JPH05328245A - Two-pattern display television receiver - Google Patents

Abstract

PURPOSE:To display two video signals of the NTSC system whose aspect ratio is 4:3, while being arranged side by side horizontally with the same size onto a screen of a High Vision receiver whose aspect ratio is 16:9. CONSTITUTION:A horizontal component of a 1st video signal 5 and a 2nd video signal 6 converted into digital signals is reduced to 1/2 and a vertical component of the signals is reduced to 2/3 by reduction pattern processing sections 7, 8. The reduced data are respectively written in field memories 11, 12, and they are read so that the other video image is synchronously with one video image. The output of each field memory is selected by a changeover circuit 13 for each half of a scanning line. A memory controller 16 applies write and read control of the field memories 11, 12 and changeover control of the changeover circuit 13. An output of the changeover circuit 13 is converted into an analog signal by a D/A converter circuit 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an NTS having an aspect ratio of 4: 3 on a screen such as a high-definition display having an aspect ratio of 16: 9.
The present invention relates to a two-screen display television receiver in which two C-type video signals are displayed side by side in the same size.

[0002]

2. Description of the Related Art Conventionally, so-called picture-in-picture, in which video signals of the same system are displayed as a parent screen and a child screen, has been implemented in many television receivers.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a two-screen display television receiver in which two NTSC screens are displayed in the same size on the screen of an HDTV display having an aspect ratio of 16: 9. To aim.

[0004]

According to the present invention, there are provided a first video signal and a second video signal of an NTSC system having an aspect ratio of 4: 3, wherein the analog first video signal is converted into a digital signal. A first A / D conversion circuit for conversion, means for reducing the data from the first A / D conversion circuit to 1/2 for the horizontal component and 2/3 for the vertical component, and reduction The first field memory for storing the stored data, the second A / D conversion circuit for converting the analog second video signal into a digital signal, and the data from the second A / D conversion circuit Means for reducing the components to 1/2 and vertical components to 2/3, a second field memory for storing the reduced data, a signal from the first field memory and the second field memory. The signal from the field memory and the memory A switching circuit that switches based on the control of the tracker, a control for writing the reduced data to the first field memory and the second field memory, and either one of the first image and the second image. A memory controller that controls reading of the other image so that the other image is synchronized with the one image on the basis of synchronization, and a switching control of a switching circuit that matches the timing of the reading control, and a signal from the switching circuit that is a digital signal. A D / A conversion circuit for converting a signal to an analog signal is provided, and the first video signal and the second video signal are displayed in the same size in left and right halves on a screen having an aspect ratio of 16: 9. The present invention provides a dual screen display television receiver.

[0005]

The data of each of the first video signal and the second video signal converted into the digital signal is reduced to 1/2 for the horizontal component and 2/3 for the vertical component. The reduced data are respectively written in the corresponding field memories, and then read so that one image is synchronized with the other image. The output of each field memory is switched by the switching circuit for each half scanning line. The memory controller controls writing and reading of each field memory and switching control of the switching circuit. The output of the switching circuit is returned to an analog signal by the D / A conversion circuit.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A dual-screen display television receiver according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of essential parts showing an embodiment of a dual-screen display television receiver according to the present invention. In the figure, 1 is an analog first video signal, 2 is the same / second video signal, and 3 and 4 are a first A / D converter circuit and a second A / D converter for converting an analog signal into a digital signal.
The conversion circuits 5 and 6 are the first digital video signal and the second digital video signal, and 7 and 8 are the data of the first digital video signal 5 and the second digital video signal 6 for the horizontal component, respectively. A first reduced screen processing unit and a second reduced screen processing unit that reduce the image size to 2 and to reduce the vertical component to 2/3, 9 and 10 denote a first reduced image signal and a second reduced image signal, 11 And 12 are the first field memory and the second field memory for storing the first reduced video signal 9 and the second reduced video signal 10, respectively, and 13 is the first field memory 11 and the second field memory 12, respectively. A switching circuit for switching the signal read from the, 14 is the first video signal 1
Horizontal and vertical sync signals corresponding to the second video signal 2, 15 horizontal and vertical sync signals corresponding to the second video signal 2, and 16 the first
A memory controller for controlling writing and reading of data to and from the field memory 11 and the second field memory 12 and switching of the switching circuit 13, 17 is a D / A conversion circuit, 18 is a video output signal, and 19 is a switching signal. is there.

