JPH0779465B2 - Video scramble transmission system and its transmitter / receiver - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a video scramble transmission system for television broadcasting and a transmitter / receiver thereof.

(Summary of the Invention) The present invention relates to a video scramble transmission system for television broadcasting and a transmitter / receiver thereof, and transmits scrambled video using scanning lines corresponding to the number of effective scanning lines, and a vertical blanking period or By using a scanning line equivalent to a part of the number of lines, another image is transmitted to the part that can be displayed by a general receiving device without being scrambled. For example, the present invention relates to a video scramble transmission system capable of transmitting information to some extent and a transmission / reception device thereof.

(Prior Art) As a prior art relating to video scrambling, for example, Japanese Patent Application Laid-Open No. 60-74888 “Image scramble descrambling method”, Japanese Patent Application Laid-Open No. 61-242187 “Image scrambling method”, Japanese Patent Application No. 61-9858 "Signal scrambling
Descrambling circuit ".

In the above-mentioned Japanese Patent Laid-Open No. 60-74888, a scrambled image is produced by replacing the period before and after the midpoint of the image period for each horizontal scanning period in the original image signal and changing the position of the midpoint for each horizontal scanning period. It is described that a signal is constituted, and in the above-mentioned JP-A-61-242187,
The method of scrambling is the same as in the case of the above-mentioned Japanese Patent Laid-Open No. 60-74888, except that the horizontal scanning cycle for scrambling is every other line, every two lines, or vice versa. There is described a system provided with a means for changing the scanning cycle every other line or every two lines. Further, the above-mentioned Japanese Patent Application No. 61-9858 discloses a line in which the order of scanning lines of an image can be arbitrarily changed. The permutation method (line replacement method) is described. In contrast to this line permutation method, the former two are also called line rotation methods.

Details of these prior art are given in the respective references.

(Problems to be Solved by the Invention) In the video scramble transmission system of the prior art, the purpose is to achieve confidentiality, and therefore, when viewed with a general receiving device, the content is almost or completely unknown. there were.

Therefore, if you receive a scrambled broadcast with a receiver that cannot descramble, you may mistakenly think that the receiver is out of order,
Inconvenience or inconvenience may occur, such as completely uncertain what the program being received is. In particular, since it is desired that many people watch the program in broadcasting, it is significant that the above inconvenience or inconvenience is solved.

Therefore, an object of the present invention is to display that a program currently being broadcast is being scrambled by using a relatively simple configuration, even if the receiving device does not have a descrambling function, and a program name currently being broadcast is displayed. The purpose is to provide a video scramble transmission method that can obtain a certain amount of information such as an overview of the program, its contents, methods and rates for viewing this program, and breaking news.

A further object of the present invention is to provide a transmitter used in the above-mentioned video scramble transmission system and a receiver capable of descrambling a transmitted television signal.

(Means for Solving the Problems) In order to achieve this object, the video scramble transmission method described in the present specification uses a scrambled main video signal from a position where the main video signal originally existed and a secondary video signal not scrambled. Is transferred to a region other than the region for inserting and transmitting and having a number of scanning lines corresponding to the effective scanning lines, and the data is transmitted. It is characterized in that only the main video signal can be displayed in the area of the effective scanning line.

Further, the transmission device described in the present specification includes a scramble circuit that scrambles a main video signal, a scan line transfer circuit that transfers a scan line that forms the scrambled main video signal to a region outside the effective scan line, and An inserter for inserting a scanning line that constitutes a non-scrambled subsidiary video signal into an area of an effective scanning line vacated by the transition.

Furthermore, the receiving apparatus described in this specification retransmits the main video signal transferred and transmitted outside the area of the effective scanning line on the transmission side to the position where the main video signal originally existed on the transmission side. It is characterized by including a scanning line transfer circuit for transferring and a descramble circuit for descrambling the main scrambled video signal.

(Example) The present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a basic configuration diagram including the receiving side of the system of the present invention.

The signal from the main video signal source 1 is scrambled by the scramble circuit 2. Next, in order to transmit the secondary image in the effective scanning area, the operation of making a gap in the effective scanning area in the scanning line transition circuit 3 and bringing the number of scanning lines corresponding to the gap to the vertical blanking portion. To do. After that, the signal from the signal source 4 of the secondary image is inserted into the gap by the inserter 5 to obtain the transmission signal in the method of the present invention. The signal thus obtained is transmitted to the receiving device via a transmission line 6 such as a cable, a terrestrial broadcast or a satellite broadcast. When received by the general receiving apparatus 10, the main image is scrambled and cannot be seen by the receiver 7-1, but the subsidiary image can see it. On the other hand, when the signal is received by the scrambled broadcast receiver 11, the scanning line transition circuit 13 and the descramble circuit 12 perform operations opposite to those of the scanning line transition circuit 3 and the scramble circuit 2, respectively, to restore the main video, and the receiver thereof. In 7-2, you can see the main image in its original state.

