JP2006148600A - Image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming system improving the color reproducibility of an image outputted from an image outputting part. <P>SOLUTION: When a master color copying machine (color copying machine 1) executes reading a prescribed number of times after executing the last calibration, a message indicating the necessity of executing calibration is displayed in an operating part 17 of the master color copying machine (color copying machine 1) or a slave color copying machine (color copying machine 2) to thereby execute periodical calibration, and the color reproducibility of a printed matter is always stabilized without depending upon a change in the lapse of time of reading performance or the like of an image forming device included in the image forming system. In addition, IEEE1394 or Ethernet is used for communication between color copying machines with each other to execute calibration without developing a new external interface for communication between color copying machines themselves. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention connects a plurality of image forming apparatuses each having an image input unit for inputting an image and an image output unit for outputting an image, and reads a plurality of original images read by the image input unit of the predetermined image forming apparatus. More particularly, the present invention relates to an image forming system capable of improving the color reproducibility of an image output from an image output unit.

  In the field of conventional image forming apparatuses, digital copiers that process image data digitized from analog copiers have appeared, and color copiers that can perform color printing as well as black-and-white printing have become widespread. Have been doing. This color copying machine generally has a scanner unit for inputting a document image, an IPU unit for performing various image processing on the input image data, and printing the image data subjected to the image processing on a transfer unit. And a printer unit that outputs a document image.

  In such a color copying machine, in order to realize copy printing having the same color reproducibility as an original, the scanner unit and the printer unit in each color copying machine are calibrated when the color copying machine is shipped from the factory. As a result, image processing parameters used for image processing in the IPU unit and printer unit are obtained. Then, a color copier having the image processing parameters set and stored is provided to the user, and printing is performed using the image processing parameters set and stored.

  In addition, with the recent development of communication technology, the situation surrounding color copiers has also changed significantly. By connecting multiple color copiers via the Internet, data can be sent and received between multiple color copiers. Large-scale image forming systems that enable this have become widespread.

  In such a large-scale image forming system, image data read by a scanner unit of a certain color copying machine is transmitted to another color copying machine, and the image data is received by the IPU unit or printer unit of the color copying machine that has received the image data. Processing can be performed for printing.

  However, in the above technique, when a plurality of color copiers are connected so that data can be transmitted and received, and printing is performed on a color copier different from the color copier that has read the original, printing is performed on a single color copier. There is a problem that the color reproducibility of the printed matter is deteriorated as compared with the method.

  That is, the image processing parameters used for image processing in the color copying machine are obtained by calibrating the scanner unit and the printer unit in the color copying machine as one set. However, similar image processing parameters are not set and stored.

  However, in the above prior art, since the image processing is performed in a color copier different from the color copier that has read the original, the combination of the scanner unit that has read the original and the printer that has performed the printing is It becomes different from the combination that calibrated.

  For this reason, if the image processing parameters of the color copier that has read the original document and the image processing parameters of the color copier that has received the image data are not the same, compared to the method of printing on a single color copier, There was a problem that the color reproducibility deteriorated.

Therefore, in Patent Document 1, when a plurality of image processing apparatuses such as color copiers are connected and an original image is output and printed by an image forming apparatus different from the image forming apparatus that has input the original image, the color reproducibility of the printed matter. Image forming system, image forming method, and computer-readable recording medium recording a program for causing a computer to execute the method have been proposed.
JP 2002-10083 A

  However, the above invention has the following problems.

  According to the image forming system, the image forming method, and the computer readable recording medium on which a program for causing the computer to execute the method is recorded, the image data read by the parent color copying machine by calibration is stored in the child. Although it is possible to improve the color reproducibility of printed matter when output from a color copier, each image forming apparatus passively executes calibration after waiting for an instruction from the user. You must judge yourself.

  Therefore, the present invention provides a method in which the parent color copying machine or the child color copying machine is read when the parent color copying machine has read a predetermined number of times after the last calibration is performed, or when the child color copying machine is connected to the image forming system. By displaying a message indicating that calibration needs to be executed on the operation unit of the copying machine, periodic calibration can be executed, so that the reading performance of the image forming apparatus included in the image forming system can be changed over time. However, an object of the present invention is to propose an image forming system that can always maintain the color reproducibility of printed matter.

  According to the first aspect of the present invention, at least one image forming apparatus having an image input unit that inputs an image and an image output unit that outputs an image is connected, and an image read by the image input unit of a predetermined image forming apparatus. In the image forming system that outputs the image at the image output unit of the image forming apparatus, when the number of readings of the image input unit of the predetermined image forming apparatus has reached a predetermined number of times since the last calibration pattern was output, Display means for displaying a message indicating that a calibration pattern needs to be output, and calibration obtained by reading the calibration pattern output from the image output unit of each image forming apparatus with the image input unit of the predetermined image forming apparatus Creating means for creating calibration data, and calibration data created by the creating means Zui it, and having a correction means for correcting the image input from the image input unit of the predetermined image forming apparatus.

  According to a second aspect of the present invention, in the image forming system according to the first aspect, the predetermined image forming apparatus includes the display unit.

  According to a third aspect of the present invention, in the image forming system according to the first aspect, the at least one image forming apparatus includes the display unit.

  According to a fourth aspect of the present invention, in the image forming system according to any one of the first to third aspects, the at least one image forming apparatus and the predetermined image forming apparatus are connected by IEEE1394. And

  According to a fifth aspect of the present invention, in the image forming system according to any one of the first to third aspects, the at least one image forming apparatus and the predetermined image forming apparatus are connected by Ethernet (registered trademark). It is characterized by being.

  According to a sixth aspect of the present invention, in the image forming system according to any one of the first to fifth aspects, the predetermined image forming apparatus includes the creating unit, and the at least one image forming apparatus includes the It has a correction means.

  According to the present invention, when the parent color copying machine has read a predetermined number of times after executing the last calibration, a message indicating that the operation needs to be performed on the operation unit of the parent color copying machine or the child color copying machine. By displaying, it is possible to perform regular calibration and maintain the color reproducibility of the printed matter constantly regardless of changes over time in the reading performance of the image forming apparatus included in the image forming system. .

  Hereinafter, an embodiment of an image forming system according to the present invention will be described.

  First, the configuration of the image forming system according to the present embodiment will be described. FIG. 1 is a block diagram illustrating a configuration of an image forming system according to the present embodiment. As shown in the figure, the image forming system according to the present embodiment is configured by connecting a color copying machine 1 and a color copying machine 2 via an Internet cable 5 and a HUB 4 so that data can be transmitted and received. The image data read by the copying machine 1 is transmitted to the color copying machine 2 for printing.

  Schematically, the image forming system according to the present embodiment causes the color copying machine 1 (parent color copying machine) to read the calibration patterns (pattern 21 and pattern 31) of the color copying machine 2 (child color copying machine). In the child color copying machine, calibration is performed based on the read data to calculate image processing parameters corresponding to the reading characteristics of the parent color copying machine. In this embodiment, the color copying machine 1 is a parent color copying machine and the color copying machine 2 is a child color copying machine, but the color copying machine 2 may be a parent color copying machine.

  The parent color copying machine transmits the image data read by the parent color copying machine to the child color copying machine, and the child color copying machine uses image processing parameters corresponding to the parent color copying machine for this image data. By performing image processing, a printed matter having the same color reproducibility as that of the parent color copying machine is output.

  1 to 8, with respect to the image forming system according to the present embodiment, (1) the schematic configuration and processing of each part in the color copying machine, and (2) the specific part of each part in the color copying machine. The configuration and processing, (3) calculation of image processing parameters, (4) calibration processing in the image forming system, and (5) linked printing processing in the image forming system will be described in order. In the image forming system according to the present embodiment, the color copying machine 1 and the color copying machine 2 have the same configuration. Therefore, in the following description, only the color copying machine 1 will be described for convenience.

(1) Schematic Configuration and Process of Each Part in Color Copier With reference to FIG. 1, a schematic configuration and process of each part in the color copier will be described. As shown in FIG. 1, the color copying machine 1 includes a scanner unit 11, an IPU unit 12, a printer unit 13, a parameter calculation unit 14, a control unit 15, a transmission / reception unit 16, and an operation unit 17. Via a bus, it is connected so that data can be transmitted and received.

