with respect to the fixed shaft 50 and functions as a fixed drum in the head drum assembly 100.

The rotor transformer 70 is a stator transformer 7 provided on the lower drum 20.
5 is aligned, but is located underneath the rotating member 40 so as to maintain a constant spacing.

The motor stator 65 is aligned with the motor rotor 60 installed on the upper drum 10, but is fitted and fixed to the upper portion of the fixed shaft 50 so as to maintain a constant interval.

When a predetermined electric signal is applied to the motor stator 65, an electromagnetic force is generated between the motor stator 65 and the motor rotor 60. Upper drum 10,
The rotating member 40, the rotor transformer 70, the pair of heads 30, and the motor rotor 60 are the motor stator 65.
The motor is rotated about the fixed shaft 50 by the electromagnetic force generated between the motor rotor 60 and the motor rotor 60.

The rotor transformer 70 is electrically connected to the pair of heads 30. Therefore, DVCR
During the reproducing operation of 1, the rotor transformer 70 receives the image information recorded on the video tape from the pair of heads 30, and supplies the received image information to the stator transformer 75. Further, during the recording operation of the DVCR, the rotor transformer 70 receives the video telegram from the stator transformer 75 and supplies it to the head 30.

However, the head drum assembly 100 shown in FIG. 1 has many problems. When the head drum assembly 100 is driven, the upper drum 10 functions as a rotating drum that rotates around the fixed shaft 50.
It is difficult to maintain the tension of the video tape in contact with 0, and irregular contact occurs between the video tape and the upper drum 10, and noise or distortion is likely to occur in the DVCR.

[0014]

SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to maintain proper contact with a video tape to ensure that it is a DV.
It is an object of the present invention to provide a head drum assembly for a DVCR that can prevent noise or distortion from occurring when driving a CR.

[0015]

In order to achieve the above object, according to the present invention, a fixed shaft having an upper end portion and a lower end portion and provided with a bearing means, and fitted to the upper end portion of the fixed shaft. Is fixed to the upper drum, and is fixed to the lower end of the fixed shaft so as to maintain a predetermined gap with the upper drum, and a motor stator is provided. A lower drum, a rotary member fitted to the fixed shaft via the bearing means, and provided with a rotor transformer and a motor rotor, and positioned in a gap between the upper drum and the lower drum, A head drum assembly for a DVCR including a plurality of heads attached to the rotating member is provided.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will now be described in more detail with reference to the drawings.

FIG. 2 is a schematic cross-sectional view of a DVCR head drum assembly 200 according to the present invention.
The same parts as those in FIG. 1 are shown by adding 100 to the same reference numerals.

The head drum assembly 200 includes a fixed shaft 150 having a pair of bearings 180 and 185, and an upper drum 11 having a stator transformer 175.
0, the lower drum 12 provided with the motor stator 165
0, and a rotary member 1 provided with a pair of a motor rotor 160, a rotor transformer 170, and a head 130.
40 inclusive.

The upper drum 110 is fitted and fixed to the upper end of the fixed shaft 150, and has a stator transformer 175 on the lower surface. The lower drum 120 is fitted and fixed to the lower end of the fixed shaft 150, and the motor stator 165 is arranged on the upper surface. Upper drum 110
And the lower drum 120 are arranged to maintain a predetermined gap therebetween.

The rotating member 140 is used for the head drum assembly 2
It is fitted to the fixed shaft 150 via a pair of bearings 180 and 185 so that it can be rotated about the fixed shaft 150 when driven. On the upper surface of the rotating member 140, a rotor transformer 170 and a stator transformer 175 are provided.
The motor rotor 160 is provided on the lower surface in alignment with the motor stator 165. The pair of heads 130 attached to the rotating member 140 is located in the gap between the upper drum 110 and the lower drum 120.

Since the upper and lower drums 110 and 120 are fixed to the upper and lower portions of the fixed shaft 150, respectively, the pair of the rotating member 140 and the head 130 rotates about the fixed shaft 150 when the head drum assembly 200 is driven. However, the upper and lower drums 110 and 120 are not rotated. That is, both the upper and lower drums function as fixed drums in the head drum assembly 200.

When a predetermined electric signal is applied to the motor stator 165, electromagnetic force is applied to the motor stator 16.
5 and the motor rotor 160. Rotating member 1
40, rotor transformer 170, head 130
Pair of motor rotors 160 and motor rotor 160
The fixed shaft 150 is rotated by an electromagnetic force generated between the motor rotor 160 and the motor rotor 160.

The rotor transformer 170 is electrically connected to the pair of heads 130. Therefore, DV
During the CR reproducing operation, the rotor transformer 170 receives the image information recorded on the video tape from the pair of heads 130 and transfers the image information to the stator transformer 175. Further, during the recording operation of the DVCR, the rotor transformer 170 is the stator transformer 1
Image information is received from 75 and transmitted to the pair of heads 130.

While specific embodiments of the invention have been described above, it will be apparent to those skilled in the art that various modifications can be made without departing from the scope of the claims set forth in the invention.

[0025]

Therefore, in the DVCR head drum assembly 200 according to the present invention, not only the lower drum 120 but also the upper drum 110 functions as a fixed drum that does not rotate around the fixed shaft 150 in the head drum assembly 200. The proper tension is maintained on the video tape in contact with the upper drum 110, the proper contact is maintained between the video tape and the head drum assembly 200, and noise and distortion are prevented.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a conventional DVCR head drum assembly.

FIG. 2 is a schematic sectional view of a head drum assembly for a DVCR according to the present invention.

[Explanation of symbols]

 110 Upper Drum 120 Lower Drum 130 Head 140 Rotating Member 150 Fixed Shaft 160 Motor Rotor 165 Motor Stator 170 Rotor Transformer 175 Stator Transformer 180, 185 Bearing 200 Head Drum Assembly

Claims (7)

[Claims] 1. A fixed shaft having an upper end portion and a lower end portion and provided with a bearing means, an upper drum fitted and fixed to the upper end portion of the fixed shaft and provided with a stator transformer, and the fixed portion. The lower drum is fitted and fixed to the lower end of the shaft so as to maintain a predetermined gap, and the lower drum provided with a motor stator is fitted to the fixed shaft via the bearing means. And a head drum assembly for a DVCR including a rotating member provided with a rotor transformer and a motor rotor, and a plurality of heads attached to the rotating member so as to be located in a gap between the upper drum and the lower drum. Three-dimensional. 2. The head drum assembly for a DVCR according to claim 1, wherein the motor rotor is arranged on a lower surface of the rotating member. 3. The head drum assembly for a DVCR according to claim 2, wherein the motor stator is disposed on the upper surface of the lower drum. 4. The head drum assembly for a DVCR according to claim 3, wherein the motor rotor is provided in alignment with the motor stator. 5. The DVCR head drum assembly according to claim 1, wherein the rotor transformer is disposed on an upper surface of the rotating member. 6. The head drum assembly for a DVCR according to claim 5, wherein the stator transformer is disposed on a lower surface of the upper drum. 7. The head drum assembly for a DVCR according to claim 6, wherein the rotor transformer is provided in alignment with the stator transformer.