JPS61126888A - Video interface device - Google Patents

Abstract

PURPOSE:To change at a high speed a color signal from RGB color system to YMC color system by equipping a color change part to change a color signal of an RGB color system fed from a video signal feed device to a YMC color system or a color signal of a color system including black. CONSTITUTION:A gate G2 takes AND of the reverse signals of R, G, and B color signals, and an NAND gate G3 outputs the reverse signal of AND of the output of an AND gate G1 and a G color signal. An NAND gate 4 outputs the reverse signal of AND of the output of gage 1 and B color signal, and an NAND gate 5 outputs the reverse signal of AND of output of AND the gate 1 and color signal of B. An OR gate G6 takes OR of the output of a gate G2 and an NAND gate G3, an OR gate G7 takes OR of the output of a gate G2 and an NAND gate G4 and an OR gate G8 takes OR of the output of the gate G2 and an NAND gate G5. Thus, high, speed change is available because a color signal is changed from the RGB color system to the YMC color system by hardware using a logic circuit, and a burden on software can be lighter. In case that the user of the data is a printer, speed down of printing can be prevented, too.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a video interface device that samples and outputs a color video signal from a video signal sending device.

[Conventional technology]

The video interface device samples the video signal sent from the video signal sending device and sends it to a color printer or the like.

Some such video interface devices process color video signals. With such a device, if the color signal sent should be of the ROB color system,
From RGB color system to MMC with video interface device
It is necessary to convert the color to a color system.

Here, the RGB color system is RED, GREEN,
It is a color system with BLUE as the three primary colors, and new colors are created by additively mixing these colors. On the other hand, the MMC color system is Y'ELLOW, MA (JN
It is a color system with TA and CYAN as three primary colors, and these colors are created by subtractive color mixing using colors of the RGB color system.

In conventional video interface devices, for example, the above-mentioned color conversion is rarely performed by software calculations.

However, such a video interface device has the problem that the conversion process takes a long time and also increases the burden on the software.

[Problem that the invention seeks to solve]

The present invention has been made in order to eliminate the above-mentioned problems64, and provides a video interface in which the conversion of color signals from the RGB color system to the MMC color system is performed at high speed, and the burden on software K for this conversion is small. The purpose is to realize the device.

In a video interface device that samples and outputs a video signal, a logic circuit is used to convert the RGB color signal sent from the video signal sending device into an MMC color signal or a color signal with black added thereto. This is a video interface device characterized by having a color conversion section that performs color conversion.

〔Example〕

The present invention will be explained below with reference to the drawings. FIG. 1 is a block diagram of the configuration of a video interface device according to an embodiment C of the present invention.

In FIG. 1, 10 is an I10 port, 20 is an oscillation circuit, 30 is a pseudo phase synchronization circuit, 40 is a delay circuit, 50 is a sampling circuit, 60 is a raster counter, 70 is a write/read control circuit, 80 is an address counter, 90 is a memo IJ, and 10G is a color conversion section.

VSYNC, )IsYNc, VIDIOR, VIDI
OG and VIDEOB are a vertical synchronization signal, a horizontal synchronization signal, a red video signal, a green video signal, and a blue video signal, respectively.

10 The board 10 serves as an interface circuit for outputting signals from the video interface device to the outside, or for inputting signals from the outside to the video interface device. Connected to this I10 port 10 is an interface bus, such as a printer interface bus, that uses data from the video interface device.

The oscillation circuit 20 generates a clock that is the basis of sampling timing.

The pseudo phase synchronization circuit 30 pseudo-synchronizes the clock from the oscillation circuit 20 with the horizontal synchronization signal H8YNC (hereinafter simply referred to as H8YNC).

The delay circuit 40 adds a delay time to the signal from the pseudo phase synchronization circuit 30 and sends it to the sampling circuit 50 .

It is selectively switched by the delay time L switch 41.

The sampling circuit 50 receives the red, green and blue video signals VIDE, timed with the signals from the delay circuit 40.
OR, VIDEOG and vxngon (hereinafter simply KVI
DEOR, VIDEOG and VIDKOB)
to sample.

The raster counter 60 indicates the address where the next instruction to be executed is stored.
Upon receiving YNC, a signal is sent to the write/read control circuit 70.

The write/read control circuit 70 receives signals from the I10 boat 10, the pseudo phase synchronization circuit 30, and the raster counter 60, as well as a vertical synchronization signal VSYNC (hereinafter simply referred to as VSYNC), and sends signals to the address counter 80 and memory 90. , controls writing and reading of the memory 90.

The memory 90 is, for example, a high-speed static RAM,
Data sampled by the sampling circuit 50 is stored.

The color conversion unit 100 is a feature of the present invention, and converts the RGB color signals that have passed through the sampling circuit 50 into YMCWHI.
It also outputs TE color signals.

Hereafter, RED, GR) JN, BLUE, YELL
OW, MAGENTA, CY notification.

BLACK, and W) IITE ftR, G, B,
Represented by Y, M, C, BL and W.

FIG. 2 is a diagram showing an example of the configuration of the color conversion section 100 shown in FIG. 1. In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals.

In FIG. 2, G1 is an AND gate), G2 is an AND gate with an inverter attached to the input section, 03 to G5 are NAND gates, and 06 to G are agates.

Antgame) Gl takes the AND of the R, G, and B color signals.

G2 calculates the AND of the inverted signals of the R, G, and B color signals.

The Nant gate G3 outputs a signal obtained by inverting the logical product of the output of the AND gate Gl and the R color signal. Nantes Gate G
4#-t Ant Game) Outputs a signal obtained by inverting the logical product of the Gl output and the G color signal. G5 outputs a signal obtained by inverting the output of the AND gate G1 and the logical brown of the B color signal.

OR gate G6 takes the output logical OR of gate G2 and gate G3. G7 takes the logical sum of the outputs of the gate G2 and the Nant gate G4. OR gate G8 takes the logical OR of the outputs of gate G2 and Nant gate G5.

And gate G1, or gate G6, or gate G7,
Oragu) G8 and Goo) G2 are both W.

These are C, M, Y, and BL color signals.

The operation of such a video interface device will now be described.

In the RGB color system in which R, G, and B are the three primary colors, new colors are created by additive color mixing using the following combinations.

Y=R+G
(1) M = B + R (branch)) C = G + B
(3)w=R+G+B
(4) Also, MMC color system 3
The primary colors Y, M, and C are created by subtractive color mixing using the following combinations.

T=W-B (5)M=
W-G (6)C=W-
R(7) Also, for W and BL, W= W+W (8) BL
== W−W (9). From formulas (5) to (9), R= W−G−B = Y+M (
G) G = W-B-R= Y+C (b) B = W-R-G = M4-C(2) BL= W-
(R+G+B) = Y+M+C ring. (1)～(
4) Expression and expressions (g) to α1 are abbreviated and expressed as K as follows.

R-RGB = YM5
a◆c==acn=ybeforeC(a) B=RGB=YMCα→y=aci=
y standing, no M=RGB=YMC(1+1 c=RGB=?C0n BL=RGB=YMCE W=RGE=YMCQl Here, the color with a bar (-) is a color that is not in the combination.α ◆~■ Expression 1 is expressed as a binary signal by assigning a 0 signal if there is a par (-) and a 1 signal if it is absent, as shown in FIG. 3.

As shown in FIG. 3, when a binary signal expressed in the RGB color system is input to the color conversion unit shown in FIG. 2, this color conversion unit converts the input signal into a binary signal expressed in the MMC color system. Convert and output. Here, whether the input signal is BL or W is determined by the AND gate Gl and G2 C
It can be determined only from the output signal.

FIG. 4 is a diagram showing another example of the color conversion section shown in FIG. 1. This color conversion section has a black and white inversion function.

In the IC of FIG. 4, G9 to GIL are gates each having an inverter attached to its input section.

Gate G9 performs a logical product of the output of AND gate G1, the output of gate G2, and a signal obtained by inverting the R color signal.

Gate G10 is the output of ant game) Gl, gate G2
The output of the G color signal and a signal obtained by inverting the G color signal are ANDed.

Gate Gll is the output of AND gate G1, gate G2
The output of B and a signal obtained by inverting the B color signal are ANDed.

2 is an inverter to which a black and white inverted signal W/BL is applied. The black and white inversion signal W/BL is H when black and white is inverted.
I become Gl' Lebel.

G12 is an AND gate, which takes the AND of the power of AND gate G1 and the signal from inverter I.

G14 is an or gate, and gates G12 and G1
Take the AND of the outputs of 3. When outputting a black color signal, the output BWd of OR gate G14 is at HIGH level.

The color conversion unit in Figure 2 creates black using three colors, Y, M, and C, whereas the color conversion unit in Figure 4 creates black using three colors, Y, M, and C.
, C, and BL are provided separately. Therefore, BL represents black by assigning an O signal to each of the Y, M, and C color signals, and assigning 1 signal to the BL color signal.

〔effect〕

According to such a video interface device, the following effects can be obtained.

From RGB color system to M using hardware using logic circuits
Since the color signal is converted to the MC color system, the conversion can be performed at high speed and the burden placed on the software can be reduced. Further, for this reason, if the side that uses the data of the video interface device is a printer, a decrease in printing speed can be prevented.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of an embodiment of a video ink face device according to the present invention, FIG. 2 is a diagram showing an example of the configuration of the color conversion section of the device of FIG. 1, and FIG. FIG. 4 is a diagram showing the correspondence of value signals. 50: sampling circuit; 100: color conversion unit. Figure 2 Figure 3 Figure 4 l

Claims (1)

[Scope of Claims] A video interface device that samples and outputs a color video signal sent from a video signal sending device, which uses a logic circuit to convert RGB color signals sent from the video signal sending device into YMC colors. 1. A video interface device comprising a color conversion unit that converts the signal into a color signal of a color system or a color system in which black is added to the color signal.