JPH0759004A - Multi-screen display device - Google Patents

Abstract

PURPOSE:To provide a main sub screen display function able to set optionally a screen size without losing the content of an original picture in the multi-screen display device. CONSTITUTION:When an original picture is multiplied by 1/m and 1/n to make video images A, B into main and sub patterns, the video images A, B are sampled by sampling frequencies which is a multiple of (m) and of (n) of a reference sampling frequency fs respectively and the sampled signals are stored in digital memories 5, 6. When they are read from each respective memory, the signals are read based on the reference sampling frequency fs while positioning the main and sub patterns on the display screen, the signals are D/A-converted by D/A converters 9, 10, and the results are composited into one pattern at a composite section 12. Thus, it is possible to zoom down plural sets of video information without losing the information in an original picture and the size of the main and sub patterns is designated preferably and the patterns are displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-screen display device for simultaneously displaying a plurality of information on the screen.

[0002]

2. Description of the Related Art Conventionally, as a multi-screen image display method for simultaneously displaying a plurality of pieces of information on a television receiver, for example, a sub-screen is displayed within a main screen as shown in FIG. 7 (a). Picture-in-picture (PIP) system, picture-out-picture (POP) system shown in Fig. 7 (b) to display sub-screen outside main screen, and Fig. 7 (c) to display sub-screen divided into whole screen. The multi-split display method shown is adopted, and as shown in FIG. 8, there is also a method of fixing the main screen and the sub-screen to two left and right split screens.

However, these conventional techniques have the following problems.

That is, in the PIP method of FIG. 7A, a part of the main screen is hidden by the sub screen, information is lost, and the sub screen size is fixed to a small size. Is hard to see. In the POP method of FIG. 7 (b), the sub-screen size is fixed and hard to see. In the multi-division display of FIG. 7 (c), each sub-screen size is fixed and difficult to see.

Further, in the left-right two-division of FIG. 8, the sizes of the main screen and the sub-screen are fixed at the same size, which is inconvenient when it is mainly desired to see one of them.

Further, as shown in FIG. 9, as a screen reduction technique, there is an application of a frame synchronizer as an example on the broadcast transmission side. This is done by digitally processing the frame pixel information stored in the memory, for example, by setting every other read address or halving the reception speed of the write address so that the data is thinned out every two pixels. Get burned. If every other horizontal read address is set for the original image in Fig. 9 (a), a 1/2 size image as shown in Fig. 9 (b) is obtained. If both are set, the vertical and horizontal reductions can be made simultaneously, and a 1/4 size image as shown in Figs. 9 (c) and 9 (d) can be obtained. Can be displayed in 4 divisions. Note that FIG.
9C and 9D show the display at different positions on the display screen by specifying the position on the display screen at the time of reading.

The technique shown in FIG. 9 has a problem that the contents of the original image are lost because pixels are thinned out.

Further, in the screen reduction technique as an example of the broadcast transmitting side, interpolation is performed by interpolation from all pixels of the original image by digitally interpolating to create new pixels. Differences from the original image occur in points. That is, the content of the original image is damaged.

[0009]

As described above, in the prior art,
In the multi-screen display where you can watch multiple video information at the same time,
There was a problem that it was not easy to use and the content of the original image was impaired in terms of image.

In view of the above problems, it is therefore an object of the present invention to provide a multi-screen display device which is easy to use and has main and sub-screen display functions which do not impair the contents of the original image. Is.

[0011]

The present invention is a multi-screen display device for displaying first and second video information on a main screen and a sub-screen, and the first and second video information are respectively A / D converted. The first and second A / D conversion means, and the first and second A / D
The first and second storage means for respectively storing the digital signals from the conversion means, and the sampling frequencies of the first and second A / D conversion means are changed according to the main and sub-screen sizes, and the first and second storage means are changed. Write control means for designating a write address of the first and second storage means, and a read address of the first and second storage means to perform reading at the basic sampling frequency of the display screen, and at the time of reading, main and sub screens Read control means for designating a display position on the display screen in accordance with the above, and first and second D / A for D / A converting the outputs from the first and second storage means, respectively.
The conversion means, the main / sub-screen combination means for combining the outputs from the first and second D / A conversion means, and the main / sub-screen size and main / The operation means for instructing the sub-screen position is provided.

[0012]

In the present invention, 1 / m of the original image is used so that the first and second video information are used as the main and sub screens, respectively.
When multiplying by 1 or n times, the sampling frequencies of the first and second A / D conversion means are respectively m times and n times the reference sampling frequency and stored in the first and second storage means, respectively.
When reading from each storage means, the main and sub screen positions on the display screen are set and read at the reference sampling frequency, and D / A conversion is performed by the first and second D / A conversion means, respectively. Since the sub-picture combining means combines the pictures into one picture, a plurality of pieces of video information can be reduced (zoomed down) without damaging the content of the original image.
It is possible to specify the size of the sub-screen and display it.

