JPH02224590A - Display device - Google Patents

Abstract

PURPOSE:To synthesize and display video images generated respectively by display signal generating means in the internal and external synchronizing modes by switching a video signal from each video signal generating means with a video signal switching means and giving the result to a display means. CONSTITUTION:A synchronizing selector 5 selects an internal video signal VI or synchronizing signals SA-SC from plural display signal generators 1-3. More over, an RGB signal changeover device 6 selects one RGB signal among plural RGB signals generated from one signal from the generators 1-3. Then a synchro nizing signal selected by a selector 5 is supplied as an external synchronizing signal of the generators 1, 2 having the external synchronizing mode to synchro nize the video signal from the display signal generator in the external synchroniz ing mode and the video signal from the display signal generator in the internal synchronizing mode. The synchronizing video signal is fed to a picture tube 19 switchingly to synthesize the video images generated by the display signal generator in the external synchronizing mode and the internal synchronizing mode and to display the result.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a display device for displaying a combination of one image represented by a plurality of RGB signals obtained from a plurality of display signal generators. .

[Conventional technology]

In recent years, there has been a wide variety of display signal generating devices such as teletext, captain, television games, personal computers, etc., and there is an increasing need for display devices such as CRTs to display a combination of these devices.

The basic structure of a prior art display device that combines images represented by a plurality of video signals from a plurality of display signal generators is shown in FIG.

In Fig. 3, 2 is a display signal generator, which can also generate its own synchronization signal under external control (hereinafter, such an operation mode will be referred to as "internal synchronization mode").
, and also generates an RGB signal synchronized with an external synchronization signal (which may be a composite video signal containing a synchronization signal, but is referred to as an "external synchronization signal" in the sense that it is synchronized with an external signal) and a control signal to be described later. (Hereinafter, this operation mode will be referred to as "external synchronization mode".
) However, in the case of external synchronization mode, the synchronization signal output is the input external synchronization signal.

3 is a third display signal generator, which is capable of only internal synchronization mode. When each display signal generator 1 to 3 is in internal synchronization mode, each control signal Ys (A), Ys
(B) and Ys (C) are at H level.

4 is an internal video signal input terminal, which receives the internal video signal V(1) from the built-in tuner or video input terminal.
is given. Reference numeral 5 denotes a video/synchronization selector which outputs an internal video signal V(1) and a synchronization signal S(A) generated from display signal generators 1 to 3.

One signal from S (B) and S (C) is converted to 1[
, 7 is an RGB selector, and display signal generators 1 to 3
RGB signal ROB(A) generated by ROB(A).

Select one signal from RGB (B) and RGB (C). 8 is a Ys selector which receives the L level signal and the control signal Y generated from the display signal generators 1 to 3.
s (A), Ys (B), Ys (C) and 1
Select one signal. 20a and 20b are selector control signal input terminals to which selector control signals Ca and Cb are applied; the selector control signal Ca;

The selectors 5, 7.8 are controlled simultaneously by cb.

16 is a synchronization/deflection circuit, and the video/synchronization selector 5
! Based on the translated signals, horizontal and vertical deflection currents are created and supplied to the picture tube 19. 17 is a color demodulation circuit which performs color demodulation of the signal selected by the video/synchronization selector 5 to create an internal RGB signal. 18 is a ROB switch, which connects the internal RGB signal created by the color demodulation circuit 17 and the RG
The RGB signal selected by the B selector 7 is switched based on the control signal Ys selected by the Ys selector 8. The picture tube 19 displays an image using the RGB signals obtained by the RGB switch 18 and the deflection current generated by the synchronization/deflection circuit 16.

The operation of the display device configured as described above will be described below. Selector control signal input terminal 20a
, 20b are supplied with selector control signals Ca, Cb (H level or L level) from a microcomputer, lock switch, etc. Selector system Hi No. Ca, C
b, each selector 5, 7, 8 selects the signal shown in Table 1 below. However, in this Table 1, X indicates that it is unrelated to the display.

Table 1 For example, when selector control signals Ca and Cb are at H level and L level, respectively, selectors 5 and 7.8 output signals S (A) and RGB (
A) and Ys (A) respectively. Here, when the display signal generator l is in the internal synchronization mode, the control signal Ys(A) becomes H level, which causes the RG
The B switch 18 supplies the RGB signal from the RGB selector 7 to the picture tube 19. Therefore, the picture tube 19 displays the image generated by the display signal generator 1.

