JP2017058399A - Image forming apparatus and image forming program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus and an image forming program for, in adjusting image quality when image formation is performed by using a color material in a first color, enabling accurate adjustment of image quality compared with a case where image formation is performed by overlapping the color material in a first color on a color material in a second color having a color difference from the first color equal to or larger than a predetermined threshold.SOLUTION: An image forming apparatus comprises: first forming means that forms a first image on a first surface of an image forming medium having translucency with a color material in a first color; and second forming means that forms a second image in a corresponding area that is on a second surface on the opposite side of the first surface and corresponds to the area where the first image is formed. The image forming apparatus acquires the density of the first image, and creates density correction information on the color material in a first color by using the acquired density and a predetermined target density of the first image.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming apparatus and an image forming program.

  Patent Document 1 discloses a head that ejects a first ink and a second ink having a color different from that of the first ink, a non-contact type density sensor for a medium, and operations of the head and the density sensor. And a controller that controls the plurality of ink jets along the predetermined direction by ejecting the first ink toward the medium while moving the head in the predetermined direction. The first pattern in which the amount of the first ink is increased from one end side to the other end side in the predetermined direction, and the head is moved in the predetermined direction while moving the head in the predetermined direction. A second pattern in which a plurality of patches are arranged along the predetermined direction by ejecting the second ink toward the medium, from the one end side to the other end side in the predetermined direction A second pattern which increases the discharge amount of the second ink and is aligned with the first pattern in an intersecting direction intersecting the predetermined direction, and forms the first pattern and the first pattern on the medium. Each of the two patterns of patches is read by the density sensor, and the ejection amount of the first ink from the head is corrected based on the reading result of the first pattern and the reading result of the second pattern. A printing apparatus is disclosed.

JP2013-146922A

  For example, when performing image quality adjustment including gradation characteristics and density maintenance when an image is formed with a white color material (first color), an image is formed with a white color material on a transparent film. Then, color measurement is performed on the area where the image has been formed, or reading is performed by a scanner. In this case, when the color of the back portion of the transparent film is the same white as the color material, it is possible to distinguish between the area formed with the white color material and the area where no image is formed. It becomes difficult. In addition, before forming an image with a white color material, it is also possible to form an image with a black (second color) color material as a background and form an image by overlaying a white color material on the black color material. Conceivable. However, in this case, there is a possibility that the white color material may permeate into the black color material that is the base, and the color of the area formed with the white color material is not always accurately measured. Absent.

  According to the present invention, when adjusting the image quality when image formation is performed using the first color material, the first color material is formed on the second color material whose color difference from the first color is equal to or greater than a predetermined threshold. An object of the present invention is to provide an image forming apparatus and an image forming program capable of adjusting image quality with higher accuracy than in the case of forming an image by superimposing color materials of colors.

  In order to achieve the above object, an image forming apparatus according to claim 1 includes: a first forming unit that forms a first image with a first color material on a first surface of a translucent image forming medium; The color material of the second color in which the color difference from the first color is greater than or equal to a predetermined threshold value in a corresponding region corresponding to the region where the first image is formed on the second surface opposite to the first surface A second forming means for forming a second image, an acquisition means for acquiring the density of the first image formed on the first surface, a density of the first image acquired by the acquisition means, and Generating means for generating density correction information of the color material of the first color using the determined target density of the first image.

  According to a second aspect of the present invention, in the first aspect of the present invention, the first forming unit may include a plurality of the first images with a first color material on the first surface. The acquisition unit acquires the density of the plurality of first images formed on the first surface for each of the first images, and the generation unit acquires the first image acquired by the acquisition unit. Using the density for each image and the target density predetermined for each first image, density correction information for the color material of the first color is generated.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the second forming unit includes the corresponding region on the second surface and has a larger area than the corresponding region. In addition, the second image is formed with the color material of the second color.

  According to a fourth aspect of the present invention, there is provided the first forming means for forming the first image with the first color material on the first surface of the image forming medium having translucency, and the opposite side of the first surface. Forming a second image with a color material of a second color having a color difference from the first color equal to or greater than a predetermined threshold in a corresponding area corresponding to the area where the first image is formed on the second surface of And a third forming unit that forms a third image with a color material of a third color different from both the first color and the second color at a position adjacent to the first image on the first surface. Means, an acquisition means for acquiring a shift amount between the first image and the third image formed on the first surface, and a color material of the first color using the shift amount acquired by the acquisition means Generating means for generating the position adjustment information.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the third forming unit forms the third image at a position adjacent to the first image and the conveyance direction of the image forming medium. The acquisition unit acquires a shift amount in the transport width direction that intersects the transport direction of the position of the first image and the third image formed on the first surface, and the generation unit includes the acquisition unit. The position adjustment information in the transport width direction of the color material of the first color is generated using the shift amount in the transport width direction acquired by the above.

  According to a sixth aspect of the present invention, in the fourth or fifth aspect of the invention, the third forming unit is adjacent to the conveyance width direction intersecting the conveyance direction of the first image and the image forming medium. The third image is formed on the first surface, and the acquisition unit acquires the shift amount in the transport direction between the position of the first image and the third image formed on the first surface, and the generation unit Position adjustment information in the transport direction of the color material of the first color is generated using the shift amount in the transport direction acquired by the acquisition unit.