In the above description, the scramble circuit 2 and the descramble circuit 12 can be used as the scramble system described in the two conventional line rotation systems described in the above-mentioned Japanese Patent Laid-Open Publication No. Time axis operation method such as permutation method,
Many scrambling methods such as amplitude axis operation method such as polarity inversion can be applied as they are. When the line permutation method is used, the scanning line transition circuits 3 and 13
The scrambling circuit 2 and the descramble circuit 12 may be incorporated into the scrambling circuit 2.

Next, as a specific embodiment of the present invention, a case where a scanning line replacement method in which 60 lines are one block is used as a scramble method will be described. FIG. 2 shows the transmission signal format. First
Lines 10 to 189 (Lines 273 to 452, the number in the parentheses below indicates the number of lines in a pair of fields) Area A and Lines 203 to 2
62 lines (466th to 525th lines) 240 lines in area B are used to scramble the main image and transmit it.
It is assumed that the sub video is transmitted using 13 lines of the area C of the 0 to 202 lines (453 to 465th lines). In this example, the format of the sync signal in the area D is the same as that of the NTSC system.

The procedure for transmitting in this signal format will be described below with reference to FIG. First, the signal from the main video signal source 1
240 lines of 23 to 262 lines (286th to 525th lines) are transmitted as an effective scanning area. This is a convenient number for just 4 blocks, where 60 lines are used as scanning line replacement blocks. Next, in the scramble circuit 2, the 23rd to 82nd lines (286th to 345th lines) and the 83rd to 14th lines
2nd line (346th-405th line), 14th-202nd line (4th line)
06-465 line and 203-262 line (466-525 line)
Each line) is set as one block, and scrambling processing is performed by interchanging scanning lines within each block. Next, in the scan line transfer circuit 3, the 23rd to 202nd lines (286th to 465th lines) are advanced by 13 lines to be moved to the 10th to 189th (273rd to 452nd lines) to be the second illustrated area A, and the 190th to 190th lines. Create a clearance area C for 13 lines of 202 lines (453rd to 465th lines). Thus, in the inserter 4, the 190th signal of the signal from the signal source 5 of the subsidiary video is displayed in the clearance area C for the above 13 lines.
~ 202 lines (453rd to 465th lines) are inserted and transmitted.

Upon receiving this signal, the scrambled broadcast receiving apparatus 11 first receives the 10th to 189th lines (273rd to 273rd lines) in the scanning line transition circuit 13.
Delay 452 lines by 13 lines to add 23rd to 202nd lines (28th line)
6 to 465 lines), and at the same time, the 10th to 22nd lines (line
273 to 285 lines) are blanked. Then, the descramble circuit 12 performs a descrambling process to restore the main video and display it on the receiver 7-2.

In addition, the receiver 7 of the general receiving device 10 that has received this signal
The screen No. 1 shows a sub video of about 13 lines at about 1/4 from the bottom of the screen, and in the example shown in the first illustration, the main video signal of this broadcast is scrambled. You can watch "Scrambled Broadcast".

Here, the scramble circuit 2 and the descramble circuit 12
The detailed description of the operation of the scanning line transfer circuit 3 will be omitted because it has been described in detail in the above-mentioned JP-A-60-74888, JP-A-61-242187, and Japanese Patent Application No. 61-9858. And 13
Will be described using the configuration shown in FIG.

In the scanning line transition circuit 3 on the transmission side, the 10th to 189th lines (second line)
The switch 18 is connected to the contact E between 180 lines (73 to 452 lines), and the switch 18 is connected to the blacking level 16 via the contact G between the 190th to 202th lines (453th to 465th lines), The remaining 60 lines and periodic signals including horizontal synchronization and burst signals are delayed by 13 lines via the 13-line delay circuit 15, and at this time, the switch 18 is connected to the contact F, and the contact switching timing of this switch 18 is the gate signal. This is done by the generation circuit 17. The above line numbers are shown as line numbers on the output side delayed by 13 lines from the input side.

On the other hand, in the scanning line transfer circuit 13 on the receiving side, the switch 18 is connected to the contact G and the 23rd line in the 10th to 22nd lines (273nd to 285th lines).
The switch 18 is connected to the contact F with a delay of 13 lines in the -202 line (286th to 465th lines), and the switch 18 is connected to the contact E in the remaining 60 lines and the synchronization signal.

Next, as another embodiment of the present invention, an example will be shown in which the number of lines of the subsidiary image is increased without reducing the number of effective lines of the main image. FIG. 5 shows the transmission signal format. The equivalent pulse in the area D of the vertical blanking period is eliminated, and the number of transmission lines of the subsidiary video is increased accordingly. 7th to 186th lines (270th to 449th lines) and 206th to 265th lines
240 lines of lines (469th to 3rd lines) are used to scramble and transmit the main video, and 19 lines of 187th to 205th lines (450th to 468th lines) are used without scrambling. The video of is transmitted.

In this example, the problem caused by eliminating the equivalent pulse in the area D does not occur. First, the scrambled broadcast receiver
In 11, the equivalent pulse may be re-added in the scanning line transition circuit 13 or the descramble circuit 12, or the horizontal and vertical drive signals used in the above circuit may be added to the receiver 7-2. Further, although there is a possibility that scanning line pairing may occur to some extent in the image receiver 7-1 of the general receiving apparatus 10, this is not a problem because the secondary image does not aim for high image quality.

In the above two embodiments, in the NTSC standard television system, the number of effective scanning lines of the main video is 240, the scramble system is the line rotation system or the line permutation system, and the position for inserting the secondary video is set. The position is about 1/4 from the bottom of the main image, but it is applied to other television systems, the number of effective scanning lines of the main image is increased / decreased, another scramble system is applied, and the position of the secondary image is inserted. Even if changes are made, the same idea can be applied.

Although it is beyond the scope of the present invention, the following application can be considered by utilizing the technical idea of transmitting the subsidiary video signal by the number of scanning lines corresponding to the vertical blanking period or a part thereof.

For example, when trying to superimpose a character on the main video, if the video of the superposed portion is transmitted as the secondary video signal, it is easy to restore the video that is not superposed on the receiving side.

The configuration of this application example is shown in FIG. The signal from the main video signal source 1 is transferred to the vertical blanking period in advance by the scanning line transfer circuit 3 during the superimposing portion (the video signal is left in the originally existing portion as well). Then, the super circuit 9 superimposes the subsidiary video signal from the super video signal source 8 on the main video. When this signal is viewed on the receiver 7-1 of the general receiver 10, a normal superposed image is viewed. On the other hand, the receiver 7 of the dedicated receiving device 21 in which the sub-video is replaced by the part not superposed by the scanning line transfer circuit 13-
If you look at 3, you can see images that are not supermarketed.

This makes it possible to watch the original program that is not affected by the emergency supermarket even if there is an unavoidable emergency supermarket, and to watch western movies with Japanese subtitles without subtitles. Have an effect.

(Effects of the Invention) As described above, scrambled broadcasting is performed using the method of the present invention, so that even a receiver of a receiving device that is not descrambled, such as a general receiving device, can be displayed in a part of the screen. For example, it becomes possible to display a video having a meaning such as “during scramble broadcasting”.

As a result, it is possible to provide various information such as the program name, overview, viewing method, fee, breaking news or mini information during scramble broadcasting to general receiving devices that do not have a descramble function, and at the same time scramble This has the effect of not affecting the confidentiality of the main video during broadcasting and the restored image quality at all.

[Brief description of drawings]

FIG. 1 shows a basic block diagram relating to the present invention, FIG. 2 shows a signal format in the embodiment of the present invention, FIG. 3 shows a diagram for explaining the operation of a scanning line in the embodiment, FIG. 4 shows a circuit diagram of a scanning line transition circuit in the same embodiment, FIG. 5 shows a signal format in another embodiment of the present invention, and FIG. 6 shows a configuration diagram of an application example of the present invention. 1 ... Main video signal source, 2 ... Scramble circuit 3, 13 ... Scan line transition circuit 4 ... Sub-video signal source 5 ... Inserter 6 ... Transmission line 7 ... Receiver 8 ... Super Video signal source 9 …… Super circuit 10 …… General receiver 11 …… Scramble receiver 12 …… Scramble circuit 15 …… 13 Line delay circuit 16 …… Blanking level 17 …… Gate signal generator 18 ...... Switch 21 …… Special receiver

Claims (4)

[Claims] 1. A number of lines corresponding to an effective scanning line in a region excluding a region where a main video signal that is scrambled originally existed is inserted and a secondary video signal that is not scrambled is inserted and is transmitted. An image characterized in that it is transferred to an area having a scanning line and transmitted, and the receiving side performs an operation opposite to that of the transmitting side so that only the main image signal can be displayed in the area of the effective scanning line. Scramble transmission method. 2. The video scramble transmission system according to claim 1, wherein the number of scan lines of the non-scrambled subsidiary video signal is the number of scan lines corresponding to a vertical blanking period or a part thereof. A video scramble transmission method characterized in that 3. A scramble circuit for scrambling a main video signal, a scan line transfer circuit for transferring a scan line constituting the scrambled main video signal to a region outside the effective scan line, and an effective scan vacated by the transfer. A transmitter, comprising: an inserter for inserting a scanning line constituting a non-scrambled subsidiary video signal in a line area. 4. A scanning line transition circuit for re-transitioning a main video signal, which has been transferred and transmitted outside the area of the effective scanning line on the transmission side, to the position where the main video signal originally existed on the transmission side. And a descramble circuit for descrambled the main scrambled video signal.