JP2006074394A - Image processing system and density correction schedule management method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always have at least one printer in which density correction processing is effective on a network to which a plurality of printers are connected.
A calibration server 104 on a network 100 has a density correction processing scheduling unit 113 that performs correction correction so that density characteristics of a color output image are maintained at desired characteristics after correction processing of color printers 102 and 103 is completed. Based on the time, a scheduled correction time scheduled to be corrected next after the correction process is completed is set. Further, the correction processing time and the correction effective time required for performing the correction processing are compared on the time axis to change the setting of the scheduled correction time, so that at least one of the printers 102 and 103 is always maintained at a desired density characteristic. Adjust as follows.
[Selection] Figure 1

Description

  The present invention relates to an image processing system and a density correction schedule management method. More particularly, the present invention relates to an image processing system in which a plurality of color printers are operably connected, and a density correction schedule management method for the plurality of color printers in the system.

  As an output device of a computer, a printer using an electrophotographic method such as a laser beam printer (hereinafter referred to as “LBP”) is widely used. These printers are a factor that rapidly expands the field of desktop publishing due to many advantages such as high-quality printing results, quietness and high speed. Furthermore, high performance of the host computer and printer image generation unit, etc. has made it easier to handle color images, and electrophotographic color printers have been developed. In addition to conventional monochrome image printing, Color image printing is also gaining popularity.

  Here, in the case of a color printer, it is known that the color and density of an output image may change as it is used for a long period of time. This is due to a change with time in image output characteristics of a printer or the like and an increase in variation between devices.

  For example, in the case of an LBP that forms an image by an electrophotographic method, a process such as laser exposure in an electrophotographic process, formation of a latent image on a photoreceptor, development with toner, transfer of a toner image onto an output medium such as paper, and fixing by heat Is susceptible to changes in temperature, humidity, or component aging around the device, and the amount of toner finally fixed on the output medium changes, resulting in changes in the color and density of the output image. .

  Such fluctuations in image output characteristics are not unique to electrophotographic printers, but also occur in printers of ink jet systems, thermal transfer systems, and other various systems.

  In order to solve the problems caused by fluctuations in image output characteristics as described above, a system that provides stable density characteristics by providing density correction means for the density level of a formed image in a printer is conventionally known. This is because patch patterns with specific density levels of several points are formed on the intermediate transfer body in the printer at a specific timing determined in advance, and the density of the patch pattern is measured by a sensor. In this method, a density correction table is created so as to obtain a density value, the input density level is adjusted with reference to the density correction table, and the density correction process of the output image is performed. Note that the patch pattern may be measured on a photosensitive drum.

  Here, as the timing of executing the density correction processing, 1. 1. When power is on 2. After the specified number of output sheets The main thing is after the lapse of the specified time. 2 is for executing density correction processing after a predetermined number of printed sheets, such as after printing 100 sheets after the previous density correction processing, and 3 is for example density correction processing for one hour after the previous density correction processing. Is to execute. By executing the density correction process at such timing, it is possible to reduce the influence of the change in the component over time on the density.

JP-A-11-177822

  As described above, changes in the color and density of an image due to the passage of time and use can be eliminated by performing density correction processing with a printer. However, the current technical problem is that the density correction processing itself takes time.

  With regard to the density correction process at timing 3, printing may not be performed at all within a specified time after the correction process is performed. In such a case, the density correction process is not actually performed immediately after the lapse of the specified time, and the density correction process is often not performed immediately before the next printing process. In image output in such a case, since the density correction processing actually starts after the user issues a print processing command, it takes time to obtain an output product, that is, printing immediately. The phenomenon of being unable to happen is occurring.

  This phenomenon occurs after the start of work on the next work day because, for example, when correction processing is performed before the end of the work time in a company or office, printing is not performed even if the specified time elapses outside the work time. When correction processing is performed before the end of working hours before a holiday, printing is not actually performed for more than one day or for several days even if the specified time has elapsed.

  Furthermore, in the case of an image processing system in which a plurality of color printers are connected via a network, the timings necessary for density correction processing of all the printers may overlap. In some cases, there are no printers on the network that can print out.

  An object of the present invention is to perform density correction processing for each printer so that at least one printer in a state where the density correction processing is effective always exists on the network when scheduling of density correction processing for a plurality of printers is performed. It is an object to provide an image processing system and a density correction schedule management method for a plurality of color printers that solve the above-described problems by adjusting the schedule of the color printer.

  In order to achieve the above object, an image processing system and a density correction schedule management method of the present invention have the following configurations.

  The image processing system according to the present invention is arranged on a network so that a plurality of image processing apparatuses including a correction unit that performs correction processing for correcting a density change of a color output image formed based on a color input image can be used. The image processing system includes a scheduling device capable of communicating with the image processing device, and the scheduling device corrects the density characteristic of the color output image to be a desired characteristic after the correction process is completed. Based on the valid time, a means for setting a scheduled correction time for performing the next correction process after the correction process is completed for each of the plurality of image processing apparatuses, and the correction determined for each of the plurality of image processing apparatuses At least one image processing device based on the correction processing time required for processing and the effective correction time set for each of the plurality of image processing devices A schedule adjustment unit configured to change the setting of the scheduled correction time of the plurality of image processing apparatuses so that at least one of the other image processing apparatuses has the correction effective time when the correction process is executed. And

  According to the density correction schedule management method for a plurality of color printers of the present invention, a plurality of image processing apparatuses that perform correction processing for correcting a density change of a color output image formed based on a color input image can be used on a network. A density correction schedule management method for the plurality of image processing apparatuses in the image processing system arranged in the image processing system, wherein after the correction process is finished, the correction effective time during which the density characteristic of the color output image is maintained at a desired characteristic Based on the setting step of setting a scheduled correction time for performing the next correction process after the correction process is completed for each of the plurality of image processing apparatuses, and the correction process determined for each of the plurality of image processing apparatuses. Based on the correction processing time required and the effective correction time set for each of the plurality of image processing apparatuses, at least one image processing Adjusting the setting of the scheduled correction times of the plurality of image processing devices so that at least one of the other image processing devices has the correction effective time. Features.

  According to the present invention, among a plurality of color printers, one or more printers can always be in a printable state, and the density characteristics of the printer can be maintained at desired characteristics.

  Hereinafter, an embodiment in which the present invention is applied to an image processing system including a plurality of color LBPs will be described. However, the present invention is not limited to this, and departs from the gist of the present invention described in the claims. In other words, the present invention can be applied to an image processing system in which a plurality of other color printers, color facsimile apparatuses, and the like are connected so that they can be used.

(First embodiment)
FIG. 1 is a block diagram showing a first embodiment according to the present invention.

  The image processing system of this embodiment shown in FIG. 1 is configured by connecting a host computer 101, a color printer A (102), a color printer B (103), and a calibration server 104 via a network 100. Both the color printer A (102) and the color printer B (103) are operably connected by the host computer 101.

  In general, a system called Ethernet (registered trademark) can be used as the network 100, and thus, information between units connected by a protocol such as TCP / IP using a physical cable such as 10BaseT is used. Send and receive and transfer data. The host computer 101 sends print information, such as color information, characters, graphics, image images, and the number of copies, to the color printer A (102) and the color printer B (103). Both color printers A and B have the same function. The calibration server 104 schedules the execution timing of density correction processing for each printer (described later).

  The configuration of the color printer A (102) in this embodiment will be described. The color printer A (102) of this embodiment includes an image processing unit 105 and a control unit 106. These are connected to each other via a bus (not shown) and also connected to the network 100 via a network interface 107 (hereinafter referred to as “network I / F”). The image processing unit 105 includes a printer engine 108 that performs actual image formation based on the image signal sent from the image processing unit 105, and a density measurement unit 109 that measures the density level on the intermediate transfer member in the printing apparatus. It is connected.

  The control unit 106 controls the operation of the entire system. This control is made possible by the CPU 110 transmitting a control signal for determining and controlling various processes to the control unit 106 in accordance with a control program stored in the ROM 111. The RAM 112 is used as a work area for storing data for the CPU 110 to perform each control.

  Also, in this embodiment, when the color printers A and B execute density correction processing, which will be described later, and are finished, the control unit 106 sends density correction processing end information to the calibration server 104.

  Next, the configuration of the calibration server 104 in the present embodiment will be described. The calibration server 104 according to this embodiment includes a density correction processing scheduling unit 113 and a control unit 114. These are connected to each other via a bus (not shown) and are also connected to the network 100 via a network I / F 115. The density correction scheduling unit 113 is connected to a scheduling data storage unit 116 that stores a calibration scheduling pattern in advance and a time acquisition unit 117 that can acquire an elapsed time.

  The control unit 114 controls the operation of the entire system. This control is performed by the CPU 118 according to the control program stored in the ROM 119. The RAM 120 is used as a work area for storing data for the CPU 118 to perform each control.

  In each embodiment of the present invention, the calibration server 104 is provided independently for each printer. However, the function of the calibration server 104 may be provided in one printer. .

FIG. 2 is a block diagram showing a detailed configuration example of the image processing unit 105 in the color printers A and B.
In FIG. 2, a reception buffer 201 holds input print information. The object generation unit 202 converts information (page description language) such as colors, characters, graphics, and image images, which is print information input from the host computer 101, into intermediate information (hereinafter referred to as “object”). The object buffer 203 stores the object converted by the object generation unit 202 for one page. At this time, when the print information is color-related data such as gray level setting, color level setting, and multi-value image image, the density level is corrected by using the density correction table 207 in the density level correction processing unit 206 described later.

  The rendering unit 204 performs a rendering process based on an object for one page stored in the object buffer 203, and converts it into a bitmap to be rendered. At this time, the dither processing unit 209 performs pseudo halftone processing to match the density level with the number of output gradations. The band buffer 205 stores the bitmap generated by the rendering unit 204 and sends data to the printer engine 108. The density level correction processing unit 206 corrects the density level using the density correction table 207 created by the density correction table creating unit 208 using the density value of the patch pattern on the intermediate transfer member measured by the density measuring unit 109. Do.

  FIG. 3 is a diagram showing the procedure of density correction table creation processing during density correction processing, and FIG. 4 is a diagram showing the state of density measurement processing by the density measurement unit 109 during density correction processing. Hereinafter, the processing operation of the density correction table creating unit in the color printers A and B of the present embodiment will be described with reference to both drawings.

  In FIG. 4, a patch pattern 401 having several halftone density levels of density levels 0 to 255 for each color of Y, M, C, and K, an intermediate transfer body 402 on which the patch pattern is actually printed, and an intermediate transfer And a sensor 403 that measures the density of the patch pattern 401 printed on the body 402. In the explanatory example of FIG. 4, the patch pattern 401 is a patch pattern of density levels 30H, 60H, and 90H for each color of YMCK.

  In FIG. 3, first, a patch pattern 401 is formed on the intermediate transfer member 402 (step S301), and then the density of the patch pattern 401 is measured by the sensor 403 (step S302).

  When the density level value measured by the density correction table creation unit and the sensor measured density value measured in step S302 are received (step S303), the density characteristic with respect to the input density level is defined as the specified density characteristic from the sensor measured density value of each density level. A density correction table that produces (linear characteristics) is created (step S304), and the process ends.

  FIG. 5 is an explanatory diagram for explaining the density characteristic table.

  The solid line in FIG. 5A represents the density characteristic with respect to the input density level obtained from the measurement value obtained by printing the density correction patch pattern in FIG. 4 described in steps S301 to S303 in FIG. The broken line in FIG. 5A is a predetermined density characteristic that is determined in advance, and has a linear characteristic. The solid line in FIG. 5B is an actually created density correction table, and by using this, the density characteristic indicated by the solid line in FIG. 5A is corrected to a linear characteristic as indicated by the broken line in the figure. Can do.

  In this embodiment, the density correction table is created when the specified output number is exceeded and when the density correction table is created by a density correction execution command (described later) input from the calibration server 104.

  FIG. 6 is a block diagram illustrating a detailed configuration example of the density correction processing scheduling unit 113 of the calibration server 104.

  In FIG. 6, the density correction execution timing table creation unit 601 includes density correction processing end information input from the control unit 106 of the color printer A (102) and the color printer B (103), time information from the time acquisition unit 117, and A density correction execution timing table 602 is created from the scheduling data from the scheduling data 116 section.

  The scheduling data from the scheduling data storage unit 116 includes information on the specified time for each printer that requires density correction processing, and the time zone during which the density correction processing is performed (settings such as no night and weekend). The method for storing the scheduling data is not particularly limited, and may be arbitrarily set and stored in advance, or may be directly set by the user of this system.

  Based on the created density correction execution timing table 602, the density correction execution command unit 603 sends a density correction execution command to each printer.

  FIG. 7 is a diagram showing details of the density correction execution timing table 602 created by the density correction execution timing table creation unit 601, and FIG. 8 is a flowchart of the density correction execution timing table creation processing. Hereinafter, the processing operation of the density correction execution timing table creation unit in the calibration server 104 of this embodiment will be described in detail with reference to both drawings.

  In the density correction execution timing table of FIG. 7, the correction density effective time 701 indicates the remaining time of the current effective time for the density correction processing previously performed for each printer. Therefore, the maximum value of the correction density effective time 701 is a specified time that the density correction processing of each printer is required, and is counted down by the elapsed time obtained from the time acquisition unit 117 and updated as needed. Takes a negative value.

  The density correction execution scheduled time 702 indicates the time from the current time to the scheduled start time for the density correction processing scheduled to be performed next time for each printer. The scheduled density correction execution time 702 is set every time density correction processing end information is received from each printer. The scheduled density correction execution time 702 is counted down by the elapsed time obtained from the time acquisition unit 117 and updated as needed. When the scheduled density correction execution time becomes 0, the calibration server 104 sends a density correction to each printer. Sends an execution instruction for processing.

  In FIG. 8, it is assumed that density correction processing end information is received from the color printer A (102) or the color printer B (103) in step S801. The end information of the density correction process here includes the end information of the correction process in response to a command from the calibration server 104 and the end information of the correction process when the specified output number is exceeded.

  In step S802, the correction density effective time of the printer that has performed the density correction processing is updated to the density correction specified time.

  Further, a correction time zone in which density correction processing is required and a non-correction time zone in which density correction processing is not required are acquired from the scheduling data storage unit 116 (step S803), and the correction density effective time updated in step S802 is obtained. The comparison is referred to, and it is determined whether it is necessary to perform density correction processing by the next non-correction time zone (step S804).

Here, when it is determined that the density correction process is to be performed by the next non-correction time period, the printer that performs the density correction process is set as the printer A, the correction density effective time in the density correction execution timing table is compared, and minus is obtained. In step S805, a determination process is performed to determine whether or not the expression (1) is satisfied with respect to the printer having the shortest effective time on the network (referred to as printer B).
Density correction scheduled execution time B−density correction processing time A <corrected density effective time A, and
Correction density effective time A <Density correction scheduled execution time B + Density correction processing time B (1)
Here, the correction density effective time, the density correction scheduled execution time, and the density correction processing time related to the printer A are referred to as a correction density effective time A, a density correction execution scheduled time A, and a density correction processing time A, respectively. The corrected density effective time, the density correction scheduled execution time, and the density correction processing time relating to the printer B are defined as a corrected density effective time B, a density correction scheduled execution time B, and a density correction processing time B, respectively.

When the determination formula (1) is not satisfied (No) in step S805, the setting is made as shown in formula (2) in step S806.
Density correction scheduled execution time A = Maximum correction density effective time A (2)
Here, the maximum correction density effective time is a specified time of each printer stored as scheduling data.

On the other hand, if the determination formula (1) is satisfied in step S805 (Yes), the setting is made as in formula (3) in step S807.
Concentration correction execution scheduled time A = Density correction execution scheduled time B−Density correction processing time A (3)
As described above, in the processes in steps S805 to S807, the density correction execution scheduled time is set so that the density correction processing time of each printer does not overlap in consideration of the density correction execution scheduled time and the density correction processing time for each printer on the network. The density correction execution scheduled time of each printer is managed. By adjusting and managing the density correction execution scheduled time in this way, the second printer can be set within the correction density effective time even when the first printer on the network is executing the density correction processing. it can.

If it is determined in step S804 that it is not necessary to perform density correction processing until the next non-correction time period, the density correction execution scheduled times of all printers are set as in equation (4) in step S808. Finish the creation.
Density correction scheduled execution time = density correction time zone start time (4)
With this setting, a density correction execution command is issued to all printers on the network when shifting from the non-correction time zone to the correction time zone (for example, after starting work).

FIG. 9 is an explanatory diagram of a specific example of the density correction execution timing table creation process according to the procedure of FIG.
In the density correction execution timing table in FIG. 9, the specified time from when the density correction process is completed until the next density correction process is required is 45 minutes for printer A and 60 minutes for printer B, and is required for the density correction process. The density correction processing time is 5 minutes for each printer.

  Reference numeral 901 is a state transition diagram of the color printer A, reference numeral 902 is a state transition diagram of the color printer B, reference numerals 903 to 906 are density corrections when each printer sends density correction processing end information to the calibration server 104. An execution timing table is shown.

  As a result of creating the density correction execution timing table according to the procedure of FIG. 8, as shown in the state correction diagrams 901 and 902 of the color printers A and B, the density correction processing of both printers may overlap on the time axis. Adjusted to not. That is, at time T, the estimated density correction execution time of the printer A is set to 40 minutes according to the equation (3), and the estimated density correction execution time of the printer B is set to 45 minutes according to the equation (2). As described above, by the processing in steps S805 to S807, one of the printers is always in a state within the correction density effective time. In this way, it is possible to always output from either printer in this image processing system.

  In addition, by setting the density correction time zone, it is possible to reduce the probability of occurrence of a situation where printing is not performed at all within a specified time after correction. In an image processing system such as a company or office, this can be realized by setting, for example, other than working hours (including closed days) as the density correction time zone.

(Second embodiment)
In the first embodiment, the number of color printers connected to be usable on the network has been described as two, but the present invention is naturally applicable to the case where three or more color printers are connected to the network.

