Video theater system and reproducing apparatus therefor

A video theater system has a reproducing apparatus by which picture reproduced from a distribution tape and picture received from a communication satellite are alternatively put on the screen. A scrambled signal transmitted from the communication satellite is converted to a scrambled signal of the same form signal as the scrambled signal reproduced from the distribution tape, thus enabling a common decoder to descramble both the two signals coming from different input routes from each other.

FIELD OF THE INVENTION AND RELATED ART STATEMENT 
1. Field of the Invention 
The present invention relates to a video theater system in which a 
distribution tape made by a tele-cine (photo-electric conversion) device 
for a movie film etc. is put on a screen. 
2. Description of the Related Art 
In Japan, there were approximately 7,500 movie theaters in the period from 
1955 to 1984, and the film industry in those days occupied the leading 
part in the picture amusement industry of Japan. However, since then, the 
leader has changed from the movies to television. Further, in recent years 
the business of renting a of video cassette tape of a movie has become 
popular. As a result, the number of the movie theaters in Japan decreased 
to 1,912, in 1989. 
On the other hand, in the United States, the movie business has grown 
through the improvement of movie theater equipments and the establishment 
of multiplex theaters. In those years, number of the movie theaters has 
increased from approximately twenty thousand to twenty-four thousand, and 
the income of the film industry increased as a whole. 
To stop the aforementioned decline of the film industry, Japanese cinema 
companies have made several countermeasures such as technical improvements 
of movie theater equipment, preparation of luxurious seats and 
establishment of miniature theaters. However, with all such efforts, there 
has been little effect yet. 
In the above-mentioned circumstances, there have appeared video theaters, 
which project image on the screen by utilizing a video cassette tape in 
place of a film, in various parts of the country. These video theaters are 
established in combination with a supermarket or a large store, etc., 
rather than as an independent movie theater. Each of these video theaters 
has approximately one hundred seats, and projection of the cinema is 
automatically operated. 
Hereafter, the video theater system is described. FIG. 4 is a block diagram 
showing a making and reproducing system for a video tape which is to be 
distributed to the video theater. In FIG. 4, pictures on a film are 
converted into electric signals by a tele-cine device 2 including a 
photo-electric converter 2a and a color corrector 2b. The tele-cine device 
2 applies photo-electric conversion to pictures on the film and makes 
color correction to improve color reproducibility. Electric signals issued 
from the tele-cine device 2 are recorded on a master tape 4 by a master 
VCR (Video Cassette Recorder) 3 such as a digital VCR. Next, the electric 
signals recorded on the master tape 4 are reproduced by another master VCR 
5, and many distribution tapes 7 are made by a dubbing VCR 6. For 
instance, an M2-format VCR such as a type AU-650 by Matsushita Electric 
Industries is used as the dubbing VCR 6. These distribution tapes 7 are 
distributed to the video theaters to be put on the screen. In the video 
theater, several M2-format reproducing VCRs 8 are used to reproduce 
signals recorded on the distribution tapes 7. An AV controller 9 selects 
video signals which are to be reproduced by the reproducing VCRs 8. Video 
signals selected by the AV controller 9 are input to an ED (Enhanced 
Definition) / WD (Wide Display) digital scanning converter 10 to thereby 
get a progressive scanning for double density; and resultant video signals 
are projected by a projector 11. 
However, there is a problem in the above-mentioned conventional system. 
That is, since management of the distribution tape 7 is entrusted to a 
manager of the video theater, it is easy to secretly make illegal dubbed 
copies from the distribution tape 7. This may result in interference with 
a rental video business. Protection against the illegal dubbing may be 
applied to some video tapes. But, many of these video tapes have only 
simple protection for the video-theater in horizontal synchronizing 
signals of video signals. Since the image signal itself exists in the tape 
as it is, it is easy to make a copy tape by taking off the protection. 
Further, with the spread of the video theaters, many distribution tapes 7 
are needed. Therefore, a distribution company has to manage many video 
tapes, and the screening cost in the theater at a remote place is high. 
OBJECT AND SUMMARY OF THE INVENTION 
An object of the present invention is to offer a system which can prevent 
rampancy of illegal dubbing of video theater tapes, etc., and to offer 
another screening system besides the distribution system necessitating the 
use of many video tapes. 
In order to achieve the above-mentioned object, a video theater system of 
the present invention comprises: 
reproducing means for reproducing a first scrambled signal recorded in a 
video tape; 
receiving means for receiving a second scrambled signal transmitted from a 
communication satellite; 
signal converting means for removing a copy-protection process from the 
second scrambled signal to thereby convert the second scrambled signal 
into a third scrambled signal which is the same form signal as the first 
scrambled signal; 
selection means for selecting one of the first scrambled signal and the 
third scrambled signal; 
descrambling means for descrambling a signal selected by the selection 
means into a picture signal; and 
display means for displaying a picture based on the picture signal. 