  In the color copying machine 1, the scanner unit 11 is a unit that reads image data (a document or a calibration pattern), reads a document reflected light by an optical system, and an electric signal in a CCD (Charge Coupled Device). Conversion processing, digitization processing with an A / D converter, shading correction processing (processing for correcting illuminance distribution unevenness of the light source), scanner γ correction processing (processing for correcting the density characteristics of the reading system), etc. To do.

  The IPU unit 12 is a unit that performs image processing such as processing editing on the image data, and includes shading correction processing (processing for correcting illuminance distribution unevenness of the light source) and scanner γ correction processing (correcting density characteristics of the reading system). Processing, MTF correction processing, smoothing processing, arbitrary scaling processing in the main scanning direction, density conversion (γ conversion processing: corresponding to density notch), simple multi-value processing, simple binarization processing, error diffusion processing, dither Processing such as processing, dot arrangement phase control processing (right-sided dots, left-sided dots), isolated point removal processing, image area separation processing (color determination, attribute determination, adaptive processing), density conversion processing, and the like are performed.

  The printer unit 13 is a unit for writing image data onto transfer paper or the like. Edge smoothing processing (jaggy correction processing), correction processing for dot rearrangement, pulse control processing of image signals, parallel data and serial data Performs processing such as format conversion processing.

  In addition, the parameter calculation unit 14 plays a role as a child color copying machine based on calibration pattern read data (hereinafter referred to as “calibration data”) transmitted from the parent color copying machine. This unit calibrates the color copier and itself (child color copier).

  In general, the parameter calculation unit 14 performs machine difference correction processing, background correction processing, high density portion correction, and the like on the calibration data, so that the reading characteristics of the parent color copying machine and the child characteristics are corrected. Image processing parameters relating to the printing characteristics of the color copying machine are calculated. The image processing parameters are stored in the control unit 15 and used for processing in the IPU unit 12 and the printer unit 13 when printing image data received from the parent color copying machine.

  The transmission / reception unit 16 is a unit that performs data transmission / reception with an external color copying machine via IEEE1394 or Ethernet (registered trademark). For example, in order to fulfill the function as the parent color copying machine, a calibration start instruction command, calibration data, a linked printing start instruction command, document image data, and the like are transmitted to the child color copying machine.

  The operation unit 17 is a unit that receives processing conditions of each unit of the color copying machine from the user. For example, when performing the function as a parent color copying machine, a calibration start instruction, a calibration pattern reading start instruction, a linked printing start instruction, an original reading start instruction, and itself (parent color) during linked printing. Copiers) and child color copiers are accepted.

  The control unit 15 is a unit that controls each unit of the color copying machine based on processing conditions received by the operation unit 17. For example, when performing a function as a child color copying machine, each part is controlled to print out a calibration pattern when a calibration start instruction command is received from the parent color copying machine.

  For example, when the calibration data is received from the parent color copying machine, the control unit 15 controls each unit to calculate image processing parameters corresponding to the reading characteristics of the parent color copying machine. When a linked printing start instruction command is received from the parent color copying machine, each unit is controlled to perform image processing using image processing parameters corresponding to the reading characteristics of the parent color copying machine.

(2) Specific Configuration and Process of Each Part in Color Copier With reference to FIG. 2, the specific configuration and process of each part in the color copier will be described. FIG. 2 is a block diagram showing a specific configuration of the color copying machine (color copying machine 1, color copying machine 2) shown in FIG.

  First, the scanner unit 11 in the color copying machine will be described. As shown in the figure, the scanner unit 11 in the color copying machine includes a CCD 123, an amplifier circuit 425, a sample hold (S / H) circuit 426, an A / D conversion circuit 427, a black correction circuit 428, and a CCD. A driver 429, a pulse generator 430, and a clock generator 431 are provided.

  In the scanner unit 11, the exposure lamp irradiates a document to be copied and a calibration pattern (pattern 21, pattern 31), and the reflected light enters the CCD 123 through a reflection mirror, an imaging lens, and the like. The RGB filter of the CCD 123 separates the reflected light into three colors of Red, Green, and Blue, and the amplifier circuit 425 amplifies the analog signal to a predetermined size.

  In addition, in order to convert an analog signal into a digital signal, the S / H circuit 426 samples and holds the amplified signal at regular timings. The A / D conversion circuit 427 converts the value at this time into a digital signal represented by, for example, an 8-bit signal value.

  Here, the amplification factor of the amplifier circuit 425 is amplified so that the digital signal is within this bit value range. That is, the amplification factor of the amplification circuit 425 is determined so that the output value of the A / D conversion circuit 427 after reading a specific document density becomes a desired value. For example, during normal copying, amplification is performed so that an original density of 0.05 (reflectance: 0.891) is obtained as 240 values of 8-bit signal values.

  Further, the black correction circuit 428 reduces variations in the black level (electric signal when the amount of light is small) between the chips of the CCD 123 and between pixels, and prevents streaks and unevenness in the black portion of the image. Note that the amplification circuit 425 reduces the amplification factor when the value after A / D conversion is, for example, 240 if the amplification factor is normal, and reduces the amplification factor at the time of shading correction, and converts the digital signal value after A / D conversion. For example, the output is as small as 180. This is done to increase the sensitivity of shading correction. The reason for this is that when shading correction is performed with the amplification factor during normal copying, when there is a large amount of reflected light, a portion where the 8-bit signal after A / D conversion saturates to the maximum value of 255 occurs, and shading occurs. This is because an error occurs in the correction.

  The CCD driver 429 supplies a pulse signal for driving the CCD 123. The pulse generator 430 supplies a pulse source necessary for driving the CCD driver 429, and supplies a timing necessary for the S / H circuit 426 to sample and hold the signal from the CCD 123. The clock generator 431 includes a crystal oscillator and supplies a reference oscillation signal to the pulse generator 430.

  Next, the IPU unit 12 in the color copying machine will be described. As shown in FIG. 2, the IPU unit 12 in the color copying machine includes a shading correction circuit 401, an area processing circuit 424, an interface I / F / selector 423, a scanner γ conversion circuit 402, an image memory 403, and an image. Separation circuit 404, MTF filter 405, hue determination circuit 432, color conversion UCR processing circuit 406, pattern generation circuit 421, scaling circuit 407, image processing (create) circuit 408, and image processing printer γ A correction circuit 409 and a gradation processing circuit 410 are provided.

  In the IPU unit 12, the shading correction circuit 401 corrects the white level (electric signal when the amount of light is large). That is, by moving the exposure lamp to the white reference plate and irradiating the irradiation light, it corrects variations in white data and sensitivity in the CCD 123 that occur when the reflected light passes through the reflecting mirror, imaging lens, etc. To do.

  The area processing circuit 424 generates an area signal (area signal) for distinguishing which area in the document the image data currently being processed belongs to. The image processing parameter used in each processing unit in the subsequent stage is switched by the area signal output from this circuit. That is, the area processing circuit 424 generates an area signal by comparing the designated area information on the document with the reading position information at the time of image reading.

  Based on the area signal, the scanner γ conversion circuit 402, the MTF filter circuit 405, the color conversion UCR processing circuit 406, the image processing (create) circuit 408, the image processing printer γ correction circuit 409, and the gradation processing circuit 410 are used. Change the parameter.

  These areas are the color correction coefficient, spatial filter, and gradation conversion that are optimal for each original, such as text originals, silver halide photographic originals, halftone photographic originals, ink jets, highlighter pens, maps, and thermal transfer originals. Image processing parameters such as a table can be selected from a plurality of table settings according to the image area.

  These image processing parameters are selected from a normal image processing parameter table when the color copying machine plays a role as a parent color copying machine (color copying machine 1). When playing a role as a copying machine (color copying machine 2), a selection is made from a table of image processing parameters corresponding to the reading characteristics of the parent color copying machine calculated by the parameter calculation unit.

  The interface I / F selector 423 is used to output an image read by the scanner unit to the outside. When used as a printer unit and a scanner / IPU unit (scanner unit, IPU unit) as in a copier, the printer unit I / F selector 411 transfers to an external device (printer controller (printing control device) 419). The read image data can be taken out.

  In the scanner γ conversion circuit 402, a read signal from the scanner unit is converted from reflectance data to brightness data. In the image separation circuit 404, the character portion and the photograph portion are determined, and the chromatic / achromatic color is determined. The MTF filter 405 performs processing for changing the frequency characteristics of the image signal such as edge enhancement and smoothing according to the user's preference, such as a sharp image or a soft image.

  The color conversion UCR processing circuit 406 corrects the difference between the input color separation characteristic and the spectral characteristic of the output color material, and calculates the amount of the color material YMC necessary for faithful color reproduction. And a UCR processing unit for replacing a portion where the three colors of YMC overlap with Bk (black).

  This color correction process is performed by a predetermined matrix calculation, and the color correction process is performed by a calculation using a predetermined color correction coefficient. This color correction coefficient is changed to 12 hues obtained by further dividing each of the 6 hues of RGBYMC into 2 parts and further to every 14 hues of black and white. Further, the hue determination circuit 432 determines to which hue the read data is determined. Based on this determination result, a color correction coefficient for each hue is selected. The scaling circuit 407 performs vertical and horizontal scaling, and the image processing (create) circuit 408 performs repeat processing and the like.

  The image processing printer γ correction circuit 409 corrects the image signal in accordance with the image quality mode such as text or photograph. In addition, it is possible to simultaneously perform the background skipping. The image processing printer γ correction circuit 409 has a plurality of (for example, 10) gradation conversion tables that can be switched in accordance with the area signal generated by the area processing circuit 424 described above. This gradation conversion table is an optimum gradation conversion table for each original such as text originals, silver halide photographic originals, halftone photographic originals, inkjets, highlighters, maps, thermal transfer originals, etc. You can choose.

  That is, in the image processing printer γ correction circuit 409, the decoder 1 decodes the area signal from the area processing circuit 424, and the selector 1 selects from a plurality of gradation conversion tables such as characters and ink jets. For example, for a character area, a gradation conversion table 1 for characters, for a silver salt photograph area, a gradation conversion table 3 for a silver salt photograph, and for a halftone dot area, The gradation conversion table 4 for halftone photo originals is selected.

  The gradation processing circuit 410 performs dither processing or pattern processing. Since the output of the gradation processing circuit 410 lowers the pixel frequency to ½, the image data bus has a 16-bit width (8-bit) so that data for two pixels can be simultaneously transferred to the printer unit. 2) of image data.

  That is, the image signal (image data) subjected to gradation conversion by the image processing printer γ correction circuit 409 is based on the signal decoded by the decoder 2 in the gradation processing circuit 410 so as to correspond to the area signal again. The selector 2 switches the gradation process to be used. As usable gradation processing, processing without dithering, processing with dithering, error diffusion processing, and the like are performed. The error diffusion process is performed on the ink jet document.

  The image signal after the gradation processing is selected by the decoder 3 as line 1 or line 2 based on the reading position information. Line 1 and line 2 are switched every time one pixel differs in the sub-scanning direction. The data of line 1 is temporarily stored in a FIFO (First In First Out) memory located downstream of selector 3, and the data of line 1 and line 2 are output. Thereby, the pixel frequency can be reduced to ½ and input to the interface I / F selector 411.

  The pattern generation circuit 421 generates gradation patterns used in the IPU unit and the printer unit, respectively.

  Next, the printer unit 13 in the color copying machine will be described. As shown in FIG. 2, the printer unit 13 in the color copying machine includes an image forming printer γ correction circuit 412, a printer 413, an I / F selector 411, a system controller 417, and a pattern generation circuit 432. Configured.

  In the printer unit 13, the I / F selector 411 outputs image data read by the scanner unit 11 to an external device such as the host computer 418, and the external host computer 418 or other color copying machine (parent color copying machine). ) Has a switching function for controlling the reception of image data from.

  Further, the image forming printer γ (procedure γ) correction circuit 412 converts the image signal from the I / F selector 411 with a gradation conversion table, and outputs it to a laser modulation circuit (not shown).

  As described above, the printer unit 13 includes the I / F selector 411, the image forming printer γ correction circuit 412, the printer 413, and the system controller 417, and is independent of the scanner unit 11 and the IPU unit 12. Even it can be used. Accordingly, the printer unit 13 inputs the image data of the parent color copying machine received by the transmission / reception unit 17 by the I / F selector 411, converts the gradation by the image forming printer γ correction circuit 412, and forms the image by the printer 413. Can be used as a printer function (printer).

  Next, the control unit 15 in the color copying machine will be described. As shown in FIG. 2, the control unit 15 in the color copying machine includes a CPU 130, a ROM 131, and a RAM 132.

  In the control unit 15, the CPU 130 controls the scanner unit 11, the IPU unit 12, the printer unit 13, the parameter calculation unit 14, the transmission / reception unit 16, and the operation unit 17. That is, the CPU 130 is connected to these units via a bus, and reads and writes data necessary for control between the ROM 131 and the RAM 132.

  Further, the CPU 130 controls a scanner driving device (not shown) and controls the driving of the scanner unit. The ROM 131 stores image processing parameters.

(3) Calculation of Image Processing Parameter Next, calculation of the image processing parameter in the parameter calculation unit 14 of the color copying machine will be described. FIG. 3 is a diagram showing a calibration pattern output from the color copying machine (color copying machine 2) shown in FIG. As shown in the figure, the calibration pattern is formed by a plurality of density gradation patterns corresponding to each image quality mode of YMCK, characters, and photographs, and is stored and set in advance in the ROM 131 of the control unit 15. Yes.

  The calibration pattern is output from the child color copying machine when the parent color copying machine has read a predetermined number of times after the last calibration is executed. It should be noted that when the parent color copying machine performs reading a predetermined number of times after the last calibration is executed, the operation unit 17 of the parent color copying machine or the child color copying machine needs to be calibrated. Is displayed (shown in FIGS. 7 and 8), prompting the user to perform calibration. When the fact that calibration needs to be executed (shown in FIG. 7) is displayed on the operation unit 17 of the child color copying machine, a calibration start instruction command is transmitted from the parent color copying machine to the child color copying machine. Is not executed. Therefore, the child color copier waits for an instruction to execute calibration from the operation unit 17 of the own apparatus, and executes the calibration. On the other hand, when the fact that calibration needs to be executed (shown in FIG. 8) is displayed on the operation unit 17 of the parent color copying machine, the parent color copying machine executes calibration from the operation unit 17 of the own apparatus. After waiting for such an instruction, a calibration start instruction command is transmitted to the child color copying machine to prompt the child color copying machine to execute calibration.

  The printer unit 13 of the child color copying machine writes the calibration pattern stored in the ROM 131 on the transfer paper in 16 hexadecimal display patterns of 00h, 11h, 22h,... EEh, FFh. In FIG. 3, patches for five gradations are displayed except for the background portion, but any value can be selected from the 8-bit signals of 00h-FFh.

  Subsequently, a transfer paper (hereinafter referred to as “pattern”) on which the calibration pattern is printed is placed on the document table of the parent color copying machine (color copying machine 1), and this pattern is read by the scanner unit 11. This read data (hereinafter referred to as “calibration data”) is transmitted to the child color copying machine (color copying machine 2). Then, the parameter calculation unit 14 of the child color copying machine performs calibration on the calibration data, and calculates image processing parameters corresponding to the reading characteristics of the parent color copying machine.

  Specifically, the parameter calculation unit 14 uses the calibration data, the reference data stored in the ROM 131 and the machine difference correction value in advance, to perform machine difference correction, background correction, high density part correction, and the like. By performing for each color, an image processing parameter (YMCK gradation correction table) is created for each image quality mode such as a photograph and text.

  The created image processing parameters are stored in the ROM 131 and used when image processing and printing processing are performed on the image data received from the parent color copying machine (color copying machine 1). Thus, the child color copying machine (color copying machine 2) can output a printed material having the same color reproducibility as the printed material of the parent color copying machine. In addition, when a child color copier is connected to the image forming system, or when the color copier has performed a predetermined number of readings since the last calibration, it is necessary to perform calibration. By using the copying machine or the child color copying machine, the image quality from the child color copying machine can be kept constant.

(4) Calibration Process in Image Forming System Next, a calibration process procedure in the image forming system according to the present embodiment will be described. FIG. 4 is a flowchart illustrating a calibration processing procedure in the image forming system according to the present embodiment.

  When the color copying machine 1 performs a predetermined number of readings after the last calibration is executed, a message indicating that calibration needs to be executed is displayed on the operation unit 17 of the color copying machine 1 (step S4000). When the user gives an instruction to start calibration with the color copier 2 from the operation unit 17 of the color copier 1, a calibration start instruction command is transmitted to the color copier 2 (step S4001).

  Next, the color copying machine 2 receives the calibration start instruction command and prints a calibration pattern (step S4002). Then, the calibration pattern is placed on the scanner unit 11 of the color copying machine 1 (step S4003), and the color copying machine 1 reads the placed calibration pattern (step S4004), and color copies the read data. It transmits to the machine 2 (step S4005).

  The color copying machine 2 receives the read data (step S4006), and the parameter calculation unit 14 calculates image processing parameters based on the received read data (step S4007), and controls the calculated image processing parameters. The data is stored in the unit 15 (step S4008).

  On the other hand, when it is displayed on the operation unit 17 of the color copying machine 2 that the calibration needs to be executed, the calibration (shown in FIG. 5) is executed through the following processing.

  First, when the color copying machine 1 performs a predetermined number of readings after the last calibration is executed, a message indicating that the calibration with the color copying machine 1 is executed is displayed on the operation unit 17 of the color copying machine 2 ( Step S5000). Then, the user requests the start of calibration with the color copying machine 1 from the operation unit 17 of the color copying machine 2 to the own apparatus (step S5001).

  Next, the color copying machine 2 prints a calibration pattern (step S5002). Then, the calibration pattern is placed on the scanner unit 11 of the color copying machine 1 (step S5003). The color copying machine 1 reads the placed calibration pattern (step S5004), and the read data is color copied. It transmits to the machine 2 (step S5005).

The color copying machine 2 receives the read data (step S5006), and the parameter calculation unit 14 calculates image processing parameters based on the received read data (step S5007), and controls the calculated image processing parameters. The data is stored in the unit 15 (step S5008).
(5) Linked Printing Process in Image Forming System Next, a linked printing process procedure in the image forming system according to the present embodiment will be described. FIG. 6 is a flowchart showing a procedure of linked printing processing in the image forming system according to the present embodiment. First, when an instruction to start linked printing processing with the color copying machine 2 is given by the operation unit 17, the color copying machine 1 transmits a linked printing processing start instruction command to the color copying machine 2 (step S6001). .

  Next, the color copying machine 2 receives the start command for the linked printing process and selects an image processing parameter corresponding to the reading characteristics of the color copying machine 1 from the ROM 131 (step S6002).

  Then, the color copying machine 1 reads an original with the scanner unit 11 (step S6003), generates image data (step S6004), and sends the image data to the IPU unit 12 and also to the color copying machine 2 (step S6004). Step S6005). Next, the color copying machine 1 performs various image processing in the IPU unit 12 (step S6006), and prints image data in the printer unit 13 (step S6007).

  On the other hand, the color copying machine 2 receives the image data from the color copying machine 1 (step S6008), and performs various image processing in the IPU unit 12 using the image processing parameters selected in step S502 (step S502). In step S6009), the printer unit 13 prints image data (step S6010).

  As described above, in this embodiment, the color copying machine 1 creates calibration data obtained by reading the calibration pattern output from the printer unit 13 of the color copying machine 2 by the scanner unit 11 of the color copying machine 1. The parameter calculation unit 14, the control unit 15, the IPU unit 12, and the printer unit 13 of the color copying machine 2 correct the document image input from the scanner unit 11 of the color copying machine 1 based on the calibration data. Therefore, the printed material of the original image output from the color copying machine 2 has the same color reproducibility as the printed material of the color copying machine 1 to which the original image is input. Therefore, when copying a large amount of originals with only one copy in a short time, the color reproducibility of the printed matter can be improved.

  In the present embodiment, the parameter calculation unit 14 of the color copying machine 2 relates to the reading characteristics of the scanner unit 11 of the color copying machine 1 and the printing characteristics of the printer unit 13 of the color copying machine 2 based on the calibration data. The image processing parameters are calculated, and the IPU unit 12 and the printer unit 13 use the image processing parameters calculated by the parameter calculation unit 14 to convert the document image input from the scanner unit 11 of the color copying machine 1. Therefore, it has a uniform color reproducibility similar to a printed matter in the color copying machine 1 to which an original image is input. Therefore, when copying a large amount of originals with only one copy in a short time, the color reproducibility of the printed matter can be improved.

