JPS631506Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stop period setting circuit for a video disc player that allows setting of a stop playback period.

A video disc record records a control code and a recording code in the vertical retrace interval, and a video disc player that plays the video disc record detects this control code and changes the mode. Among these control codes, the picture stop code is superimposed and recorded on the 16th, 18th, or 279th and 280th H in the vertical retrace interval, and the picture stop code is used to control the video disk player playing in normal playback mode. Upon detection, the mode is changed to stop playback mode. However, in this stop reproduction mode, the track on which the picture stop code is recorded is continued to be reproduced while skipping over the recording track formed in a spiral shape, so that it is possible to move to the next reproduction mode.

Therefore, in view of the above points, the present invention has been developed by superimposing and recording a stop period designation code for specifying a stop playback period in advance within the vertical retrace interval of a video disc record, and by having the video disc player side read this stop period designation code. We would like to propose a novel stop period setting circuit that can detect and set the stop period.

Hereinafter, the present invention will be explained according to an illustrative embodiment. This embodiment utilizes a video disk record in which a stop period designation code is recorded in the 16th H instead of the conventional picture stop code, and this stop period designation code indicates the stop playback period in number of frames. code,
Frame number codes are recorded in the 17th and 18th H. The stop period setting circuit of this embodiment operates when reproducing a video disc record as described above, and its main circuit has a circuit configuration as shown in FIG. In this example,
The present invention is added to a basic circuit for converting a pickup output into a reproduced video signal V by a video reproduction circuit 1. First, as shown in FIG. 2, the sampling pulse generation circuit 2 which inputs the reproduced video signal outputs a first sampling output a which extracts the stop period designation code superimposed on the 16th H, and the 17th and 18th H. A second sampling output b for extracting the frame number superimposed on the second sampling output b is respectively derived. Both sampled outputs a and b are applied to the first AND circuit _A1 together with the reproduced video signal V via the OR circuit O, and the stop period designation code and the frame number are derived as an AND output. This AND output is the data latch circuit 3.
is latched each time. A second AND circuit _A2 , which receives the first sampled output a and the inverted output of the stop control output C, which will be described later, inputs the AND output as a preset output to the subtraction circuit 4, thereby maintaining the data latch during the normal playback period. The 16th H latch output latched in circuit 3 is preset in subtraction circuit 4. The data identification circuit 5, which receives the output of the subtraction circuit 4, detects the input of the stop period designation code and immediately issues a stop control output c, thereby setting the video disc player in the stop mode.
By generating this stop control output c, the second AND circuit _A2 prevents the generation of the preset output, and the third AND circuit _A3 allows the generation of the subtraction output.
Vertical synchronization separation circuit 6 that receives the reproduced video signal V as input
The vertical synchronizing signal generated is input to the next stage 1/2 frequency divider circuit 7, and is converted into a frequency divided output of the frame period. . This frequency-divided output is input to the subtraction circuit 4 as a subtraction output only in the stop mode via the third AND circuit _A3 . This subtraction count counts the stop mode setting period, and the subtraction value is “0”.
At the same time, the stop control output c is deenergized,
The video disc player is again switched to the normal playback mode, and thereafter the subtraction circuit 4 repeats the preset operation in preparation for the next stop playback. The frame number latched by the data latch circuit 3 is not input to the subtraction circuit 4, but is led to a frame number display circuit (not shown).

As described above, according to the present invention, by making it possible to arbitrarily set the stop period, not only can the playback period be lengthened, but also the playback mode including the stop playback mode can be automatically switched. , the effect is great.

[Brief explanation of the drawing]

FIG. 1 shows a circuit block diagram of an embodiment of the present invention, and FIG. 2 shows a waveform diagram of the main parts thereof. Explanation of main figure numbers, 3...Data latch circuit, 4
...Subtraction circuit, 5...Data identification circuit.

Claims (1)

[Scope of utility model registration request] A data latch circuit that latches a stop period designation code that displays the stop playback period in terms of the number of frames from the playback video signal in a video disk player that plays back a video signal while rotating a video disk record at a frame cycle, and the latch output. and a data identification circuit that detects when the subtracted value becomes "0" and cancels the stop playback mode. A stop period setting circuit consisting of: