JPS6142914B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a still operation for a video tape recorder that performs a still operation in which the playback screen is paused during image playback and a still screen is played back, and when the still screen is released, the original image is played back again. It is about the method.

A still operation method in a conventional video tape recorder (hereinafter referred to as VTR) will be explained with reference to FIGS. 1 and 2. A supply reel 2 and a take-up reel 3 are disposed within the cassette half 1, a magnetic tape 4 is suspended between the supply reel 2 and the take-up reel 3, and the magnetic tape 4 is wound around a cylinder 36. Reference numeral 5 denotes a tension pin, which gives a winding angle to the full-width erasing head 6 while the magnetic tape 4 is running. 7 is an impedance roller, 8 is a loading pin on the supply side, and 9 is a loading pin on the take-up side. I do. 10 is an impedance roller, 11 is a control audio head, 12 is a capstan, and 13 is a flywheel that rotates integrally with the capstan 12. 14 is a capstan motor,
15 is a capstan motor pulley, 16 is a flywheel belt for rotationally driving the capstan, 17 is a pinch roller that is pressed against the capstan 12 and drives the magnetic tape 4, 18 is a pinch roller arm, and 19 is a rotation of the pinch roller arm. The dynamic support axis is shown.

20, 21, 22, 23 are operating arms for attaching and detaching the pinch roller 17; 24, 25, 26, 2;
Reference numerals 7 and 28 indicate support shafts for attaching and detaching the pinch roller 17, 29 a solenoid for operating the operating arms 20, 21, 22, and 23, and 30 a spring for applying pressure to the pinch roller 17. 31 is a flywheel pulley of the flywheel 13; 32 is a winding belt that transmits power to the winding roller 34;
3 is a take-up pulley; 34 is a take-up roller coaxially with the take-up pulley 33 and rotated by power transmission via a slip mechanism (not shown); and 35 is a direction conversion pulley. The cylinder 36 is equipped with a recording/playback head (not shown). 37 is a reel motor, 3
8 is a reel motor pulley, 39 is a reel belt,
40 is a reel pulley to which power is transmitted by the reel belt 39, 41 is a reel roller that rotates coaxially with the reel pulley 40 via a slip mechanism (not shown), and 42 is in pressure contact with the reel roller 41 for rolling rotation. Indicates an idler.

During playback, when the cassette half 1 is installed and the playback operation is performed, the supply side loading pin 8 and the take-up side loading pin 9 located inside the cassette half 1 are removed.
is moved to the position shown in FIG. 1, and the magnetic tape 4 is pulled out from inside the cassette half 1, wound around the cylinder 36, and connected to the recording/playback head. The pinch roller 17 is pressed against the capstan 12, the magnetic tape 4 is held between the capstan 12 and the pinch roller 17, and the rotation of the capstan 12 in the direction of arrow A causes the magnetic tape 4 to travel in the direction of arrow B. In order to wind the driven magnetic tape 4 onto the take-up reel 3 without slack, the take-up roller 34
is pressed onto the take-up reel 3, and by rotation of the flywheel 13 in the direction of arrow A, the take-up pulley 33 is rotated via the take-up belt 32, and the take-up roller 34 is rotated in the direction of arrow C via the slip mechanism. Then, the take-up reel 3 is rotated in the direction of arrow D to wind up the magnetic tape 4. At this time, the cylinder 36 rotates in the direction of arrow E, and the track of the video signal recorded on the magnetic tape 4 is reproduced by the magnetic head built into the cylinder 36. Then, the supply reel 2 is moved by running in the direction of the magnetic tape B.
rotates in the direction of arrow F. The back tension of the magnetic tape 4 is generated by rotating the reel pulley 40 in the direction of arrow H by the rotation of the reel motor 37 in the direction of arrow G, and rotating the reel roller 41 in the direction of arrow H via the slip mechanism, while the idler 42 is being rotated. Arrow I
It is applied against rotation in the direction.

Next, when a still operation is performed, the rotation of the capstan 12 is stopped as shown in FIG. At this time, in order to keep the tape touch of the magnetic tape 4 on the recording/playback head built in the cylinder 36, the magnetic tape 4 is held between the capstan 12 and the pinch roller 17 with the pinch roller 17 pressed against the capstan 12. has stopped rotating. Also, the magnetic tape 4 has a reel motor 3.
By adjusting the rotational force in the direction of arrow G in 7, a slight back tension is applied to the magnetic tape 4, and the magnetic tape 4 is wound around the cylinder 36 so that it does not slacken. The same image is reproduced by tracing the recorded signal on 4. Here, in order to return to the playback state by the still release operation again, the pinch roller 17 is moved to the capstan 1 in order to stop the running of the magnetic tape 4 during still.
The drive of the capstan 12 was started from a state where the rotation of the capstan 12 had been stopped while the capstan 12 was crimped to the capstan 2.

Therefore, the capstan 12 is connected to the pinch roller 1.
7, the rotation is started from the brake-applied state, and as shown in FIG. 4A, it takes a long time f for the stabilized reproduced image. In Fig. 4, α is the pinch roller plunger drive pressure curve, b is the pinch roller drive motor rotation speed curve, c is the point at which the still operation starts when play is continued, and d is the start point of the still operation. Image freeze period due to still operation, e is the time when still is released, f is motor rotation speed rise time, q is pull-in time for servo stabilization, h
is the stable point of image reproduction. Therefore, it takes a long time to stabilize the reproduced image, making the screen unsightly.In order to shorten this time, it is necessary to increase the size of the capstan drive motor. In addition, in order to shorten the time required for this playback image stabilization time,
When the magnetic tape is paused during recording, the pinch roller is removed from the capstan so that the capstan does not stop rotating, even though the tape is stopped in the same way as during still recording. It was necessary to switch to a different operation.

An object of the present invention is to provide a still operation method for a video tape recorder that can shorten the start-up time of stabilizing the rotation of the capstan when releasing the still, and can reduce the time for disturbance of the playback screen. At the same time as the still release operation, the pinch roller that was pressed against the capstan is released from the capstan, the capstan is started to rotate, and after stable rotation, the pinch roller is pressed against the capstan again.

The still operation method of the video tape recorder according to the present invention will be explained below with reference to FIGS. 3 and 4B. Along with the still release operation, the solenoid 29 is turned off as shown in FIG. 3, and the operating arm 22 is moved in the direction of the arrow K with the return force of the spring 43 in the direction of the arrow K. The operating arm 2 is rotatably mounted on a support shaft 25 as the operating arm 22 moves.
0 and 21 as shown in FIG. 3, and by this operation, the operating arm 23, which was rotatably attached to the support shaft 26, moves in the direction of arrow M of the spring 30 around the fixed support shaft 27. The pinch roller 17 moves in the direction of arrow N, releases the pressing force on the capstan 12, and shortens the start-up time of the capstan motor 14. At that time,
The take-up roller 33 is removed from the take-up reel 3 in the direction of arrow C via a separate mechanism (not shown) so that the tape does not run. Capstan motor 1
4, the solenoid is turned on and the state shown in FIG. 1 is returned to the regeneration state. To explain this with reference to FIG. 4B, the pinch roller solenoid drive pressure becomes zero at the still release time l, and returns to the original drive pressure upon completion of the motor rotational speed rise time f. Furthermore, the motor rotation speed rise time f is significantly reduced compared to the conventional method.

As described above, according to the still operation method for a video tape recorder of the present invention, it is possible to significantly shorten the time required for the rotation of the capstan to start up when the still is released, thereby reducing the time required for disturbances in the playback screen.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a video tape recorder in a playback state in which the conventional still operating method is implemented, FIG. 2 is a plan view of the still operating state from the state shown in FIG. 1, and FIG. 3 is a plan view in which the still operating method of the present invention is implemented. Figure 4A is a time chart diagram of a conventional video tape recorder when performing stills;
B is a time chart when the video tape recorder of the present invention performs still operation. 4...Magnetic tape, 12...Capstan, 1
7...Pinch roller, 36...Cylinder.

Claims (1)

[Claims] 1 Equipped with a still function, the capstan is stopped with the pinch roller pressed against the capstan by the still operation, the running of the magnetic tape is stopped, and the magnetic tape is held with a constant tape touch while maintaining the tension of the magnetic tape to the cylinder. A still operation method for a video tape recorder in which the image head is rotated is characterized in that when the still is released, the pinch roller is temporarily released from the capstan by a release operation, the capstan is started to rotate, and after stable rotation, the pinch roller is pressed against the capstan again. How to operate stills on a videotape recorder.