  In the present embodiment, the parameter calculation unit 14 of the color copying machine 2 compares the calibration data with the predetermined target data to calculate the image processing parameters used for gradation conversion. Has the same uniform color reproducibility as the printed matter in the color copier 1. Therefore, when copying a large amount of originals with only one copy in a short time, the color reproducibility of the printed matter can be improved.

  In the present embodiment, the control unit 15 of the color copier 2 stores the image processing parameters calculated by the parameter calculation unit 14, the IPU unit 12 and the printer unit 13, and the scanner unit 11 of the color copier 1. Only when the input original image is output, the original image input from the scanner unit 11 of the color copying machine 1 is converted using the image processing parameters stored in the control unit 15. Even when used as a single color copying machine, the color reproducibility of printed matter can be maintained.

  In this embodiment, the case where the image processing parameter is calculated in the color copying machine 2 is shown. However, the present invention is not limited to this, and the color copying machine 1 calculates the image processing parameter. Image processing parameters can be stored, image processing using image processing parameters, and the like can be performed. It is also possible to cause another apparatus to perform processing such as calculation of image processing parameters, storage of image processing parameters, and image processing using image processing parameters.

  Furthermore, in this embodiment, when the parent color copying machine performs reading a predetermined number of times after executing the last calibration, it is necessary to perform calibration on the operation unit of the parent color copying machine or the child color copying machine. By displaying a message to that effect, periodic calibration is performed, and the color reproducibility of the printed matter is always kept constant regardless of changes over time in the reading performance of the image forming apparatus included in the image forming system. be able to. Further, by using IEEE 1394 or Ethernet (registered trademark) for communication between color copying machines, calibration can be executed without developing a new external interface for communication between color copying machines.

1 is a block diagram illustrating a configuration of an image forming system according to an exemplary embodiment. FIG. 2 is a block diagram showing a specific configuration of a color copying machine. It is a figure which shows the calibration pattern output from a color copying machine. 6 is a flowchart illustrating a calibration processing procedure in the image forming system according to the present embodiment. 6 is a flowchart illustrating a calibration processing procedure in the image forming system according to the present embodiment. 5 is a flowchart illustrating a procedure of linked printing processing in the image forming system according to the present embodiment. 6 is an example of a message prompting a user to execute calibration displayed on an operation unit of a child color copier. 6 is an example of a message prompting the user to execute calibration displayed on the operation unit of the parent color copying machine.

Explanation of symbols

1, 2 Color copier 4 HUB
5 Internet cable 11 Scanner section 12 IPU
13 Printer unit 14 Parameter calculation unit 15 Control unit 16 Transmission / reception unit 17 Operation unit

Claims (6)

At least one image forming apparatus having an image input unit for inputting an image and an image output unit for outputting an image is connected, and an image read by the image input unit of a predetermined image forming apparatus is output by the image forming apparatus. In the image forming system that outputs in the
Display means for displaying a message indicating that a calibration pattern needs to be output when the number of readings of the image input unit of the predetermined image forming apparatus has reached a predetermined number of times since the calibration pattern was last output When,
Creating means for creating calibration data obtained by reading the calibration pattern output from the image output unit of each image forming apparatus with the image input unit of the predetermined image forming apparatus;
An image forming system comprising: a correcting unit that corrects an image input from an image input unit of the predetermined image forming apparatus based on calibration data generated by the generating unit.   The image forming system according to claim 1, wherein the predetermined image forming apparatus includes the display unit.   The image forming system according to claim 1, wherein the at least one image forming apparatus includes the display unit.   4. The image forming system according to claim 1, wherein the at least one image forming apparatus and the predetermined image forming apparatus are connected by IEEE 1394. 5.   The image forming system according to claim 1, wherein the at least one image forming apparatus and the predetermined image forming apparatus are connected by Ethernet. The predetermined image forming apparatus includes the creating unit,
The image forming system according to claim 1, wherein the at least one image forming apparatus includes the correcting unit.

Images