JP2016181861A - Image forming device having color correction function, system having the same and method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of easily performing color correction, a system having the same and a method for the same.SOLUTION: An image forming system includes an image forming device 100 and an extension device 200. A second image forming unit 208 as a sublimation type printer corrects a control signal input based on color correction image data by using primary color correction data, and prints a color correction sheet. A document reading unit 106 generates image data by reading the color correction sheet. When primary color correction data is not valid because of a comparison result between the color correction image data and the generated image data, the extension device 200 stores the comparison result as secondary color correction data. When an image is formed by the second image forming unit 208, the input control signal is corrected based on the primary and secondary correction data. Thus, even when the color of ink in an ink ribbon varies due to aging or the like, color correction can be properly performed and photograph printing can be performed.SELECTED DRAWING: Figure 1

Description

  The present invention includes an image forming apparatus capable of easily performing color correction in an image forming apparatus capable of color printing, such as a sublimation type photographic printer using an ink ribbon that easily changes in color over time. The present invention relates to a system and a method thereof.

  As one type of image processing apparatus that is an electronic device, an image forming apparatus (typically a copier) that forms an image on recording paper is introduced in many offices (company, office, etc.). A multifunction peripheral (MFP (Multi Function Peripheral)), which is one type of such an image forming apparatus, has a copy mode, a facsimile mode (hereinafter referred to as a facsimile), a network compatible printer mode, and a scanner mode. A plurality of basic operation modes are provided.

  An image forming apparatus is also installed in a public space such as a convenience store, and not only providing a copy function but also providing a complex service to the user. For example, a system that includes an MFP, which is an electrophotographic image forming apparatus, and a sublimation type image forming apparatus to improve user convenience is known. In an image forming apparatus including an electrophotographic image forming unit, a toner image recorded and reproduced on a photosensitive member is transferred onto a recording sheet. The heat fixing unit includes a heat source such as a heater, and fixes the toner transferred onto the recording paper onto the recording paper at a predetermined temperature and pressure. In a sublimation type image forming apparatus, an ink ribbon provided with ink of each color such as yellow (hereinafter also referred to as Y), magenta (hereinafter also referred to as M), and cyan (hereinafter also referred to as C) for color printing. Then, the ink is sublimated by the thermal head and attached to the recording paper. A photo printing service is provided by a sublimation image forming apparatus.

  Various image quality degradations may occur in an image printed on recording paper by an image forming apparatus depending on the printing method. Therefore, various image quality improvements have been proposed depending on the printing method. For example, Patent Document 1 listed below relates to a heat-melting type thermal transfer image forming apparatus that performs printing by heating and pressurizing an ink ribbon with a thermal head, resulting from variations in the heat generation distribution of the heating resistors of the thermal printer head. There is disclosed a thermal transfer type image forming apparatus that corrects output distortion of a printing section and reduces image distortion. This image forming apparatus is a printing unit including a thermal printer head, prints a reference pattern on a recording sheet based on predetermined reference pattern data, and converts the reference pattern into a photoelectric converter (CCD line image sensor of the image forming apparatus). ) And the original reference pattern data are compared to detect a difference, and a correction value for the output distortion of the printing unit is calculated from the detected value. The image forming apparatus corrects the output distortion of the printing unit based on the calculated correction value when the original is read and printed by the photoelectric converter.

  Further, in Patent Document 2 below, in order to solve the problem that a lot of unused ink sheets remain depending on the size of an image to be printed in an image forming apparatus of a sublimation thermal transfer system using an ink sheet, A technique for controlling the ink sheet so that the remaining portion is minimized is disclosed. Specifically, in a color printer that thermally transfers and records image data on recording paper using three or four color ink sheets, an identification symbol that can detect a boundary is added to the ink sheet for each unit area. Information indicating the usage status of the sheet is stored. In response to the print request, the color printer automatically determines the size of the ink sheet to be used, selects the optimum ink sheet with reference to the information on the ink sheet usage status, and executes printing.

JP-A-5-37749 JP-A-6-106805

  In sublimation type photographic printers, the characteristics of the printing unit (image forming unit) are different from each other. Therefore, even if printing is performed using the same color data (that is, at the same control signal level) and controlling the thermal head, the color to be printed. Is different. Therefore, at the time of shipment from the factory, the printing unit is adjusted so that the color within the standard determined at the time of printing is reproduced. Specifically, the color correction data is adjusted so that the level of the control signal input to the printing unit is corrected by the color correction data and printing is performed, and the color within the reference is printed. The color correction data is stored in each printer as, for example, data in a table format (hereinafter referred to as a color correction table) including input values and output values corresponding to the input values. The color correction table is different for each printer.

  Consumables such as ink ribbons used in sublimation type photographic printers are likely to change in color due to storage conditions and passage of time. When a color change occurs, the color correction table set at the time of shipment becomes invalid. That is, the color correction table set at the time of shipment cannot be corrected sufficiently, and printing of a desired color cannot be realized. For example, even if printing is performed based on the same photograph data (RGB data) using the same printer on which the same ink ribbon is set, there is a problem that the hue changes when printed at different times. Patent Documents 1 and 2 do not solve this problem.

  Therefore, according to the present invention, color correction can be easily performed in an image forming apparatus capable of color printing, such as a sublimation photographic print using an ink ribbon that easily causes a color change with time (including the influence of storage conditions). An object of the present invention is to provide an image forming apparatus, a system including the same, and a method therefor.

  An image forming system according to a first aspect of the present invention forms an image forming unit that forms a color image on a recording sheet, a document reading unit that reads a color document to generate color image data, and an image forming unit. A control unit for inputting a control signal for designating the color of the image and a storage unit for storing primary color correction data for correcting the control signal input from the control unit are included. The image forming unit corrects the control signal input from the control unit with primary color correction data, forms a color image based on the corrected control signal, and applies color to the recording paper based on predetermined color correction image data. An image is formed to generate a color correction sheet. The image forming system includes a comparison unit that compares image data generated by reading a color correction sheet with a document reading unit and color correction image data, and primary color correction data based on a comparison result of the comparison unit. The primary color correction stored in the storage unit based on the comparison result when the determination unit determines whether the primary color correction data is invalid by the determination unit and the determination unit And a color correction unit that corrects the data or stores the comparison result in the storage unit as secondary color correction data. When the image forming unit forms a color image after the processing by the color correcting unit is executed, the image forming unit receives a control signal input from the control unit, and when the primary color correction data is corrected by the color correcting unit, When correction is performed based on the corrected primary color correction data and the secondary color correction data is stored in the storage unit by the color correction unit, the correction is performed based on the primary color correction data and the secondary color correction data. .