Furthermore, when the display signal generation bag W,1 is in the external synchronization mode, the output synchronization signal S (A) is the internal video signal V (
r) (external synchronization signal), and the synchronization/deflection circuit 1
6 and color demodulation circuit 17, the internal video signal V (+
) will be supplied.

In the color demodulation circuit 17, the supplied internal video signal V(!)
is demodulated into a primary color signal to obtain an internal ROB signal. In the external synchronization mode, the control signal Ys(A) is a signal that changes between torubel and torubel. And R.G.
The B switch 18 outputs the internal RGB signal from the color demodulation circuit 17 when the control signal Ys (A) which has been subjected to ifl[ by the Ys selector 8 is at Trubel, and outputs the internal RGB signal from the color demodulation circuit 17 to the RGB selector 7 when the control signal Ys (A) is at H level. The RGB signal ROB (A) selected in is sent to the picture tube 19.
give to As a result, in the picture tube 19, images respectively represented by the internal video signal V(1) and the RG B No. 48(A) from the display signal generator 1 are combined and displayed.

When the selector control signals Ca and Cb are at Torbel and H levels, respectively, the signal S (
B), RGB (B), and Ys (B) are selected, resulting in the same operation as in the above case. That is, when the display signal generator IB is in the internal synchronization mode, the RGB signal R
An image represented by GB (B) is displayed on the picture tube 19,
When in external synchronization mode, internal video signal V (1
) and RGB signals RGB (B) are combined and displayed on the picture tube 19.

When the selector control signals Ca and Cb are both torubel, the video/synchronization selector 5 selects the internal video signal
An image represented by an internal video signal V(1) is displayed on the picture tube 19.

Similarly, when selector control signals Ca and Cb are both at H level, each selector 5, 7.8 receives signals S(C) and RGB(C) from display signal generator 3.

Select Ys(C). Here, since the display signal generator 3 has only internal synchronization mode, the Ys (C) signal is always H.
level, and the RGB switch 18 is set to the RGB selector 7.
The selected RGB signal RGB (C) is applied to the picture tube 19.

[Invention tries to solve! ! ! ! However, in the above-mentioned prior art, display signal generation in external synchronization mode! a
Since it is not possible to supply the synchronizing signal generated by the display signal generator in internal synchronization mode to the internal synchronization mode, the video generated by the display signal generator in external synchronization mode and the video generated by the display signal generator in internal synchronization mode are different. Therefore, the images generated by both could not be combined and displayed.

An object of the present invention is to provide a display device that can synthesize and display a video generated by display signal generation means in external synchronization mode and a video generated by display signal generation means in internal synchronization mode.

(Means for Solving the Problems) The display device of the present invention has an internal synchronization mode in which it generates a self-generated synchronization signal and a video signal synchronized with this synchronization signal, and a display device in synchronization with an external synchronization signal given from the outside. Out of the two modes of operation, including the external synchronization mode that generates a video signal synchronized with the external synchronization signal, it is equipped with a plurality of display signal generation means capable of operating in at least the synchronization mode. A switching means is provided for switching between video signals from a plurality of display signal generation means and synchronization signals from the plurality of display signal generation means and applying the same to the display means; The present invention is designed to provide a display signal generating means that can perform the following operations.

When each of the display signal generation means outputs a control signal for switching between the video signal generated by itself and another video signal, the video signal switching means receives each control signal in a weighted manner and selects the input with the largest weight. and a selector that switches and outputs video signals from the plurality of display signal generating means based on the output of the priority encoder.

(Function) According to the configuration of the present invention, the synchronization signal generated by the display fε signal generation means in the internal synchronization mode is supplied via the synchronization signal switching means as the external synchronization signal of the display signal generation means in the external synchronization mode. The video signal generated by the display signal generation means in the internal synchronization mode is synchronized with the video signal generated by the display signal generation means in the external synchronization mode, and the video signals are switched by the video signal switching means and supplied to the display means. Accordingly, the video generated by the display signal generation means in the internal synchronization mode and the video generated by the display A3 generation means in the external synchronization mode can be combined and displayed on the display means.

〔Example〕

A display device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the basic configuration of a display device according to a first embodiment of the present invention. This first
In the figure, parts equivalent to those shown in Figure 3 above are given the same reference numerals. In Figure 0, 2 is a display signal generator, which is capable of internal synchronization mode and external synchronization mode. In the case of external synchronization mode, the output synchronization signals s (A) and S (B) become the input external synchronization signals. 3 is a third display signal generator, which is capable of only internal synchronization mode. In addition, the display signal generator 1~
3 is in internal synchronization mode, its control signal Ys
(A), Ys (B), and Ys (C) are at H level. On the other hand, in the external synchronization mode, it changes between H level and L level.

Reference numeral 4 denotes an internal video signal input terminal, to which an internal video signal V (1) from a built-in tuner or video input terminal is applied.

5 is a video/synchronization selector provided as a synchronization signal switching means, which connects the internal video signal V(+) and the display signal generator 1.
The synchronization signal S (A) S (B) generated from ~3,
Select one signal from S (C). 7 is the first
RGB signals RC;B (A) generated by the display signal generators 1 to 3 at the ROB selector.

One RGB from RGB (B), RGB (C)
A signal is selected as a first RGB signal. 8 is the first Y
With the s selector, the L level signal and display signal generator 1~
Control signals Ys (A), Ys generated from 3
(B) and Ys (C), one signal is selected as the first control signal. 20a and 20b are selector control signal input terminals to which the first selector control No. H3 C1a and C1b are input;
The selectors 5, 7.8 are controlled simultaneously by la and Clb.

9 is a second RGB selector, which connects display signal generators 1 to 3;
RGB signal RGB (A) generated by RGB.

One RGB from RGB (B), RGB (C)
A signal is selected as a second RGB signal. 10 is a second Ys selector, which outputs an L level signal and display signal generator 1;
Control signals Ys (A), Y generated from ~3
One signal is selected from s (B) and Ys (C) and used as the second control signal. 21a and 21b are selector control signal input terminals to which second selector control signals C2a and C2b are manually input;
The selectors 9 and 10 are simultaneously controlled by a and C2b.

11 is the second RGB switch (however, 18 is the first RGB switch)
GB switch. ), when the second control signal selected by the second Ys selector lO is at L level, it is sent to the first RGB selector 7 side, and when the second control signal is at H level, it is sent to the second RGB selector 9 side.
connected to the side.

12 is a logical sum circuit which outputs the logical sum of the first control signal selected by the first Ys selector 8 and the second control signal selected by the second Ys selector IO. Reference numeral 6 denotes an RGB signal switching device serving as video signal switching means, which is composed of an RGB selector 7.9, a Ys selector 8.10, a second RGB switch 11, and an OR circuit 12.

16 is a synchronization/deflection circuit that creates horizontal and vertical deflection currents from the signal selected by the video/synchronization selector 5 and supplies them to the picture tube 19; 17 is a color demodulation circuit which demodulates the color of the signal selected by the video/synchronization selector 5 and outputs the internal RG signal.
Create B signal.

18 is a first RGB switch, which outputs the internal RGB signal created by the color demodulation circuit 17 and the RG from the RGB switch 11.
B signal is switched based on the output signal of the OR circuit 12. 19 is a picture tube, R from RGB switch 18
An image is displayed using the GB signal and the deflection current generated by the synchronization/deflection circuit 16. In this example, the display means includes a synchronization/deflection circuit 16, a picture tube 19, and the like.

In FIG. 1, display signal generators 1 to 3, selector 5
,7.8. First selector control signal C1a.

C1b (equivalent to selector control signals Ca and Cb in Fig. 3)
, synchronization/deflection circuit 16, color demodulation circuit 17, first RGB
The switch 18 and the picture tube 19 perform the same operations as those denoted by the same reference numerals in FIG. 3, so a detailed explanation will be omitted. Further, the second RGB selector 9 and the second Ys selector 10 receive a second selector control signal C2a,
The signals shown in Table 2 are selected depending on the state of C2b. However, in this Table 2, X indicates that it is unrelated to the display.

Table 2 For example, when the first selector control signals C1a and C1b are both set to H level, each selector 5, 7.8 receives a signal S (C) from the display signal generating circuit N3.

Select RGB (C) and Ys (C). At this time, when both the second selector control signals C2a and C2b are set to L level, the control signal selected by the second Ys selector IO becomes L level, and the second RGB switch 11
is always the RGB selected by the first RGB selector 7
Outputs the signal RGB (C). Furthermore, since the Ys (C) signal from the display signal generator 3 in the internal synchronization mode is always at H level, the signal output from the OR circuit 12 is H level.
level, the picture tube 19 receives the RGB signal RGB (C) from the display signal generation bag Wt, 3 from the ROB selector 7.
It is provided via the GB switches 1 and 18.

Also here, the second selector control signals C2a, C2b
are set to L level and H level respectively, the second RGB selector 9 receives the RGB signal RGB (B) and the second Y
The s selector 10 selects the control signal Ys (B). At this time, the synchronization signal S (C) signal selected by the video/synchronization selector 5 is supplied as the external M signal of the display signal generation bag W12 via the line 30, and the display signal generation bag W2 is externally synchronized. If it is in mode, the display signal generator 3 and display signal generation! Each video signal generated by the J position 2 is synchronized, and the control signal Ys (B) selected by the second Ys selector 10 is set to H.
By changing between the level and the L level, the second RGB switch 11 transfers the RGB signal RGB (C) from the first RGB selector 7 to the picture tube 19 from the first ROB switch 18 and the second RGB from RCB selector 9
The signals RGB (B) are alternately switched and supplied. As a result, the display signal generator 3 and the display signal generator 2
The images generated by and are combined.

Similarly, the display signal generator W1 is set to the internal synchronization mode, the display signal generator 2 is set to the external synchronization mode, the first selector control signals C1a and C1b are set to H level and L level, respectively, and the display signal generator 1 is selected. If the display signal generator 2 is selected by setting the selector control signals C2a and C2b of 2 to L level and H level, respectively, the display signal generator 1
and the video generated by the display signal generator 2 can be combined.

In addition, in order to synthesize the internal video signal V(1) and the video of the display ε signal generator 1, the first selector control signal C1
a, C1b may both be set to L level, and the second selector control signals C2a, C2b may be set to H level and L level, respectively. However, in this case, the second selector control signals C2a,
If the signals from the display signal generator 3 are selected with both C2b at H level, the image will flow (synchronization cannot be achieved), so such selection of the second selector control signals C2a and C2b is prohibited.

As described above, according to this embodiment, the internal video signal v(1
) or synchronization signals S (A), S (B) output from the plurality of display signal generators 1 to 3.

A video/synchronization selector 5 that selects S(C) and a plurality of RGB signals %RGB(A) generated from one signal from the plurality of display signal generators 1 to 3.

One RGB from RGB (B), ROB (C)
A display signal generator 2 having an external synchronization mode is provided with an RGB (i) switching device 6 for selecting a signal, and a display signal generator 2 having an external synchronization mode is provided with a synchronization signal selected by the video/synchronization selector 5.
By supplying the external synchronization signal as an external synchronization signal, it is possible to synchronize the images generated by the display signal generation device in the external synchronization mode and the display signal generation device in the internal synchronization mode.
By switching this synchronized video signal and supplying it to the picture tube 19, it is possible to synthesize and display the video generated by the display signal generator in the external periodic mode and the display signal generator in the internal synchronization mode.

FIG. 2 is a block diagram showing the basic configuration of a second embodiment of the present invention. In FIG. 2, parts equivalent to those shown in FIG. 1 are designated by the same reference numerals.

This embodiment differs from the first embodiment shown in FIG. 1 by using a priority encoder 14 as a video signal switching means, an RGB selector 13 that selects rlGB signals based on its output, and a control signal Ya (
A), YS (B), and a logical sum circuit 15 which calculates the logical sum of the signals A) and YS (B). be.

The priority encoder 14 receives a control signal Ys from the weighted display signal generator 2.
(A), Ys (B), and control signal CY
s is input, and the signal corresponding to the human power with the largest weight among them is output, and the RGB selector 13 is controlled. Further, the OR circuit 15 receives control signals Ys (A) and Ys (B) from the display signal generator 2.
and the control signal CYs.
Controls the GB switch 18.

Here, the display signal generator 2 is capable of an internal synchronization mode and an external synchronization mode, and in the external synchronization mode, the control signals Ys (A) and Ys (B) can be set freely. Also, since the display signal generator 3 is only capable of internal synchronization mode, the control signal Ys (C) is H
Since the level is fixed and cannot be controlled, the control signal CYs is the control signal Ys of the display signal generator 3.
Used in place of (C).

As shown in FIG. 2, when there are three display signal generators, the priority encoder 14 has two output signals AO,
It is sufficient to output A1. For example, the control signals input to the priority encoder 14 are sorted in descending order of weight (high priority), Ys (A),
Assuming Ys (B) and CYs, the truth table of the priority encoder 14 is as shown in Table 3. However, in Table 3, X indicates that it is unrelated to H level and L level.

