JP3487682B2 - Color printing control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention stores image data in a memory according to a print command from a host computer,
The present invention relates to a color print control device that executes printing by a color printer of an electrophotographic system when all images of one page have been developed in a memory, and particularly prints by changing image density of an edge portion of image data to be printed. The present invention relates to a color printing control device.

[0002]

2. Description of the Related Art A conventional electrophotographic color printer is disclosed in, for example, Japanese Patent Publication No. 5-165293. First, the image forming process of this type of color printer will be described with reference to FIG. Electrophotographic color image formation is performed by utilizing the property that the photoconductor 1 is charged. First, a high voltage current is applied to the charging charger 2 to cause corona discharge in the photoconductor 1 in an uncharged state. To be charged. For example, the photoreceptor 1 stores a negative charge. (Negative charge in this example, but positive /
The negative polarity is determined by the property of the photoconductor 1 and may be a positive charge. ) Next, the image data to be written on the surface of the charged photosensitive member 1 is printed by the laser scanner L.
Exposure is performed line by line with the S laser beam. That is, at the time of exposure, a laser beam is emitted when image data = 1 (data exists). Further, in the case of a printer capable of expressing multi-values, for example, when 8 bits = 256 gradations can be printed, image data for 256 gradations are prepared, and the laser beam power is set to 2 in accordance with the image data.
The exposure is adjusted to 56 levels of strength. The image data for the exposure is based on an image captured by a document scanner (not shown) or digital data transmitted from a host computer described later. The negative charge charged on the surface of the photoconductor 1 is
Due to the characteristic (1), the charge changes to a positive charge corresponding to the exposed dot, and as a result, a printed image (electrostatic latent image) formed by the positive charge is formed on the photoconductor 1. Further, before exposure of image data, exposure of a value of image density, which is always determined, called a γ pattern is also performed.

In order to perform color printing, in order to faithfully reproduce the three primary colors of printing, C (cyan), M (magenta), Y (yellow) and K (black), and to remove the undercolor. In addition, it is necessary to superimpose four colors of K (black), and the exposure by the laser beam is also C, M, Y,
The component of each color of K is performed every time the photosensitive body 1 makes one revolution.

Next, the potential of the surface of the photosensitive member 1 is measured by the potential sensor 3, and the subsequent printing process conditions are controlled (adjustment of toner adhesion amount by development and transfer). Development unit 4
In order to form a color image, a developing unit is prepared for each color of K, C, M, and Y, and the black developing unit 5 approaches the photoconductor 1 in the first rotation of the photoconductor drum. Then, the black image is developed. Inside the developing unit, particles (carriers) having a positive charge, which are called developer 6, are attached to the surface of the roller 7, and the minus surface called toner 8 is attached to the outer surface of the attached developer 6. Particles of the coloring material having a charge of 1 are uniformly attached. When the uniformly adhered toner 8 and the photoconductor 1 forming the electrostatic latent image come close to each other, they are exposed to the positive charge of the developer 6 and changed on the photoconductor 1. Toner with negative charge because positive charge is stronger 8
Is attracted toward the photoconductor 1 having a stronger positive polarity,
It adheres to the electrostatic latent image on the surface of the photoconductor 1. The P sensor 9 detects the amount of toner 8 adhered to the γ pattern that has been exposed in advance, and controls the printing process conditions together with the potential sensor 3.

Next, from the back side of the intermediate transfer belt 10, a transfer bias roller 20 gives a charge stronger than the positive charge on the surface of the photoconductor 1 to transfer the toner 8 adhering to the photoconductor 1 to the intermediate transfer belt. Move to 10. At the time of transfer, the toner that could not be completely attached to the intermediate transfer belt remains on the photoconductor 1 after the transfer, so a negative corona discharge is performed by the pre-cleaning charger (PCC) 11 and the positive charge on the surface of the photoconductor 1 is obtained. Is suppressed and the electrostatic force of the negative charge of the toner 8 is reduced.

Further, by the drum cleaning 12,
Toner 8 that could not be completely transferred is cleaned by blade 1.
The toner 8 on the surface of the photoconductor 1 is removed by scraping off with 3. By charging, exposing, developing, transferring, cleaning, etc.,
Since the charges on the surface of the photoconductor 1 are not uniform, the static elimination lamp 14 emits a red LED to remove the residual charges and prepare for the second printing operation.

As a result of the above operation, the first color (black) toner 8 is transferred to the intermediate transfer belt 10 as the photosensitive member 1 makes one round.

Next, as in the case of the black printing operation, in the case of cyan, the cyan developing unit 15 develops the cyan toner, and the cyan toner is transferred to the intermediate transfer belt on which the black toner is transferred. Is transcribed so as to overwrite. At that time, the intermediate transfer belt 10 performs the transfer operation by accurately aligning the position of the front end with the position where the black transfer is performed.

The magenta and yellow printing operations are performed in the same manner as the cyan printing operation. By using the magenta developing unit 16 and the yellow developing unit 17, the intermediate transfer belt 10 is Four
The toner will be transferred in the form of overlapping colors.

Since the toner 8 of each color transferred to the intermediate transfer belt 10 is strongly negatively charged, the negative charge of the toner 8 is applied by the sweeper brush 18 in order to facilitate the transfer to the paper for printing. Weaken.
The four-color toner image thus formed on the intermediate transfer belt 10 is applied to the conveyed printing paper 21 by the transfer roller 19 so that the four-color overlapping toner image is collectively transferred onto the paper. I do. At the time of transfer, the toner that has not completely adhered to the printing paper 21 remains on the intermediate transfer belt that has completed the transfer. Therefore, the belt cleaning 22 scrapes off and removes the toner 8 that cannot be completely transferred. Further, in the state of being transferred, the negative charge of the toner 8 and the positive charge of the transfer roller 19 are attracted to each other, and the paper and the transfer roller 19 are wound around each other.
In order to prevent this, the separation claw 23 separates the paper,
The paper is carried by the paper carrying unit 24. By the above operation, the image formed on the printing paper is printed by the electrophotographic method by melting the toner and fixing it on the paper under high temperature and high pressure by a fixing device (not shown).

Next, a description will be given of a conventional method in which the image data created by the host computer is connected to the color printer by using the conventional color print control device and the image data is color printed. .

FIG . 13 is a block diagram showing the configuration of a conventional color printing control device (color printer controller). Kara prior art by FIG. 13 - is described relates to print control. First of all, the user is to use the host computer 3
In step 1, application software is used to create image data for which printing is desired. Host computer 3
In No. 1, the created image data is converted back into the page description language (PDL) typified by Postscript based on the print data from the user, and output to the controller of the printer 36 through the printer driver. To do. The output is based on various interface methods (RS-232
C, RS-422, Ethernet, etc.) to the host interface in the controller of the printer 36.

That is, in the host interface 32, when the image data to be printed is received, an interrupt (INTR) is generated in the CPU 33 to inform the host computer 31 that the image data has been received. C
Upon detecting the interrupt, the PU 33 receives the image data through the shared memory in the host interface 32. The received image data expressed in the page description language is decoded by the CPU 33 and converted into one image image to be printed. In the page description language, various image data such as text data, graphic data and image data are all represented by vector data. These vector data are stored in the CPU 33.
The image data is converted into image data and stored in a predetermined area of the RAM 34. That is, the CPU 33 causes the RAM
It is designated as a frame buffer area for printing in 34, and is stored as image data for each color of C, M, Y, and K at a location where an address is given. Further, when each pixel of the RAM 34 is connected to a printer capable of expressing multi-values and there are a plurality of bits, each color is stored in multi-values. For example, if the frame buffer area of the RAM 34 is 8 bits per pixel, the image data to be stored also has 256 levels of 0 to 255 in order to set the amount of toner to be loaded in 256 levels when printing. Store by value.

When the CPU 33 converts the image data received from the host interface 32 into an image image to be printed entirely and stores it in the RAM 34, the CPU 33
Communicates with the digital color printer 36 through the video interface 35.

First, the CPU 33 inquires whether or not the digital color printer 36 is busy due to the copying operation or the like using the internal controller. When the controller of the color printer 36 is ready to print, the CPU 33 causes the color printer 36 to color.
Notify the printer controller that image data will be sent. The color printer controller is the CPU
When the print execution command is received from 33, the image data stored in the RAM 34 is transferred by DMA (Direct Memory Access) through the video interface 35,
It is sent to the digital color printer 36. The image data sent is color printed by the controller inside the digital color printer 36 by the above-described color electrophotographic method.

At this time, in the above-mentioned electrophotographic system, the photosensitive drum is rotated four times to perform full-color printing of C, M, Y and K.
The image transmission to the printer 36 through 5 is also performed four times (however, if there is no image data for each color component in the image data to be printed, the image data of that color is not transmitted. ).

By repeating the operation described above, the color image data created by the host computer 31 is printed by the digital color printer 36. The flow of the above operation is shown in FIG .

[0018]

However, when the above-described color printing control device and a digital color printer are connected to perform color printing, the printing density is too high, or the edge portion of the image is There is a problem that the image looks blurry. That is, in general, a color printer is designed to print the image data captured by the original scanner beautifully, and halftone image data can be beautifully copied, while it is created by the host computer 32 or the like. The generated digital image data has a sharp change between the data of the portion where the toner is placed and the data of the portion where the toner is not placed (white: background portion),
In addition, there are many high density images. If it is possible to express with 8 bits per pixel, if a high-density image (black) that can be seen by human eyes is taken as an example, it is difficult to reach a gradation value of 200 with a scanner, but from the host computer 32 Since the user can freely set the image density, a dark color almost always tries to be expressed by the maximum density, and therefore the value of 255 (maximum value) increases.

Further, in the case of printing in color, in the method by electrophotography described above, since the toners for four colors are superimposed and printed, when the toners are transferred onto the intermediate transfer belt 10 in FIG. If the amount of toner to be used is large, the toner is made of ultrafine powder, and is scattered to more places than originally intended to be transferred. As a result, the edges of the image are blurred. Such an image will appear, and significant image deterioration will be seen. Figure 1
See 5 . The nature of the intermediate transfer method, the toner is not scattered in the transfer of the first color As shown in FIG. 15, FIG. 1
As shown in FIG. 6 , in the transfer of the second color and thereafter, the toner of the second color scatters at the image edge portion and the image deterioration is severe.

Therefore, the present invention has been made in view of the above-mentioned problems caused by the color electrophotographic method, and by changing the value of the image data at the edge portion of the image, the amount of toner to be transferred is limited to prevent toner scattering. A first object is to perform high-quality image printing without pressing and degrading the image. Further, a second object is to suppress the image deterioration caused by changing the value of the image data of only the edge portion, prevent the image deterioration of the entire area of the image to be printed, and further improve the quality.

[0021]

(1) According to the present invention, a storage unit capable of storing a plurality of colors as a print image and a print command from a host computer are received, and the contents of the print command are decoded to obtain a print image. Hands to store in the storage means
And a printing unit that sequentially prints the print images of a plurality of colors stored in the storage unit on paper with each color.
In the color print control device, the print image of the preceding print color
And the subsequent printing color that is printed over it
Both of the high-density areas of the print image of the subsequent print color
Includes a processing means for reducing the concentration in the region edge portion, the printing
The means prints the print image from the processing means on paper.
That, characterized in that.

According to this, it is possible to suppress toner scattering by limiting the amount of toner transferred in the second color and after which toner scattering easily occurs, to eliminate deterioration of the image and to improve the quality of the printed image.

[0023]

DETAILED DESCRIPTION OF THE INVENTION (2) processing means, the preceding print color
Printing the print image and the trailing print color overlaid on it
Printing of the preceding printing color in the area where both images are high density
Ru lowers the inner density region edge portion of the image. According to this, it is possible to limit the amount of toner inside the image edge of the first color, suppress the scattering of toner transferred in the second and subsequent colors at the image edge, eliminate image deterioration, and improve the quality of the printed image. Become. (3) The processing means prints with three or more colors
Printing of each area of each color where the image is high density area
Reduce the density of the image and reduce the density of the area edge
In addition Ru down. According to this, the image deterioration of the entire image is suppressed. By changing the value of the image data at the image edge portion, it is possible to limit the toner amount to be transferred, suppress toner scattering, eliminate image deterioration, and improve the quality of the printed image.

