JPH057782B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to endless videotape recorders.

Video tape recorders are required to have a small tape running load, small load fluctuations, and stable tape running.

In particular, in a video tape recorder in which an endless loop of tape is wound around a fixed reel, and the tape forming the innermost turn of the wound body is pulled out inside the fixed reel, the tape running load tends to be large. Efforts are needed to reduce the tape running load.

Prior Art FIG. 5 shows an example of a conventional endless video tape recorder. In the figure, 1 is a fixed reel that does not rotate, 2 is a fixed head, 3 is a capstan, 4 is a pinch roller, 5 is an endless loop magnetic tape, and 6 is a tape winding formed on the fixed reel 1.

When the magnetic tape 5 is clamped and driven, the tape of the tape winding body 6 is pulled out to the inside of the fixed reel 1 from the innermost turn side. The drawn-out tape 5 runs along the fixed head 2, is guided by the overturn guide 7, changes direction, reaches the outer periphery of the tape roll 6, and is wound there.

The fixed reel 1 has a structure consisting of a hub 8 and a flange 9.

Problems to be Solved by the Invention Since the hub 8 is not rotatable, the tape winding body 6
The fixed reel 10 at the innermost turn constantly slides on the circumferential surface of the hub 8 over 360 degrees.

Therefore, the tape running load in this area is high, and this high tape running load easily changes due to temperature changes, etc., and the tape running tends to become unstable, causing jitter, skew, etc., and making it difficult to reproduce a good image. The problem was that it was difficult.

SUMMARY OF THE INVENTION An object of the present invention is to provide an in-reel drive mechanism for an endless video tape recorder that effectively reduces the tape running load by devising the structure of the fixed reel and makes it possible to stabilize the tape running.

Means for Solving the Problems The present invention has a recording and reproducing section inside a fixed reel that has an endless loop-shaped tape winding body and is fixedly provided, and the tape is mounted on a tape clamp. The tape is clamped and driven by the drive unit and pulled out from the innermost circumference of the tape winding of the fixed reel to the inside of the fixed reel, passes through the recording and reproducing unit, where the recording position is set, and the tape is pulled out from the tape clamp drive unit. In an endless video tape recorder in which the fed tape is wound around the outermost circumference of a tape winding body of a fixed reel, a tape feeding belt is wound around the fixed reel in a substantially C-shape along the inner circumference thereof. , the tape winding body is arranged around the tape feeding belt, and the portion of the tape feeding belt that is in contact with the magnetic tape at the innermost turn of the tape winding body is configured to have the tape winding body around the tape feeding belt. Belt running means for running the tape feeding belt so as to run in the same direction as the running direction of the magnetic tape at the innermost turn of the tape winding body as the tape runs by the clamping drive means; The belt running means operates together with the tape clamping drive means, and the magnetic tape is gripped and driven by the tape clamping drive means and travels, and the running belt moves around the magnetic tape at the innermost turn of the tape winding body. The structure is such that the material is fed out to the inside of the fixed reel.

Function: By causing the belt of the fixed reel to run by the belt running means, the tape at the innermost turn of the tape winding body is sent out to the inside of the fixed reel. As a result, the load on the tape running by the tape holding drive means can be reduced, and the stability of tape running can be improved.

Embodiment FIG. 1 is a plan view showing an embodiment of the fixed reel structure of the endless video tape recorder of the present invention, with the upper flange of the fixed reel omitted.

In FIG. 1, 20 is a large-diameter fixed reel, which is fixed to the chassis 21. This configuration will be described later. 22 is a magnetic tape, and 23 is a tape winding body having more than 100 turns.

Reference numeral 24 denotes a guide drum having a rotating head constituting a recording/reproducing section, and 25 and 26 a capstan and a pinch roller constituting a tape holding drive section, both of which are provided inside the fixed reel 20 in the plan view.

27 is a full-width erasing head, 28 is an audio head, 29 is a control head, and 30 is an impedance roller, which are arranged inside the fixed reel 20 in the plan view.

Reference numerals 31 to 36 indicate tape guide poles constituting a tape guide section, with the guide pole 31 being disposed inside the fixed reel 20 and the guide poles 32 to 36 being disposed outside the fixed reel 20.

During recording and reproduction, the tape 22 is held and driven by a capstan 25 and a pinch roller 26, and runs in the direction of the arrow at a speed _V1 .

The tape 22 is pulled out horizontally to the inner peripheral side of the fixed reel 20, wound around the impedance roller 30, attached to the head 27, and reaches the peripheral surface of the guide drum 24.

Subsequently, the tape 22 is wound around the guide drum 24 over approximately 180 degrees and runs around the drum circumferential surface.
The rotary heads 37 and 38 rotate to helically scan the tape 22, and a video signal is recorded during recording and is reproduced during playback.

Tape 22 that has passed around the circumferential surface of guide drum 24
extends obliquely downward, is attached to the heads 28 and 29, is driven between the capstan 25 and the pinch roller 26, is guided by the pole 31, passes under the fixed reel 20, and is connected to the fixed reel 2 in the plan view.
Go outside of 0. The tape 22 is attached to the guide pole 3
2, 33, 34, and 35, and extends diagonally upward on the outside of the fixed reel 20 in the plan view substantially along the fixed reel 20, and finally the guide pole 3
6 to be at the same height as the fixed reel 20, guided to the outermost circumference of the tape roll 23, and wound around the tape roll 23. The tape roll 23 as a whole rotates clockwise.

The tape 22 has an endless loop shape, and is pulled out from the innermost periphery of the tape winding body 23 and is wound around the outermost circumference of the tape winding body 23 while the tape winding body 23 is connected to the fixed reel 20. runs endlessly while independently rotating clockwise. Recording and playback are performed endlessly.

Next, the structure of the fixed reel 20 and the internal reel drive mechanism provided in the fixed reel 20 will be explained.

As shown in FIG. 2, a fixed reel 20
, a lower flange 40, an upper flange 41, and rollers 42 to 42 distributed at equal angular intervals in the circumferential direction.
53, rollers 54 to 62 that guide the belt so that it does not come into contact with the guide drum 24, etc., and the belt is wound around the rollers 42 to 62 and wound around the fixed reel 20 in a substantially C shape along the inner circumference. It consists of a loop-shaped tape feeding belt 63.

The belt 63 has a C-shaped path 63a extending substantially all the way around the fixed reel 20 from the rollers 42 to 53.

The tape winding body 23 has upper and lower flanges 40, 4 on the outside of the belt 63 constituting the above-mentioned path 63a.
The height is regulated by 1. This tape winding body 23 has a structure in which the tape is wound around the path 63a to form an innermost circumferential turn, and the tape is sequentially wound on the outer side of the innermost turn to form turns one after another.

The belt 63 has appropriate bending elasticity, and as shown in FIG. 3, the belt 63 bulges outward between adjacent rollers, and the path 63a becomes nearly a perfect circle. Thereby, the tape winding body 23 is also in a state close to a perfect circle.

The reel drive mechanism that constitutes the belt running means includes a feed roller 65 around which the belt 63 is wound between rollers 59 and 60, and a motor 66 that rotates the feed roller 65.
and a motor drive circuit 67.

In the recording/reproducing mode, the motor 66 is driven, the roller 65 rotates in the direction of the arrow, and the belt 63 moves in the direction of the arrow at a speed slightly slower than the above tape running speed _V1 .
Runs on _V2 . A portion of the belt 63 forming the path 63a runs clockwise.

As a result, the tape 68 at the innermost turn of the tape winding body 23 is removed from the belt 68 forming the path 63a.
Reel 2 is fed by roller 53 from roller 53.
0 to the inner periphery at a speed V ₂ and pulled out by the capstan 25 and the pinch roller 26.

Therefore, the capstan 25 and the pinch roller 2
The running load on the tape 22, which runs along a predetermined tape path while being held between the tapes 6 and 6, is significantly reduced compared to the conventional tape 22.

Furthermore, even if the overall length of the tape 22 shortens due to changes in temperature, etc., and the winding force of the tape 68 around the belt 63 changes, the tape 68 continues to be fed by the belt 63, so the tape running load does not increase. , stay low.

The video tape recorder described above also includes a tape path 22a extending from the tape winding body 23 to the inner periphery of the fixed reel 20 and reaching the impedance roller 30.
A tension detection circuit 71 is provided which detects tension based on the tension pole 70 attached to the tape 22 and the position of this tension pole 70 and sends a control signal corresponding to the detected tension to the motor drive circuit 67.

