JPH025688A - Transmission method of video signal for wide screen - Google Patents

Abstract

PURPOSE:To provide compatibility with the NTSC system by dividing a video signal for wide screen into a center standard screen corresponding part and wide parts forming both sides of this part and multiplexing wide parts with the blanking level part of a horizontal blanking time to transmit them. CONSTITUTION:A video signal period R is divided into three, namely, a leading edge period R1, a center period R2 and a trailing edge period R3 in 2:12:2. The video signal in the center period R2 is put on a horizontal video signal period R' of the television signal of the NTSC system, and video signals in the leading edge period R1 and the trailing edge period R3 are multiplexed with the blanking level part of a horizontal blanking period H'. A picture formed with the video signal put on the video signal period R' is reproduced on a receiver of the NTSC system. In case of a receiver having a wide screen, the video signal put on the video signal period R' is compressed to 3/4 and video signals put on a back porch bp of the horizontal blanking period H' are expanded twice by sampling. Thus, a picture where right and left wide parts 3 and 1 are added to both sides of said standard picture corresponding part 2 is reproduced on the screen of 16:9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for transmitting a television video signal for a wide screen that is laterally enlarged than a standard television screen.

[Conventional technology]

Currently, the NTSC system is adopted for transmitting television signals in Japan, and in this NTSC system, video signals are transmitted corresponding to a television screen with an aspect ratio of 4:3.

However, recently there has been a movement to make TV screens wider in the horizontal direction, for example to 5:3, and with this,
In addition to the current television signal, consideration is being given to transmitting a television signal that includes a video signal compatible with a wider screen.

(Problems to be Solved by the Invention) However, as described above, if a wide-screen television signal that is completely different from the current television signal is used, the transmitting side or relay station may be unable to process this wide-screen television signal. There was a problem in that not only was it necessary to install new equipment, but also receivers who wanted to view broadcasts using this television signal had to purchase a dedicated receiver.
With the above-mentioned broadcasting means, it is not possible to watch broadcasts produced for wide screens on the NTSC system receivers that are currently in use in millions of households. If they do not wait, their commercial value as a broadcasting medium will not be realized, which in turn will cause a delay in the spread of the product, creating a vicious cycle.

The present invention has been made in view of the above-mentioned circumstances, and is an NTSC system that allows broadcasts to be viewed even on a conventional color television system, that is, an NTSC system receiver.
The object of the present invention is to provide a method for transmitting wide-screen video signals that is compatible with the SC system.

[Means to solve the problem]

In order to achieve the above object, the wide screen video signal transmission method according to the present invention divides the wide screen video signal into a center portion corresponding to a standard screen and wide portions forming both sides of the standard screen portion. The present invention is characterized in that the standard screen equivalent portion is placed on a horizontal video signal period, and the wide portion is multiplexed and transmitted on a blanking level portion of a horizontal blanking period.

[For production]

By doing the above, you can see a wide screen using a wide screen dedicated receiver, and
Even with an NTSC receiver, it is possible to view the central image placed in the horizontal video signal period.

〔Example〕

Hereinafter, an embodiment of the present invention will be explained with reference to the drawings.

Figure 2A shows a screen with an aspect ratio of 16=9.
Figure A shows a video signal of a horizontal blanking period and a subsequent horizontal video signal period corresponding to one scanning line segment of an image captured by a camera having a screen with an aspect ratio of 16:9 as shown in Figure 2A. It shows.

In this FIG. 1A, H is a horizontal blanking period, R is a video signal period, and in the following, this video signal period R
A method of transmitting a video signal carried on the NTSC system while maintaining compatibility with the NTSC system will be explained.

By the way, in the current standard NTSC system, as mentioned above, the screen aspect ratio is 4:3, or 12:9.
It is. Therefore, the video signal period R of the video signal shown in FIG. 2A is relatively 16/12 times as long as the video signal period of the NTSC television signal. Therefore, the video signal period R is set to 2:12:2.
The front end period R is divided into three parts: a middle period R8 and a rear end period R5.

To decompose the video signal period R in this way means to decompose the screen into a left wide part l, a standard screen equivalent part 2, and a right wide part 3, as shown in FIG. 2B. That is, the standard screen equivalent portion 2 is a screen portion with an aspect ratio of 12:9 corresponding to the central period R2, and this corresponds to an NTSC screen.

Further, the left and right wide portions 1.3 are screen portions with an aspect ratio of 2:9 corresponding to the leading edge period R1 and trailing edge period R5, and these are screen portions that do not exist in the NTSC system.

In the video signal of the video signal period R decomposed as described above, as shown in FIG. 1B, the video signal of the center period is placed on the horizontal video signal period R° of the NTSC television signal, The video signals of R1 and trailing period R3 are multiplexed onto the blanking level part of the horizontal blanking period H°.

At this time, the video signal of the central period R1 is stretched in the time axis direction so as to be included in the horizontal video signal period R°. That is, in the case of this embodiment, the video signal of the central period R8 is stretched by 473 (16/12) times in the time axis direction and placed on the horizontal video signal period R°. As described above, if the video signal is not placed in the horizontal video signal period R, blank portions of the video will be created on both sides of the screen when the video is played back on an NTSC receiver.

On the other hand, the video signals of the leading end period and the trailing end period R1 are
As shown in the figure, the signal is compressed to 1/2 in the time axis direction and then placed on the blanking level portion BL of the horizontal blanking period H°. That is, the horizontal erasing period of the NTSC television signal at -a is 4.7 μsec, as shown in FIG.
A horizontal synchronizing signal H5 having a width of
ρ and a back porch bp which is also at the blanking level and forms the rear part, and a color burst CB, which is a base vehicle signal of the color subcarrier, is inserted into this back porch BP. In period H, the fourth
As shown in the figure, the width of the horizontal synchronizing signal HS is set to 2°0μ.
sec and color burst CB
By moving forward, the back pouch bp
The width of the back porch BP is expanded to 4.6 μsec or more, and the video signals of the compressed leading end period R2 and trailing end period R3 described above are placed on this expanded back porch BP, that is, the blanking level portion. In this way, the horizontal synchronization signal H
The width of the horizontal synchronizing signal H8 was reduced to 4.7 μ? because the current technology level has significantly improved signal rise characteristics compared to the past. This is because even if the ulC is not secured, it is possible to sufficiently synchronize each scanning line, and according to experiments, by setting the width of the horizontal synchronizing signal H3 to 2.0 μsec as in this embodiment,
There was no effect on existing receivers.

However, in the above, as shown in FIG. 4, the video signal to be placed on the back porch bp is the rear end period R1 of the video signal period of the previous scanning line, and then the video signal period of the subsequent scanning line. The continuity of the video signal is maintained by adding a leading edge period R1. Furthermore, each of the divided periods n1. of the video signal period R. It is desirable to provide an overlap margin for transmission between L+Rs in order to prevent the occurrence of discontinuous portions during reproduction.

In the NTSC receiver, the video signal transmitted in the above manner reproduces only the image formed by the video signal placed in the video signal period R°, that is, the standard screen equivalent portion 2 shown in FIG. 2B. be done.

On the other hand, in a receiver with a wide screen, the video signal period R'
By compressing the video signal placed on the 16:9 screen to 374, and extracting the video signal placed on the back porch bρ during the horizontal blanking period H° and enlarging it twice, the portion corresponding to the standard screen is displayed on a 16:9 screen. Left and right wide part 1 on both sides of 2
．． The image with 3 added is played back.

FIG. 3 is a diagram showing a video signal processing system according to the above-mentioned transmission method, in which 11 is a camera, 12 is an encoder that converts the video signal of the camera into a transmitted television signal, 13 is a transmission system, and 1
4 is a decoder for converting the transmitted television signal into a wide-screen reproduction television signal; 15 is a wide-screen receiver; and 16 is an NTSC receiver into which the television signal is directly input.

By transmitting the video signal as described above, the NT
Even viewers who only have an SC system receiver can now enjoy the content of wide-duplex broadcasts.

It should be noted that the present invention is of course not limited to the above embodiments, and for example, the ratio of horizontal lines for wide screen can be set arbitrarily, and therefore, the ratio of horizontal lines can be set to the blanking level of the horizontal blanking period. If possible, the video signal may be loaded as is without being compressed, or it may be loaded with a higher compression ratio.

〔Effect of the invention〕

As is clear from the above description, according to the wide screen video signal transmission method according to the present invention, wide screen video signals can be transmitted with compatibility with standard television signal transmission methods. This makes it possible to view wide-screen broadcasts on an existing television receiver without having to own a dedicated wide-screen television receiver. Therefore, wide-screen broadcasting can be widely viewed, and this can be effective in increasing the popularity of wide-screen broadcasting.

[Brief explanation of the drawing]

Figure 1A is an explanatory diagram showing the video signal of the camera, Figure 1B is an explanatory diagram showing the transmission television signal, Figure 2A is a front view of the wide screen, Figure 2B is a split diagram of the wide screen, and Figure 3 is the transmission. FIG. 4 is an explanatory diagram showing the horizontal blanking period of the embodiment, and FIG. 5 is an explanatory diagram showing the general horizontal blanking period.

Claims (1)

[Claims] (1) A wide screen video signal is divided into a central standard screen equivalent part and wide parts forming both sides of this standard screen equivalent part, and the standard screen equivalent part is placed on the horizontal video signal period, and the A method of transmitting a video signal for a wide screen, characterized in that the wide part is multiplexed with the blanking level part of the horizontal blanking period and transmitted.