JP3010218B2 - Color printer control device and color printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a color printer.

[Related Art] In recent years, color printers for printing computer graphics, color documents, color video signals, and the like have been actively developed.

One of the conventional color printers, faithfully input information,
Some recordings do not perform any color correction. Separately from this, in the field of full-color printers, color printers that emphasize color reproducibility, perform processing to remove asymmetric color components of ink color materials, and perform color correction of specific colors such as skin color have emerged. .

[Problems to be Solved by the Invention] If a conventional color printer that does not perform any color correction faithfully is used, high-quality characters and false color graphs can be obtained. Therefore, it is not possible to obtain a satisfactory quality full-color image due to the problem of the asymmetric color component and the reproduction color area. In order to obtain a high-quality full-color image using the above-mentioned color printer, input information must be processed according to the printer before inputting to the above-mentioned color printer, which requires a great deal of labor. There is a problem that there is.

On the other hand, if a conventional color printer that emphasizes color reproducibility and incorporates color correction functions such as masking processing and skin color correction is used, full-color images can be obtained with very high quality, but false color images can be obtained. There is a problem that the quality of graphs and characters deteriorates. For example, when cyan characters are obtained, even if only cyan data is input, magenta or yellow ink may be printed in addition to cyan ink by masking processing inside the printer. In this case, multiple inks are printed, and in the case of an ink jet printer, a dot landing point shift or bleeding due to an increase in the amount of ink occurs, and in the case of a thermal transfer printer, a registration shift of overprinting occurs. The quality of the characters is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a color printer which can easily obtain a full-color image with high quality and can easily obtain false-color graphs and characters with high quality.

Means for Solving the Problems According to the present invention, mode setting information input from a host computer is determined, and a color reproduction process corresponding to characteristics for a full-color image is performed according to the determination result.
Indicates whether to perform color reproduction processing corresponding to the character and false color image characteristics, and performs color reproduction processing corresponding to the full color image characteristics and color reproduction processing corresponding to the character and false color image characteristics. The color image data obtained by performing color processing on the input color image data is output to the image forming unit based on the designated processing.

[Operation] The present invention determines mode setting information input from a host computer, and performs a color reproduction process corresponding to characteristics for a full-color image, according to the determination result, or
Indicates whether to perform color reproduction processing corresponding to the character and false color image characteristics, and performs color reproduction processing corresponding to the full color image characteristics and color reproduction processing corresponding to the character and false color image characteristics. At this time, based on the processing instructed above, color image data obtained by color processing of the input color image data is output to the image forming unit, so only by inputting mode setting information from the host computer,
The apparatus can determine the mode setting information and appropriately set the color reproduction processing for color printing according to the characteristics of the input color image. Therefore, high-quality full-color images, false-color graphs and characters can be obtained. Can be obtained extremely easily.

Embodiment FIG. 1 is a block diagram showing an embodiment of the present invention.

This embodiment is a diagram showing an embodiment in a case where it is adapted to an ink jet printer.

The black component extraction circuit 1 is a circuit that inputs data C, M, and Y of cyan, magenta, and yellow, and extracts a black component necessary for performing undercolor removal. The removal rate coefficient setting circuit 2 receives the black output data BK output from the black component extraction circuit 1 and outputs the data B according to the set UCR (under color removal) rate.
This is a circuit that multiplies K by a coefficient and outputs data BK ′, and is usually configured by a multiplier or a lookup table. The UCR circuit 3 inputs data C, M, Y, and BK ', and
This circuit removes undercolor from M and Y and outputs data C ', M' and Y '.

The image processing circuit 4 is a circuit that receives data C ′, M ′, and Y ′, performs image processing such as masking processing and color correction, and outputs data C ″, M ″, and Y ″. The processing circuit 4 is a circuit that outputs the input data C ′, M ′, and Y ′ as they are in the non-image processing mode (mode in which no image processing is performed).

The memory 5 stores output data C ″ of the image processing circuit 4,
A head driver 6 is a memory for temporarily storing M ″, Y ″ and data BK ′, and a head driver 6 is a means for converting an output of the memory 5 into a signal for driving a recording head.
Is a head for performing recording by discharging ink droplets. The mode switch 8 is a switch for instructing whether or not to perform image processing on input data. The system controller 9 is usually constituted by a microprocessor and controls the entire printer. In addition, a motor driver that is controlled by the system controller 9 and drives the carriage motor of the recording head 7
10, a carriage motor 11, a motor driver 12 for driving a paper feed pulse motor, and a pulse motor 13 for paper feed.

 Next, the operation of the above embodiment will be described.

The black component extraction circuit 1 generates undercolor removal black data BK based on the input data C ', M', Y '. data
BK is usually represented by the following relational expression.

BK = min (C, M, Y) The removal rate coefficient setting circuit 2 sets the under color removal rate BK ′ according to the data BK and the mode specified by the mode switch 8.

