JPH0561434A - Interface circuit - Google Patents

Abstract

PURPOSE:To reduce a circuit scale by using a gradation selector circuit both as for monochromatic data and color data. CONSTITUTION:The monochromatic data is inputted to input of either R, G, or B, and it is used in the gradation selector circuit of either R, G, or B. In other words, gradation data is generated in a gradation generation circuit 19, and the gradation data is outputted from the gradation selector circuits 14-16 by selecting a monochromatic input data signal. When a selector 13 selects the monochromatic signal by a status signal, the monochromatic signal is inputted to the gradation selector circuit 16, and specific gradation data is selected and outputted. The output of the gradation selector circuits 14, 15 are inputted to an LCD data conversion circuit 17 for color, and that of the gradation selector circuit 16 is also inputted to an LCD data conversion circuit 11 for monochrome. Therefore, the circuit scale by the share of one gradation selector circuit part can be reduced.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flat panel interface circuit.

[0002]

2. Description of the Related Art A conventional flat panel interface circuit for both color and monochrome is separate from a color interface circuit and a monochrome interface circuit as shown in FIG.

Referring to the drawing, as shown in FIG. 2, the gradation data created by the 29 gradation generating circuits is 21.
It is selected and output by each of the red, green, blue, and monochrome data input in each of the gradation selector circuits 22, 23, and 24. The output data is a color LCD data conversion circuit of 26 for color data and 28 for monochrome data.
Input to the monochrome LCD data conversion circuit of
Converted to data.

[0004]

As described above, when an interface for color and an interface for monochrome are made to coexist in one chip, there are few sharable parts and data is output just before the LCD output. It was just multiplexed.

However, as the number of bits of the data signal increases and the gradation display circuit becomes complicated, the circuit scale becomes large,
It has been a cause of increase in chip size. In addition, this increases power consumption, making it unsuitable for flat panel interfaces of products such as laptops and notebooks that aim to be lightweight and thin due to increased power consumption and increased mounting area. ..

[0006]

Therefore, according to the present invention, red,
In a flat panel interface circuit having digital inputs of green, blue, and monochrome, a grayscale generation circuit, a grayscale selector circuit, a color LCD data conversion circuit, and a monochrome LCD data conversion circuit are provided, and the red, green, The monochrome data is input to any one of the blue inputs, and the one of the red, green, and blue gradation selector circuits is used for the monochrome data.

[0007]

By using the flat panel interface circuit configured as described above, the gradation selector circuit can be used for both monochrome data and color data, so that the circuit scale can be reduced by one gradation selector circuit section. Yes, and by using the status signal to stop the LCD data conversion circuit, the power consumption can be reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, R is red, G is green, B is blue,
Mono is a monochrome n-bit input image data signal. Grayscale data is generated in the grayscale generation circuit 19 and is input to the grayscale selector circuits 14, 15, and 16. The status signal indicates whether the input signal is color or monochrome. The selector 13 selects B or Mono signal according to the status signal. R, G
While the signal No. is directly input to the gradation selector circuits 14 and 15, the signals B and Mono are input to the gradation selector circuits 16 after being selected by the selector 13. In the gradation selector circuits of 14, 15 and 16,
The grayscale data from the 19th grayscale generation circuit is selected by an R, G, B, or Mono input data signal and output. The outputs of the gradation selector circuits 14, 15 and 16 are input to a color LCD data conversion circuit 17 and converted into a data format for a color flat panel and output. The outputs of the 16 gradation selector circuit circuits are also input to 11 monochrome LCD data conversion circuits. Here, the data is converted into a monochrome flat panel data format and output. 17, 11 LCD
The output of the data conversion circuit is input to 12 selectors.
Like the selector 13, the selector 12 selects color data or monochrome data according to the status signal, and
Output to LCD of 8.

Now, assume that color data is input.
The status signal indicates that it is a color signal, and the selector 13 selects the B signal. This gives 14,1
The R, G, and B signals are input to the gradation selector circuits 5 and 16, respectively. Each gradation selector circuit has
Grayscale data from the 19th grayscale generation circuit is input, and specific grayscale data is selected and output by the input of R, G, and B. The data output from the gradation selector circuits 14, 15, 16 is input to the color LCD data conversion circuit 17 and converted into the color LCD data format. The output of 17 is input to the selector of 12. The status signal points to color, so 17
The output signal of is output from 12 selectors as it is,
8 is input to the LCD.

Next, assume that monochrome data is input. The status signal indicates that it is a monochrome signal,
The selector 13 selects the Mono signal. As a result, the Mono signal is input to the 16 gradation selector circuits. The grayscale selector circuit receives grayscale data from 19 grayscale generation circuits, and selects and outputs specific grayscale data by the input of the Mono. The data output from the 16 gradation selector circuits is input to the monochrome LCD data conversion circuit 11 and converted into a monochrome LCD data format. The output of 11 is input to the selector of 12. Since the status signal indicates monochrome, the output signal of 11 is directly output from the selector of 12 and input to the LCD of 18.

Further, using the status signal required in the present invention, CLK of 11 monochrome LCD data conversion circuits for color data input and 17 color LCD data conversion circuits for monochrome data input.
By stopping the input of (clock), it is possible to suppress the sequential circuit in the LCD data conversion circuit and reduce the current consumption.

[0013]

In the prior art, when integrating the interface for the color flat panel and the interface for the monochrome flat panel, there was no shared circuit. According to the present invention, the circuit scale is reduced, and the circuit is stopped by shutting out the input to an unnecessary portion, so that a large consumption current can be deleted.

[Brief description of drawings]

FIG. 1 is a block diagram of an interface circuit according to the present invention.

FIG. 2 is a block diagram of an interface circuit according to a conventional example.

[Explanation of symbols]

 11 ... Monochrome data LCD data conversion circuit 12 ... Selector 13 ... Selector 14 ... Gradation selector circuit 15 ... Gradation selector circuit 16 ... Gradation selector circuit 17 ... Color LCD data conversion circuit for data 18 ... LCD 19 ... Gradation generation circuit 21 ... Gradation selector circuit 22 ... Gradation selector circuit 23 ... Gradation selector circuit 24 ... Gradation selector Circuit 25 ... Selector 26 ... Color data LCD data conversion circuit 27 ... LCD 28 ... Monochrome data LCD data conversion circuit 29 ... Grayscale generation circuit

Claims (1)

[Claims] 1. A grayscale generation circuit, a grayscale selector circuit, and a color LCD in a flat panel interface circuit having digital inputs of red, green, blue, and monochrome.
A data conversion circuit and a monochrome LCD data conversion circuit are provided. Monochrome data is input to any one of the red, green, and blue inputs, and the red, green, or blue gradation selector circuit is input. An interface circuit characterized by being used for monochrome data.