According to the above-mentioned video theater system, the scrambled signal 
transmitted from the communication satellite is converted to the scrambled 
signal of the same form signal as the scrambled signal reproduced from the 
video tape. Therefore, both the two signals of different input routes from 
each other are descrambled by the common descrambling means. This system 
is also advantageous in lowering the screening cost at the remote place 
that the screening can be realized by the signal transmitted from the 
communication satellite besides the ordinary screening system dependent on 
the distribution tape only. 
From another standpoint, the present invention offers a reproducing 
apparatus for the video theater, comprising: 
a reproducing video cassette recorder for reproducing a signal recorded in 
a video tape in a form scrambled by a process of line permutation: 
receiving means for receiving a signal transmitted from a communication 
satellite in a copy-protected form by at least two processes including the 
line permutation; 
a first decoder for removing a copy-protection process other than the line 
permutation from a signal received by the receiving means; 
multiplexing means which extracts a scramble key signal from an output 
signal of the first decoder and multiplexes a picture signal of the output 
signal by a signal made by adding a synchronization signal to the scramble 
key signal; 
selection means for selecting one of signals issued from the reproducing 
video cassette recorder and the multiplexing means; 
a second decoder for removing a scrambling process of the line permutation 
from a signal selected by the selection means; and 
display means for displaying a picture based on an output signal of the 
second decoder. 
According to the above-mentioned reproducing apparatus for the video 
theater, both the two signals of different input routes from each other 
are descrambled by the common decoder, and very excellent concealment 
against the illegal recording is realized in a communication satellite 
transmission system by an intermediate process that the code processing is 
changed thereat. 
While the novel features of the invention are set forth particularly in the 
appended claims, the invention, both as to organization and content, will 
be better understood and appreciated, along with other objects and 
features thereof, from the following detailed description taken in 
conjunction with the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Hereafter, preferred embodiments of the present invention are described 
with reference to the accompanying drawings. 
First Embodiment 
FIG. 1 is a block diagram showing a process of making distribution tape 7 
from a film 1 and a reproducing apparatus for a video theater by which a 
picture reproduced from the distribution tape 7 and a picture received 
from a communication satellite via radio waves are alternatively put on a 
screen. 
In FIG. 1, pictures on the film 1 are converted into electric signals by a 
tele-cine device 2 including a photo-electric converter 2a and a color 
corrector 2b. The tele-cine device 2 applies photo-electric conversion to 
pictures on the film 1 and makes color correction to improve color 
reproducibility. Electric signals issued from the tele-cine device 2 are 
recorded on a master tape 4 by a master VCR 3 such as a digital VCR. The 
electric signals recorded in the master tape 4 are reproduced by another 
master VCR 5. Next, signals reproduced by the master VCR 5 are scrambled 
by a scrambler 12. The scrambler 12 includes a circuit for multiplexing 
the signals by a scramble key signal K.sub.S (e.g., a 64 bit random number 
which also is used at the time of descrambling. In this embodiment, 
scrambling by line permutation is executed, and the multiplexing by the 
scramble key signal K.sub.S is executed during a vertical blanking period 
of video signals. Signals issued from the scrambler 12 are recorded in 
many distribution tapes 7 by a dubbing VCR 6. 
On the other hand, a communication satellite CS also is transmitting 
scrambled signals. More specifically, scrambling by line permutation is 
executed, and copy-protection processes by 
synchronization-suppression-and-synchronization-level-shift and video 
inversion are executed. 
Radio waves transmitted from the communication satellite CS are received by 
an antenna 13 and thereafter selected by a tuner 14. Signals selected by 
the tuner 14 are input to a first decoder 15, and thereat the 
copy-protection (processes) by the 
synchronization-suppression-and-synchronization-level-shift and the video 
inversion are decoded (removed). Decoded signals are input to a 
multiplexing device 18. At the same time, an extractor 16 reads the coded 
scramble key signal K.sub.S out of output signals of the first decoder 15. 