That is, when performing image processing (when processing a full-color image), the undercolor removal rate is set in the range of 80 to 90% for the purpose of smoothing the texture and gradation of the image, but no image processing is performed. If you are working with text or false-color images, reduce the undercolor removal rate to 10 to increase the resolution and sharpen the ink by reducing the amount of ink and bleeding.
Set it close to 0% or 100%.

FIG. 3A shows an example in which a full-color image is processed, in which the undercolor removal rate is set to 80 to 90%. FIG. 3 (2) shows a case where a character or a false color image is handled, and shows an example in which the undercolor removal rate is set to 100%.

The UCR circuit 3 performs UCR (under color removal) using the input data C, M, Y and the under color removal data BK '.

UCR is usually represented by the following relational expression according to data BK '.

C '= C-BK' M '= M-BK' Y '= Y-BK' The image processing circuit 4 performs data C ', M' from which undercolor has been removed in accordance with the mode designated by the mode changeover switch 8. ,
Y ′ is processed to perform image processing.

FIG. 2 is a circuit diagram specifically showing the image processing circuit 4 in the above embodiment.

The image processing table 15 stores input data C ', M', Y '
Is a table for performing a masking process and a color correction for. The changeover switch 16 outputs the image processing table 15 in the case of the image processing mode (when processing a full-color image) according to the mode control signal from the mode changeover switch 8, but in the case of the non-image processing mode ( When dealing with characters and false color images), the data C ', M',
Y ′ is output as it is as data C ″, M ″, Y ″.

The data C ", M", and Y "output from the image processing circuit 4 are temporarily stored in the memory 5, and the data C", M "read from the memory 5 according to the movement of the carriage motor 11 and the instruction from the system controller 9. , Y ″ are converted by the head driver 6 into printhead drive signals, and the printhead 7 ejects ink droplets according to the drive signals. Also,
Each time recording for one line is completed, a paper feed pulse motor
13 feeds the paper for one line, repeats the above-described series of operations, and the printing is completed.

In the above embodiment, since the image processing mode and the non-image processing mode can be easily selected by the mode changeover switch 8, a color image can be easily obtained with high quality, and false color graphs and characters can be formed with high quality. Can be easily obtained.

In the above embodiment, the mode changeover switch 8 is provided as the mode instructing means. However, a mode setting command is inputted by an external device (host computer or the like), and the discriminating means for performing the discrimination to determine the mode is replaced by the mode setting command. It may be used instead of the changeover switch 8.

In FIG. 2, the image processing table 15 and the changeover switch 16 are shown. However, the image processing table 15 may have a through output table for directly outputting an input, and the changeover switch 16 may be omitted. In this case, the through output table may be selected by the mode control signal. Further, instead of the image processing table 15, image processing may be performed using an arithmetic circuit.

[Effects of the Invention] According to the present invention, the mode setting information input from the host computer is determined, and the color processing characteristics when outputting color image data for image formation are determined according to the determination result. Or character false color image, so that only by inputting the mode setting information from the host computer, the device judges the mode setting information and according to the characteristics of the input color image,
The color reproduction process for color printing can be set well, so that a high-quality full-color image and false-color graphs and characters can be obtained extremely easily.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. FIG. 2 is a circuit diagram showing an example of the image processing circuit in the above embodiment. FIGS. 3A and 3B are explanatory diagrams of the above embodiment. 1 ... black component extraction circuit, 2 ... removal rate coefficient setting circuit, 4 ... image processing circuit, 8 ... mode changeover switch, 9 ... system controller, 15 ... image processing table.

Continuation of the front page (56) References JP-A-59-163944 (JP, A) JP-A-62-220072 (JP, A) JP-A-61-1171 (JP, A) JP-A-58-72144 (JP JP-A-61-1171 (JP, A) JP-A-62-47269 (JP, A) JP-A-62-236254 (JP, A) JP-A-63-40477 (JP, A)

Claims (2)

(57) [Claims] An input unit for inputting color image data to be formed; determining mode setting information input from a host computer; and performing a color reproduction process corresponding to a characteristic for a full-color image in accordance with the determination result. Determination instruction means for instructing whether to perform the color reproduction processing corresponding to the character or false color image characteristic; and the color reproduction processing corresponding to the full color image characteristic, the character or false color. Outputs color image data obtained by performing color processing on the color image data input through the input means based on the processing instructed by the determination instruction means among the color reproduction processes corresponding to the image characteristics. And a color image data conversion means. Input means for inputting color image data to be formed; determining mode setting information input from a host computer; and performing color reproduction processing corresponding to characteristics for a full-color image in accordance with the determination result. Determination instruction means for instructing whether to perform the color reproduction processing corresponding to the character or false color image characteristic; and the color reproduction processing corresponding to the full color image characteristic, the character or false color. Color image data for outputting color image data obtained by performing color processing on the color image data input through the input means, based on the processing instructed by the determination instruction means, among the color reproduction processing corresponding to the image characteristics. Conversion means; and image forming means for forming an image corresponding to the color image data converted by the color image data conversion means. A color printer, characterized in that: