JPH02235497A - Picture display circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a screen display circuit for displaying characters or symbols on the screen of a color display such as a cathode ray tube, for example, a television.

[Conventional technology]

FIG. 3 is a block circuit diagram showing an example of a conventionally used screen display circuit. In the figure, I is a display integrated circuit, @
is a color display, here indicating a television. ■ is a display circuit, α4 is a display R O iJ ( Rsad O
nly M@mory).

Next, the operation will be explained. The display circuit [phase] is indicated as R.
O M (According to the shape of the displayed characters from 14, a color signal is generated at each terminal of R (red), G (green), and B (blue) in synchronization with the scanning of the scanning line of the color display (self). Figure 4 is a timing diagram showing the output waveform of one terminal among the R, G, and B terminals mentioned above.When not displaying (at o1?), the output level of the R, G, and B terminals is GNI. ) level, and when displaying (when ON) the output level is v
It becomes a rectangular wave with the amplitude of Go and GND level.

[Problem to be solved by the invention]

Conventional screen display circuits are configured as described above, so there is only one way to display on the color display (Og) or to erase the display (OFF), so the display instantly turns ON. There are only two ways to do this: to enter the OFIP state or to enter the OFIP state K, and there is a problem in that, for example, it is not possible to gradually increase the brightness for display.

This invention was made to solve the above-mentioned problems, and uses a single-chip integrated circuit to gradually display characters, etc. on the screen of a color display device, or to gradually erase displayed characters, etc. An object of the present invention is to provide a screen display circuit that provides such functions.

[Means to solve the problem]

The screen display circuit according to Jin's invention K is equipped with a circuit that outputs a color signal of ζ corresponding to each color terminal, and a means for outputting an analog signal in synchronization with time in response to this color signal. According to the present invention, the display can be gradually changed to OH or OIFF.

〔Example〕

Hereinafter, one embodiment of the present invention will be specifically described based on the drawings. Figure 1 is a block circuit diagram showing a screen display circuit. In Figure 1, (1) is a display integrated circuit, (2) is a color display (for example, a television), (3) is a display circuit, and (4) is a display integrated circuit.
is display ROM (Rsad Only M@mo
ry ) is a D/A:i inverter, and the output of the 01)/A converter <<5) connected to the true, G, and B outputs of the display circuit (3) is 1',
The zero-order k operation connected to the G's B' terminal and serving as the output terminal of the display integrated circuit (1) will be explained. According to the character and symbol shapes stored in the display R OM (4), an R character signal, a G character signal, and a B character signal are output from the display circuit (3). These signals are connected to a D/k converter (5). The D/▲ converter (5) is controlled by a time signal.Now, only the n character signal will be explained, and the changes in this signal are shown in the timing diagram K in FIG. When the display is OFF, the D/A converter (5)
The output of GN terminal, that is, the signal of GN
When the 0 display (D level) is sufficiently ON, the signal at the R terminal becomes %B# level (Too level) 0 During this period, the display is clearly displayed because it is sufficiently ON L. The display is 011 The period between and ON is the D/A converter p (
5) By controlling υ, GM over time
By changing the intermediate value between the D level and the Too level from the GWD level to the Woo level, it is possible to gradually display the value. This means II',
The same can be said about the G' terminal. Further, the display can be gradually changed to 01F1 by gradually lowering the output of the D/▲ converter (5) from the Woo level to the GND level with time. If so, it can be controlled by connecting the 'D/▲ converter to the R, G, and B character signals, so the display can be gradually turned on or gradually oyy.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a screen display circuit according to one embodiment of the invention of ζ, Fig. 2 is a timing diagram showing the waveform of the λ character signal of the circuit of Fig. 1, and Fig. 3 is a diagram of a conventional screen display circuit. The block diagram, FIG. 4, is the R, G, ! of the circuit in FIG. 3. FIG. 4 is a timing diagram showing an output waveform of one terminal. In the figure, (1) is a display integrated circuit, (2) is a color display, (3) is a display circuit, (4) is a display ROM, and (5) is a display integrated circuit.
) is a /A converter.

Claims (1)

[Claims] In a screen display circuit that performs color display by outputting color signals from the display circuit to a plurality of color terminals of a color display path, the display can be performed by providing means for outputting analog signals corresponding to each of the color terminals. A screen display circuit characterized in that the display is gradually displayed or the display is gradually erased.