When the detected tension is higher than a predetermined appropriate value, the motor 66 is
rotation speed is increased. As a result, the running speed of the belt 63 increases, the tape feeding speed increases, the amount of slippage between the tape 68 and the belt 63 decreases, and the tape tension decreases and returns to the above-mentioned appropriate value.

Conversely, when the tension becomes lower than a predetermined appropriate value, the rotational speed of the motor 66 is reduced via the circuits 71 and 67. As a result, the belt 63
The running speed of the tape 68 decreases, the tape feeding speed decreases, the amount of slip between the tape 68 and the belt 63 increases, and the tape tension increases and returns to the above-mentioned proper value.

Further, an impedance roller 30 is provided on the entrance side of the upper drum 24 in the tape running direction.

This allows the tape to maintain low running loads even when the ambient temperature changes significantly.
Moreover, the tension is maintained at an appropriate value, and tape vibrations are suppressed by the impedance roller 30, so that the tape runs stably. As a result, recording and reproduction are always performed satisfactorily, and especially during reproduction, high-quality images without jitter or skew are reproduced.

In addition, when the tape is directly wound around the rollers 42 to 53, the tape winding body is shown at 7 in FIG.
As shown in 5, each roller is bent at a location, and there is a straight line between the rollers, and the slippage between the tapes at each turn varies depending on the location, causing the tape running load to fluctuate and tape running to become unstable. On the other hand, when the belt 63 is stretched around the rollers 42 to 53 and the tape winding is formed around the belt 63 as in this embodiment, the tape winding is as shown in FIGS. As shown in Fig. 2, the tape is in a substantially perfect circular state, and the slippage between the tapes is uniform at each portion in the circumferential direction, and the tape running load hardly fluctuates.
This also makes the running properties of the tape stable.

Effects of the Invention As explained above, according to the endless video tape recorder of the present invention, the tape at the innermost turn of the tape winding body of the fixed reel is fed out by the belt running by the belt running means. To considerably reduce the load on tape running by a tape holding drive means, and to maintain stable tape running at all times even when the ambient temperature changes during operation, and to perform recording and playback well. It has the advantage of being able to reproduce images without jitter or skew, especially during reproduction.

[Brief explanation of the drawing]

FIG. 1 is a plan view of an embodiment of the endless video tape recorder of the present invention, FIG.
Figure 4 showing an enlarged view of a part of the tape roll in the figure.
The figure shows a part of a tape roll formed by winding the tape directly around a roller without a belt, and FIG. 5 is a plan view of an example of a conventional endless video tape recorder. 20...Fixed reel, 22...Magnetic tape, 2
3...Tape winding body, 24...Guide drum, 2
5...capstan, 26...pinch roller, 4
0...Lower flange, 41...Upper flange, 42~
62...Roller, 63...Tape feeding belt,
63a...pass, 65...feed roller, 66...
Motor, 67... Motor drive circuit, 68... Innermost turn tape, 70... Tension pole,
71...Tension detection circuit.

Claims (1)

[Scope of Claims] 1. A recording and reproducing section is provided inside a fixed reel that is fixedly provided and has an endless loop-shaped tape roll, and the tape is held and driven by a tape holding drive section. The tape is pulled out from the innermost periphery of the tape winding body of the fixed reel to the inside of the fixed reel, passes through the recording and reproducing section, where recording and reproducing are performed, and the tape fed out from the tape holding drive section is In an endless video tape recorder configured to be wound around the outermost periphery of a tape roll of a fixed reel, a tape feeding belt is wound around the fixed reel in a substantially C-shape along the inner periphery of the fixed reel. The tape winding body is arranged around the belt, and the portion of the tape feeding belt that is in contact with the magnetic tape at the innermost turn of the tape winding body is driven by the tape holding drive means. A belt running means for running the tape feeding belt so as to run in the same direction as the running direction of the magnetic tape at the innermost turn of the tape winding body as it runs, and together with the tape holding drive means. The belt traveling means operates, and the magnetic tape is gripped and driven by the tape gripping drive means and travels, and the traveling belt carries the magnetic tape at the innermost turn of the tape winding body onto the fixed reel. An endless video tape recorder characterized in that it has a configuration in which the tape is fed inward.