[0013]

EXAMPLES Examples will be described with reference to the drawings. FIG. 1 is a block diagram showing a multi-screen display device according to an embodiment of the present invention.

In FIG. 1, input terminals 1 and 2 are supplied with video signals A and B for the main screen and the sub screen, respectively.
While being input to the D / D converters 3 and 4, it is also input to the write control units 7 and 8. Based on the horizontal cycle of the supplied video signals A and B and the screen size instruction from the control unit 15, the write control units 7 and 8 automatically set frequencies according to the screen sizes of the main screen and the sub screen. The sampling pulse (the sampling frequency is varied in inverse proportion to the screen size) is generated to
Supply to the / D converters 3 and 4, respectively. The A / D converted video signals for the main screen and the sub screen are supplied to the digital memories 5 and 6, respectively, and the write control units 7 and 8 are provided.
It is written according to the write address specified by. Each video data of the main screen and the sub screen written in the digital memories 5 and 6 is read out by the read control unit 11
It is read according to the read address specified in. At this time, each video data is read from the digital memories 5 and 6 at the basic horizontal sampling frequency fs of the display screen, and the main and sub screens set on the display screen are set based on the display position instruction from the control unit 15. Each video data of the main and sub screens is read at each display position timing. The video data of the main and sub-screens read from the digital memories 5 and 6 are input to the D / A converters 9 and 10, where they become analog video signals for the main and sub-screens, and the main and sub-screens are combined. Is supplied to the section 12. In addition to the main and sub-screen video signals from the D / A converters 9 and 10, on-screen signals such as characters and symbols are input from the on-screen circuit 16 to the main / sub-screen combining unit 12. These three signals are combined so as to form one screen, supplied to the video processing circuit 13 in the next stage, subjected to necessary video processing, and output to the output terminal 14. The control unit 15 is composed of, for example, a remote control signal receiving unit or an operation panel, and indicates the main and sub screen sizes to the write control units 7 and 8 and displays the main screen on the read control unit 11. The display positions of the main and sub screens on the screen are designated, and on-screen information (reception channel and source information of the main and sub screens) is supplied to the on-screen circuit 16.

In the above structure, the A / D converters 3, 4
Sampling frequency (ie digital memories 5, 6
The writing frequency) is controlled by the writing control units 7 and 8, and the sampling frequency is variably set according to the main and sub screen size instructions from the control unit 15. That is, the image is reduced from the original image so that the image A from the input terminal 1 is 1 / m times larger and the image B from the input terminal 2 is 1 / n times larger according to the main and sub screen size instructions. If it is to be displayed, the sampling frequency for the image A is set to m × fs and the sampling frequency for the image B is set to n × fs. As a result, the contents of the original image will not be lost even if the screen size is reduced. Here, fs is a basic horizontal sampling frequency of the display screen. For example, assuming that the horizontal resolution is 780 lines, in the case of NTSC, the aspect ratio of the screen is 4: 3 and the horizontal scanning frequency is 15.75 kHz.

[Equation 1] The size change in the vertical direction is also made variable according to the size change rate in the horizontal direction. The main and sub screens are stored by sampling the images A and B at sampling frequencies of m times and n times by the digital memories 5 and 6, respectively. Therefore, the data A1, ..., Am for each sampling period (1 / mfs) of the image A stored in the digital memory 5 is represented as shown in FIG. Data B1 for each sampling period (1 / nfs) of image B
Is represented as shown in FIG. When the images A and B are read from the digital memories 5 and 6, for example, the data A1 of the image A shown in FIG. It is read at fs (that is, frequency fs) and is made to correspond to the portion A1 of the display screen (composite screen) shown in FIG.
The data B1 of the image B shown in (b) is read at a cycle of 1 / fs, and is made to correspond to the portion B1 of the display screen (composite screen) shown in FIG. 2 (c). 1
Synthesize the screen.

That is, as shown in FIG. 3, the original image A,
B can be reduced to 1 / m and 1 / n, respectively, and combined and displayed as a main screen and a sub screen on the display screen.

The images of the images A and B thus obtained can be arbitrarily changed in screen size, and the zoomed-down image is data obtained by oversampling the original image by (zoom-down ratio) -1. Is not damaged during sampling.

In FIG. 2, the average values of m times and n times oversampling data A1 to Am and B1 to Bn are taken to correspond to a composite image, or motion detection by front and back fields can be considered. Is.

FIG. 4 is a block diagram showing another embodiment of the present invention.