  As a result, even if a change over time or the like occurs in an ink ribbon or the like for forming a color image, it is possible to appropriately perform color correction and realize printing of an appropriate color.

  Preferably, the image forming unit receives the fact that the image forming unit has formed an image on a predetermined number of recording sheets, or the predetermined period has elapsed without performing the processing by the color correcting unit. In response, a color correction sheet is generated.

  Thereby, the color correction process can be automatically started.

  More preferably, the image forming system further includes an operation unit that receives a user instruction, and the image forming unit receives the user instruction from the operation unit and generates a color correction sheet.

  Thereby, the color correction process can be started manually.

  More preferably, the image forming unit includes an ink ribbon that holds ink regions of a plurality of colors to be transferred to the recording paper, and the ink ribbon is rewound to be unused among the ink regions that have already been used for image formation. A color correction sheet is generated using the portion.

  Thereby, it is possible to avoid the use of an unused ink area for color correction, and to reduce the consumption amount of the ink ribbon.

  Preferably, the size of the color correction sheet is ½ of the size of the L size.

  Thereby, the amount of recording paper used for the color correction process can be reduced.

  More preferably, the document reading unit has a platen unit on which the document is placed, and reads a color correction sheet set on the platen unit.

  More preferably, the comparison unit calculates a difference between corresponding pixel values between the image data generated by reading the color correction sheet by the document reading unit and the color correction image data, and the determination unit determines that the difference is If it is not within the predetermined range, it is determined that the primary color correction data is not valid.

  Thereby, color correction processing with high accuracy can be executed.

  Preferably, the image forming system further includes a confirmation unit that confirms to the user whether or not to correct the primary color correction data when the determination unit determines that the primary color correction data is not valid. In response to an instruction to correct the primary color correction data by the confirmation unit, the color correction unit corrects the primary color correction data based on the comparison result.

  As a result, the primary color correction data after the correction color correction is executed is read from the recording unit without correcting the primary color correction data at the time of shipment using the secondary color correction data, so that the image can be quickly formed. The control signal can be corrected.

  More preferably, the image forming system includes an image forming apparatus including an electrophotographic printer and an expansion device. The image forming unit is a sublimation type printer, and the expansion device includes an image forming unit and a storage unit. The image forming apparatus further includes an image reading unit.

  Thus, when a sublimation printer is added as an optional device to an image forming apparatus including an electrophotographic printer that has been used alone, color correction of the sublimation printer can be easily performed.

  An image forming apparatus according to a second aspect of the present invention includes: an image forming unit that forms a color image on a recording sheet; and a control unit that inputs a control signal for designating the color of the image to be formed to the image forming unit. A storage unit that stores primary color correction data for correcting a control signal input from the control unit. The image forming unit corrects the control signal input from the control unit with primary color correction data, forms an image based on the corrected control signal, and forms a color image on a recording sheet based on predetermined color correction image data. To generate a color correction sheet. An image forming apparatus includes: a receiving unit that receives image data generated by reading a color correction sheet by an external device; and a comparison unit that compares the image data received by the receiving unit with the color correction image data. And a determination unit that determines whether or not the primary color correction data is valid based on the comparison result by the comparison unit, and the comparison result that the determination unit determines that the primary color correction data is not valid. The color correction unit further modifies the primary color correction data stored in the storage unit, or stores the comparison result in the storage unit as secondary color correction data. When the image forming unit forms a color image after the processing by the color correcting unit is executed, the image forming unit receives a control signal input from the control unit, and when the primary color correction data is corrected by the color correcting unit, When correction is performed based on the corrected primary color correction data and the secondary color correction data is stored in the storage unit by the color correction unit, the correction is performed based on the primary color correction data and the secondary color correction data. .

  Accordingly, the image forming apparatus can acquire the image data generated by reading the printed color correction sheet by the external apparatus, and can perform color correction of the image forming unit of the image forming apparatus.

  An image forming apparatus according to a third aspect of the present invention is an image forming apparatus including an electrophotographic image forming unit. The image forming apparatus includes a receiving unit that receives predetermined color correction image data from an external device, and a document that reads the color correction sheet generated based on the color correction image data by the external device and generates image data. A comparison unit that compares the image data generated by reading the color correction sheet by the reading unit and the document reading unit with the color correction image data received by the reception unit, and the comparison result by the comparison unit And a transmission unit for transmitting to the apparatus.

  Accordingly, the image forming apparatus enables the external apparatus to perform color correction of the image forming unit of the own apparatus based on the comparison result.

  A color correction method according to a fourth aspect of the present invention is a method for correcting the color of an image formed on recording paper by an image forming apparatus. The color correction method includes an image forming step of forming a color image on a recording paper by an image forming unit of the image forming apparatus, a document reading step of reading a color original to generate color image data, and a recording paper on the image forming unit. A control step for inputting a control signal for designating the color of the image to be formed, and a storage step for storing primary color correction data for correcting the control signal. In the image forming step, the control signal is corrected by the primary color correction data, and an image is formed based on the corrected control signal. The image forming step includes a step of generating a color correction sheet by forming a color image on recording paper based on predetermined color correction image data. In the color correction method, the primary color correction data is obtained by comparing the image data generated by reading the color correction sheet in the document reading step with the color correction image data and the comparison result in the comparison step. A determination step for determining whether or not the primary color correction data is valid. In response to a determination that the primary color correction data is not valid by the determination step, the primary color correction data is corrected or compared based on the comparison result. In the color correction step of storing the result as secondary color correction data and the image forming step executed after the color correction step is executed, the control signal is corrected when the primary color correction data is corrected. If the correction is made based on the subsequent primary color correction data and the secondary color correction data is stored, the correction is made based on the primary color correction data and the secondary color correction data. Further comprising a flop.

  As a result, even if a change over time or the like occurs in an ink ribbon or the like for forming a color image, it is possible to appropriately perform color correction and realize printing of an appropriate color.

  According to the present invention, in an ink ribbon or the like used for image formation (printing), even if the color of the ink changes due to a change with time or the like, the color correction is appropriately performed and the photographic printing can be executed. it can. That is, the primary color correction corrects the color shift due to the characteristics of the printer itself, and further corrects the color shift caused by the deterioration of the ink ribbon or the like. Therefore, appropriate color printing can be realized.

1 is a front view showing an image forming system according to a first embodiment of the present invention. It is a block diagram which shows the structure of the image forming system shown in FIG. 3 is a flowchart showing a control configuration of a color correction program executed in the image forming system shown in FIG. 1. It is a figure which shows a home screen. It is a figure which shows the screen displayed when performing color correction. It is a front view which shows the ink ribbon used with a sublimation type printer. It is a front view which shows the sheet | seat for color correction. 6 is a flowchart illustrating a control configuration of a color correction program executed in an image forming system according to a second embodiment of the present invention. 10 is a flowchart illustrating a control configuration of a color correction program executed in an image forming system according to a third embodiment of the present invention. It is a front view which shows the ink ribbon used with a sublimation type printer. FIG. 3 is a block diagram illustrating a configuration of an image forming system different from FIG. 2.

  In the following embodiments, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

(First embodiment)
Referring to FIG. 1, the image forming system according to the embodiment of the present invention includes an image forming apparatus 100 and an expansion apparatus 200. The image forming apparatus 100 is a digital multifunction peripheral having a plurality of functions such as a print function, a copy function, a FAX function, and a scanner function. The expansion device 200 also has a print function. Since the image forming apparatus 100 and the expansion apparatus 200 include similar components, the terms having “first” and “second” are used for convenience to distinguish them.

  The image forming apparatus 100 includes a document reading unit 106, a first image forming unit 108, a first paper feeding unit 110, an operation unit 112, and a paper discharge tray 140 in the cylinder. The expansion device 200 includes a media reader unit 206, a second image forming unit 208, and a photo discharge unit 240.

  Referring to FIG. 2, image forming apparatus 100 further includes a control unit 102, a first storage unit 104, a network I / F unit 120, and a first bus 122. Data (including control information) is exchanged between the units constituting the image forming apparatus 100 via the first bus 122.

  The control unit 102 is, for example, a CPU (Central Processing Unit). The first storage unit 104 includes a storage device such as a ROM (Read Only Memory), a RAM (Random Access Memory), and a HDD (Hard Disk Drive). The ROM is a nonvolatile storage device, and stores programs and data necessary for controlling the operation of the image forming apparatus 100. The HDD is a rewritable nonvolatile storage device that stores image data and the like. The RAM is a rewritable volatile storage device. The control unit 102 reads a predetermined program and predetermined data from the ROM and HDD to the RAM, and executes the program using a part of the RAM as a work area. Image processing or the like for image data is also executed on the RAM. The control unit 102 controls the entire image forming apparatus 100 in accordance with a program stored in the ROM, and implements each function (copy function, print function, FAX function, scanner function, etc.) of the image forming apparatus 100.

  The document reading unit 106 detects a document set on a CCD (Charge-Coupled Device), a document table (for example, a glass platen), an automatic document feeder (ADF), or the like for reading a document. A document detection sensor for reading the document located on the document table and inputting image data. The document is directly placed on the document table by the user, or after being set on the automatic document feeder, the document is conveyed to the document table by the automatic document feeder. For example, the image data is temporarily stored in the RAM of the first storage unit 104.

  The first image forming unit 108 prints image data generated by performing various image processing on the read image data on a recording sheet supplied from the first sheet feeding unit 110. The first image forming unit 108 is an electrophotographic printer. For example, recording paper such as B5, B4, A4, and A3 is held in the first paper feeding unit 110.

  The operation unit 112 is, for example, a touch panel display configured by a display panel configured by a liquid crystal panel or the like and a touch panel that is disposed on the display panel and detects a touched position. Hardware keys such as a power key for turning on / off the power may be arranged around the touch panel display.

  The operation unit 112 receives an input such as an instruction from the user to the image forming apparatus 100 and the expansion apparatus 200. Specifically, a screen (image) displayed on the display panel is generated by a screen generation unit (not shown) under the control of the control unit 102. The user checks the state of the image forming apparatus 100 and the job processing status on the screen displayed on the display panel. The user selects a key displayed in the form of an icon or the like on the display panel on the touch panel overlaid on the display panel (touches a corresponding portion on the touch panel), and thereby the expansion device 200 of the image forming apparatus 100. Function setting and operation instruction can be performed.

  The control unit 102 monitors the user's operation on the touch panel and hardware keys provided in the operation unit 112 and controls the screen generation unit to notify the user of information regarding the state of the image forming apparatus 100 on the display panel. Display information to be notified.

  The network I / F unit 120 is connected to the network 190 and is an interface for the image forming apparatus 100 to communicate with an external device via the network 190. The network I / F unit 120 is, for example, a NIC (Network Interface Card).

  The image forming apparatus 100 includes a FAX modem (not shown). The FAX modem is an interface that is connected to an external telephone line (not shown) and allows the image forming apparatus 100 to perform FAX communication with an external apparatus via the telephone line.

  With reference to FIG. 2, the expansion device 200 further includes a second storage unit 204, a second paper feeding unit 210, an expansion I / F unit 220, and a second bus 222. Data (including control information) is exchanged between the units constituting the expansion device 200 via the second bus 222.

  Similar to the first storage unit 104, the second storage unit 204 includes storage devices such as ROM, RAM, and HDD.

  The media reader unit 206 includes a drive for mounting an optical disc and a socket for mounting a portable memory. Data can be read from and written to the mounted optical disk or portable memory. There are various types of optical disks such as CD-R disks and DVD-RAM disks. There are various portable memories such as a USB memory and a flash memory card (such as an SD memory card, a memory stick, and a compact flash (registered trademark)). Since the optical disc and the portable memory have different standards, only the optical disc and the portable memory corresponding to the drive and socket included in the media reader unit 206 can be used. Hereinafter, the optical disk and the portable memory are also collectively referred to as “storage media”.

