JP3139822B2 - Video synthesis device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image synthesizing apparatus for synthesizing an image in a two-screen receiver or the like in which an A-channel broadcast screen is fitted into an A-channel broadcast screen.

[0002]

2. Description of the Related Art Recently, in a television receiver or the like, a screen of a B-channel broadcast (hereinafter referred to as a sub-screen) can be reduced and fitted into a screen of an A-channel broadcast (hereinafter referred to as a parent screen). Has been done. In this method, two field memories are provided, and a video signal of a small screen (hereinafter, referred to as a small screen signal) is alternately written to these memories one field at a time. The sub signal written in the other memory is read out in synchronization with a video signal of a main screen (hereinafter, referred to as a main screen signal). The sub-screen signals alternately read out one by one in this manner are inserted into blanking sections formed in a predetermined period of the main screen signal to obtain a composite screen video signal (hereinafter, referred to as a composite screen signal). I have. Hereinafter, a conventional video synthesizing apparatus will be described in detail with reference to FIGS.

In FIG. 4, a main screen signal is supplied to one end of a switch 17 and a timing generation circuit 14 via a terminal 11.
Supplied to The small picture signal is supplied to the A / D converter 13 and the timing generation circuit 14 via the terminal 12.
The small picture signal supplied to the A / D converter 13 is converted into a digital signal and supplied to the memory 15.

The timing generation circuit 14 outputs a memory control signal for controlling the memory 15 and a switching control signal for controlling the switch 17 in accordance with the supplied signals from the terminals 11 and 12, respectively. The memory 15 is controlled by a memory control signal from the timing generation circuit 14, compresses and stores the signal from the A / D converter 13, or outputs the stored signal to the D / A converter 16.
The signal supplied to the D / A converter 16 is converted into an analog signal and supplied to the other end of the switch 17. The switch 17 is controlled by a switching control signal from the timing generation circuit 14, and switches between the main screen signal and the compressed sub-screen signal from the D / A converter 16 to combine the sub-screen into the main screen. A screen signal is obtained and supplied to the terminal 18.

A method of compressing a small picture signal in the memory 15 will be described. For example, both the vertical and horizontal
In the case of compression to 3, the thinning is performed so that one signal is sequentially extracted for every three scanning lines in the vertical direction from the original signal, and the writing to the memory is 1.5 [MH] in the horizontal direction.
z], and reading is performed at 4.5 [MHz], so that the reading speed to the memory is changed to three times the writing speed. Control of these memories 15 is performed by control signals output from the timing generation circuit 14.

The manner in which a child screen is compressed by the video synthesizing apparatus and fitted into the parent screen will be described with reference to FIG. FIG.
FIG. 5A shows an original signal to be a child screen. This signal is compressed in the memory 15 to obtain a child screen signal, and the child screen signal and the main screen signal are appropriately switched by the switch 17 as shown in FIG. A composite screen shown in (c) is obtained.

On the other hand, EDTV broadcasting for improving the image quality of current television broadcasting is being studied. One of the image quality improvement items is to increase the aspect ratio. This is currently 4: 3
Is expanded to 16: 9. At this time, in order to maintain compatibility with the current receiver, 1
A screen having an aspect ratio of 6: 9 is compressed in the vertical direction, and broadcast is performed with no image portions at the top and bottom of the screen. Accordingly, the current receiver displays the image as shown in FIG. 6, and the EDTV receiver displays the original 16: 9 aspect ratio screen. Therefore, when an EDTV broadcast is supplied as a small-screen signal, a non-image portion appears near the center of the screen as shown in FIG.

[0008] Also, if a current 4: 3 screen is to be displayed on a 16: 9 screen, the image will be vertically compressed. In order to return the roundness of the compressed video to 1, compression is performed in the horizontal direction or expanded in the vertical direction. According to this method, the roundness can be easily returned to 1 without performing signal processing such as scanning line conversion. However, in this method, since the processing is performed on the monitor, there is a problem that, for example, the child screen also extends in the vertical direction at the same time, and the roundness of the child screen changes.

[0009]

As described above, in the conventional video synthesizing apparatus, when an EDTV broadcast having an upper and lower non-image portion is supplied as a sub-screen signal, the non-image portion appears near the center of the screen. However, there is a problem that the screen becomes very difficult to see. Further, when the amplitude of the vertical deflection of the monitor is changed and the monitor is extended in the vertical direction, there is a problem that the roundness of the child screen does not become one.

The present invention eliminates the above-mentioned disadvantages of the prior art, and can display a good small-screen image even when an EDTV broadcast having an upper and lower non-image portion is supplied as a small-screen signal. It is an object of the present invention to provide a video synthesizing apparatus capable of setting the roundness of a sub-screen to 1 even when the amplitude of the vertical deflection of the monitor is changed.

[0011]

In order to achieve the above-mentioned object, the present invention provides a method for determining whether a small-screen signal is a current broadcast or an EDTV broadcast having a non-image portion above and below by a discriminating means. A video synthesizing apparatus is provided which determines and inserts only an image signal portion excluding upper and lower non-image portions as a child screen into a main screen in the case of EDTV broadcasting. Further, when changing the amplitude of the vertical deflection of the monitor, a video synthesizing apparatus is provided which simultaneously changes the reduction ratio of the child screen.

[0012]

With this arrangement, when an EDTV broadcast having a non-image part at the top and bottom is supplied, an EDTV broadcast is provided.
Since the non-image portion of the TV broadcast is not displayed on the screen as a child screen, a good composite screen can be obtained. Further, when the amplitude of the vertical deflection of the monitor is changed, the reduction ratio of the child screen is also changed, so that the roundness of the child screen can be kept at one.

[0013]

FIG. 1 shows a first embodiment of the present invention.
This will be described in detail with reference to FIG. FIG. 1 is a block diagram showing a first embodiment of the video synthesizing apparatus according to the present invention. In FIG. 1, the same components as those in FIG. 4 used in the conventional technique are denoted by the same reference numerals, and description thereof is omitted.

The small picture signal is also supplied to a signal discriminating circuit 20 through a terminal 12, and it is discriminated whether the small picture signal is a current broadcast or an EDTV broadcast having a non-image portion above and below. The determination result is supplied to the control signal switching circuit 19. The control signal switching circuit 19 includes a switching control signal from the timing generation circuit 14 and the signal discrimination circuit 2.
The determination result from 0 is supplied. When the sub-screen signal is the current broadcast, the supplied switching control signal is output to the switch 17 as it is. When the sub-screen signal is an EDTV broadcast having an upper and lower non-image portion, the D / A The switch 17 outputs a switching signal for selecting the small-screen signal side to the switch 17 only in the image portion excluding the upper and lower non-image portions in the small-screen signal output from the converter 16. As described above, when the small screen signal is the current broadcast, the operation of the video synthesizing apparatus is the same as that of the related art.

FIG. 2 is a diagram showing a screen on which the synthesizing has been performed in the video synthesizing apparatus configured as described above. FIG.
FIG. 2A shows a screen when the current broadcast is input to the sub-screen, and FIG.
This is a screen when a DTV broadcast is input. As described above, even when an EDTV broadcast having a non-image portion above and below a sub-screen signal is input, unnecessary non-image portions are not displayed. A good image composition screen can be obtained.

Next, a second embodiment of the present invention will be described in detail with reference to FIG. FIG. 3 is a block diagram showing a second embodiment of the video synthesizing apparatus according to the present invention.
This is used for a V receiver. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

The parent screen signal is also supplied to a signal discriminating circuit 21, a 3 → 4 scanning line converting circuit 22, and a switch 23 via a terminal 11. The signal discrimination circuit 21 has the same configuration as that of the signal discrimination circuit 20, and determines whether the supplied main screen signal is an EDTV broadcast or a current broadcast.
And outputs it to the timing generation circuit 14.

The switch 23 selects the output of the 3 → 4 scan line conversion circuit 22 in the case of EDTV broadcasting, and selects the signal from the terminal 11 in the case of current broadcasting, according to the result of the determination from the signal determination circuit 21. 3 → 4 scanning line conversion circuit 22
Expands the supplied main screen signal of EDTV broadcast of 360 effective scanning lines vertically by 4/3 times,
The signal is converted into zero signals and output to one end of the switch 23.
When this output signal is an EDTV broadcast, it becomes the main screen.

The timing generating circuit 14 is a signal discriminating circuit 2
According to the discrimination result from No. 1, when the main screen is an EDTV broadcast, a memory control signal for setting the compression rate of the sub-screen to 3/4 times the conventional one in the vertical direction (or 4/3 times the conventional one in the horizontal direction) Is output to the memory 15. In the case of the current broadcast, the amplitude of the vertical deflection of the monitor is increased to 4/3 by a deflection circuit (not shown). Therefore, the vertical deflection amplitude of the monitor is set to 4
Even in the case of / 3 times, the roundness of the child screen can be kept at 1.

According to the present invention, even when an EDTV broadcast having a non-image portion above and below is input as a sub-screen signal, the non-image portion is not displayed on the screen. A good composite screen can be obtained .

[Brief description of the drawings]

FIG. 1 is a block diagram of a first embodiment of a video synthesizing apparatus according to the present invention.

FIG. 2 is a diagram illustrating a screen on which the image is synthesized by the video synthesizing apparatus.

FIG. 3 is a block diagram of a second embodiment of the video synthesizing apparatus according to the present invention.

FIG. 4 is a block diagram of a conventional video synthesizing apparatus.

FIG. 5 is a diagram showing a state in which a child screen is compressed by a video synthesizing apparatus and is fitted into a main screen.

FIG. 6 is a diagram showing a screen when an EDTV broadcast is received by a conventional television receiver.

FIG. 7 is a diagram showing a screen when a small screen of a current broadcast and an EDTV broadcast is displayed on a conventional television receiver.

[Explanation of symbols]

13 ... A / D converter, 14 ... Timing generation circuit, 15
... Memory, 16 ... D / A converter, 17 ... Switch, 19
... Control signal switching circuit, 20 ... Signal discrimination circuit

Claims (1)

(57) [Claims] 1. A 4: 3 non-wired broadcast of the current broadcast.
1st video signal with image aspect ratio
A first input terminal, and a 4: 3 non-wide antenna broadcast by EDTV broadcasting.
16: 9 wide aspect ratio image different from the aspect ratio
It has an image part, and upper and lower non-image parts are added above and below this image part.
The same as the 4: 3 non-wide aspect ratio
Signal with the same aspect ratio or
Sent with 4: 3 non-wide aspect ratio image area
A second input terminal to which a second video signal which is a signal is supplied
And the second video signal input from the second input terminal is
Whether the signal is broadcast by the EDTV broadcast or the current
Discriminating means for discriminating whether a signal is broadcast by line broadcasting
If, for determination by said determining means that said second video signal
The signal is determined to be a signal broadcast by the EDTV broadcast.
The upper and lower non-image portions from the second video signal
Outputting a signal of only the image portion except for the second video
Determines that the signal is a signal broadcast by the current broadcast
Image of the 4: 3 non-wide aspect ratio
Image section output means for outputting a signal of an image section, and an image section output means for outputting the signal of the first video signal supplied from the first input terminal.
At a predetermined position, the image input from the image unit output means
Combining means for fitting the signal of the image portion of the second video signal.
An image synthesizing device, comprising: