JPS6284685A - Television signal synthesizer - Google Patents

Abstract

PURPOSE:To allow a current television set to receive a picture without hindrance by providing a means applying time base compression to some part of the image pickup signal of an original picture having an aspect ratio larger than 4:3, a means applying time base expansion to the remaining part and a control signal generation means and generating a video signal corresponding to the original picture. CONSTITUTION:Where a compression ratio is 1/4, a luminance signal Y and color difference signals I and Q, all of which are inputted to subsampling circuits 5, 7 and 9, are subsampled at 4:1. The signals subjected to the time base compression and expansion are modulated by a balance modulator circuit 17. Its output is added to the time base-compressed and time base-expanded signals through a switch 12 by means of an adder 18. An adder 21 adds the output of the adder 18 to an identification signal for identifying a synchronizing signal from a signal generator circuit 19, a bust signal, a television signal and a current broadcasting television signal, and said output turns out to be an NTSC composite video signal output 22.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a television signal synthesis device, and in particular, the current television system has an aspect ratio (horizontal to vertical ratio) of 4:
Generates a television signal that is suitable for transmitting scene information (transmission in a broad sense including recording, etc.) with an aspect ratio larger than 3, and is compatible with current television systems. The present invention relates to a television signal synthesis device that performs the following operations.

Conventional technology Japan's current National TSC (National TSC)
e1evisi-on System Comm1tt
Approximately 25 years have passed since color television broadcasting using the EE) system began in 1961. In the meantime, various new television systems have been proposed in response to demands for high-definition screens and improvements in the performance of television receivers.

Furthermore, the content of the programs provided is changing from simple studio programs and relay programs to programs with higher quality and more realistic images, such as cinema-sized movie broadcasts.

Against this background, the Japan Broadcasting Corporation (NIIK) proposed a high-definition television system. (For example, Literature Special Feature on High Definition Television (Television Society Journal No. 36S)
, No. 10, 1982))) The number of scanning lines is 1125, 2:1 interlaced scanning, and the luminance signal horizontal bandwidth is 2.
In addition to increasing the resolution to 0MHz, we also increased the aspect ratio (the ratio of the width to the height of the screen) to 5 from the perspective of visual engineering to create a sense of realism.
:3. This system has already been almost completed in closed systems, and with the start of satellite broadcasting, satellite
MUSE method for transmitting high-definition television in the channel band (Reference, Tasuku Ninomiya et al., Satellite 1-channel transmission method (MUSE) for high-definition television (IEICE technical research report)
We have proposed IE84-72.1984) and are conducting experiments.

On the other hand, current broadcasting uses 525 scanning lines, 2:1 interlaced scanning,
Luminance signal horizontal bandwidth 4.2MHz, aspect ratio 4:3
(For example, see Document Broadcasting Technology Multi-Book, Color Television Giran, Japan Broadcasting Corporation, Japan Broadcasting Publishing Association, 1961).And when providing a movie as the above program, its screen size. Either the ends of the screen are cut off to match the 4:3 aspect ratio of current television receivers, or invalid screens are placed at the top and bottom of the screen, and the aspect ratio of the active screen is sent out to match the movie value.

Problems to be Solved by the Invention As mentioned above, when transmitting and servicing movie programs and immersive screens in current broadcasting, some parts of the screen are cut or the screen area becomes smaller, so producers have to There was a problem in that the intention was not fully conveyed. Furthermore, if a signal with an aspect ratio larger than 4:3 is simply transmitted, it will not be able to be received by a normal receiver.

The present invention has been made in view of the above, and an object of the present invention is to provide a television signal synthesis device that is compatible with the current television broadcast system and that generates a television signal having a more horizontally elongated aspect ratio. do.

Means for Solving the Problems In order to solve the above problems, the television signal synthesis device of the present invention converts a part of the electrical signal obtained by capturing an original image having an aspect ratio larger than 4:3 into It is equipped with means for subsampling and compressing the time axis, means for expanding the remaining portion on the time axis, and means for generating a control signal for identifying that the data has been compressed.

Effect of the present invention With the above-described configuration, the present invention can be received without any problem even with current television receivers, and by conversely applying time axis compression and compression on the time axis compression and expansion of the electric signal on the receiving side, horizontal aspect It is possible to synthesize television signals such that a screen with a ratio of

EXAMPLE An example of the present invention will be described below with reference to the drawings. In FIG. 2, (al indicates an example of the display screen of a current television, and the mountain) indicates a composite video signal for one scanning line period near the center of the screen.

Since the aspect ratio is 4:3, part of the left and right circles among the three circles may be missing, as in the display example of fa+. Figure 3 [81 is an example of a display screen with a larger aspect ratio than the current one, for example 5:3; Figure 3) shows the video signal for one scanning line period near the center of the screen. , tel has the time axis scale shown in Figure 2 (b
This shows a composite video signal obtained by rewriting the video signal shown by the mountain so that it is equal to 1 and adding a synchronization signal and a color burst signal. Note that the aspect ratio is not limited to 5:3. If you increase the aspect ratio as shown in Figure 3 (al), you can obtain more video information than the screen shown in Figure 2 (tal). Even when receiving a video signal with a ratio of 5:3, it can be received without any problems compared to conventional methods.
That is, in order to maintain compatibility, time axis expansion is applied to the television signal during the period displayed on the screen of the current television receiver.