Next, the operation of the present invention will be described. The first video signal 1 and the second video signal 2 are non-interlaced signals that do not include a synchronization signal. Each of these video signals includes a first A / D conversion circuit 3 and a second A / D conversion circuit 3.
It is converted into a first digital video signal 5 and a second digital video signal 6 by the D conversion circuit 4, and is input to the first reduced screen processing section 7 and the second reduced screen processing section 8. In the first reduced screen processing unit 7 and the second reduced screen processing unit 8, each data of the first digital video signal 5 and the second digital video signal 6 is reduced to 1/2 in the horizontal component, and vertically reduced. The components are reduced to 2/3 because the image of the same size is finally made into two screens. Then, as a method of reduction, one in three scanning lines is used in the vertical direction.
Books are thinned out, and every other pixel data in the horizontal direction is thinned out. The thinning ratio differs between horizontal and vertical for the following reasons. That is, when a 4: 3 signal is displayed in a vertical / horizontal manner on a display having an aspect ratio of 16/9, a horizontally elongated image (horizontally elongated image) is obtained. When both vertical directions are matched, the horizontal direction is 16/12 times, that is, 4 / of the original signal.
It is stretched 3 times. This also applies to the reduced screen. For example, when both horizontal and vertical data are reduced to 1/2, the horizontal direction of each reduced image is stretched by 4/3 times to form a horizontally long image. .. Therefore, in order to reduce both the horizontal and vertical data to 1/2 respectively, it is necessary to perform a scan line conversion in the latter stage circuit to increase the number of scan lines to 4/3 times and to extend the vertical amplitude. .. By this scanning line conversion, the horizontal and vertical become a normal ratio, and for example, a circle becomes a true circle. From the above, vertical data decimation from the beginning is 2/3 [(1/2) × (4 /
3)] and the horizontal data is reduced to 1/2, it is possible to obtain a normal reduced screen without the above-mentioned scanning line conversion. This is the reason why the thinning ratio differs between horizontal and vertical.

The first reduced video signal 9 and the second reduced video signal 10 reduced in this way are written into the first field memory 11 and the second field memory 12 under the control of the memory controller 16. Here, one field is one frame of the screen. The signals written in the respective field memories are sequentially read by the memory controller 16, and at that time, the signals are read so as to synchronize one image with the other image (horizontal / vertical). For example, the second video is synchronized with the first video as a reference. The reverse is also possible. The signal thus read out enters the switching circuit 13. The switching timing of the switching circuit 13 is 1/2 scanning point of each scanning line. For example, the first video side is selected in the first half of scanning, the second video side is selected in the latter half, and this is repeated for each scanning line. The switching signal 19 output from the memory controller 16 determines the switching timing.
Is. Then, the switching signal 19 is generated with reference to the first synchronizing signal and the second synchronizing signal.

As described above, by reading one image in synchronization with the other image and further switching in the first half and second half of scanning, one image signal composed of two images synchronized with each other is established. One video signal thus established is returned from digital to analog, and the video output signal 19 for two screens is completed. FIG. 2 shows a conceptual diagram when such a video signal is displayed. The shaded area in the figure is the non-projected area (blanking).

[0010]

As described above, according to the present invention, by utilizing the feature of the high-definition horizontally long screen having the aspect ratio of 16: 9, the NTSC system image having the aspect ratio of 4: 3 has two screens and the same size. Since the display is full, it is possible to obtain a function having a characteristic different from that of the conventional parent-child screen composed of large and small screens. Another major feature is that scanning line conversion is not required.

[Brief description of drawings]

FIG. 1 is a main block diagram showing an embodiment of a dual-screen display television receiver according to the present invention.

FIG. 2 is a conceptual diagram when two screens are displayed.

[Explanation of symbols]

 1 1st video signal 2 2nd video signal 3 1st A / D conversion circuit 4 2nd A / D conversion circuit 7 1st reduction screen processing part 8 2nd reduction screen processing part 11 1st Field memory 12 Second field memory 13 Switching circuit 16 Memory controller 17 D / A conversion circuit

Claims (1)

[Claims] 1. An NTSC first video signal and a second video signal having an aspect ratio of 4: 3, wherein the analog first video signal
Of the first A / D conversion circuit for converting the video signal of No. 2 into a digital signal, and the data from the first A / D conversion circuit are reduced to 1/2 for the horizontal component and 2 for the vertical component.
Means for reducing to ⅓ and storing the reduced data first
Field memory, a second A / D conversion circuit for converting the analog second video signal into a digital signal, and the data from the second A / D conversion circuit are halved for horizontal components. Means for reducing and reducing the vertical component to 2/3, a second field memory for storing the reduced data, a signal from the first field memory and a signal from the second field memory. A switching circuit that switches under the control of a memory controller, a control for writing the reduced data in each of the first field memory and the second field memory, and either one of a first image and a second image. Based on the synchronization of the other video, a control for reading the other video so as to be synchronized with the one video, and a switching control of a switching circuit in timing with the read control. A re-controller and a D / A conversion circuit for converting a signal from the switching circuit from a digital signal to an analog signal are provided, and the first video signal and the second video signal are displayed on a screen having an aspect ratio of 16: 9. A dual-screen display television receiver characterized in that the video signal and the left and right halves are displayed in the same size.