Table 3 RGB selector 13 is priority encoder 14
RGB shown in Table 4 below according to the output signals AO and AI of
Select a signal.

(Margin below) Table 4 Therefore, for example, when you want to display only the video generated by the display signal generator 3, selector control signals C1a and C
Both 1b and 2 (select the synchronization signal S (C) of the display signal generator 3 by the video/synchronization selector 5 as the level, and set the display signal generator and 2 to external synchronization mode and control signals Ys (A), Ys (B) is fixed at the L level.Then, the control signal CYs may be set to the level (■).In other words, at this time, the RGB signal RGB (C) is selected in the ROB selector 13,
Further, the output of the OR circuit 15 becomes H level, and the RGB
The switch 18 applies the RGB signal from the RGB selector 13 to the picture tube 19.

At this time, if the control signal Ys (B) is changed between the H level and the L level by controlling the display signal generator 2 from the outside, the RGB selector 13 selects the RGB signal RGB (B).

RGB (C) alternately i! Since it will be an IR,
The video generated by the display signal generation device 3 and the video generated by the display signal generation device 2 can be combined and displayed. Furthermore, if the control signal Ys (A) is changed by controlling the display signal generator 1 from the outside,
A video generated by the display signal generation device 1 can be further synthesized and displayed on a composite image obtained by combining the images generated by the display signal generation device 3 and the display signal generation device 2.

In addition, in this state, both the selector control signals C1a and C1b are set to L level, and the internal video signal V (1) is selected by the video/synchronization selector 5.
By setting the internal video signal V (1
) The images generated by the display signal generator 2 and the display signal generator 1 can be combined and displayed on the image corresponding to the image.

As described above, the priority encoder 14 and the RGB selector 13 that selects RGB signals based on the output thereof
By providing an RGB signal switching device 22 composed of can be selected, and the RGB signals of multiple display signal generators can be
They can be displayed in combination according to the weighting (order of priority) of the words.

In addition, in the first and second embodiments described above, the number of display signal generation devices is three, but the number of display signal generation devices may be any number as long as it is plural, and the number of display signal generation devices may be as many as the number of display signal generation devices. By using a selector and a priority encoder, a display 'A''ll with similar functionality can be constructed.

〔Effect of the invention〕

As described above, according to the display device of the present invention, the synchronization signal from the display signal generation means in the internal synchronization mode is given to the display signal generation means in the external synchronization mode, and the video signals output from each display signal generation means are Since it becomes possible to synchronize with a common synchronization signal, by switching the video signals from each of the display signal generation means using the video signal switching means and applying them to the display means, it is possible to synchronize with the display signal generation means in internal synchronization mode. It becomes possible to synthesize and display images generated by the display signal generation means in external synchronization mode.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of a display device according to the first embodiment of the present invention, FIG. 2 is a block diagram showing the basic configuration of the second embodiment of the present invention, and FIG. FIG. 1 is a block diagram showing the basic configuration of the technology. 1, 2. 3...Display signal generator, 5...Video/synchronization selector (synchronization signal switching means), 6.22...
・RGB signal switching device (video signal switching means), 79.1
3... RGB selector, 8, 10... Ys selector, 14... Priority encoder, 16...
Synchronization/deflection circuit, 17...color demodulation circuit, 18...R
CB switch, 19... picture tube

Claims (2)

[Claims] (1) A display means that performs display based on a synchronization signal and a video signal, an internal synchronization mode that generates a self-generated synchronization signal and a video signal synchronized with this synchronization signal, and synchronization with an external synchronization signal given from the outside. a plurality of display signal generating means capable of operating at least in the internal synchronization mode among two modes of operation; video signal switching means for switching and outputting a video signal from a display signal generating means and providing it to the display means; and synchronous signal switching means for switching and outputting a synchronization signal from the plurality of display signal generation means and providing it to the display means. means, wherein the output of the synchronization signal switching means is applied to the display signal generation means capable of operating in the external synchronization mode. (2) Each of the plurality of display signal generation means outputs a control signal for switching between the video signal generated by itself and another video signal, and the video signal switching means is configured to output a control signal for switching between the video signal generated by the plurality of display signal generation means and another video signal. a priority encoder that outputs a signal according to the input with the largest weight in which each control signal to be output is weighted; and a video signal from the plurality of display signal generation means is switched based on the output of the priority encoder. 2. The display device according to claim 1, further comprising a selector for outputting.