JPS6376679A - Video disk player - Google Patents

Abstract

PURPOSE:To enable a dubbing by a VTR by processing only information signal inserted into a reproduced composite video signal. CONSTITUTION:In a VHD system video disk player, the information signals are inserted into 17H/280H, 18H/281H and 20H/283H and a line detecting unit 2 counts a horizontal synchronizing signal C considering a vertical synchronizing signal B as a reference and detects a horizontal (H) line where the information signal F is inserted. A signal generating unit 3 generates a second information signal D only in section where information signal is inserted according to the output from the line detecting unit 2. When the second information signal D is impressed in a mixer 4, it acts to fix the information signal F included in the composite video signal A to a constant DC voltage and the composite video signal output E which is an output from the mixer 4 becomes a waveform whose information signal F is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention records an information signal by inserting it into a video signal, and during playback, controls a video disc player and its related equipment with the information signal, thereby achieving functions. This invention relates to a means for preventing dubbing in a video disc system.

Conventional technology Video disk players generally output composite video signals of standard television signals such as NTSC, PAL, or SECAM, so they can be easily converted into video tape recorders (hereinafter referred to as V
Dubbing can be done using TR. For this reason, copyright is a particular issue in the software industry. Therefore, attempts have been made to change the pulse width and signal level of the vertical synchronizing signal as a means of preventing VTR dubbing on the hardware side of the video disc player.

Problems to be Solved by the Invention However, none of these methods can be said to be a sufficiently effective method due to the restriction that the reproduction signal of the video disc player is viewed using a general-purpose television receiver.

The present invention attempts to process the inserted information signal so that even if a composite video signal can be dubbed using a VTR, the system will not be able to perform its original function even if the dubbed signal is used.

In particular, this means is particularly effective in preventing stereoscopic reproduction by dubbing a reproduced video signal of a stereoscopic VHD video disc (to be described later) with a VTR and using an external adapter.

Means for Solving the Problems To achieve this objective, the video disc player of the present invention includes a sync separation circuit and a horizontal line detector.

A signal synthesizer is provided, and the information signal is processed and outputted after processing the information signal inserted in the vertical blanking period of the reproduced composite video signal, so that the information signal cannot be deciphered from outside the player. .

Effect With this configuration, the composite video signal output from the player receives a normal video signal and a synchronization signal, but only the information signal during the vertical blanking period is processed, so it can be directly connected to a general-purpose television receiver. Moreover, it is possible to make it impossible for outsiders to accurately decipher the information signals required to perform the functions of the video disc system. Therefore, dubbing can be prevented.

EXAMPLE An example of the present invention will be described below with reference to the drawings. In particular, the present invention is effective for stereoscopic VHD video discs in which information inserted into a composite video signal is decoded to control both the playback track and electronic shutter of a video disc player, a block diagram of which is shown in FIG. ing.

FIG. 1 is a basic block diagram of the present invention, and FIG. 2 shows signal waveforms of each part.

The reproduced composite video signal A is a composite video signal that includes a video signal, a vertical synchronization signal B, a horizontal synchronization signal C9, and an information signal F inserted during the vertical blanking period. A sync separator 1 detects and generates a vertical sync signal B and a horizontal sync signal C from a composite video signal A.

In a VHD video disc player, the information signal is 17
H/280H, 1s H/281H, 20H/2
83H, the line detector 2 counts the horizontal synchronizing signal C based on the vertical synchronizing signal B and detects the horizontal (H) line in which the above-mentioned information signal F is inserted.

The signal generator 3 generates a second information signal only in the information signal insertion section according to the output of the line detector 2. This second information signal is a suitable DC voltage, and when applied to the mixer 4, it acts to fix the information signal F included in the composite video signal A to a certain constant DC voltage. The output composite video signal output E has a waveform from which the information signal F has been deleted, as shown in FIG.

FIG. 3 shows a stereoscopic VHD video disc player using this. The information signal inserted into the reproduced composite video signal A is read by the information decoder 6, and the control signal generator 6 controls the electronic shutter 8 and the pickup control circuit 9 through the electronic shutter drive circuit 7 based on this information.

As a result, the video signal that is reproduced and sent to the television receiver 10 is alternately switched between the left eye and the right eye for each field, and the electronic shutter 8 is alternately opened and closed corresponding to the left eye and right eye. Therefore, you can enjoy stereoscopic images. However, if the playback signal of a video disc player is
In the block configuration shown in FIG. 4 dubbed by R, the information signal included in the composite video signal output E has the waveform shown in the second diagram and E, so the information decoder 4
6, it is impossible to decipher the information. Therefore, the control signal generator 46. Electronic shutter drive circuit 47 It is no longer possible to perform shutter switching control for the left eye or right eye using the electronic shutter 48 in accordance with the television image.

This means that even though the television image is for the left eye, the electronic shutter 48 opens the right eye and closes the left eye, and the shutter opens and closes even when the image is not stereoscopic. It will no longer be able to perform its original function.

Therefore, this is a very effective means for preventing dubbing by a VTR.

In the above embodiment, dubbing by a VTR is prevented by fixing the signal level of the section in which the information signal is inserted to a specific DC level. However, if a second information signal is added to the above information signal, Alternatively, the video signal processing circuit may be equipped with a comb filter using a CCD, and a luminance signal component obtained as the sum of a certain signal and a signal delayed by one horizontal line may be added as a difference. In a configuration in which low-frequency components of color signal components are added, addition of the low-frequency components is prohibited during the information signal insertion period or vertical blanking period, or conversely, after subtracting the low-frequency components, the composite video signal is A similar effect can be obtained by outputting the information.

Effects of the Invention As described above, since the present invention processes only the information signal inserted into the reproduced composite video signal, the video disc player can be connected to a conventional general-purpose television receiver, and the output video can be processed. Since it is impossible to decipher the information necessary to perform the function from the signal, it is very effective in preventing dubbing by a VTR.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the main parts of a video disc player according to an embodiment of the present invention, Fig. 2 is a signal waveform diagram of each part of Fig. 1, and Fig. 3 is an embodiment of a stereoscopic VHD video disc player. FIG. 4 is a block diagram showing the circuit configuration when dubbing to a VTR. 1... Synchronous separator, 2... Line detector, 3... Signal generator, 4... Mixer.

Claims (4)

[Claims] (1) When reproducing a composite video signal accompanied by an information signal based on a pulse train, a synchronization separation circuit, a horizontal line detector, and a signal synthesizer are provided, and the information signal is deleted from the reproduced composite video signal or a part of the information signal or A video disc player characterized by outputting after replacing everything. (2) A horizontal line in which an information signal is inserted is detected from the reproduced composite video signal, and the signal level of the horizontal video section is fixed to a specific DC level. video disc player. (3) A video disc player according to claim 1, characterized in that the second information signal is added to the information signal inserted into the reproduced composite video signal and then outputted. (4) The video signal processing circuit is equipped with a comb-shaped filter using a CCD, and the low-frequency component of the color signal component obtained as the difference with respect to the luminance signal component obtained as the sum of a certain signal and a signal delayed by 1H is In the configuration for adding, addition of the low-frequency component is prohibited during the vertical blanking period or the information signal insertion period, or conversely, the composite video signal is output after subtracting the low-frequency component. A video disc player according to claim 1.