  Regarding the scheduling of three or more printers, comparing the printer that performs density correction processing and updates the density correction execution timing table with the printer that has the shortest correction density effective time, a method for scheduling two printers is used. You can come back.

  That is, if one of the two units on the compared network is within the correction concentration effective time, one of all three units on the network is within the correction concentration effective time.

  As described above, in an image processing system in which a plurality of printers are connected via a network, a calibration server that schedules the density correction processing timing of each printer is placed on the network, whereby the correction processing is performed as described above. By adjusting the execution schedule, there is at least one printer that does not require density correction processing, so even if correction processing for other printers is being performed, using this printer allows you to quickly output products. Is obtained.

  Furthermore, by having a plurality of patterns of scheduling data, it is possible to cope with a time zone that does not always need to be corrected, such as at night or on weekends.

It is a block diagram which shows 1st embodiment of this invention. FIG. 3 is a block diagram illustrating a configuration example of an image processing unit in a color printer. It is the figure which showed the procedure of the creation process of the density correction table at the time of density correction. It is the figure which showed the mode of the density | concentration measurement process at the time of density correction. It is the figure which showed the relationship between a density measured value, a density level, and a correction density level. It is the figure which showed the structural example of the density | concentration correction process scheduling part in a calibration server. It is the figure which showed the density correction execution timing table. It is the figure which showed the procedure of the preparation process of a density correction execution timing table. It is the figure which showed the time chart of density correction processing scheduling processing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Network 101 Host computer 102,103 Color printer 104 Calibration server 105 Image processing part 106,114 Control part 107,115 Network interface 109 Density measurement part 110,118 CPU
111,119 ROM
112,120 RAM
113 density correction processing scheduling unit 116 scheduling data storage unit 117 time acquisition unit 206 density level correction processing unit 207 density correction table 208 density correction table creation unit 601 density correction execution timing table creation unit 602, 903 to 906 density correction execution timing table 603 Density correction execution command section 701 Corrected density effective time 702 Density correction execution scheduled time

Claims (6)

An image processing system in which a plurality of image processing apparatuses including correction means for performing correction processing for correcting density changes in a color output image formed based on a color input image are arranged on a network so as to be usable. ,
A scheduling device capable of communicating with the image processing device, the scheduling device comprising:
After completion of the correction process, based on a correction effective time during which the density characteristic of the color output image is maintained at a desired characteristic, a scheduled correction time for performing the next correction process after the correction process is completed is the plurality of correction times. Means for setting for each image processing device;
Correction processing of at least one image processing device based on the correction processing time required for the correction processing determined for each of the plurality of image processing devices and the correction effective time set for each of the plurality of image processing devices Schedule adjustment means for changing the setting of the scheduled correction time of the plurality of image processing devices so that at least one of the other image processing devices has the correction effective time at the time of execution;
An image processing system comprising: The image processing system according to claim 1,
The image processing apparatus further includes an end notification unit that outputs correction end information when the correction processing ends.
The image processing system according to claim 1, wherein the scheduling apparatus obtains an elapsed time after the correction process is completed based on the correction end information, and performs each setting based on the elapsed time. The image processing system according to claim 1 or 2,
An image processing system, further comprising means for setting, for each of the plurality of image processing apparatuses, a time zone in which the scheduled correction time is set and a time zone in which the scheduled correction time is not set. A plurality of image processing devices in an image processing system in which a plurality of image processing devices that perform correction processing for correcting density changes in a color output image formed based on a color input image are usable on a network. A density correction schedule management method,
After completion of the correction process, based on a correction effective time during which the density characteristic of the color output image is maintained at a desired characteristic, a scheduled correction time for performing the next correction process after the correction process is completed is the plurality of correction times. A setting step for each image processing apparatus;
Correction processing of at least one image processing device based on the correction processing time required for the correction processing determined for each of the plurality of image processing devices and the correction effective time set for each of the plurality of image processing devices An adjustment step of changing the setting of the scheduled correction times of the plurality of image processing devices so that at least one of the other image processing devices has the correction effective time at the time of execution;
A density correction schedule management method characterized by comprising: In the density correction schedule management method according to claim 4,
An end information input step of receiving correction end information when the correction processing of the image processing apparatus ends;
In the setting step and the adjustment step, a density correction schedule management characterized in that an elapsed time from the end of the correction processing is obtained based on the correction end information, and each setting is performed based on the elapsed time. Method. In the density correction schedule management method according to claim 4 or 5,
The density correction schedule management method further comprising the step of: setting a time slot for setting the scheduled correction time and a time slot for not setting for each of the plurality of image processing apparatuses.

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