  According to a seventh aspect of the present invention, there is provided a first forming means for forming a first image with a first color material on a first surface of an image forming medium having translucency, and an opposite side of the first surface. Forming a second image with a color material of a second color having a color difference from the first color equal to or greater than a predetermined threshold in a corresponding area corresponding to the area where the first image is formed on the second surface of 2 forming means, acquisition means for acquiring densities at a plurality of positions in the first image formed on the first surface, and using the densities at the plurality of positions acquired by the acquisition means, Generating means for generating unevenness adjustment information of the color material of the first color.

  According to an eighth aspect of the present invention, in the invention according to the seventh aspect, the acquisition means has positions in the transport direction of the image forming medium in the first image formed on the first surface. The density is acquired at a plurality of different positions, and the generating unit transports the color material of the first color by using the densities at the plurality of positions different in the transport direction acquired by the acquiring unit. Direction unevenness adjustment information is generated.

  The invention according to claim 9 is the invention according to claim 7 or 8, wherein the acquisition means intersects the conveyance direction of the image forming medium in the first image formed on the first surface. The generation means acquires the density at a plurality of different positions in the conveyance width direction, and the generation means uses the densities at the plurality of positions different in the conveyance width direction acquired by the acquisition means. The unevenness adjustment information in the conveyance width direction of the first color material is generated.

  The invention according to claim 10 is the invention according to any one of claims 1 to 9, wherein the first color is white and the second color is black.

  On the other hand, in order to achieve the above object, an image forming program according to an eleventh aspect causes a computer to function as an acquisition unit and a generation unit constituting the image forming apparatus according to any one of the first to tenth aspects. It is a program for.

  According to the first and eleventh aspects of the present invention, when adjusting the image quality when image formation is performed using the first color material, the second color difference from the first color is equal to or greater than a predetermined threshold. Compared with the case where an image is formed by overlaying the first color material on the color material, the image quality can be adjusted with higher accuracy.

  According to the second aspect of the present invention, the image quality adjustment of the color material of the first color can be performed with higher accuracy than in the case where the first image having a constant density is formed on the first surface of the image forming medium. Can do.

  According to the third aspect of the present invention, as compared with the case where the second image is formed only in the corresponding region corresponding to the first image on the second surface, the registration shift is smaller in the image formation using the color material of the first color. Even when this occurs, the image quality adjustment of the color material of the first color can be performed with high accuracy.

  According to the fourth aspect of the present invention, when adjusting the image forming position when image formation is performed using the first color material, the second color difference from the first color is equal to or greater than a predetermined threshold value. Compared to the case where the first color material is superimposed on the color material, and the image formation position of the first color material is adjusted, the image forming position of the first color material can be adjusted with high accuracy.

  According to the fifth aspect of the present invention, it is possible to accurately adjust the image forming position of the color material of the first color in the transport width direction that intersects the transport direction of the image forming medium.

  According to the sixth aspect of the present invention, it is possible to accurately adjust the image forming position of the first color material in the conveying direction of the image forming medium.

  According to the seventh aspect of the present invention, when adjusting in-plane unevenness in the case of forming an image using the first color material, the second color difference from the first color is equal to or greater than a predetermined threshold value. Compared with the case where the first color material is superimposed on the color material and the image is formed, the in-plane unevenness of the first color material can be adjusted with high accuracy.

  According to the eighth aspect of the present invention, it is possible to accurately adjust the periodic in-plane unevenness that occurs in the conveyance direction of the image forming medium.

  According to the ninth aspect of the present invention, it is possible to accurately adjust in-plane unevenness that occurs in the conveyance width direction of the image forming medium.

  According to the invention described in claim 10, the image quality adjustment of the white color material can be performed with high accuracy.

1 is a schematic configuration diagram (a cutaway side view) illustrating a configuration of an image forming apparatus according to an embodiment. FIG. 2 is a block diagram illustrating functions of the image forming apparatus according to the embodiment. FIG. 6 is a schematic diagram illustrating an example of toner information according to an embodiment. It is a schematic diagram which shows an example of the media information which concerns on embodiment. It is a schematic diagram which shows an example of the image formation mode information which concerns on embodiment. It is a front view which shows an example of the surface reference pattern which concerns on 1st Embodiment, and an example of a back surface reference pattern. It is a side view which shows an example of the surface reference pattern which concerns on 1st Embodiment, and an example of a back surface reference pattern. It is a front view which shows another example of the surface reference pattern which concerns on 1st Embodiment, and another example of a back surface reference pattern. It is a side view which shows another example of the surface reference pattern which concerns on 1st Embodiment, and another example of a back surface reference pattern. 1 is a block diagram illustrating a main configuration of an electrical system of an image forming apparatus according to an embodiment. It is a flowchart which shows the flow of the program of the calibration process which concerns on 1st Embodiment. 6 is a graph illustrating an example of a relationship between print coverage of white toner and output density in a region where image formation with white toner is performed in the image forming apparatus according to the first embodiment. It is a front view which shows an example of the surface reference pattern which concerns on 2nd Embodiment, and an example of a back surface reference pattern. It is a flowchart which shows the flow of the program of the registration shift adjustment process which concerns on 2nd Embodiment. It is a front view which shows an example of the surface reference pattern which concerns on 3rd Embodiment, and an example of a back surface reference pattern. It is a flowchart which shows the flow of the program of the in-plane nonuniformity adjustment process which concerns on 3rd Embodiment. 10 is a graph illustrating an example of a relationship between a position of image formation with white toner and a detected density value in an image forming apparatus according to a third embodiment. 12 is a graph illustrating an example of a relationship between a position of image formation with white toner and a laser light amount in an image forming apparatus according to a third embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]

