JPH0321989A - Display control circuit - Google Patents

Abstract

PURPOSE:To represent not only eight kinds of output colors based upon combinations of an R, a G, and a B output, but neutral tints, etc., by providing a control circuit which outputs different color outputs of >=2 colors alternately or sequentially. CONSTITUTION:This display control circuit has an R control circuit 4 which controls an R signal inputted from an R input terminal 1, a G control circuit 5 which controls a G signal inputted from a G input terminal 2, and a B control circuit 6 which controls a B signal inputted from a B input terminal. Further, the circuit is equipped with an alternate output control circuit 13 which outputs a control signal CNTG signal 10 to the R control circuit 4, a control signal CNTG signal 11 to the G control circuit 5, and a control signal CNTB signal 12 to the B control circuit 6. Consequently, an output color can represent subtle differences of not only the eight kinds of colors based upon the combinations of the R, G, and B outputs, but neutral tints, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a display control circuit, and particularly to a display control circuit such as an LSI for on-screen character display.

[Conventional technology]

3. As shown in Fig. 3, a display control circuit in an image display device having RGB output outputs eight types of colors by combining three color signals of R, G, and B.

FIG. 4 is a diagram showing combinations of the above-mentioned eight types of color output and RGB signals.

For example, cyan is a combination of G and B signals of R, G, and B signals, and magenta is a color that is a combination of R and B signals.

[Problem to be solved by the invention]

In the above-mentioned image display device, since the output colors are limited to eight types based on the combination of RGB output, there is a drawback that subtle differences such as intermediate colors cannot be expressed.

[Means to solve the problem]

The display control circuit of the present invention includes an alternate output control circuit that controls alternate output of R, G, and F3 signals, an R control circuit that controls the R signal, a G control circuit that controls the G signal, and a B signal that controls the B signal. It has a control circuit. [Example] The details of the present invention will be described below with reference to the drawings.

FIG. 1 shows a display control circuit according to an embodiment of the present invention.

R input terminal 1, G input terminal 2, B input terminal 3, and the R
R control circuit 4 that controls the R signal input from input terminal 1
, a G control circuit 5 for controlling the G signal inputted from the G input terminal 2, and a B control circuit 6 for controlling the B signal inputted from the B input terminal. A control signal CN'T' R signal 10 to be input, a control signal CNTG signal 11 input to the G control circuit 5, and a control signal CNTB signal 12 input to the B control concave path 6.
It has an alternate output control circuit 13 that outputs.

Next, the operation of this embodiment will be explained with reference to FIG.

Figure 2 shows the circuit in Figure 1 with magenta (R and B) and blue (B).
2 is a timing chart when outputting an intermediate color.

When outputting an intermediate color between magenta (R and B) and blue (B), CNTB is always at a high potential, and blue (B signal) is always output.

On the other hand, the R signal is output ○N/OFF by the CNTR signal.
is output repeatedly.

As a result, magenta (R and B) and blue (B) are outputted alternately, and the color visually appears to be an intermediate color between magenta and blue.

Although the above description has been made regarding an example in which the present invention is implemented to output a color intermediate between magenta and blue, it is clear that the present invention is not limited to the above example and can be applied to other colors as well.

〔Effect of the invention〕

According to the display control circuit of the present invention, it is possible to obtain a display control circuit that can express not only eight types of output colors by combining R, G, and B outputs but also intermediate colors and the like.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a display control circuit according to an embodiment of the present invention, Fig. 2 is a timing chart when the circuit of Fig. 1 outputs an intermediate color between blue and magenta, and Fig. 3 is a conventional display control circuit. It is a circuit diagram of an example of a circuit, and FIG. 4 is a diagram showing the relationship between RGB signal combinations and colors. 1...R input terminal, 2...G input terminal, 3...B
Input terminal, 4...R control circuit, 5...G control circuit,
6...B control circuit, 7...R output, 8...G output, 9...B output, 10...CNTR signal, 11...
・CNTG signal, 12...CNTB signal, 13
...Alternate output control circuit.

Claims (1)

[Claims] A display control circuit for an image display device having an RGB output, comprising a control circuit that alternately or sequentially outputs two or more different color outputs.