JPS62131668A - Color copying machine - Google Patents

Abstract

PURPOSE:To obtain an optimum print by the selection of the operator by selecting the full color mode and the multi-color mode emphasizing the print speed. CONSTITUTION:In case of the multi-color mode, the black part of an original is transferred onto the transfer paper by using the information read by three CCDs, 16B, 16G and 16R through the first original scanning. Then a color of each picture element on the original is discriminated to be a specific color near it by using the information read by the 3 CCDs 16B, 16G and 16R. Thus, the original in one color is discriminated as any of yellow magenta, cyan and black colors, then one image forming is enough and the time is reduced to 1/4 in comparison with the time of the full color copy. In case of the copy of a black/read original, the time is halved in comparison with that of the full color.

Description

Detailed Description of the Invention Technical Field The present invention scans an original once, separates the colors into blue, green, and red, reads them, and then reads them into black, yellow, and blue based on the separated image information.
The present invention relates to a color copying machine that outputs image writing information to form images in magenta and cyan colors to a printer as electrical signals, and forms images in each of the above colors sequentially, overlapping them, and printing them.

As one method of conventional color copying machine, Japanese Patent Application Laid-Open No. 59-1.5
In Publication No. 3970, a document is scanned once and three colors of blue, green, and red are printed.
The colors are separated and read, and from the read image information of each color,
It determines whether the color of each image on the original is a specific color: black, yellow, magenta, cyan, blue, green, or red, and prints the four-color printing device of black, yellow, magenta, or cyan. For example, if it is only black, print once with black, and if it is black and red, print black, yellow, and magenta multiple times, and so on. A color copying machine has been proposed that performs an image forming process, performs overlapping printing, and then discharges the paper.

However, with the exception of black, there is almost no possibility that the actual color of a manuscript is a pure specific color, and most colors are a mixture of yellow, magenta, and cyan, such as red ballpoint pen or vermillion ink color. There are also a wide variety of colors, and it is not necessarily magenta printed by a printer or red obtained by mixing yellow and magenta in a specific ratio. Therefore, the current t
l-"It is true that a specific color copy that can be reproduced in a pair of prints addressed to 14"--almost impossible.

However, apart from photographs and paintings that require color reproducibility, for office documents, for example, when writing with black and red ballpoint pens, it is sufficient to be able to distinguish between black and red. The red on the print does not have to be the same as the red on the original. However, it is more important to reduce the number of prints and increase the copy speed by printing in a specific color that is close to the color of the original.

Purpose In view of the above-mentioned circumstances, the present invention aims to provide optimal printing based on the operator's selection, emphasizing color reproducibility for color photographs and paintings, and emphasizing printing speed for office documents, etc., depending on the nature of the original. The purpose is to provide a color copying machine that can be obtained.

Structure In order to achieve the above object, the present invention separates and reads a document into the three colors of blue, green, and red, and reads the original into the three colors of black, yellow, magenta, and cyan based on the separated image information of each color. Output the image writing information to the printer as an electrical signal 1 - In a color copying machine that forms images in the above colors sequentially and prints them overlappingly, emphasis is placed on color reproduction 1 - Full color mode and print speed It has a selectable multi-color mode that emphasizes color, and in full-color mode, parts determined to be black based on the color separation information of the original are black.
The chromatic color parts separated into blue, green, and red are imaged in yellow, magenta, and cyan, respectively.In multicolor mode, the color of each part of the document is changed to black, yellow, magenta, cyan, or Determine which color is closest to a specific color expressed by mixing two colors, create an image with that color,
At the same time as the 11 originals are read and scanned once, an image is created in black, and it is determined whether or not to create an image in each other color, and the image is created by scanning the required number of times, overlaid, printed, and ejected. Features.

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

FIG. 1 shows an example of the configuration of a color copying machine to which the present invention is applied, plus (1) a control device according to the present invention.

A color copying machine has a color scanner 1 as the document reading section.
, a color printer 2 and a color scanner 1 to process image information that has been separated into colors and read, and outputs the processed image information to the color printer 2 to control the system, and a color processor and a system coat roller 6.

A contact glass 11 is provided on the top surface of the color scanner 1, and an original 12 placed on the top surface of the contact glass 11 is irradiated by a light source 13, and the reflected light is transmitted through a reading scanning optical system 14 to a spectroscopic prism 15 to be divided into blue, blue, and blue. It is separated into five color beams of green and red, and each is sent to separate CCDs 16B, 16G, and 16R.
The photoelectrically converted digital signal is sent to the color image processing section 3 in the color processor/system controller 6.
Image information processed in step 1 and to be imaged in each color of yellow, magenta, cyan, and black is output to the laser drive circuit 32. In FIG. 1, each circuit within the color processor/system controller is drawn outside due to space limitations.

The color printer 2 includes a laser writing optical system 21, a photoreceptor drum 22, and yellow, magenta, cyan, and black developing units 23Y arranged around the photosensitive drum 22 in this order.

23M, 23C, 23Bt, transfer drum 24, paper feed section 2
5. It has a fixing device 26, and the laser optical system writes on the photosensitive drum 22 using the image information signals of each color inputted to the laser via the laser drive circuit 32, thereby forming an electrostatic latent image. , are developed with a developing device for each color for each writing scan, are fed to the transfer drum 24 from the paper feed section 25, and are superimposed and transferred onto the wrapped transfer paper, completing the required number of transfers. The transferred paper is transferred to the transfer drum 24.
After being peeled off and fixed in the fixing device 26, the paper is discharged to a paper discharge tray 27 outside the machine.

Now, the color copying machine of the present invention has a full-color mode that emphasizes color reproducibility for color photographs and paintings, and a multi-color mode that emphasizes copy speed rather than faithful color reproduction, such as for business documents. It is provided in a selectable manner so that the operator can easily select it on the operation panel.

