JPS58103280A - Video disk reproducer - Google Patents

Abstract

PURPOSE:To obtain a perfect static picture with a video disk system in which plural fields are recorded on a track of one round, by reproducing consecutively only the same field and therefore eliminating the lateral deflection a picture. CONSTITUTION:A video disk device 9 has a spiral recording track and reproduces a disk containing four video fields recorded on a round, a video disk device 10, in which only a field of the video signals of the device 9 is recorded on the track of one round and then reproduced, is provided. A desired field is selected by the external control signal and recorded on the device 10. Then the recorded signals are consecutively reproduced by the control devices 26 and 27.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method in which a video signal is transmitted to the front surface f4 i! of a disk-shaped object. ,
”.

This relates to a playback device for so-called video disks, which record data in a spiral manner.

In order to increase the recording density on a disk, that is, to record over a long period of time, there is a method in which not only one field but several fields of signals are recorded during one rotation of the disk. This system is, for example, a 7I system generally called a VHD system. This method records 4 feet/L per revolution (see Figure 1).

Figure 2 shows the [I
) By reducing the raw trajectory by 1°, for example, if playback is started from position 3, as the disc rotates, [8
,lf! ] Field 6, field 6, field 7
field, (then regenerate the field of 8 between cars, f1″I
', l? ! '4, 1,7101, jump to position 3 to play the same track. - result, interval 5, 6.7
Then, 4 filts of 8 are played. This means that 1
During the 4 fields of rotation, the signal changes if there is a change in the video signal, i.e. the TV whose reproduced image is the image display.
The image is displayed on the receiver's cathode ray tube and appears as an unnatural image. Field 4 period is 1/1 in terms of NTSC signal.
Since this corresponds to 6 seconds, a complete still image cannot be obtained unless a still life image is being recorded.

An object of the present invention is to obtain a complete still image in a video disc system in which several fields are recorded on a track of one rotation as described above.

The present invention provides a first video disc device that plays back a disc in which several fields are recorded on one track of one rotation, and a video disc device that reproduces only one field from the playback signal of the device.
a second video disc device for recording and reproducing data on the same track; It consists of an operating device that subsequently reproduces the signal continuously, thereby allowing a complete still image to be obtained even in the video disc device 6 in which several fields are recorded in one trunk. be.

FIG. 3 is a block diagram illustrating one embodiment of the present invention. In the figure, reference numeral 9 denotes a main video disc playback device that plays back a video disc having a video trunk (for example, as shown in FIG. 1) recorded in a spiral manner. The video disc device 19 may be an optical device, a device that uses capacitance change, or a device that uses piezoelectric effect, regardless of the essence of the present invention. . Also, the video track is 1 of the disc.
It is assumed that two or more fields of video signals are recorded between one rotary wheel. Let N be the number of fields in one rotation. In the following explanation, N=
Case 4 will be described below.

1o is a magnetic disk device used as an auxiliary memory, and in this embodiment, the rotation speed of the video disk 14i7°9 is adjusted to approximately N times, that is, approximately 4 times, by the rotation device B23. One video track is recorded and reproduced by the magnetic head 21.

Now, from the main video disc device 9, the signal recorded on the video track from the pickup 14 guided by the pickup arm 13 is detected, sent to the playback device 16, and processed through the terminals a - c of the switch A16. The signal is applied to a circuit 17, restored to a regular television signal, and sent from a video signal output terminal to a television receiver.

When a control signal is applied to the still terminal 28 (generally, an electric signal is applied through a switch means such as a pushbutton), the operation circuit B 27 starts the field from the one field start time detected by the field start edge detection circuit 26. Switch B20 is pressed for one field period until the completion time.
a'', and the output of the pickup 14 is amplified from the playback device 16 through the recording amplifier 19, supplied to the magnetic head 21, and recorded on the magnetic disk 22. Since the number of revolutions is approximately four times that of the rotation speed of the magnetic disk 22, one field of signals recorded between positions 3 and 3' shown in FIG. 2, for example, is recorded in one revolution of the trunk of the magnetic disk 22. Simultaneously with the completion, the switch B20 is turned to "'b'" by the operation circuit B27, and henceforth the magnetic disk device 1o operates in the reproduction mode.On the other hand, the operation circuit A2
6, like 27, switches switch A at the start time of the field.
16 to "b" and the signal processing circuit 17 to the regenerative amplifier 2.
Connect to 4. This connection is maintained as it is, and one field of signals recorded on the magnetic disk device 10 is continuously and repeatedly sent to the signal processing circuit 17, and appears at the terminal 18 as a television signal. Therefore, only one field of complete still images is continuously displayed on the television receiver. The signal of the operation circuit A26 is also sent to the pickup arm 13, and the movement of the arm is controlled by the second
Trace the track drawn by the thick line in the figure.

That is, the continuous spiral movement of the pickup is stopped.

Signal processing circuit 1 of regenerative amplifier 24 using switch A1e
7 and the restriction on the pickup movement is released by applying a signal to the reset terminal 29, the pickup 14 normally traces the spiral video track, and the playback device 16 is connected to the signal processing circuit 17. 1, and a normal video signal, not a still image signal, is sent to the output terminal 18.

When it is desired to obtain a still 1F image, a control signal is applied to the still terminal 28, and the still image signal appears again at the output terminal 18 through the above-described operation. Usually, magnetic disk device 1
By applying a video signal to the magnetic head 21, the signal previously recorded on the video disk is erased without using a video signal erasing head, so in practical use, an erasing head is not required. However, if an even better quality reproduction signal is to be obtained, an erasing head may be provided. In this case, it is easy to understand that the erasing head can be operated using the signal from the operating circuit B27.

In FIG. 3, the main video disk device 9 and the auxiliary magnetic disk device 10 each use separate rotating devices 12 and 23; however, as shown in FIG. By attaching a pulley having a diameter one diameter equal to the diameter of the boot IJ 30 attached to the main video disc device 9 and connecting the two with a belt 32, different rotation speeds can be achieved as required.

In order to obtain a more accurate number of rotations, the method shown in FIG. 6 may be used. That is, the speed detectors 32 and 33 detect the rotation speeds of both disk devices, and the control device 34 performs a ratio rotation so that the rotation speed ratio between the two becomes N, thereby controlling the rotation device 31.

In the above description, the rotational speed ratio of both disk devices has been described as N. However, there are some problems with this. In other words, because it is necessary to interleave scanning lines, the distance between pupils in one field is not an integral multiple of the horizontal scanning time;
There is a fraction of 0.5H. 1 in NTSC system
．． This becomes 525/2=262.5. Therefore, the H intervals of successive still image fields are not continuous, but have a discontinuity of 0.5H, which may appear as ski distortion on the reproduced image. In practical terms,
In many cases, this does not appear on the screen, but sometimes a large ski-distortion appears, that is, the music at the top of the image appears as a blank. In order to eliminate this problem, the number of horizontal scanning lines recorded on the auxiliary disk device 10 may be set to an integer around 262. In FIG. 6, a magnetic disk device 1o
The rotation speed of ((262-ta)/262, cs:I
What is necessary is just to adjust the control device 34 so that it becomes N. In Figure 3, it is a trench.
That's fine.

As explained in the above embodiment, when a video disk device that records N fields during one rotation is set to still image mode, different signals between the N fields cause the horizontal difference in the reproduced image. Shaking occurs, especially in fast-moving screens, but with the present invention, only the same field is played back in succession, so a completely still image with no horizontal image blur can be obtained. This produces the effect of 1.

Ru.

[Brief explanation of drawings]

Figure 1 is a diagram showing the spiral video track of a video disc that records four fields in one revolution, Figure 2 is a diagram showing the trajectory traced by Pinkup when obtaining a still image, and Figure 3 is a diagram showing the trajectory traced by the pink-up when obtaining a still image. FIG. 4 is a block diagram showing an embodiment of the present invention, FIG. 4 is a diagram showing one method of rotationally driving a disk device according to the present invention, and FIG. 6 is a diagram showing another method of rotationally driving a disk device according to the present invention. . 1...Video track, 9...Video disk device, 10...Magnetic disk device, 12
・・・・・・r! J1 transfer device A116...Playback device, 16...Switch A117...
Signal processing circuit, 19... Recording amplifier, 20...
...Switch B121...Magnetic head, 2
2... Magnetic disk, 23... Rotating device B
, 24... Regenerative amplifier, 26... Field start detection 1 [11 path, 26... Operation circuit A1
27...Operating circuit B, 28...Stell terminal, 29...Reset terminal, 34...
Control device.

Claims (3)

[Claims] (1) It has a spiral recording track, and 1
A first video disc device that plays back a disc on which N video fields are recorded in one circumference, and a first video disc device that records only one field from the playback signal of this first video disc device on one track of one circumference, and records it in a pf. a second video disc device for recording a desired field, and an operating device for selecting a desired field according to an external control signal and recording it on the second video disc device, and thereafter continuously reproducing the recorded signal. A video disc playback device consisting of: (2) The video disc playback device according to claim 1, wherein the second video disc device uses a magnetic disc. (3) The number of rotations of the second video disc device is approximately (262,6)N times that of the first video disc device, where a is an integer. .