In FIG. 1, the image data A and B are D / A converted by the D / A converters 3 and 4 and then combined by the combining unit 12, but in this embodiment, as shown in FIG. As shown, the image data A and B from the digital memories 5 and 6 are combined in a digital state in the combining unit 12a, and then D / A conversion is performed using one D / A converter 17. . At this time, the on-screen circuit 16a also becomes a digital output.

FIG. 5 is a block diagram showing another embodiment of the present invention.

The embodiment shown in this figure is a modification of the embodiment shown in FIG. 4, and enables a plurality of video signals A, B, ..., I to be combined and displayed on a display screen. Is.
Video signal A input to input terminals 1, 2, ..., 18
B, ..., I are converted into digital signals by A / D converters 3, 4 ,.
..., stored in 20. A / D converters 3, 4, ..., 1
9 and the digital memories 5, 6, ..., 20 perform sampling and writing according to the sampling frequency and the writing address designation from the writing control unit 7, 8 ,. Be seen. Then, the written video data A, B, ..., I
Is read at the reference horizontal sampling frequency fs by the designation of the read address by the read control unit 11 and corresponding to each display position of a plurality of screens on the display screen.
The synthesizing unit 12a synthesizes one screen, and the D / A converter 1
It is converted into an analog signal in 7 and is output through the video processing circuit 13 in the next stage. The control unit 15
Each size of multiple screens displayed on multiple screens and each display position of multiple screens can be arbitrarily keyed in.

According to this embodiment, a plurality of video information can be zoomed down and displayed in a multi-screen state in any size regardless of the aspect ratio. FIG. 6 shows an example of the combined screen at this time. FIG. 6A shows an example in which the image A is displayed in the horizontal and vertical size 16: 9 and the image B is displayed in the 4: 3 size. In this example, video inputs other than the videos A and B are not displayed on the screen. In FIG. 6 (b), the image A is displayed in a horizontal and vertical size of 16: 9, the image B is displayed in a ratio of 15: 9, and the images C and D are 4: 3.
It is an example displayed by. In this example, images A, B, C,
Video inputs other than D are not displayed on the screen. Figure 6
In both (a) and (b), the non-display area is a masking area such as black.

The main and sub screens to be displayed are not limited to the horizontal and vertical sizes of each image being 16: 9, 4: 3, Vista size, sources such as cinema scope, and the overall screen size to be displayed. It is not limited to 4: 3, 16: 9, etc. Further, since the zoom-down control can be arbitrarily changed for each sub-screen by a key operation means such as a remote control key or a jog shuttle on the remote control, it is necessary to perform a switching operation between the main and sub-screens adopted in the conventional PIP method. Absent.

[0025]

As described above, according to the present invention,
When the sub-screen size is multiplied by 1 / m or 1 / n with respect to the original image, the sampling frequency of each A / D conversion means is m.
Since it is scaled to double or n times, it is possible to display multiple pieces of video information in a reduced size without damaging the information of the original picture, and it is possible to display the main and sub screens by specifying the desired size. Becomes

[Brief description of drawings]

FIG. 1 is a block diagram showing a multi-screen display device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation of FIG.

FIG. 3 is a diagram for explaining the operation of FIG.

FIG. 4 is a block diagram showing a multi-screen display device according to another embodiment of the present invention.

FIG. 5 is a block diagram showing a multi-screen display device according to another embodiment of the present invention.

6A and 6B are views for explaining the operation of FIG.

FIG. 7 is a diagram showing a conventional multi-screen image display method.

FIG. 8 is a diagram showing a conventional multi-screen image display method.

FIG. 9 is a diagram showing a conventional screen reduction technique.

[Explanation of symbols]

 1, 2 ... Video input terminal 3, 4 ... A / D converter 5, 6 ... Digital memory 7, 8 ... Write control unit 9, 10 ... D / A converter 11 ... Read control unit 12 ... Main / sub screen synthesis unit 15 ... Control part

Claims (1)

[Claims] 1. A multi-screen display device for displaying first and second video information on a main screen and a sub-screen, wherein the first and second video information are respectively A / D converted.
Second A / D conversion means, first and second storage means for storing the digital signals from the first and second A / D conversion means, respectively, according to the main and sub-screen sizes, Write control means for changing the sampling frequencies of the first and second A / D conversion means and designating write addresses of the first and second storage means; and read addresses of the first and second storage means And a reading control means for designating a display position on the display screen according to the main and sub screens at the time of reading, and the outputs from the first and second storage means. D / A for each
The first and second D / A conversion means for conversion, the main and sub-screen combination means for combining the outputs from the first and second D / A conversion means, the write control means and the read control means. On the other hand, a multi-screen display device comprising an operating means for instructing the main and sub-screen sizes and the main and sub-screen positions.