When full color mode is selected, the document is scanned four times, the first time using six CCD16Bs.

From the outputs of 16G and 16R, the color image processing unit 31 determines that pixels for which no color signal is output are black, and outputs and writes image signals to be developed in black to the laser drive circuit;
Black developer 23 Develops with Bt, then 16B, 16G
, 16R are input to the laser drive circuit as write signals for MCi, yellow, yellow, and cyan, and the latent images in the dark areas formed on the photoreceptor are developed in yellow, magenta, and cyan, respectively, through the laser writing optical system 21. By superimposing and transferring the images onto the transfer paper on the transfer drum 24, a copy that is faithful to the color of the original is created.

Next, in the case of multicolor mode, the information read by the six CCIs (16B, 16G, and 16R) during the first document scan is input to the laser drive circuit as a black writing signal, and the information is input to the laser drive circuit as a black writing signal. It is similar to the full color mode in that the latent image formed on the photoconductor is developed in black with a writing optical system and transferred to transfer paper, but in order to reduce the number of colors to be developed, six CCD 16B, 16G, 16
Based on the information read by R, the color of each pixel on the document is determined to be a specific color close to that color. If the specific colors are yellow, magenta, cyan, blue, green, red, black, and white, the areas determined to be yellow, magenta, cyan, or black will be reproduced in one development, and will be reproduced in blue, green, red. The portions determined as such are reproduced by two development steps.

FIG. 2 shows an example of a color determination method. As shown in Figure 2(a), when a document written with a red ballpoint pen is read with ColorsGanner-1, the density of magenta is approximately 52%, yellow is 23%, and cyan is 25%. (
As shown in b), magenta is regarded as 100%, yellow and cyan as 0%, and the color processor outputs it to the laser drive circuit.

By doing this, copying of an original written with black and red ballpoint pens can be completed by scanning the original twice. The criteria for determining a specific color from CCD read information are as follows.

b) If the color density of all three colors is 50% or less, it is determined to be the maximum color.

2) If yellow and cyan are 50% or more, it will be green.

C) If yellow and magenta are 50% or more, it is considered light.

2) If magenta and cyan are 50% or more, it is considered front.

e) If only yellow is 50% or more, it is considered yellow.

f) If only magenta is 50% or more, mark it as magenta.

g) If only cyan is 50% or more, it is considered cyan.

As a result of the above, if a document written in one color is determined to be yellow, magenta, cyan, or black, only one image creation is required, which takes % of the time required for full-color copying.

Copying the black and red original mentioned above takes half the time compared to full color copying.

1, the color information of yellow, magenta, and cyan outputted from the color image processing section 61 is input to the color judgment section 36, and the color judgment is performed according to the above criteria. It determines whether a color imaging step is necessary and outputs the result to the system controller 64. The system controller 64 selects a necessary work procedure and issues instructions to each station by a method not shown. For example, what color to output the optical information to be developed next to the laser drive circuit 32, what color developing device to operate in the developing section, when to eject the transfer paper to the transfer drum, how to feed the paper, etc. It instructs the unit when to feed the next paper, and if the unit is equipped with an automatic document feeder (ADF), when to replace the original. The display unit also displays the color to be copied so that the operator can understand.

Note that it will be even easier to express blue with cyan and red with magenta. For office documents, this is sufficient.

As an example, an apparatus using a laser printer using an electrophotographic method as a printer has been described above, but it is also possible to use a thermal transfer method that performs field-sequential recording. Furthermore, when applied to a color facsimile or the like other than a copying machine, the transmission speed can be reduced.

Effects As described above, according to the present invention, a black-only original can be copied at four times the speed of full-color copying, and a two-color original can be copied at twice the speed. Furthermore, since the number of times to scan and the print color are automatically determined, even originals of different colors can be copied at the optimum speed for each original by placing them on the automatic document feeder. Also, by selecting full color mode and multicolor mode,
Printing can be performed that suits the nature of the original.

[Brief Description of the Drawings] Fig. 1 is a sectional view and a control circuit diagram showing an embodiment of the present invention;
FIG. 2 is a graph showing an example of a color determination method in multicolor mode according to the present invention. 1... Color scanner (original color separation reading/scanning unit) 2.
...Color printer 5...Color processor/system controller 12
...Original 14...Reading optical system 15.
... Spectroscopic prism 16B, 16G, 16R...
・CCD21...Writing optical system 22...Photoreceptor 23Y, 23M, 21C, 25Bt...Developer 31.
...Color image processing section 32...Laser drive circuit 66...Color judgment section 34...System controller 2: 鵡(a) '/a MC 2 times(b) Om MC

Claims (1)

[Claims] The document is separated into three colors (blue, green, and red) and read, and based on the image information of each color separated, image writing information to create an image in each color of black, yellow, magenta, and cyan is sent to the printer as an electrical signal. A color copying machine that prints images in the above colors sequentially and overlays them, has a selectable full-color mode that emphasizes color reproduction and a multi-color mode that emphasizes print speed, and when in full-color mode, Based on the color separation information of the original, the parts determined to be black will be imaged in black, and the chromatic parts separated into blue, green, and red will be imaged in yellow, magenta, and cyan, respectively, and in multicolor mode, the color separation of the original will be performed. Based on the reading information, the color of each part of the document is determined to be an approximate color of black, yellow, magenta, cyan, or a specific color expressed by a mixture of these two colors, an image is created with that color, and the first document is read. A color copying machine characterized by forming an image in black at the same time as scanning, determining whether or not it is necessary to form an image in other colors, scanning a required number of times to form an image, overlapping the images, printing, and ejecting the image. .