JPH03214870A - Multiple station display picture device - Google Patents

Abstract

PURPOSE:To make a picture small to improve image resolution in a horizontal direction at a reception device which displays plural programs simultaneously by raising the scanning speed of a part corresponding to a reduction display and delaying the signal of the part corresponding to the reduction display. CONSTITUTION:An input signal is alternately written into field memories 8, 9 in terms of a field, and read out. The color carrier wave of the D/A converted 12 signal becomes (n) times. A color carrier wave extracted through a Y/C separation circuit is frequency-converted 25 by the output 24 of an oscillator of (n-1)fSC and is added to a luminance signal at an adding circuit 27 through a BPF 26. Next, at a demodulation part, the output of the circuit 27 is Y/C separated 28, the luminance signal is passed through a delay line 35, the color carrier wave signal is orthogonally detected 31, 32 by a sub-carrier wave 29, each are supplied to a matrix amplifier 36, and a three primary color signal is obtained. That output is given to an electronic switch through a delay circuit 37 of a time tau which is equivalent to the pitch of a CRT and a delay circuit 38 of 0.5tau, and the image resolution of the luminance of the part with the small picture size is multiplied two times.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-channel display image device that simultaneously displays other programs in a reduced size on a part of a standard scanning screen. [Summary of the invention] In a device that simultaneously displays other programs reduced to a small size on a part of a standard scanning screen, (1) the bandwidth of the video signal is increased by increasing the scanning speed in the reduced part; 2)
Let τ be the pitch time (from G to G) of the R, G, and B pixels of a CRT whose color pixels are a trio of RGB, then delay EG by τ for the reduced screen part and set Eo to 0. Delay by .5τ. [Prior art] Displaying programs from other stations in a small size on a part of a receiving screen,
There are television receivers on the market that divide one screen into four and display four stations at the same time, and are known as ``picture-in-picture''.For example, the majority of the reception screen (A) in Figure 3.
I am watching the news, and a multi-game baseball program (B) is displayed in the upper left corner. Figure 3 shows the standard scanning state of (A) and the picture-in-picture (B) of 1/2 size, that is, n
= 2, and the main program is shown on the (A) screen,
(B) You will see the subprogram on the screen. Figure 4 shows an example in which the scanning time axis is reduced and used for picture-in-picture. FIG. 4(a) shows, for example, a horizontal scanning line, and the scanning period of the image component is reduced to T/n to form a picture-in-picture as shown in FIG. 4(b). The same goes for the vertical direction, but since the vertical direction has a scanning line structure, the scanning lines of A are thinned out to 1/2 in (B). FIG. 5 is an example of such scan conversion, in which there is no suitable memory for analog signals and a digital memory is used, but this is not essential.

In FIG. 5, the television signal l is a subprogram,
2 shall be the main program. A television signal 1 is AD converted by an AD converter 3, and is alternately written field by field into field memories 8 and 9 and read out alternately. The output of the AD converter 3 is sent to an electronic switch 6 using a down-down circuit such as a flip-flop using the vertical synchronization signal 4 as the timing.
5 for frame synchronization, and in the figure, data is written into the memory 8 at the clock frequency fc of the standard clock signal 10. During this time, the signal written in the memory 9 is read out by the NFC clock 11 and outputted by the electronic switch 7. Electronic switches 6 and 7 operate in opposite phases. The output of electronic switch 7 is DA converter 1
2 and passed through a low-pass filter 13. In addition,
When reading the field memory 9 with the NFC clock 11, if n is an integer, the reduced scanning line and the standard scanning line match, but if n is arbitrary, the edge of the screen (
In Figure 3, the timing at the left end) is standard horizontal synchronization.

The reduced signal of the output of the low-pass filter l3 and the standard signal 2 are controlled by a gate 15 driven by an electronic switch 16 with a synchronizing signal 14, and for example, as shown in FIG.
Display the sub-program of B). If n is 2 or more, there will be unused portions of memories 8 and 9, which is uneconomical. FIG. 6 is an example of economical use of memory. In the figure, reference numbers common to FIG. 3 represent parts that are the same as or correspond to those in FIG. 3, and 18 denotes a clock signal fc. 19
is 1/n clock signal f. /n, 20 represents an electronic switch, and 21.22 represents a memory. Input signal 1 is sampled by electronic switch 20. Clock signal (frequency fc) 18 to clock signal 19
1/n of the output of the AD converter 3 in the horizontal direction (the vertical direction is not shown, but it is set to 1/n in scanning line units). If the signals thinned out to 1/n both horizontally and vertically are written to the memories 20 and 21 at the clock frequency f0 and read out at fC, the signal similar to the fifth (!I) will be obtained. It is shown sampled at frequency fc. (C) is the standard signal, and (e) is the time axis of (c) simply reduced to 172, with a sampling interval of 1/2 fc,
This is the method shown in FIG.

Figure 7(d) is an example of Figure 6, with the time axis compressed to 1/2 by taking only the time indicated by the black circle in (c). [Problems to be Solved by the Invention] At this time, the embedded screen (B) (child screen) generally lacks definition due to the video signal display capability of the receiver.

This is because the number of scanning lines assigned to the screen (B) is smaller than that of the main screen (A), and in the horizontal direction, although there is originally a 4MHz luminance signal in the part (B), the band of the video amplifier is , spatial MT due to the pixel configuration of color CR-T, etc.
This is because F decreases. That is, the current picture
In-picture has the disadvantage that the image information is displayed in a reduced form as the screen size is reduced.