  The second image forming unit 208 prints image data generated by performing various image processing on the image data read from the media reader unit 206 on the recording paper supplied from the second paper feeding unit 210. . The second image forming unit 208 is a sublimation printer suitable for photographic printing. The second image forming unit 208 includes a roll-shaped ink ribbon 214 and a driving unit 216 that sends the ink ribbon 214. The second paper feed unit 210 accommodates, for example, roll-shaped recording paper for outputting in L size (89 × 127 mm), which is a size generally used for photographic printing.

  The expansion I / F unit 220 is an interface for connecting the second bus 222 to the first bus 122. As a result, each unit constituting the expansion device 200 can exchange data with each unit constituting the image forming apparatus 100 and can be controlled by the control unit 102.

  Hereinafter, modes for executing the functions (copy function, print function, FAX function, and scanner function) installed in the image forming apparatus 100 and the functions (photo print function) installed in the expansion apparatus 200 will be briefly described. .

(Copy mode)
When the image forming apparatus 100 is used as a copying machine, the image data of the document read by the document reading unit 106 is output from the first image forming unit 108 as a copy.

  An image of the original set at the reading position can be electronically read by the CCD provided in the original reading unit 106. The read image data is completed as output data (printing data) on the RAM of the first storage unit 104, and then the image data is transmitted to the first image forming unit 108 in accordance with the timing of image formation. The

  The recording paper is pulled out from the first paper supply unit 110 by a pickup roller and conveyed to the first image forming unit 108 by a plurality of conveyance rollers. The first image forming unit 108 exposes the charged photosensitive drum according to the input image data, thereby forming an electrostatic latent image according to the image data on the surface of the photosensitive drum. After the toner is attached to the electrostatic latent image portion on the photosensitive drum, the toner image is transferred onto the conveyed recording paper via the transfer belt. Thereafter, the recording paper is heated and pressurized (this fixes the image on the recording paper), and is discharged to the paper discharge tray 140.

(Printer mode)
When the image forming apparatus 100 is used as a printer, a print job (image data) is received from an external device such as a computer via the network I / F unit 120 and output from the first image forming unit 108.

(Photo print mode)
When a storage medium is loaded in the media reader unit 206 and the operation unit 112 is operated by the user and image data is designated and photo printing is instructed, the expansion device 200 reads the designated image data and outputs the second image. The forming unit 208 prints on the recording paper conveyed from the second paper supply unit 210. The printed recording paper is discharged from the photo discharge unit 240.

(Scanner mode)
When the image forming apparatus 100 is used as a network scanner, for example, image data of a document read by the document reading unit 106 is transmitted to an external device such as a computer via the network I / F unit 120 and the network 190. . Also in this case, the original is electronically read by the CCD provided in the original reading unit 106.

  In addition, when a storage medium is mounted on the media reader unit 206 and the operation unit 112 is operated by the user, the image forming apparatus 100 stores image data generated by reading a document with a CCD on the recording medium. Image data generated by reading a document with a CCD is transmitted from the image forming apparatus 100 to the expansion apparatus 200. The expansion device 200 receives the image data transmitted from the image forming apparatus 100 via the expansion I / F unit 220 and stores it in a storage medium designated by the user.

(FAX mode)
When the image forming apparatus 100 is used as a FAX transmitter, the document image data read by the document reading unit 106 is output from the FAX modem as in the copy mode.

  Hereinafter, a control structure of a program for executing color correction of the second image forming unit 208 of the expansion device 200 in the image forming system will be described with reference to FIG. Here, it is assumed that the expansion device 200 stores a color correction table (hereinafter also referred to as primary color correction data) determined by adjustment at the time of shipment in the second storage unit 204. As described above, the color correction table includes data for correcting the level of the control signal of the thermal head of the second image forming unit 208 so that the same color is printed with respect to the same color data. .

  This program is activated when the image forming system is powered on. When the power is turned on, a home screen is displayed on the operation unit 112. The home screen is a screen for selecting each mode of the image forming system as shown in FIG. The home screen 300 includes a copy key 302 for selecting a copy mode, a FAX key 304 for selecting a FAX mode, a photo print key 306 for selecting a photo print mode, and a scanner mode. A scan save key 308 is included. The setting key 310 is a key for displaying a screen for performing basic setting and adjustment regarding the image forming system.

  In the image forming system, a plurality of programs are executed in parallel by multitasking. For example, a program (print function) that receives a print job via the network 190 and executes the print job is also executed in parallel with the program.

  In step 500, the control unit 102 determines whether or not the operation unit 112 has been operated. If it is determined that it has been operated, control proceeds to step 502. Otherwise, step 500 is repeated.

  In step 502, the control unit 102 determines whether execution of color correction is instructed. The color correction is instructed, for example, by operating (pressing) a predetermined key included in a screen displayed when the setting key 310 of the home screen 300 is pressed. If it is determined that color correction has been instructed, control proceeds to step 504. Otherwise control passes to step 528.

  In step 504, the control unit 102 displays a color correction screen on the display panel of the operation unit 112. The color correction screen is a screen as shown in FIG. 5, for example. The area 322 of the color correction screen 320 displays that the color correction is executed and an explanation regarding the content. From this, it can be understood that the user needs to set the printed correction sheet on the document reading unit 106 and press the scan start key 324 as described later. When the cancel key 326 is operated, the color correction screen 320 is deleted and the home screen 300 is displayed, and the control returns to step 500.

  In step 506, the control unit 102 generates color correction image data. Specifically, the control unit 102 reads out color correction data stored in advance in the second storage unit 204, and generates color correction image data from the color correction data. The color correction data is a set of color data and coordinate data (for example, coordinate data of rectangular diagonal vertices) for specifying an area associated therewith (an area on the recording paper that outputs the color). And include multiple sets of them. Here, the color data is internal data (for example, data specifying the temperature of the thermal head) used by the control engine of the second image forming unit 208 in order to output (print) a specific color. The color correction image data is color image data, and includes data for each color of the ink ribbon used for image formation by the second image forming unit 208. Here, as shown in FIG. 6, it is assumed that a roll-shaped ink ribbon including inks of three colors of yellow, magenta, and cyan is used. The ink ribbon 214 includes a Y ink region 400, an M ink region 402, a C ink region 404, and a clear coat material region 406 having a predetermined size. The color correction image data is assumed to be 8 bits for each color of YMC and a total of 24 bits. The clear coat material area 406 provides a clear coat for protecting the print area and adding gloss on the print area with YMC ink on the recording paper.

  Thereafter, the control unit 102 executes photographic printing by the second image forming unit 208 in accordance with the color correction image data generated in step 506 as follows.

  In step 508, the control unit 102 adjusts the positions of the ink ribbon 214 and the recording paper, and matches the printing start position. Specifically, the control unit 102 controls the second paper feeding unit 210 to move the recording paper by a predetermined distance. The control unit 102 further controls the driving unit 216 to move the ink ribbon 214 by a predetermined distance. As a result, the leading portion of the unused ink area of a specific color (for example, Y) and the leading portion of the recording paper are positioned at the position of the thermal head.

  A known method can be used to align the ink ribbon (ink region) and the recording paper with respect to the thermal head. For example, by adding information specifying each ink region to the ink ribbon and detecting this with a sensor, the control unit 102 can adjust the predetermined ink region to a predetermined position. Further, the leading end of the recording paper can be adjusted to a predetermined position by detecting the leading end of the recording paper with a sensor.

  In step 510, the control unit 102 determines the thermal of the second image forming unit 208 according to each pixel data regarding the ink (for example, Y) aligned in step 508 among the color correction image data generated in step 506. The head temperature is calculated, and the temperature of the thermal head is adjusted to be the calculated temperature. At this time, correction is performed by primary color correction data (color correction table determined by adjustment at the time of shipment) stored in the second storage unit 204.

  In step 512, the control unit 102 controls the drive unit 216 to move the ink ribbon 214 by a predetermined distance. The control unit 102 further controls the second paper feeding unit 210 to convey the recording paper by the same distance as the distance to which the ink ribbon 214 is moved. The control unit 102 transfers the ink (for example, Y) of the ink ribbon 214 to the recording paper by the thermal head (sublimates the ink and attaches it to the recording paper).

  In step 514, the control unit 102 determines whether printing (transfer) of one color (for example, Y) has been completed. If it is determined that the process has been completed, control proceeds to step 516. Otherwise, control returns to step 510. Steps 510 and 512 are repeated until the transfer of one color to the recording paper is completed.

  In step 516, the control unit 102 determines whether printing of the color correction image data is completed. If it is determined that the process has been completed, control proceeds to step 518. Otherwise, control returns to step 508.

  When the printing (transfer) of one color on the recording paper is completed (the determination result in step 514 is YES), in step 508, the head of the already transferred area (hereinafter also referred to as the transferred area) on the recording paper is The recording paper is returned until it reaches the position of the thermal head. Further, the ink ribbon 214 is conveyed so that another color ink can be transferred to the transferred area. Thereafter, steps 510 to 514 are repeated to transfer the color.

  Steps 508 to 516 are repeated until the transfer of all the colors of YMC is completed. When printing of the color correction image data is completed (the determination result in step 516 is YES), the transferred area of the recording paper is cut and discharged to the photo discharge unit 240 as a color correction sheet. The clear coat process on the color correction sheet is optional.

  For example, the color correction sheet 340 shown in FIG. 7 is discharged. An area 342 is an area printed based on the color correction image data generated from the color correction data. Actually, the color correction sheet 340 is color-printed. Each block of the area 342 is printed with the color data of the color correction data and the coordinate data associated therewith.

  In step 518, the control unit 102 determines whether or not an instruction to scan a document has been issued. Specifically, the control unit 102 determines whether or not the scan start key 324 of the color correction screen 320 has been operated. If it is determined that it has been operated, control proceeds to step 520. Otherwise, step 518 is repeated.

  A user who knows that the correction sheet has been discharged from the photo discharge unit 240 sets the discharged correction sheet in the document reading unit 106 in accordance with an instruction on the color correction screen 320 and presses the scan start key 324. Accordingly, in step 520, the control unit 102 controls the document reading unit 106 to read the color correction sheet and generate image data (for example, YMC format data of the correction sheet region 342). Here, it is assumed that the image data generated by the document reading unit 106 is data that correctly represents the color of the document. That is, it is assumed that color misregistration due to the characteristics of the document reading unit 106 has been adjusted (uncorrected image data (YMC data) generated by reading the document is adjusted according to the characteristics of the document reading unit 106). Deviate from the data you represent).

  In step 522, the control unit 102 compares the image data generated in step 520 (hereinafter also referred to as scan image data) with the color correction image data generated in step 506. For example, the control unit 102 calculates a difference between corresponding pixel values of the scan image data and the color correction image data. Since the colors of the pixels in each block in the area 342 are the same, the difference between the pixel values of the scan image data and the color correction image data corresponding to the representative point of each block may be calculated. Further, the difference between the average values of the pixel values in the corresponding blocks of the scan image data and the color correction image data may be calculated.

  In step 524, the control unit 102 determines whether or not all the differences calculated in step 522 are within a predetermined range. For example, it is determined whether or not the ratio of the difference (absolute value) to the average value of the two pixel values used for calculating the difference is equal to or less than a predetermined value (for example, 5%, 10%, etc.). If it is determined that it is within the predetermined range, control returns to step 500. Otherwise, control passes to step 526.

  In step 526, the control unit 102 transmits the difference obtained in step 522 to the expansion device 200 via the expansion I / F unit 220 and stores it in the second storage unit 204 as secondary color correction data. At this time, the secondary color correction data is stored in the same format as the color correction table which is the primary color correction data. If the secondary color correction data is already stored in the second storage unit 204, the new secondary color correction data is overwritten. Thus, the color correction ends.

  Thereafter, when the operation unit 112 is operated and an instruction other than color correction is given (the determination result of step 502 is NO), in step 528, the control unit 102 determines whether or not the instruction is a photo print (photo print) instruction. Determine. If it is determined that the instruction is a photo print instruction, the control proceeds to step 530. Otherwise, the control proceeds to step 532, and in step 532, the control unit 102 executes the corresponding process, and then the control returns to step 500.