  First, the image forming apparatus according to the first embodiment will be described. In the first embodiment, a case where density correction (calibration) of a white color material (toner) is performed using a translucent image forming medium will be described.

  In the present embodiment, a case where a colorless transparent film is used as an image forming medium having translucency will be described. However, the present invention is not limited to this, and a colored transparent film such as red or yellow may be used. It may be a translucent film such as a color.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to a so-called tandem type full-color image forming apparatus using an electrophotographic system will be described.

  First, the configuration of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG. In the following, yellow is represented by Y, magenta by M, cyan by C, black by K, and white by W. Further, when it is necessary to distinguish each component for each color, a description will be given with a color code (Y, M, C, K, W) corresponding to each color at the end of the code. Further, in the following, when the component parts are collectively referred to without being distinguished for each color, the description will be made with the color code at the end of the code omitted.

  The image forming apparatus 10 according to the present embodiment includes photoconductors 12Y, 12M, 12C, 12K, which are four image carriers that rotate in the direction of arrow A in FIG. 1 for each of Y, M, C, K, and W. It has 12W. Further, the image forming apparatus 10 includes chargers 14Y, 14M, 14C, 14K, and 14W that charge the surface of each photoconductor 12 by applying a charging bias.

  The image forming apparatus 10 exposes the surface of the charged photoconductor 12 with exposure light modulated based on image information of each color, and forms an electrostatic latent image on the photoconductor 12. 16M, 16C, 16K, 16W. Further, the image forming apparatus 10 includes developing rolls 18Y, 18M, 18C, 18K, and 18W that hold developers (toners) of the respective colors.

  Further, the image forming apparatus 10 includes a developing bias power source (not shown). Then, the image forming apparatus 10 applies a developing bias to the developing roll 18 to develop the electrostatic latent image on the photoconductor 12 with toner of each color to form a toner image on the photoconductor 12. , 20M, 20C, 20K, 20W. The developing device 20 is provided with a stirring member (not shown) that stirs the replenished toner, and the toner discharged into the developing device 20 is stirred by the stirring member so that the toner density becomes uniform. .

  Further, the image forming apparatus 10 includes toner replenishing rods 21Y, 21M, 21C, 21K, and 21W that store toner therein and replenish the stored toner to each of the developing devices 20. The toner replenishing rod 21 is provided with a screw (not shown) that rotates at a constant speed to discharge stored toner at a constant replenishment speed and replenish the developing device 20.

  Further, the image forming apparatus 10 includes primary transfer devices 24Y, 24M, 24C, 24K, and 24W that transfer the toner images of the respective colors on the photoreceptor 12 to the intermediate transfer belt 22.

  Further, the image forming apparatus 10 includes a paper storage unit 26 that stores an image forming medium P such as paper and a transparent film, a secondary transfer device 28 that transfers a toner image on the intermediate transfer belt 22 to the image forming medium P, It has. Note that when there are a plurality of types of image forming media P used in the image forming apparatus 10, the image forming apparatus 10 includes a plurality of paper storage units 26 for each type of image forming medium P. The image forming apparatus 10 also cleans the toner remaining on the surface of the intermediate transfer belt 22 after the toner image transferred to the image forming medium P is fixed to the fixing device 30 that fixes the toner image transferred to the image forming medium P. And a belt cleaner (not shown). Further, the image forming apparatus 10 includes a reversing device 62 that carries in the image forming medium P and carries it out in a state where the front and back sides are reversed.

  The image forming apparatus 10 is a colorimeter 60 that detects the density of an image formed on the image forming medium P, and is movable in the transport direction of the image forming medium P and the transport width direction intersecting the transport direction. A color measuring device 60 is provided. In the present embodiment, the density of the image formed on the image forming medium P is detected by the colorimeter 60, but the apparatus for detecting the density of the image formed on the image forming medium P is not limited to this. For example, the image forming apparatus 10 includes a scanner instead of the colorimeter 60, and the image density is determined based on the pixel value of each pixel of the read image obtained by reading the image formed on the image forming medium P by the scanner. You may ask for.

  Next, an image forming process in the image forming apparatus 10 according to the present embodiment will be described.

  When image information indicating an image to be formed is input, the image forming apparatus 10 applies a charging bias to the charger 14 and charges the surface of the photoreceptor 12 to the negative electrode.

  On the other hand, the image forming apparatus 10 decomposes the image information into image information of each color of YMCKW, and then outputs a modulation signal based on the image information of each color to the laser output unit 16 of the corresponding color. The laser output unit 16 outputs a laser beam L modulated according to the input modulation signal.

  Each of the modulated laser beams L is irradiated on the surface of the photoreceptor 12. The surface of the photoconductor 12 is in a state of being negatively charged by the charger 14, but when the surface of the photoconductor 12 is irradiated with the laser beam L, the charge of the portion irradiated with the laser beam L disappears and the photoconductor 12 is exposed. An electrostatic latent image corresponding to the image information of each color of YMCKW is formed on the body 12.

  When the electrostatic latent image formed on the photoreceptor 12 reaches the developing device 20, a developing bias is applied to the developing roll 18 in the developing device 20 by a developing bias power source (not shown). Then, the toner of each color held on the peripheral surface of the developing roll 18 adheres to the electrostatic latent image on the photoreceptor 12, and a toner image corresponding to the image information of each color is formed on the photoreceptor 12.

  Further, the rollers 32A to 32C and the backup roll 28A of the secondary transfer device 28 are rotated by a motor (not shown), and the intermediate transfer belt 22 is conveyed to a gap formed by the primary transfer unit 24 and the photosensitive member 12 to be intermediate. The transfer belt 22 is pressed against the photoconductor 12. At this time, when a primary transfer bias is applied by the primary transfer unit 24, the toner images of the respective colors formed on the photoconductor 12 are transferred to the intermediate transfer belt 22. In this case, the rotations of the rollers 32A to 32C and the backup roll 28A are controlled so that the transfer start positions of the toner images of the respective colors onto the intermediate transfer belt 22 are matched. By superimposing the toner images of the respective colors in this way, a toner image corresponding to the image information is formed on the intermediate transfer belt 22. In FIG. 1, the conveyance direction of the intermediate transfer belt 22 is indicated by an arrow B.

  The photosensitive member 12 having transferred the toner image to the intermediate transfer belt 22 is removed of the adhered toner and other adhered matter on the surface by a cleaner, and the residual charge is removed by a static eliminator.

  On the other hand, the secondary transfer device 28 includes, for example, a backup roll 28A that supports the intermediate transfer belt 22, a secondary transfer roll 28B that sandwiches the image forming medium P together with the backup roll 28A, and an auxiliary roll 28C. The secondary transfer device 28 also includes a secondary transfer belt 34 that is stretched around the secondary transfer roll 28B and the auxiliary roll 28C and conveys the image forming medium P following the rotation of the secondary transfer roll 28B. . Then, the secondary transfer roll 28 </ b> B rotates following the conveyance of the intermediate transfer belt 22 by contacting the intermediate transfer belt 22.

  Further, the sheet transport roller 36 is rotated by a motor (not shown), so that the image forming medium P in the sheet storage unit 26 is transported to a gap formed by the backup roll 28A and the secondary transfer roll 28B.

  When the image forming medium P is sandwiched in the gap between the backup roll 28A and the secondary transfer roll 28B in a state of facing the surface of the intermediate transfer belt 22 on which the toner image is formed, the secondary roll is placed on the backup roll 28A. A transfer bias is supplied. Further, the toner image formed on the intermediate transfer belt 22 is transferred to the surface of the image forming medium P. Then, the image forming medium P is conveyed to the fixing device 30 by the intermediate conveying rollers 38A and 38B, and the toner image transferred onto the image forming medium P by the fixing device 30 is heated and melted so that the toner image is transferred to the image forming medium P. It is fixed.

  When forming an image on both surfaces of the image forming medium P, the image forming medium P having a toner image fixed on the surface is conveyed to a transfer position by the secondary transfer device 28 with the reversing device 62 reversed front and back. Is done. Then, the toner image formed on the intermediate transfer belt 22 in the same process as the front surface is also transferred to the back surface of the image forming medium P and fixed on the back surface of the image forming medium P by the fixing device 30.

  Next, functions of the image forming apparatus 10 according to the present embodiment will be described with reference to FIG.

  As shown in FIG. 2, the image forming apparatus 10 includes an image data input unit 40, a toner detection unit 42, an image quality adjustment determination unit 44, an image data generation unit 48, a paper determination unit 46, an image formation mode setting unit 50, and an image output. A unit 52 and a storage unit 54 are provided.

  The storage unit 54 stores toner information 54A indicating usable toner, media information 54B indicating usable image forming medium P, and image forming mode information 54C indicating settable image forming modes.

  As shown in FIG. 3 as an example, the toner information 54A is information in which information indicating whether or not the toner can be used is associated with each toner type. In the present embodiment, the image forming apparatus 10 is provided with a detection unit (not shown) that detects whether a toner bottle is connected to each toner replenishing pot 21. Then, in the toner information 54A, it is assumed that the toner detected that the toner bottle is connected can be used, and the toner detected that the toner bottle is not connected is disabled. However, the method for detecting whether or not each toner can be used is not limited to this, and a known method such as allowing the user to input information indicating whether or not each toner can be used can be applied. Is possible.