[Purpose of the Invention] The purpose of the present invention is to improve the horizontal resolution of a picture-in-picture device that simultaneously displays multiple programs on a single picture-receiving screen by reducing the size of the screen, thereby making it easier to see the sub-screens. The object of the present invention is to provide a multi-display image device that can perform the following functions. [Means for Solving the Problems] In order to achieve the above object, a multi-display image device of the type mentioned at the beginning according to the present invention includes means for increasing the scanning speed of a portion corresponding to a reduced display, and a means for increasing the scanning speed of a portion corresponding to a reduced display. E of the part corresponding to the display
The gist includes means for delaying R by τ and simultaneously delaying EGti by 0.5τ.

[Effect] In standard scan main programs, images with normal resolution are displayed.
In some sub-programs, the horizontal resolution is improved even though the screen size is small, by compressing the video signal and doubling the resolution of the achromatic signal with the brightness components of G and R+B in color display. Regardless, the horizontal resolution of the subprogram image improves, making it possible to visually receive the necessary information if you look closer. [Examples] The present invention will be explained in more detail below using Examples with reference to the drawings, but these are merely illustrative and various modifications and improvements can be made without going beyond the scope of the present invention. Of course it is possible.

FIG. 1 shows the basic configuration of a multi-display image device according to the present invention. In the figure, reference numbers common to Figure 5 represent parts that are the same as or correspond to those in Figure 5;
3 is a YC separation circuit, 24 is (n 1) f s
c signal, 25 is a frequency converter (fsc component generation), 2
6 is a band pass filter (fsc), 27 is an addition circuit, 28 is a YC separation circuit, 29 is a subcarrier cosωsc
t, 30 is a 90° phase shift circuit, 31.32 is a synchronous detection circuit, 33.34 is a low-pass filter, 35 is a delay circuit, 36 is a matrix amplifier, and 37 is a delay circuit (
ER τ), 38 is a delay circuit (EG 0.5r
), 39.40 are mode selection switches, 41, 42 .
43 represents the three primary color output signals. The operation of the above embodiment will be explained below.

In FIG. 1, the process from the input of the input signal 1 to the output of the electronic switch 16 is basically the same as in FIG. Since the frequency is n times higher (nfsc), the output 24 of the (n-1)fsc oscillator (naturally locked to fsc) is YC separation circuit 23
The frequency of the color carrier wave signal obtained by the frequency converter 25 is converted. fsc = 3.58 MHz The luminance signal E is passed through a band pass filter 26 centered at an adder circuit 27.
Add to v.

The lower half of FIG. 1 shows the demodulation of the NTSC signal and the supply of the three primary color signals of ER, EO, and Ee to the display device. The output of the adder circuit 27 is YC separated by a YC separation circuit 28, and E
Y passes through a delay line 35 to a matrix amplifier 36;
The color carrier signal Eccos (ωsct+θ) is applied to synchronous detectors 31 and 32. Subcarrier cosωSCt2
9 and sinωs through 906 phase shifter 30
ct is quadrature detected at 31.32 and added to the matrix amplifier 36 and combined with EY of the output of the delay line 35 to output ER, EG, EG to the output of the matrix amplifier 36.
Obtain the three primary color signals. Three primary color output signals 41, 42, 43
When connected directly to the drive terminal for the CRT, picture-in
The picture sub-program ((B) in FIG. 3) has a small screen size and lacks definition. 37 is a color pixel of a delay circuit having a time τ corresponding to the pitch of a striped CRT. Electronic switch 39.4
0 is connected to the upper side, the brightness distribution of the CRT screen in the horizontal direction becomes as shown in Figure 2 for achromatic colors, and in part (B), the horizontal sampling is doubled and becomes finer. 1st
The electronic switch 39.40 is driven by the gate signal 15 shown in the figure, and the luminance resolution is doubled for the part (B) of the sub-program.

FIG. 2 is an explanation of how the horizontal resolution of picture-in-picture luminance signals is improved according to the present invention. (b) shows the pixel array of a color CRT, and (a) shows the time distribution of the corresponding video signal. Normally, signals sampled at pitch τ corresponding to part (A) are displayed simultaneously on R, G, and B.

On the other hand, in part (B), the pitch between the black and white circles in (a) is
By sampling and displaying the video signal at τ/2, G and R+B are distributed at equal intervals, and the sampling frequency is doubled. For an achromatic color, R+B = 0.41 G = 0.59, which is a nearly equal brightness ratio, and a high-frequency brightness signal can be displayed on the screen with the brightness of G and (R+B). 7th
As shown in figure (e), the band of the video signal in part (B) has increased by twice (n = 2), so the band of the video signal to be displayed is twice that of part (A). Since there is, (B)
The definition of the image is improved. Part (A) is the same as the standard display. [Effects of the Invention] As explained above, according to the present invention, it is possible to obtain the advantage that the resolution in the horizontal direction is improved, details can be seen by approaching the screen when it attracts attention, and the sub-screen can be easily viewed. ．．

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a multi-display image device according to the present invention, and FIG. 2 is a diagram for explaining differences in sampling fineness depending on the mode. Figure 3 is a picture-in-picture
Figure 4 is a diagram showing an example of a picture, Figure 4 is a diagram to explain the reduction of the time axis of picture-in-picture, Figure 5 is a conventional scan conversion system diagram, and Figure 6 is another conventional scan conversion diagram. The scan conversion system diagram, FIG. 7, is a diagram for explaining the relationship between signal readout and band in the apparatus shown in FIGS. 5 and 6.

Claims (1)

[Scope of Claims] In a multi-station display image device that reduces and simultaneously displays other programs on a part of a standard scanning screen, means for increasing the scanning speed of the part corresponding to the reduced display, and compatible with the reduced display. 1. A multi-display image device characterized by comprising means for delaying E_R of a portion of the image by τ and simultaneously delaying E_G by 0.5τ.