  In step 530, the control unit 102 executes photo printing. Control then returns to step 500. Specifically, the control unit 102 receives the setting of the image data to be printed and the printing conditions, and when instructed to execute, controls the second image forming unit 208 to perform printing in the same manner as in steps 508 to 516. A photo print of the target image data is executed. At this time, if the secondary color correction data is stored in the second storage unit 204, the primary color correction data and the secondary color correction data are read from the second storage unit 204 and used for color correction. If secondary color correction data is not stored in the second storage unit 204 (no color correction has been performed), the primary color correction data is read from the second storage unit 204 and used for color correction. Is done.

  As described above, even when the ink ribbon 214 has changed over time and the color correction table (primary color correction data) set at the time of shipment from the factory is not valid, the color correction is appropriately performed and the photographic print is printed. Executed. That is, the primary color correction data corrects the color shift due to the characteristics of the second image forming unit 208 itself, and further corrects the color shift caused by the deterioration of the ink ribbon. Therefore, appropriate color printing can be realized.

  If the image data generated by the document reading unit 106 is not data that accurately represents the color of the document, it is preferable to determine the secondary color correction data in consideration of the effect of color misregistration caused by the document reading unit 106. That is, it is preferable to calculate the color misregistration amount generated by the document reading unit 106 in advance and correct the secondary color correction data using the calculated amount.

(Second Embodiment)
In the first embodiment, the color correction is started manually. In the second embodiment, the color correction can be automatically started in addition to the manual operation.

  The image forming system according to the present embodiment is configured in the same manner as the image forming system according to the first embodiment, and the reference numerals in FIGS. 1 and 2 are cited. The expansion device 200 stores a color correction table (primary color correction data) determined by adjustment at the time of shipment in the second storage unit 204.

  In the image forming system according to the present embodiment, the color correction program shown in FIG. 8 is executed. In the flowchart of FIG. 8, a new step 600 is added between steps 528 and 530 in the flowchart of FIG. 3, a new step 602 is added after step 530, and a new step 526 is added. Step 604 is added.

  This program is activated when the image forming system is powered on. When the power is turned on, a home screen (see FIG. 4) is displayed on the operation unit 112. In the image forming system, a plurality of programs are executed in parallel by multitasking. For example, a program (print function) that receives a print job via the network 190 and executes the print job is also executed in parallel with the program.

  When the operation unit 112 is operated to instruct a photo print (photo print) (the determination result in step 528 is YES), in step 600, the control unit 102 prints a photo print number counter (hereinafter simply referred to as a counter). It is determined whether or not the value is equal to or greater than a predetermined number. The value of the counter represents the cumulative number of photo prints executed so far. If the counter value is equal to or greater than the predetermined value, control proceeds to step 504. Thus, as in the first embodiment, color correction is executed in steps 504 to 526, and secondary color correction data is stored in the second storage unit 204.

  If it is determined in step 600 that the counter is less than the predetermined number, photo printing is executed in step 530. At this time, if the secondary color correction data is stored in the second storage unit 204, the primary color correction data and the secondary color correction data are read from the second storage unit 204 and used for color correction. If secondary color correction data is not stored in the second storage unit 204 (no color correction has been performed), the primary color correction data is read from the second storage unit 204 and used for color correction. Is done.

  Thereafter, in step 602, the control unit 102 updates the counter with the number of printed photos. That is, the number of printed photos is added to the current counter value. Control then returns to step 500.

  When the operation unit 112 is operated and color correction is instructed (the determination result in step 502 is YES), color correction is executed in steps 504 to 526 in the same manner as in the first embodiment, and secondary color correction is performed. Data is stored in the second storage unit 204.

  Thereafter, in step 604, the control unit 102 resets the counter. That is, the control unit 102 sets the counter value to “0”. Control then returns to step 500.

  As described above, not only when the color correction is manually instructed, but also when the user instructs to print the photo after the predetermined number of photo prints are executed without performing the color correction, the color is automatically set. Correction is performed. Therefore, even if a change with time or the like occurs in the ink ribbon, the user can obtain a photographic print with appropriate color correction.

  In the above description, a case has been described in which it is determined whether or not the number of photo prints exceeds a predetermined number when the user instructs photo print. However, the present invention is not limited to this. After the photo print is executed, it is determined whether or not the number of photo prints exceeds a predetermined number, and if it exceeds the predetermined number, color correction may be executed.

  In the above description, the timing for automatically executing the color correction is determined based on the cumulative number of photo prints. However, the present invention is not limited to this. If color correction has not been executed for a predetermined period, color correction may be executed.

(Third embodiment)
In the first and second embodiments, the color correction sheet is printed using an unused ink area of the ink ribbon. On the other hand, in the third embodiment, in order to reduce the consumption amount of the ink ribbon, the color correction sheet is printed using the used ink region.

  The image forming system according to the present embodiment is configured in the same manner as the image forming system according to the first embodiment, and the reference numerals in FIGS. 1 and 2 are cited. The expansion device 200 stores a color correction table (primary color correction data) determined by adjustment at the time of shipment in the second storage unit 204.

  In the image forming system according to the present embodiment, the color correction program shown in FIG. 9 is executed. The flowchart of FIG. 9 is obtained by replacing step 508 with a new step 620 in the flowchart of FIG. 3.

  This program is activated when the image forming system is powered on. When the power is turned on, a home screen (see FIG. 4) is displayed on the operation unit 112. In the image forming system, a plurality of programs are executed in parallel by multitasking. For example, a program (print function) that receives a print job via the network 190 and executes the print job is also executed in parallel with the program.

  In the present embodiment, color correction is started manually as in the first embodiment. That is, when the operation unit 112 is operated to instruct color correction, a color correction screen (see FIG. 5) is displayed (step 504), and image data for color correction is generated (step 506).

  Thereafter, in step 620, the control unit 102 controls the drive unit 216 to rewind the ink ribbon 214, adjust the positions of the ink ribbon 214 and the recording paper, and adjust the printing start position. Specifically, the control unit 102 rewinds the ink ribbon 214 so that the ink area of a specific color (for example, C) used in the previous photographic print is positioned at the position of the thermal head.

  FIG. 10 shows the ink area of the ink ribbon 214 used in photographic printing. For example, regarding the Y ink region 400, the maximum region used in photo printing is a region surrounded by a broken line 420. Similarly, for the M ink region 402, the C ink region 404, and the clearcoat material region 406, the largest regions used in photographic printing are the regions surrounded by dashed lines 422, 424, and 426, respectively. Therefore, even if photographic printing using the Y ink region 400 is executed, the region surrounded by the broken line 440 remains unused. Even in the next photo printing, the area surrounded by the broken line 440 is not used. Similarly, the area surrounded by the broken lines 442 to 446 remains unused.

  During execution of photographic printing, the ink ribbon 214 is conveyed in the direction indicated by the arrow 460 in FIG. When printing is completed (clear coat is completed), the thermal head is located near the lower end of the clear coat material region 406. Therefore, when the alignment for transferring the C ink to the recording paper is performed in step 620, for example, the ink ribbon 214 is rewound so that the upper end portion of the region surrounded by the broken line 444 is at the position of the thermal head. (Conveyed in the direction opposite to the arrow 460). Thereafter, Steps 510 to 514 are repeated to transfer the C ink onto the recording paper.

  When the transfer of the C ink to the recording paper is completed (the determination result in step 514 is YES), in the same manner, the alignment for transferring the M ink to the recording paper is performed in step 620. That is, the ink ribbon 214 is rewound so that the upper end portion of the area surrounded by the broken line 442 comes to the position of the thermal head. Thereafter, Steps 510 to 514 are repeated to transfer the M ink onto the recording paper.

  When the transfer of the M ink to the recording paper is completed, in step 620, alignment for transferring the Y ink to the recording paper is performed. That is, the ink ribbon 214 is rewound so that the upper end portion of the region surrounded by the broken line 440 comes to the position of the thermal head. Thereafter, Steps 510 to 514 are repeated to transfer the Y ink onto the recording paper.

  When the transfer of the YMC ink to the recording paper is completed, it is determined in step 516 that the printing is completed, and the color correction sheet 340 (see FIG. 7) is discharged. Thereafter, the secondary color correction data is stored in the second storage unit 204 in steps 518 to 526.

  As described above, even if the ink ribbon 214 has changed over time, color correction is appropriately performed and photographic printing is performed. Therefore, appropriate color printing can be realized. At this time, since the color correction sheet is printed using the unused portion of the ink area used for printing, it is avoided that the unused ink area is used for color correction. . As a result, the consumption amount of the ink ribbon can be reduced.

  In the above description, the case where the color correction sheet is printed using the unused portion of the ink region used immediately before is described, but the present invention is not limited to this. Any unused part of the ink area may be used, and an unused part of the ink area used earlier may be used. If the image for forming the color correction sheet is larger than the unused portion of each ink area, the ink ribbon may be further rewound and a plurality of unused areas may be used.

  In the first to third embodiments, the case where the expansion device 200 is controlled by the control unit 102 of the image forming apparatus 100 has been described. However, the present invention is not limited to this. For example, as illustrated in FIG. 11, the expansion device may include a control unit similar to the control unit 102 of the image forming apparatus 100. 11 is different from FIG. 2 only in that the expansion device 290 includes the second control unit 202. The second control unit 202 is a CPU that executes an appropriate control program, for example.

  In the case of the configuration of FIG. 11, the control program shown in FIGS. 3, 8, and 9 is changed to be executed by the control unit 102 of the image forming apparatus 100 and the second control unit 202 of the expansion device 290 ( Split). That is, the control unit 102 of the image forming apparatus 100 controls the processing of each unit of the expansion device 200. The second control unit 202 receives an instruction from the control unit 102 of the image forming device 100, and the expansion device 290. What is necessary is just to change to the process which controls each part of. For example, the process of step 522 may be executed by the second control unit 202. That is, the second control unit 202 receives the image data generated in step 520 via the expansion I / F unit 220, and compares the received image data with the color correction image data.

  In the first to third embodiments described above, the secondary color correction data is stored separately from the primary color correction data. However, the present invention is not limited to this. Even if the result obtained by adding the secondary color correction data to the primary color correction data is stored separately from the primary color correction data, it is obtained by adding the secondary color correction data to the primary color correction data. The obtained result may be overwritten on the original primary color correction data. In addition, the operation unit 112 displays a screen for confirming to the user whether the secondary color correction data is added to the primary color correction data and overwritten, and receives the user's operation to display the primary color correction data. It may be overwritten.

  In the first to third embodiments described above, in step 524 (see FIGS. 3, 8, and 9) for determining the validity of the primary color correction data, the scan image data and the color correction image data are processed. The criterion for determining whether or not the corresponding pixel value difference is within a predetermined range can be set as appropriate. For example, a value other than the above values (5%, 10%) may be used as the determination reference value. Also, a reference value (upper limit value) may be set with respect to the difference (absolute value) itself instead of the ratio.

  In the first to third embodiments, the case where one ink ribbon having a plurality of ink regions is used has been described. However, ink ribbons of respective colors may be used.

  In the first to third embodiments described above, the color correction sheet can be read by the document reading unit 106 while distinguishing each color area and can be distinguished by a person. That's fine. The consumption of the recording paper may be reduced by making the image formed on the recording paper as a color correction sheet relatively small. For example, the color correction sheet is formed with a size about 1/2 of the L size (44.5 × 127 mm or 89 × 63.5 mm).

  In the first to third embodiments, the case where the second image forming unit 208 of the expansion device 200 is a sublimation printer has been described. However, the present invention is not limited to this. Any printer that uses a color material for color printing that is susceptible to color change with time (including the effect of storage conditions) may be used. For example, a hot-melt printer that melts the ink on the ink ribbon and transfers the ink onto a recording sheet may be used.

  In the first to third embodiments, the case where the expansion device 200 is connected to the first bus 122 of the image forming apparatus 100 has been described. However, the present invention is not limited to this. The expansion device 200 and the image forming apparatus 100 may be connected by a cable (USB cable or the like) based on a predetermined standard.

  In the first to third embodiments described above, the image forming system including the image forming apparatus 100 and the expansion apparatus 200 that is an optional apparatus has been described. However, the present invention is not limited to this. The image forming apparatus 100 may be equipped with a second image forming unit 208 that is a sublimation printer.

  The present invention has been described above by describing the embodiment. However, the above-described embodiment is an exemplification, and the present invention is not limited to the above-described embodiment, and is implemented with various modifications. be able to.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 102 Control part 104 1st memory | storage part 106 Original reading part 108 1st image forming part 110 1st paper feed part 112 Operation part 120 Network I / F part 122 1st bus 140 Paper discharge tray 190 Network 200 Expansion apparatus 204 Second storage unit 206 Media reader unit 208 Second image forming unit 210 Second paper feeding unit 214 Ink ribbon 216 Drive unit 220 Expansion I / F unit 222 Second bus 240 Photo discharge unit

Claims (12)

Image forming means for forming a color image on recording paper;
An original reading means for reading a color original and generating color image data;
Control means for inputting a control signal for designating the color of the image to be formed to the image forming means;
An image forming system including storage means for storing primary color correction data for correcting a control signal input from the control means,
The image forming unit includes:
Correcting the control signal input from the control means with the primary color correction data, forming the color image based on the corrected control signal,
Based on predetermined color correction image data, a color image is formed on the recording paper to generate a color correction sheet,
The image forming system includes:
Comparison means for comparing the image data generated by reading the color correction sheet by the document reading means and the color correction image data;
Determination means for determining whether or not the primary color correction data is valid based on a comparison result by the comparison means;
When the determination means determines that the primary color correction data is not valid, the primary color correction data stored in the storage means is corrected based on the comparison result, or the comparison Color correction means for storing the result in the storage means as secondary color correction data;
The image forming unit receives the control signal input from the control unit when forming a color image after the processing by the color correction unit is executed.
When the primary color correction data is corrected by the color correction means, the correction is made based on the corrected primary color correction data, and
An image forming system in which, when the secondary color correction data is stored in the storage unit by the color correction unit, correction is performed based on the primary color correction data and the secondary color correction data. The image forming unit includes:
In response to execution of image formation on a predetermined number of recording sheets by the image forming unit, or
In response to the elapse of a predetermined period without executing the process by the color correction unit,
The image forming system according to claim 1, wherein the color correction sheet is generated. An operation means for receiving a user instruction;
The image forming system according to claim 1, wherein the image forming unit generates the color correction sheet in response to an instruction from the user by the operation unit. The image forming unit includes:
Including an ink ribbon for holding a plurality of color ink areas to be transferred to the recording paper;
4. The color correction sheet according to claim 1, wherein the color correction sheet is generated by rewinding the ink ribbon and using an unused portion of the ink area that has already been used for image formation. Image forming system.   The image forming system according to claim 1, wherein a size of the color correction sheet is ½ of a size of an L size. The document reading means includes:
It has a platen part where the document is placed,
The image forming system according to claim 1, wherein the color correction sheet set on the platen unit is read. The comparison unit calculates a difference between corresponding pixel values of the image data generated by reading the color correction sheet by the document reading unit and the color correction image data,
The image forming system according to any one of claims 1 to 6, wherein the determination unit determines that the primary color correction data is not valid if the difference is not within a predetermined range. And a confirmation means for confirming to the user whether or not to correct the primary color correction data when the determination means determines that the primary color correction data is not valid.
The color correction means corrects the primary color correction data according to the comparison result in response to an instruction to correct the primary color correction data by the confirmation means. Image forming system. The image forming system includes an image forming apparatus including an electrophotographic printer, and an expansion device,
The image forming means is a sublimation printer,
The expansion device includes the image forming unit and the storage unit,
The image forming system according to claim 1, wherein the image forming apparatus further includes the document reading unit. Image forming means for forming a color image on recording paper;
Control means for inputting a control signal for designating the color of the image to be formed to the image forming means;
An image forming apparatus including storage means for storing primary color correction data for correcting a control signal input from the control means,
The image forming unit includes:
Correcting the control signal input from the control means with the primary color correction data, forming the color image based on the corrected control signal,
Based on predetermined color correction image data, a color image is formed on the recording paper to generate a color correction sheet,
The image forming apparatus includes:
Receiving means for receiving image data generated by reading the color correction sheet by an external device;
Comparing means for comparing the image data received by the receiving means with the image data for color correction;
Determination means for determining whether or not the primary color correction data is valid based on a comparison result by the comparison means;
When the determination means determines that the primary color correction data is not valid, the primary color correction data stored in the storage means is corrected based on the comparison result, or the comparison Color correction means for storing the result in the storage means as secondary color correction data;
The image forming unit receives the control signal input from the control unit when forming a color image after the processing by the color correction unit is executed.
When the primary color correction data is corrected by the color correction means, the correction is made based on the corrected primary color correction data, and
An image forming apparatus that corrects, based on the primary color correction data and the secondary color correction data, when the secondary color correction data is stored in the storage unit by the color correction unit. An image forming apparatus including an electrophotographic image forming unit,
Receiving means for receiving predetermined color correction image data from an external device;
Document reading means for reading the color correction sheet generated based on the color correction image data by the external device and generating image data;
Comparing means for comparing the image data generated by reading the color correction sheet by the document reading means and the color correction image data received by the receiving means;
An image forming apparatus including: a transmission unit configured to transmit a comparison result by the comparison unit to the external device; A method for correcting the color of an image formed on recording paper by an image forming apparatus,
An image forming step of forming a color image on recording paper by an image forming unit of the image forming apparatus;
A document reading step of reading a color document and generating color image data;
A control step of inputting a control signal for designating a color of an image formed on the recording paper to the image forming unit;
Storing a primary color correction data for correcting the control signal,
In the image forming step, the control signal is corrected by the primary color correction data, and an image is formed based on the corrected control signal,
The image forming step includes a step of generating a color correction sheet by forming a color image on the recording paper based on predetermined color correction image data,
A comparison step of comparing the image data generated by reading the color correction sheet by the document reading step and the color correction image data;
A determination step of determining whether or not the primary color correction data is valid based on a comparison result of the comparison step;
In response to the determination that the primary color correction data is not valid in the determination step, the primary color correction data is corrected based on the comparison result, or the comparison result is converted into secondary color correction data. A color correction step stored as
In the image forming step executed after the color correction step is executed, the control signal is
When the primary color correction data is corrected, it is corrected based on the corrected primary color correction data, and
And a step of correcting the primary color correction data based on the primary color correction data and the secondary color correction data when the secondary color correction data is stored.

Images