To explain the outline of the present invention more specifically, in the present invention, the host interface 32 uses the host interface 32 to generate the image data expressed in the page description language created by the host computer 31, as in the above-mentioned conventional method. Upon receipt, the CPU 33 is notified by interrupt (INTR) that the image data has been received. The CPU 33 converts the received image vector data into image data and stores it as a C, M, Y, K color image image in a predetermined area of the RAM 34.

At this time, it is determined whether or not a plurality of colors are superposed with respect to the color to be printed and whether or not the color density is high, and when the plurality of colors are developed at the same pixel, Change the density value of the edge part of the image to a small value, change the density value of the edge part of the image data of the colors to be printed in the second and subsequent colors to a small value, and slightly change the edge part of the image of the first color. An image changing process is performed in which the image data on the inner side is lost and the overall image density is reduced.

When all the image data is stored in the RAM 34 after the image density of the edge portion or the total image density is reduced, communication with the digital color printer 36 is performed as in the conventional method. To do. The color print control device is thereby operated by the digital color printer 36.
When the status is detected and the ready status is detected, the changed image data stored in the RAM 34 is transferred to the digital color printer 36 through the video interface 35.
Control to perform color printing.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 shows the configuration of a color printing control apparatus according to the first embodiment of the present invention, and FIG. 2 shows the digital color printer 3 shown in FIG.
6 shows an outline of the mechanical portion of FIG. 6, and FIG. 3 shows the CPU 3 shown in FIG.
3 shows an image data transfer control operation of No. 3. Since the configuration and function of the digital color printer 36 have already been described,
Detailed description here is omitted.

For example, image data as shown in FIG.
The operation of the first embodiment when specified by the host computer 31 will be described. In the example of FIG. 4, both the cyan image data and the magenta image data have the gradation value 2
This is the case when 55 is designated. In image printing by the digital color printer 36, when the toner is overlaid, the second and subsequent colors tend to scatter ( FIG. 16 ) . To prevent this, when drawing the image data on the intermediate transfer belt 10, Is designed so that the toner will be applied thereto as shown in FIG.

Therefore, the first color cyan is as shown in FIG.
The value of the image data is not changed, but with the second color magenta
Is the location corresponding to the address of Magenta on RAM34 is gradually expand the values as shown in FIG. That is, in FIG. 1, the CPU 33 rewrites the value of the portion corresponding to the magenta address (XA, YA) on the RAM 34 to 215, and then rewrites it to 215 in the same manner until (XB, YA). Next, the value at the location corresponding to the address (XA, YA + 1) is rewritten to 215, and the value at the location corresponding to the address (XA + 1, YA + 1) is rewritten to 230. Similarly, up to (XB-1, YA + 1), the value is rewritten as 230, and the value at the location corresponding to the address (XB, YA + 1) is rewritten as 215.

Next, the value at the location corresponding to the address (XA, YA + 2) is rewritten to 215, and (XA + 1, YA)
The value of the part corresponding to the address of +2) is rewritten as 230. The value of the portion corresponding to the address of (XB + 2, YA + 2) is written as 255, and thereafter, 255 is similarly written until (XB-2, YA + 2). The value at the location corresponding to the address of (XB-1, YA + 2) is rewritten as 230, and (X
B, YA + 2) address value 215
And rewrite.

By repeating the above operation and drawing up to the YB line which is the last line of the square, the image data as shown in FIG. 7 is written in the drawing of magenta .

However, in the first embodiment, the image data to be written is 255, but it does not have to be 255 (maximum density value), and if the density is high, the density of the edge portion of the image is high. Conversion of. Further, it is not always necessary to develop two colors, and even when there are three or more colors, the density of the edge portion of the second and subsequent colors (CMY) is converted.