As can be seen by comparing Figure 2 (BL) and Figure 3 (C1), when the signal in Figure 3 (C1) is received by a current television receiver, even though the original image is a circle, figure,
Since it becomes a vertically elongated ellipse, it is necessary to expand the time axis of the signal in Figure 3 (C1).In other words, when the original image is captured with a horizontally elongated aspect ratio m:3 (m is a real number of 4 or more) than before. To achieve this, the image signal corresponding to the part displayed on the screen of a current television receiver can be expanded by a factor of m/4 in time.Furthermore, in order to obtain screen information with an aspect ratio of m:3, the remaining signal is Time axis compression is applied to the portion.The relationship between time axis compression and expansion when the compression ratio is k (k is a positive real number less than or equal to 1) is shown in Figure 4.The video signal period is h
μs, and the part to be time-axis compressed of the video signal hps obtained by capturing the original image with an aspect ratio of m:3 is
ps, and the time axis expanded portion is Xμs, then the time axis compressed signal is kyμS before and after, and the time axis expanded signal is mx74μs.

Here, the relationship between X and y is as shown in the following equation.

X-4h (1-k)/ (m-4k)y=h (m-
4) / (m-4k) /2 Also, the ratio 2 of the period of the time-axis compressed signal to the whole is: z-2ky/hX100 (%) Here, - for example, if the aspect ratio is 5:3, i.e. m= 5
．． When the compression ratio is 1/4, that is, -0.25, and the video signal period is 53 μs, that is, h=53, each parameter is as follows.

x = 39.8 (μ5) y = 6.6 (μS) 2 6.2 (%) If current television receivers overscan by an average of about 7%! The value =6.2 ensures compatibility in that the time-base compressed signal is not displayed on the screen of current television receivers, that is, it can be received without any problem.

FIG. 1 is a block diagram of a television signal synthesis device according to an embodiment of the present invention. In Fig. 1, 1 is R, G, B signals from a camera etc., 2 is a YIQ matrix circuit, 3 is an I filter, 4 is a Q filter, 5, 7.9 are sub-sampling circuits, and 6.8.10 are time axis compression circuit,
11.13゜15 is the time axis expansion circuit, 12.14.16
17 is a balanced modulation circuit, 18.2 is a switch (the switch is shown as a mechanical one to simplify the explanation);
1 is an adder, 19 is a signal generation circuit, 20 is a switching signal, 2
2 is an NTSC composite video signal output. R, G, and B signals 1 from a camera or the like enter a YrQ matrix circuit 2, where a luminance signal (Y) and a color difference signal (1, Q) are generated. I,Q
The signals are each passed through an I filter 3. After passing through the Q filter 4, the Y signal is passed through the time axis expansion circuit 11 as it is.
．． 13,15. The sub-sampling circuits 5, 7 and 9 are manually powered. The switches 12, 14, and 16 switch between time-base compression and expansion, and are operated by a switching signal 20 indicating the time-base compression period.

The switching signal 20 is generated by the signal generating circuit 19. for example,
When the compression ratio is set to 1/4, the subsampling circuit 5
, 7.9 are sub-sampled at a ratio of 4:1. Next, the time axis is compressed to 1:4 by the time axis compression circuits 6, 8, and 10. Note that a band-limiting filter may be used when subsampling. By subsampling here, high-frequency components are cut off, but by changing the subsampling position for each field, still images can be transmitted without deteriorating resolution. Further, time axis expansion can be performed by, for example, changing the write and read clocks to the memory. Switching signal 2
Time axis compression through switch 14.16 toggled by 0.

The expanded signal is modulated by a balanced modulation circuit 17 in a known manner. The output is added by an adder 18 to the time-base compressed and expanded signal that has passed through the switch 12. The output of the adder 18 is then outputted by an adder 21 to a synchronization signal from the signal generation circuit 19, a burst signal (not shown), and a signal for distinguishing the television signal from the currently broadcast television signal. The signal is added to the identification signal and becomes the NTSC composite video signal output 22. For example, the identification signal can be superimposed on the vertical retrace period.

Furthermore, for the time-axis expanded signal portion, the band is expanded by time-axis compression on the receiving side, so the resolution does not deteriorate even if the aspect ratio increases.

Effects of the Invention As is clear from the above description, the present invention includes a means for subsampling and time-base compressing a part of an electrical signal obtained by imaging an original image having an aspect ratio larger than 4:3; It is equipped with a means for expanding the remaining portion on the time axis and a means for generating a control signal to identify that it has been compressed, and by generating a video signal corresponding to the original image having the above aspect ratio, the aspect ratio can be improved from the current one. The purpose of the present invention is to provide a device for synthesizing television signals that is compatible with the ability to transmit large-scale scene information and to be able to receive it without any problems even with current televisions.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a television signal synthesis device according to an embodiment of the present invention, FIG. 2 Ta+ is a schematic diagram showing an example of a display screen of a current television, and FIG. A schematic diagram showing a composite video signal for one scanning line period, Figure 3 (al is a schematic diagram of an example of a display screen when the aspect ratio is set to, for example, 5:3, Figure 3) is the center of the above screen. A waveform diagram showing the video signal for one scanning line period in the vicinity, Figure 3 [el is the video signal shown in Figure 3 (bl) is rewritten so that the scale of the time axis is the same as that in Figure 2 (b). A waveform diagram showing a composite video signal with a synchronization signal and a color burst signal added, and FIG. 4 is a waveform diagram showing the relationship between time axis compression and expansion. 5.7.9... Subsampling circuit, 6, 8
゜10... Time axis compression circuit, 11, 13.15
・・・・・・Time axis expansion circuit. Name of agent: Patent attorney Toshio Nakao (1 person) Figure 2 4'3 Figure 3 5.3 Figure 4

Claims (1)

[Claims] Means for subsampling and time axis compression of a part of the electrical signal obtained by capturing an original image having an aspect ratio larger than 4:3, means for time axis expansion of the remaining part, and means for compressing the compressed part. 1. A television signal synthesis device, comprising: means for generating a control signal for identification, and generating a video signal corresponding to an original image having the above aspect ratio.