A synchronizing signal adder 17 adds a synchronizing signal of the video 
signal to the scramble key signal K.sub.S, and the resultant signals are 
input to the multiplexing device 18. In the multiplexing device 18, the 
scramble key signal K.sub.S with the synchronizing signal added is used to 
multiplex the video signal scrambled by the line permutation within a 
vertical blanking period, and the resultant signals are input to an AV 
controller 9. Output signals issued from a reproducing VCR 8, which 
reproduces scrambled signals recorded on the distribution tape 7, are also 
input to the AV controller 9. The AV controller 9 selects and issues one 
of the scrambled signals coming from the communication satellite CS and 
the reproducing VCR 8. Output signals issued from the AV controller 9 are 
descrambled by a second decoder 19 to be restored into normal video 
signals. These video signals are input to an ED/WD digital scanning 
converter 10 and put on the screen by a projector 11. 
As has been stated above, the signals transmitted from the communication 
satellite CS are converted to the scrambled signals of the same form as 
the signals recorded on the distribution tape 7. Therefore, both the two 
signals of different input routes from each other are descrambled by a 
common (second) decoder 19; and software supplied in the form of a radio 
wave transmission and software supplied by the distribution of video 
cassettes are selectably put on the screen. Further, concealments against 
the illegal dubbing and recording are applied to the distribution tape 7 
and the signals transmitted from the communication satellite CS, 
respectively. Also, the screening cost at the remote place is lowered 
because the screening can be realized by the signals transmitted from the 
communication satellite CS besides the ordinary system dependent on the 
distribution tape 7 only. 
Apart from the above-mentioned first embodiment in which the second decoder 
19 is disposed outside of the projector 11, another embodiment may be such 
that the second decoder 19 is incorporated in the projector 11 or a 
display (not shown) equivalent to the projector 11. 
Although it is probably most preferable in terms of the concealment to 
execute the descrambling within the casing of the projector 11 (as shown 
by a projector 21 in FIG. 2), there is no particular problem if the 
descrambling is executed in the ED/WD digital scanning converter 10 at a 
stage prior thereto. 
Second Embodiment 
FIG. 2 is a block diagram showing the second embodiment of the present 
invention. Corresponding parts are labeled with numerals or marks which 
are the same as the first embodiment, and descriptions thereon made in the 
first embodiment are similarly applied. In this second embodiment, an 
encoder 20 is provided, and the projector 21 includes the ED/WD digital 
scanning converter 10 and the second decoder 19. A process of making the 
distribution tape 7 and a system for distribution to the video theater are 
substantially the same as the first embodiment. 
Hereinafter, a scrambling method by line permutation, which is the same as 
the first embodiment, is described. Scrambling by the scrambler 12 is 
executed by a process of line permutation. Since synchronizing signal of 
video signals is maintained as it is, recording in the dubbing VCR 6 is 
carried out by means of an ordinary recording method. FIG. 3 is an 
illustration showing a method of line permutation. In FIG. 3, a usual 
picture area of each field has 240 scanning lines. These scanning lines 
are divided into blocks of 30-line and 60-line. The appearance of these 
two types of the block is made random, and further randomization is 
realized by exchanging the scanning lines in each of the blocks at random. 
Thus, line permutation makes it difficult to find a boundary of adjacent 
blocks. At that time, the scramble key signal is stored within the 
vertical blanking period, and descrambling is carried out with the help of 
this scramble key signal to restore the signals. Although a 
copy-protection method for audio is not shown in this figure, a scramble 
method, in which a PN code (pseudorandom code) is added to PCM voice, is 
used to protect the audio portion of the signal. 
In FIG. 2, the scramble key signal K.sub.S, which is extracted by an 
extractor 16 from the first decoder 15, consists of a block code. This 
coded scramble key signal K.sub.S is converted by the encoder 20 to 
another block code having another code table. The synchronizing signal 
adder 17 adds a synchronizing signal of the video signal to the block 
code, and the resultant output is input to the multiplexing device 18. 
Signals recorded on the distribution tape 7, which are in a similar 
scrambled state to signals issued from the multiplexing device 18, are 
reproduced by the reproducing VCR 8. The signals issued from the 
multiplexing device 18 and the signals issued from the reproducing VCR 8 
are input to the AV controller 9 and subjected to selection. Selected 
signals are input to the projector 21, which includes the ED/WD scanning 
converter 10 and the second decoder 19, or the display (not shown) to be 
put on the screen. 
As has been stated above, in the second embodiment, both the two signals of 
different input routes from each other are descrambled by the common 
(second) decoder 19, and the concealment against illegal recording is 
improved in the communication satellite transmission system by the 
intermediate process that the code processing is changed thereat. 
Although the present invention has been described in terms of the presently 
preferred embodiments, it is to be understood that such disclosure is not 
to be interpreted as limiting. Various alterations and modifications will 
no doubt become apparent to those skilled in the art after having read the 
above disclosure. Accordingly, it is intended that the appended claims be 
interpreted as covering all alterations and modifications as fall within 
the true spirit and scope of the invention.