As described above, at the edge portion of all the image data to be printed, it is detected whether or not overlapping printing of a plurality of colors and high density are detected, and if so, For example, after converting the image data into the values shown in FIG. 7 , the image is printed by the electrophotographic method. The flow of the above operation is shown in FIG.

In the first embodiment, the printing operation is performed in the order of K, C, M, and Y, and accordingly, in the case of this image data, the cyan image data is first expanded. Since cyan is the first color to be printed, the image data conversion of the edge portion is not performed. At the time of the drawing of magenta, as shown in FIG. 5
In order to allow the toner to be loaded as shown in the upper part, the values shown in FIG. 7 are expanded to the locations corresponding to the respective magenta addresses on the RAM 34.

As described above, it is detected whether or not overlapping printing of a plurality of colors and high density are detected at the edge portions of all image data to be printed, and if so, For example, after the image data is converted to the values shown in FIG. 7 for the second and subsequent colors of superimposition, printing is performed by the electrophotographic method. The flow of the above operation is shown in FIG .

[0036] - second embodiment - the configuration of the second embodiment is the same as FIG. 1, the CPU33
The image data transfer control operation is also similar to that shown in FIG. 3, but in the second embodiment, as shown in FIG.
"The edge part of the first and subsequent colors is converted (enclosed by zero data)". For example, the operation when the image data as shown in FIG. 4 is designated by the host computer 31 as in the first embodiment will be described. In the example of FIG. 4, the cyan image data and the magenta image data are both 25
This is the case when 5 is specified.

In the above-described digital color printer 36, since the second and subsequent colors are scattered when the toners are overlaid, the printing operation is performed in the order of K, C, M and Y in this third embodiment. In order to perform this, the cyan image data is first expanded in the case of this image data.

The CPU 33 of the second embodiment rewrites the value of the portion corresponding to the addresses XA to XB of the cyan YA line on the RAM 34 to 255. Then YA + 1
Line, the value at the location corresponding to the address (XA, YA + 1) is rewritten as 255. Next, (XA + 1,
The part corresponding to the address of YA + 1) is rewritten to 0,
After that, the operation of rewriting to 0 is repeated to count up the address, and (XB-1, YA +
Continue writing a value of 0 to the location corresponding to the address in 1). Next, the portion corresponding to the address (XB, YA + 1) is rewritten to 255 again.

Next, in the line of YA + 2, (XA, YA
The value of the part corresponding to the address of +2) is rewritten as 255. Next, the part corresponding to the address of (XA + 1, YA + 2) is rewritten to 0, the value of the part corresponding to the address of (XA + 2, YA + 2) is rewritten to 255, and after that, the operation of rewriting to 255 is repeated to rewrite the address. Counting up, (XB-2, YA + 2)
Continue writing the value of 255 up to the location corresponding to the address of. Next, the address corresponding to the address (XB-1, YA + 2) is rewritten to 0 again, and 255 is written at the position corresponding to the address (XB, YA + 2). By repeating the above-described operation and drawing up to the YB line which is the last line of this square, the image data shown in FIG. 10 is written in cyan drawing.

Next, when drawing magenta, the values shown in FIG. 4 are expanded as they are in the locations corresponding to respective magenta addresses on the RAM 34. Ie
Magenta image data as shown in FIG. 6 is written. By developing in this way, the toners are superposed as shown in FIG . However, although the image data to be written is 255 in this embodiment, it does not necessarily have to be 255 (maximum density value), and if the density is high, the density of the edge portion of the image is converted. .

Further, it is not always necessary to develop two colors, and in the case of three-color superposition printing, the densities of the edge portions of the first color and the second color are converted. In the case of color overlay printing, the first color, the second color,
And the density of the edge portion of the third color is converted. Furthermore, it goes without saying that the printing order does not necessarily have to be K, C, M, Y.

As described above, it is detected whether or not overlapping printing of a plurality of colors and high density are detected at the edge portions of all the image data to be printed, and if so, For example, when the electrophotographic printing is performed after converting the image data as shown in FIG. 10 , there is a portion having no image density immediately inside the edge portion of the image of the toner of the first color. In addition, a large amount of positive charge is generated in a portion of the first color having no density, and the toner of the edge portion of the second color is spilled to the outside. , Will spill inward.

Further, in the electrophotographic system, since the toner is fixed as a powder after the second transfer onto the paper, the powder solid toner is melted, and the toner density of the edge portion of the first color is 0.
In the part of, also attracted to the melted toner of the second color,
This portion also has the same density after fixing. (In this example,
Even in the area where the cyan density is 0, the cyan and magenta colors are fixed by melting the cyan and magenta toners. Therefore, the edges and the inside of the area appear to have the same density. become. ) The flow of the above operation is shown in FIG .

[0044] - Third Embodiment - construction of the third embodiment is the same as FIG. 1, the CPU33
The image data transfer control operation of is similar to that shown in FIG. 3 , but in this third embodiment, the contents of "convert each color edge portion" in FIG. 3 are converted into those shown in FIG. Execute the process you did. When the image density of the edge portion is converted and the superposition of three or more colors is performed, the toner scattering is obviously reduced as compared with the case where the conversion is not performed . However, as shown in FIG. And the toner of the fourth color is the transfer belt 1
The toner will fall outside rather than being attracted to the positive charge of 0, and as a result, toner scattering is difficult to be eliminated.

In order to avoid this, in the third embodiment,
As shown in FIG. 12B, the total amount of toner density of C, M, Y, K is reduced and stored in the RAM 34. When such a method is used, the toners of the third and fourth colors are also attracted to the positive charges of the transfer belt 10, so that the toner is not scattered and the ratios of the respective densities of C, M, Y, and K are reduced. Since it does not change, the density change at the edge density conversion is small. The flow of the above processing is shown in FIG . In the third embodiment, the total amount is regulated when the toner amount is 80% or more of the total amount, but this value is due to the characteristics of the color image forming apparatus and is not necessarily 80%. It doesn't have to be.

[0046]

EFFECT OF THE INVENTION At the edge portion of the image, the toner density is low, so that toner scattering does not occur. Therefore, it is possible to perform a high quality color printing operation without image deterioration.

In the mode of reducing the density of the image edge portion of the second and subsequent colors, toner scattering does not occur at the edge portion of the image because the toner density of the second color is low. Therefore, in comparison with a mode in which a high-quality color print operation without image deterioration can be performed and the efficiency of the image edge portion from the first color is reduced, the edge portion of the first color image is calculated and its image density is reduced. Since there is no time required for the conversion, the processing can be performed at high speed.

By omitting the image data slightly inside the edge portion of the image of the first color, toner scattering is eliminated at the edge portion of the image, and high-quality color printing operation without image deterioration can be performed, and 2 By superimposing printing of more than one color, there is little change in density when converting the density of the edge portion, and a higher quality image can be obtained.

In the mode of reducing the overall density, it is possible to obtain a high-quality image in which three or more colors are superposed and toner is not scattered even when the amount of toner is large.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a print control apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a mechanical portion of the digital color printer 36 shown in FIG.

FIG. 3 is a flowchart showing an image data transfer control operation of the CPU 33 shown in FIG.

FIG. 4 is a CP from the host computer 31 shown in FIG.
FIG. 3 is a plan view showing an example of image data sent to a U-bus,
(A) shows image data for cyan color recording, and (b) shows image data for magenta color recording.

5 is a graph schematically showing the toner density formed on the transfer belt 10 shown in FIG. 2 by the image data in which the CPU 33 of the first embodiment changes the density of the image data shown in FIG. is there.

FIG. 6 is a plan view showing the image data of the first color transferred by the CPU 33 of the first embodiment, and schematically the toner density formed on the transfer belt 10 by the image data of the first color. It is a graph shown in.

7 is a plan view showing image data in which the CPU 33 shown in FIG. 1 changes the density of the image data shown in FIG. 4, and FIG.
6 is a graph schematically showing the toner density formed on the transfer belt 10 by the image data whose density has been changed.

FIG. 8 is an image data of the CPU 33 of the second embodiment of the present invention.
3 is a flowchart showing a data transfer control operation.

9 is a graph schematically showing the toner density formed on the transfer belt 10 shown in FIG. 2 by the image data obtained by changing the density of the image data shown in FIG. 4 by the CPU 33 of the second embodiment. is there.

FIG. 10 is a plan view showing the image data subjected to the density conversion processing by the CPU 33 of the second embodiment, and schematically shows the toner density formed on the transfer belt 10 by the image data of the first color. It is a graph.

FIG. 11 is a flowchart showing the contents of image density conversion processing of the CPU 33 of the third embodiment of the present invention.

12 is a graph schematically showing the toner density formed on the transfer belt 10 shown in FIG. 2 by the image data in which the CPU 33 of the third embodiment changes the density of the image data shown in FIG. Yes, (a) shows the state where only the image density conversion of the edge portion is performed, and (b) shows the state where the total C, M, Y toner density is reduced in addition to the image density conversion of the edge portion.

FIG. 13 is a block diagram showing a configuration of a conventional color printing control device.

FIG. 14 is a flowchart showing the image data transfer control operation of the CPU 33 shown in FIG.

FIG. 15 is a cross-sectional view showing a state of the first-color toner moving from the photosensitive drum 1 shown in FIG. 2 to the transfer belt 10.

16 is a cross-sectional view showing a state of a second-color toner moving from the photosensitive drum 1 shown in FIG. 2 to the transfer belt 10. FIG.

[Explanation of symbols]

1: photoconductor 2: charging charger 3: Potential sensor 4: Development unit 5: Black developing unit 6: Developer 7: Roller 8: Toner (coloring agent) 9: P sensor 10: Intermediate transfer belt 11: Pre-cleaning charger (PCC) 12: Drum cleaning 13: Cleaning blade 14: Static elimination lamp (red LED) 15: Cyan developing unit 16: Magenta developing unit 17: Yellow-Development Unit 18: Sweeper brush 19: Transfer roller 20: Transfer bias roller 21: Printing paper 22: Belt cleaning 23: Separation Claw 24: Paper Transport Unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H04N 1/409 H04N 1/40 101D 1/60 B41J 3/00 B (58) Fields investigated (Int.Cl. ⁷ , DB name) ) H04N 1/40-1/409 H04N 1/46 H04N 1/60

Claims (3)

(57) [Claims] 1. Storage means capable of storing a plurality of colors as a print image, means for receiving a print command from a host computer, decoding the contents of the print instruction, and storing the print image in the storage means, the storage means. In a color printing control device having a printing unit that sequentially prints a print image of a plurality of colors stored in a unit on a sheet in each color, a print image of a preceding print color and a trailing line to be overprinted on the print image.
If the print image of the print color has a high density area,
A region of a print image of a print color has processing means for reducing the density of the edge portion , and the printing means prints from the processing means.
A color print control device , which prints an image on paper . 2. Storage means capable of storing a plurality of colors as a print image, means for receiving a print instruction from a host computer, decoding the contents of the print instruction, and storing the print image in the storage means, the storage means. In a color printing control device having a printing unit that sequentially prints a print image of a plurality of colors stored in a unit on a sheet in each color, a print image of a preceding print color and a trailing line to be overprinted on the print image.
If the print image of the print color is high density area,
Area of print image of print color Lower the density inside the edge
Has a gel processing means, said printing means prints the print image from the processing unit to the paper, color printing control apparatus, characterized in that. 3. Storage means capable of storing a plurality of colors as a print image, means for receiving a print instruction from a host computer, decoding the contents of the print instruction, and storing the print image in the storage means, the storage means. In a color print control device having a printing means for sequentially printing a plurality of print images of a plurality of colors stored in the means on paper in each color, a print image of three or more colors is a high density area for each color.
It has a further lower processing means the concentration of a region d <br/> Tsu di unit with lowering the density of the printed image of the region of the print Hand
The stage prints the print image from the processing means on paper.
That, color printing control apparatus, characterized in that.