JPH0262917B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recording medium that can accurately display the playback elapsed time for each program.

The video disc player is configured to display the playback position on the TV screen by detecting frame numbers (total playback progress information) superimposed on the 17th and 18th H of the vertical blanking section of the video disc record during playback. It is possible to check the playback position. However, when a plurality of programs are recorded on the same record surface, the outer diameter of the record, the frame number, and the pick-up playback position do not provide any clues for detecting the playback elapsed time.

Therefore, the present invention provides a new disk record that records elapsed program playback time information for each program on a disk record that records continuous main information such as video signals, thereby making it possible to display the playback elapsed position for each program. We aim to provide the following.

The present invention will be explained below according to an illustrative embodiment. First, in this embodiment, the present invention is applied to a well-known video disc record that reproduces video signals using an optical video disc player. Such a video disc record forms an FM video signal as a spiral recording track, and the 17th H of the vertical retrace section of the video signal
As is well known, a total frame number of 24 bits (total playback progress information) including the identification code of the upper 4 bits is encoded as a bi-phase code and recorded in a superimposed manner on the 1st and 18th H. It is also equipped with a circuit that detects the frame number by extracting and decoding the biphase signal during playback.

Therefore, in this embodiment, no signal is superimposed on the 14th and 15th H in the vertical retrace interval of such a video disc record, and the video disc player detects the frame number encoded in the biphase code. In view of this, the program frame number (program time information) _S1 and the frame number for each program (playback elapsed time information) _S2 are encoded into a biphase code similar to the frame number described above. The data are superimposed and recorded on the 14th and 15th H, respectively.

FIG. 1 schematically shows the waveform diagram of the 14th and 15th H obtained after FM demodulation of the FM video signal reproduced from the video disc record of this embodiment. The converted 24-bit signals are respectively expressed in hexadecimal notation as "05650" and "00E10", and the contents are that the program frame number S ₁ is 18000, the program frame number S ₂ is 3600, i.e. 10
This shows that the program for 20 minutes has been played for exactly 2 minutes.

The circuit block diagram in Fig. 2 shows a circuit for calculating the remaining time after reading and storing such a biphasic code and displaying it on a part of the television screen. The reproduced video signal is input to a decoding circuit 2 that decodes the biphasic code and a sampling pulse generation circuit 3 that generates sampling pulses corresponding to each signal multiplexing area in the vertical retrace section, and each decoded output is as follows. The corresponding 14th H,
According to each of the 15th and 17th sampling pulses, the frames are stored in a frame number storage circuit 4, a frame number storage circuit 5, and a total frame number storage circuit 6, which are comprised of shift registers. Note that the OR output input to each of the storage circuits is a shift pulse, and the OR input derived from the decoding circuit 2 is a synchronization pulse synchronized with the decoding output. In this embodiment, each bit output of the frame number storage circuit 4 and the frame number recording circuit 5 is input to a subtraction circuit 7 to calculate the remaining frame number.
The multiplexer 8, which receives the subtraction output and the frame number as selection inputs, selects the input signal by the control input CN, and the selection output is converted from frame display to seconds display by the next-stage conversion circuit 9, and then sent to the character generator 10. The output of a character generator synchronized with the video signal is superimposed on the video signal. Therefore, the elapsed time and remaining time of the program are selectively displayed on the television screen on which the reproduced image is displayed.

In the above-mentioned embodiment, the number of frames of the program and the number of elapsed frames of the program are superimposed on the vertical retrace interval, but the present invention can also record second information instead of frames, and can also record the number of elapsed frames on the number of elapsed frames. Needless to say, the number of remaining frames may be recorded instead.

[Brief explanation of the drawing]

FIG. 1 shows a waveform diagram of a superimposed signal according to an embodiment of the present invention, and FIG. 2 shows a main circuit block diagram of the embodiment. Explanation of the main figure numbers, S ₁ ... frame number, S ₂ ... frame number.

Claims (1)

[Claims] 1. In a recording medium in which total playback elapsed time information is multiplexed at a predetermined period for main information consisting of a plurality of programs, the program playback elapsed time information set for each program is A recording medium characterized by periodic multiplex recording. 2. The recording medium according to claim 1, wherein the recording medium is a disk record forming a spiral recording track.