  As an example, the media information 54B is information in which information indicating whether or not the image forming medium P can be used is associated with the type (material, size, etc.) of the image forming medium P, as shown in FIG. In the present embodiment, for example, when the A4 size white paper is stored in the paper storage unit 26 for storing the A4 size white paper is detected by the optical sensor, and the white paper is stored. A4 size white paper can be used. Further, for example, when the transparent film is stored in the paper storage unit 26 for storing the transparent film, it is detected that the transparent film can be used when the transparent film is stored. Is done.

  As shown in FIG. 5 as an example, the image forming mode information 54C includes a surface mode in which the selected image forming mode forms an image on the front surface, a back surface mode in which an image is formed on the front surface, and image formation on both the front and back surfaces. This is information indicating which of the two-sided modes to be performed. In the example shown in FIG. 5, the selected image forming mode is indicated as “selected”, and the unselected image forming mode is indicated as “non-selected”. In the image forming mode information 54C, one of the front surface mode, the back surface mode, and the double surface mode is selected.

  The image data input unit 40 inputs an image as an image formation target. Note that the image data input unit 40 does not input an image when performing a calibration process, which will be described later, a registration deviation adjustment process of the second embodiment, and an in-plane unevenness adjustment process of the third embodiment.

  The toner detection unit 42 detects whether or not the toner used for image formation in the image forming apparatus 10 can be used. When performing a calibration process to be described later, it is mainly detected whether or not white toner can be used in the toner information 54A.

  The image quality adjustment determination unit 44 determines whether to perform white toner calibration. At this time, for example, when the user inputs an instruction to perform white toner calibration by operating the operation display unit 78, it is determined that white toner calibration is performed. When the white toner calibration is performed, the image quality adjustment determination unit 44 forms an image with the white toner on the first surface (front surface) of the image forming medium P, and the second surface (on the opposite side of the first surface) It is determined that an image is formed on the back surface with toner of a color other than white (for example, black).

  When the image quality adjustment determination unit 44 determines that white toner calibration is to be performed, the paper determination unit 46 confirms whether or not a transparent film can be used in the media information 54B. In addition, when a transparent film can be used, the paper determination unit 46 sets the acquisition source of the image forming medium P that is an image formation target as the paper storage unit 26 in which the transparent film is stored.

  The image data generation unit 48 generates a calibration surface reference pattern formed on the front surface P1 of the image forming medium P and a calibration back surface reference pattern formed on the back surface P2.

  As an example, as shown in FIG. 6, the surface reference pattern 56 is a plurality of regions 56 </ b> A (first image) drawn with white (first color) toner, and a plurality of regions drawn with different print coverages. A region 56A is provided. In the example illustrated in FIG. 6, each area 56 </ b> A includes a print coverage display area 56 </ b> B that draws information indicating print coverage. Thus, by drawing information indicating the print coverage on the image forming medium P, the user can confirm the print coverage of each area 56A. Information indicating the print coverage may not be formed.

  As an example, as shown in FIGS. 6 and 7, the back surface reference pattern 58 is 100 (black) (second color) toner at positions corresponding to the front and back directions with respect to the plurality of regions 56 </ b> A in the front surface reference pattern 56. And a plurality of regions 58A (second image) drawn with% print coverage. In the example shown in FIG. 6 and FIG. 7, each print coverage display area 56B has a plurality of areas 58B drawn with 100% print coverage with black toner at positions corresponding to the front and back directions. Note that an arrow X in FIGS. 6 and 7 represents the conveyance direction X of the image forming medium P.

  The front surface reference pattern 56 and the back surface reference pattern 58 are not limited to this. As an example, as shown in FIGS. 8 and 9, the back surface reference pattern 58 includes a region 58A that includes a region corresponding to the front and back direction with respect to the plurality of regions 56A and is wider than the region 56A, and is 100 with black toner. An area 58A drawn with% print coverage may be included. In this case, even when the image forming position in the front and back direction is shifted in the double-sided mode image formation, the calibration is performed with high accuracy.

  In the present embodiment, the case where the first color is white and the second color is black is described. However, the first color and the second color are not limited to this, and the color difference between the first color and the second color is not limited. What is necessary is just to be more than a predetermined discrimination threshold. In the present embodiment, when the colorimeter 60 measures the area formed with the first color toner and the area formed with the second color toner, each area can be identified. As the color difference between the color and the second color, a color difference obtained in advance through experiments is used as the discrimination threshold.

  In this embodiment, the case where the image is formed in the region 58A with black toner and 100% print coverage will be described. However, the print coverage of black toner is not limited to this, and a predetermined threshold (for example, (95%) or more print coverage.

  If the image quality adjustment determination unit 44 determines that white toner calibration is to be performed, the image formation mode setting unit 50 sets the image formation mode to the duplex mode, and the image selected in the image formation mode information 54C. The formation mode is a double-sided mode.

