JPS5923674B2 - Dual display color method for colorizing the small screen of a receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dual-screen television receiver that simultaneously displays a small monitor image within a standard image, and more particularly to a dual-screen television receiver that displays both the standard image and the small image in color. Concerning how to colorize the screen.

In a dual-screen color TV receiver, the video signal for another small color TV screen that is inserted into the main color TV large screen is stored in the storage device, and then becomes part of the color large screen signal. The stored color small screen signals are switched, and two large and small color screens are displayed on one color television picture tube.

In the above-mentioned dual display television, when displaying the small screen in color, the present invention provides primary color signals of R (red), G (green), and B (blue) in a system that drives the color picture tube in primary colors.
It was developed for the purpose of obtaining a small color screen by writing the primary color signals of these Ξ colors into a storage device line-sequentially and reading them simultaneously.

In addition, in recent years, along with the integration of color demodulation circuits, matrix circuits for exciting color picture tubes have been incorporated into this color demodulation circuit, and integration of Ξ primary color demodulation circuits for R, G, and B has become mainstream. From this point of view, the small screen colorization method of the present invention is extremely effective in simplifying circuit blocks.

An embodiment will be described below based on the schematic diagram of FIG. 1
is an antenna for receiving broadcast waves, and A is for converting ordinary broadcast waves for large screens into R, G, and B signals.
11 is a tuner for receiving a desired channel; 1
2 is an intermediate frequency amplifier, 13 is a video detector, and 14 is a matrix circuit for demodulating chroma signals and for luminance signals, which outputs primary color signals R, G, and B.

B is a receiver for small screens, and like A, it receives broadcast radio waves, R,
These are a circuit for converting into three primary color signals of G and B, and a storage circuit for this signal. Figure 2 is a detailed block diagram of the small screen signal storage unit and the circuit for inserting the small screen into any part of the large screen. 41 in the figure is the large screen color signal demodulation and matrix circuit. , 48 is a large screen/small screen switching circuit, 49
42 is a small screen color signal demodulation and matrix circuit; 43 is a primary color signal, g and b switching circuit; 44 is a g and b analog-to-digital conversion circuit; 45 is a switching circuit for storing digitally converted signals in a memory for primary color signals R, G, and B; 46 is a storage circuit for primary color signals; and 4T is a converter for converting the output from the storage circuit into an analog signal.

The operation will be explained below.

The signal for large screen is led to terminal A, and the color signal is 41 BP.
separated by F2 and demodulated by 41 demodulators 2,
The R.41 matrix circuit adds the luminance signal to the R.41 matrix circuit.
G. It is output as a B primary color signal.

This signal is input to the next 48 signal switching circuits. On the other hand, the signal for small screen is led to terminal B, and the color signal is sent to terminal B of 42.
The signal is separated by PFl, demodulated by 42 demodulators 1, added to a luminance signal by 42 matrix circuits, and output as R, g, and b primary color signals.

These R, g, and b signals are sequentially switched to R, g, and b by switch circuit SW 43 as shown in FIG. 3A, and are simultaneously input to the A/D converter 44. The output of the A/D converter is 45 switch circuits SW2
When r is input, 46 R, MEM
It is controlled by line switching signal B' to write to ORY.

The line switching signal B' is obtained by converting the SB-HD pulse, which is the horizontal synchronizing signal for the small screen shown in FIG. 3, into three-phase pulses using a ternary counter. That is, for the first line 1H, the r1 signal in FIG. 3 is selected by SW1 of 43 and SW2 of 45, the analog signal is converted into a digital signal, and the digital signal is written in R and MEMORY of 46.

For the next line, write the G2 signal in the same way, then write the B3 signal.
Write the signal. Similarly, one image is written to each of the 46 memories by repeating R4, g5, b6, and the r', g', b' signals written to the 46 memories are the small screen display signals of A'. RC, gC, and bZ are read simultaneously by 49 clocks controlled by 4
7 digital-to-analog converters convert the analog signal r″
', g''', b'5'. Similarly, each line is read out as Rc, g//I, b'6 as shown in Figure 3B. The primary color signal of the small screen is converted into the small screen display signal A' by the 48 switch circuits SW3 in the next stage.
, and is replaced with a part of the large screen.

Of course, the r''5 signal on the small screen is switched to a part of the R signal on the large screen, the g''5 signal is switched to a part of the G signal, and the b''5 signal is switched to the B signal. When the composite signals Rl, Gl, and Bl are displayed on a color picture tube, a small color screen can be displayed within a large color screen.

As described above, the present invention provides primary color demodulation for a small screen in a dual display color receiver that can insert a small screen color image into the color screen of a color receiver that can be excited with signals of three primary colors. The signals from the circuit are stored line sequentially, Rl, g2
, b3 and 3H are simultaneously read out, and a part of the three primary color signals for the large screen is switched to the three primary color signals for the small screen for display. This is a small screen colorization method for a dual display color receiver, which allows the circuit block of the dual display color receiver to be integrated into an integrated circuit, and also simplifies the circuit configuration.

In particular, as shown in FIG. 3, when the scale of the small color screen is reduced to one third of that of the large color screen, the signals R, g, and b from the primary color demodulation circuit 42 for the small screen are converted into one horizontal scanning line. In other words, as a result of switching every 1H, the brightness component of the color small screen becomes close to the average of the brightness components during the 3H period, which is the period of three horizontal scans, so the image quality of the color small screen improves. It turns out.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a detailed block diagram of the main part of the same, and FIG. 3 is a time chart explaining the embodiment. A...Video signal for large screen, A'...
Small screen display signal, B... Video signal for small screen,
B5... Line switching signal, 41, 42...
...Primary color demodulation circuit, 43, 45, 48...Switch circuit, 44...Analog, digital converter, 46...Memory, 47...Digital , analog converter, 49... readout clock signal, R, G, B, r, g, b... three primary color signals.

Claims (1)

[Claims] 1. In a dual display color television, the three primary color symbols (R, G, B) for the small screen are switched line by line, stored line sequentially, and the stored three primary color signals are simultaneously read out and displayed on the large screen. 1. A method for colorizing a small screen of a dual display color receiver, characterized in that a desired part of the three primary color signals (R, G, B) is switched and displayed.