JPS63245190A - Television signal broadcasting system - Google Patents

Abstract

PURPOSE:To view a normal picture even by an uncontractor during a period on which a scrambling is not applied and to promote a new contract by the uncontractor by applying no scrambling to a video signal only during a prescribed period and transmitting. CONSTITUTION:To an input terminal 1, the video signal, a digital data signal and an analog sound signal are supplied. The digital data signal includes a combination code signal for returning the scrambled video signal in a transmission side to an original video signal. When only the video signal is scrambled and the sound signal is not scrambled, the video signal and the digital data signal are supplied to a decoder circuit 3, herein, descrambled, and the analog sound signal is supplied directly to a display device 4 from a tuner circuit 2. Since the decoder circuit 3 can be used only by the contractor who paid a charge or the like, the uncontractor cannot connect the decoder circuit 3. During a time t1 and a time t2 on which the video signal is not scrambled, the uncontractor can obtain the normal video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Field of Industrial Application The present invention relates to a television signal broadcast system used when charging CATV, satellite broadcasting, etc.

(2) Conventional Technology Television signals have been transmitted through CATV, satellite broadcasting, and the like. Additionally, scrambling is used to prevent normal images and sound from being available to viewers other than those who have paid the fee.

Many scrambling methods have been proposed and used, including methods of changing the arrangement of scanning lines called "line rotation" and "line permutation." Among the scrambling methods that change the arrangement of scanning lines, ``line rotation'' is a method of changing the order of horizontal scanning lines, and ``line permutation'' is a method of dividing horizontal scanning lines into several parts. This is a way to change the order. The "line rotation" and "line permutation" may be used in combination.

(3) Problems to be Solved by the Invention When such scrambling is performed, normal images and sounds cannot be obtained by anyone other than the subscriber who has paid the fee. However, by allowing non-subscribers to view normal images even if there is only a small gap, it is possible to encourage non-subscribers to make a new contract.

Another advantage is that the time during which normal images can be viewed can be used for new purposes, such as showing commercials.

(4) Means for Solving the Problems The present invention has been made in view of the above points, and allows subscribers to obtain normal images and sounds, and also allows non-subscribers to receive normal images and sounds for a short period of time. In order to achieve this purpose, the video signal is transmitted without being scrambled for a predetermined period of time.

(5) Effect With this configuration, the subscriber can always obtain a properly descrambled video signal regardless of whether or not it is scrambled, and even non-subscribers can view a normal image during a predetermined period when scrambling is not applied. act.

(6) Examples Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a block diagram showing an embodiment of a television signal broadcasting system according to the present invention. FIG. 1 shows the configuration of a receiver for a pay television subscriber.

In FIG. 1, an input terminal 1 is supplied with video signals, digital data signals, and analog audio signals transmitted via cable lines, satellite broadcasting, and the like. Here, the digital data signal is a digital signal that includes a combination code signal for returning the scrambled video signal to the original video signal on the transmitting side, a digital audio signal, and other control signals.

The audio signal is supplied as an analog audio signal and a digital audio signal, and there are cases where both are combined to perform bilingual broadcasting, stereo broadcasting, etc., and there are cases where only one of the audio signals is used.

Furthermore, in addition to the video signal, the audio signal may also be scrambled and transmitted; however, for the sake of brevity, the following explanation assumes that only the video signal is scrambled and the audio signal is not scrambled.

The video signal and digital data signal are supplied to a decoder circuit 3, where they are descrambled.

Further, the analog audio signal is directly supplied from the tuner circuit 2 to the display device 4, and outputted from the display device 4 as audible sound.

FIG. 3 shows the configuration of a receiver for a person who has not subscribed to pay television reception. In the figure, the same reference numerals are given to the same components as in FIG. 1, and explanations thereof will be omitted.

Since the decoder circuit 3 can be used only by subscribers who have paid the fee, non-subscribers cannot connect the decoder circuit 3 as shown in FIG. However, when the video signal is not scrambled, the decoder circuit 3 is not required, so even non-subscribers can obtain a normal video signal with the configuration shown in FIG.

In this way, the device configuration on the receiving side is either the configuration shown in FIG. 1 or FIG. 3. On the other hand, from the sending side,
As shown in FIG. 2, time tl and time 1': j t 2
At the leaps, a video signal is transmitted as a normal screen without being scrambled, and at the leaps at time T1 and time T2, scrambled video signals are transmitted.

In the configuration of the receiver of the paid broadcasting subscriber shown in FIG. 1, the leaps at time TI and time T2 are a scrambled video signal and a combination code signal for returning the scrambled video signal to the original video signal. and are supplied. Further, between time ti and time t2, a non-scrambled video signal and a corresponding combination code signal are supplied. Therefore, time tl, time T1, time t2,
A normal image can be viewed on the display device 4 throughout the time T2, without synchronization disturbance or the like.

On the other hand, in the configuration of the receiver of the paid broadcasting subscriber shown in FIG. 3, normal images cannot be seen at the time TI and time T2 because the video signal is scrambled. However, since an unscrambled video signal is supplied between time t1 and time t2, a normal image can be viewed on the display device 4 in this case.

In this way, the subscriber receives a scrambled video signal, a combination code signal for returning the scrambled video signal to the original video signal, and an unscrambled video signal and a corresponding combination code signal. In addition, non-scrambled video signals are supplied to unscrambled video signals for only a short period of time, so that they can always see normal images. .

(7) Effects of the Invention As explained above, the present invention is configured so that the video signal is transmitted without being scrambled for only a predetermined period of time. A scrambled video signal can be obtained, and even non-subscribers can view normal images during the period in which the scramble is not applied.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a receiver in a paid broadcast subscriber as an embodiment of the television signal broadcasting system according to the present invention, and FIG. 2 is an embodiment of the television signal broadcasting system according to the present invention. FIG. 3 is a block diagram showing the configuration of a receiver for a subscriber who has not subscribed to pay television as an embodiment of the television signal broadcast system according to the present invention. 2...Tuner circuit 3...Decoder circuit 4...Display device patent applicant NEC Home Electronics Co., Ltd.

Claims (1)

[Claims] In a television signal broadcasting system that scrambles video signals by changing the arrangement of scanning lines,
A television signal broadcasting system characterized in that the video signal is transmitted without being scrambled for only a predetermined period of time.