  When the image quality adjustment determination unit 44 determines that white toner calibration is to be performed, the image output unit 52 has a surface reference pattern 56 formed with the white toner on the surface P1 of the image forming medium P. Image information indicating the reference pattern 56 is output. Further, when the image output adjustment determination unit 44 determines that the white toner calibration is to be performed, the image output unit 52 forms the back reference pattern 58 with the black toner on the back surface P2 of the image forming medium P. In addition, image information indicating the back surface reference pattern 58 is output. In the present embodiment, the surface reference pattern 56 is formed on the front surface P1 of the image forming medium P, and the back surface reference pattern 58 is formed on the back surface P2 of the image forming medium P. However, the present invention is not limited to this. For example, the back surface reference pattern 58 may be formed on the front surface P1 of the image forming medium P, and the front surface reference pattern 56 may be formed on the back surface P2 of the image forming medium P. The image output unit 52 is an example of a first forming unit, a second forming unit, and a third forming unit.

  The correction data generation unit 53 acquires the density of the surface reference pattern 56 formed on the image forming medium P detected by the colorimeter 60. Then, the correction data generation unit 53 is density correction information (calibration) that is information for correcting the output density so as to cancel the difference between the density of the surface reference pattern 56 formed on the image forming medium P and the target density. Generation information). The correction data generation unit 53 is an example of an acquisition unit and a generation unit.

  As shown in FIG. 10, the image forming apparatus 10 according to the present embodiment is realized by controlling each unit by a CPU (Central Processing Unit) 70 that controls the operation of the entire apparatus. That is, the image forming apparatus 10 according to the present embodiment includes a CPU 70 and a ROM (Read Only Memory) 72 in which various programs, various parameters, and the like are stored in advance. Further, the image forming apparatus 10 includes the above-described storage unit 54 including a RAM (Random Access Memory) 74 used as a work area when the CPU 70 executes various programs, and a nonvolatile memory such as a flash memory.

  Further, the image forming apparatus 10 includes a communication line I / F (Interface) unit 76 that transmits and receives communication information to and from an external device. In addition, the image forming apparatus 10 includes an operation display unit 78 that receives an instruction from the user to the image forming apparatus 10 and notifies the user of various types of information regarding the operation status of the image forming apparatus 10. The operation display unit 78 includes, for example, a display button that realizes reception of an operation instruction by executing a program, a touch panel display on which various information is displayed, and hardware keys such as a numeric keypad and a start button.

  In addition, the image forming apparatus 10 includes an image forming unit 80. The image forming unit 80 includes each component that performs various processes related to image formation in the image forming process described above.

  The CPU 70, ROM 72, RAM 74, storage unit 54, communication line I / F unit 76, operation display unit 78, and image forming unit 80 are connected via a bus 82 such as an address bus, a data bus, and a control bus. Are connected to each other.

  As described above, in the image forming apparatus 10 according to the present embodiment, the CPU 70 performs access to the ROM 72, RAM 74, and storage unit 54, and transmission / reception of communication information via the communication line I / F unit 76. In the image forming apparatus 10, the CPU 70 acquires various information via the operation display unit 78 and displays various information on the operation display unit 78. In the image forming apparatus 10, the CPU 70 causes the image forming unit 80 to form an image. Further, the image forming apparatus 10 acquires a detection value by the colorimeter 60 by the CPU 70.

  Next, a flow of calibration processing executed by the image forming apparatus 10 according to the present embodiment every time a predetermined period elapses will be described with reference to a flowchart of FIG. In the present embodiment, the calibration processing program is stored in the storage unit 54 in advance, but is not limited thereto. For example, a calibration processing program may be received from an external device via the communication line I / F unit 76 and stored in the storage unit 54. Further, the calibration processing may be executed by reading a calibration processing program recorded on a recording medium such as a CD-ROM with a CD-ROM drive or the like.

  In step S101, the toner detection unit 42 determines whether white toner can be used. If it is determined in step S101 that white toner can be used (S101, Y), the process proceeds to step S103. If it is determined that white toner cannot be used (S101, N), the calibration process is performed. Terminates program execution.

  In step S103, the image quality adjustment determination unit 44 determines whether to perform white toner calibration. If it is determined in step S103 that white toner calibration is to be performed, the process proceeds to step S105. If it is determined that white toner calibration is not to be performed, execution of the calibration processing program is terminated.

  In step S105, the paper determination unit 46 determines whether or not a transparent film can be used. If it is determined in step S105 that the transparent film can be used, the process proceeds to step S107. If it is determined that the transparent film cannot be used, the execution of the calibration process program is terminated.

  In step S <b> 107, the image data generation unit 48 generates the front surface reference pattern 56 and the back surface reference pattern 58.

  In step S109, the image formation mode setting unit 50 sets the image formation mode to the duplex mode.

  In step S111, the image output unit 52 outputs the surface reference pattern 56, and forms the surface reference pattern 56 with white toner on the surface P1 of the image forming medium P.

  In step S113, the image output unit 52 outputs the back surface reference pattern 58, and forms the back surface reference pattern 58 on the back surface P2 of the image forming medium P with black toner.

  In step S115, the correction data generation unit 53 acquires the density of each region 56A of the surface reference pattern 56 formed with white toner on the surface P1 of the image forming medium P detected by the colorimeter 60.

  In step S117, the correction data generation unit 53 performs calibration from the density of each region 56A of the surface reference pattern 56 formed of white toner on the surface P1 of the image forming medium P and the predetermined target density. Generate application information. In addition, the correction data generation unit 53 ends the execution of the calibration processing program.

  The calibration information is information indicating a correction amount for canceling the difference between the density of the surface reference pattern 56 formed on the surface P1 of the image forming medium P and the target density. That is, there may be a deviation between the detected density value detected by the colorimeter 60 and the target density of the surface reference pattern 56 formed on the surface P1. In this case, as shown in FIG. 12 as an example, an output density correction value 84 for canceling the difference between the detected density value and the target density 86 is stored as calibration information.

  As described above, in this embodiment, the first image is preliminarily applied to the surface P1 that is the first surface of the transparent film that is the translucent image forming medium P with the white toner that is the first color material. Form with defined print coverage. Further, in the corresponding area corresponding to the area where the first image is formed on the back surface P2 which is the second surface of the transparent film, the black toner which is the second color whose color difference from the first color is equal to or more than a predetermined threshold value. Thus, a second image is formed. Further, the density of the first image is acquired, and density correction information for white toner is created using the acquired density and a predetermined target density of the first image. Then, when performing image formation with white toner, the density of the image formed with the white toner on the image forming medium P is corrected by correcting the image data using the white toner density correction information. . Thereby, when an image is formed on the image forming medium P with white toner, the density of each pixel in the image is faithfully reproduced on the image forming medium P.

[Second Embodiment]

  Next, an image forming apparatus according to the second embodiment will be described. In the second embodiment, a description will be given of a case where white toner registration deviation adjustment is performed using a light-transmitting image forming medium P.

  That is, in the first embodiment, the case where the calibration information of the white toner is generated using the density and the target density of the surface reference pattern 56 formed on the surface P1 has been described. On the other hand, in the second embodiment, the registration deviation adjustment information for the white toner is generated by using the deviation amount of the position of the image formation area of the white toner and the image formation area of the color toner other than white toner. explain.

  Since the configuration of the image forming apparatus according to the second embodiment is the same as that of the image forming apparatus 10 according to the first embodiment, description of each configuration is omitted.

  However, in the second embodiment, a surface reference pattern 56C and a back surface reference pattern 58C that are different from the surface reference pattern 56 and the back surface reference pattern 58 of the first embodiment are used.

  As an example, as shown in FIG. 13, the surface reference pattern 56 </ b> C of the surface P <b> 1 is a region 56 </ b> D (first image) drawn with white toner adjacent to the conveyance direction X, and a color different from both white and black ( There are a plurality of sets of areas 56E (third image) drawn with toner of the (third color). In this case, the set of the region 56D and the region 56E is arranged so that the positions in the transport width direction Y that is the direction intersecting the transport direction X are equal. Further, the surface reference pattern 56C includes a plurality of sets of regions 56D and regions 56E that are adjacent to each other in the transport width direction Y that is a direction orthogonal to the transport direction X. In this case, the set of the region 56D and the region 56E is arranged so that the positions in the transport direction X are equal. In the present embodiment, as the third color toner, toner of any one color of cyan (C), magenta (M), and yellow (Y) is used.

  As an example, as shown in FIG. 13, the back surface reference pattern 58C of the back surface P2 is black in a region including a region corresponding to the front and back direction with respect to a set of a plurality of regions 56D and regions 56E in the front surface reference pattern 56C. An area 58D (third image) is drawn with 100% print coverage with toner.

  In addition, the correction data generation unit 53 acquires a mutual shift amount of the set of the region 56D and the region 56E from the read image obtained by reading the surface reference pattern 56 formed on the image forming medium P with the scanner. Then, the correction data generation unit 53 is information for adjusting the displacement of the image forming position when forming an image with white toner so as to cancel out the mutual displacement amount of the set of the region 56D and the region 56E. Generate adjustment information.

  Note that, in the present embodiment, as described above, the shift amount in the transport width direction Y in the pair of the plurality of regions 56D and regions 56E adjacent to each other in the transport direction X is acquired. Therefore, the registration shift in the transport width direction Y at the image forming position when an image is formed with white toner is adjusted. In addition, the shift amount in the transport direction X between the plurality of areas 56D and 56E adjacent to each other in the transport width direction Y is acquired. For this reason, the registration shift in the transport direction X of the image forming position when an image is formed with white toner is adjusted.

  Next, the flow of registration deviation adjustment processing executed by the image forming apparatus 10 according to the present embodiment every time a predetermined period elapses will be described with reference to the flowchart of FIG. In the present embodiment, the registration error adjustment processing program is stored in the storage unit 54 in advance, but is not limited thereto. For example, a registration deviation adjustment processing program may be received from an external device via the communication line I / F unit 76 and stored in the storage unit 54. Also, the registration error adjustment processing program recorded on a recording medium such as a CD-ROM is read by the CD-ROM drive or the like via the communication line I / F unit 76, so that the registration error adjustment processing is executed. It may be.

  In steps S201 to S213, processing similar to that in steps S101 to S123 is performed. In step S203, the image quality adjustment determination unit 44 determines whether or not to perform registration deviation adjustment of white toner.

  In step S215, a read image obtained by reading the surface reference pattern 56C formed on the image forming medium P with a scanner is acquired. In this embodiment, a read image read by a scanner provided outside is acquired via the communication line I / F unit 76, but the present invention is not limited to this. For example, a scanner may be connected to the bus 82 of the image forming apparatus 10 and a read image may be acquired from the connected scanner. Further, a scanner may be incorporated in the image forming apparatus 10 and a read image read by a scanner incorporated in the image forming apparatus 10 may be acquired.

  In step S217, the mutual displacement amount of the group of the region 56D and the region 56E is acquired from the acquired read image, registration displacement adjustment information is generated, and the execution of the registration displacement adjustment processing program is terminated.

  As described above, in the present embodiment, the surface that is the first surface of the transparent film that is the image forming medium P having translucency is different from the white that is the first color and the black that is the second color. A third image is formed adjacent to the first image with yellow (W) toner, which is a color material of the color. Further, the amount of deviation between the first image and the third image is acquired, and white toner position adjustment information is generated using the acquired amount of deviation. When image formation with white toner is performed, the registration error of the image formed with white toner is adjusted by correcting the image data using the position adjustment information of the white toner.

[Third Embodiment]

  Next, an image forming apparatus according to the third embodiment will be described. In the third embodiment, a case where in-plane unevenness adjustment of white toner is performed using an image forming medium P having translucency will be described.

  That is, in the second embodiment, the registration deviation adjustment information for white toner is generated using the amount of deviation of the position of the image formation area for white toner and the image formation area for toner of a color other than white. explained. On the other hand, in the third embodiment, a case will be described in which in-plane unevenness adjustment information for white toner is generated using the densities at a plurality of positions in the first image formed on the surface P1.

  Since the configuration of the image forming apparatus according to the third embodiment is the same as that of the image forming apparatus 10 according to the first embodiment and the second embodiment, description of each configuration is omitted.

  However, in the third embodiment, the front reference pattern 56F and the back reference, which are different from the front reference pattern 56 and the back reference pattern 58 of the first embodiment, and the front reference pattern 56C and the back reference pattern 58C of the second embodiment. A pattern 58E is used.

  As an example, as shown in FIG. 15, the surface reference pattern 56 </ b> F has a region 56 </ b> G (first image) drawn with white toner extending in the transport direction X. In the present embodiment, the surface reference pattern 56F has four areas 56G arranged in parallel along the transport width direction Y in an area where an image can be formed with white toner, but the form of the area 56G is not limited to this. The entire area where the image can be formed with white toner may be the area 56G, and a plurality of areas arranged in parallel along the transport direction X may be each the area 56G.

  In addition, the back surface reference pattern 58E includes a region 58F (second image) drawn with 100% print coverage with black toner in a region including a region corresponding to the front and back direction with respect to the region 56G in the front surface reference pattern 56F. .

  Further, the correction data generation unit 53 acquires the densities at a plurality of positions in the region 56G of the surface reference pattern 56F formed on the image forming medium P, detected by the colorimeter 60. In the present embodiment, the density at a plurality of positions along the transport direction X is acquired in the region 56G. Thereby, in-plane unevenness along the transport direction X, that is, periodic in-plane unevenness generated by the developing roll 18, the secondary transfer roll 28B, and the like is detected.

  It should be noted that the density at a plurality of positions along the conveyance width direction Y in the region 56G may be acquired. In this case, in-plane unevenness along the transport width direction Y, that is, in-plane unevenness caused by distortion of the developing roll 18, the secondary transfer roll 28B, etc. is detected.

  Then, the correction data generation unit 53 generates in-plane unevenness adjustment information that is information for leveling the density at each position of the region 56G where the image is formed with white toner.

  Next, the flow of in-plane unevenness adjustment processing executed by the image forming apparatus 10 according to the present embodiment every time a predetermined period elapses will be described with reference to the flowchart of FIG. In the present embodiment, the in-plane unevenness adjustment processing program is stored in the storage unit 54 in advance, but is not limited thereto. For example, a program for in-plane unevenness adjustment processing may be received from an external device via the communication line I / F unit 76 and stored in the storage unit 54. Also, the in-plane unevenness adjustment process recorded in a recording medium such as a CD-ROM is read by the CD-ROM drive or the like via the communication line I / F unit 76, whereby the in-plane unevenness adjustment process is executed. You may make it do.

  In steps S301 to S313, processing similar to that in steps S101 to S123 is performed. In step S303, the image quality adjustment determination unit 44 determines whether to perform in-plane unevenness adjustment of white toner.

  In step S315, the correction data generation unit 53 acquires the density at a plurality of positions in each region 56G of the surface reference pattern 56F formed by the white toner on the surface P1 detected by the colorimeter 60.

  In step S317, the correction data generation unit 53 obtains in-plane unevenness adjustment information from the density at a plurality of positions in each region 56G of the surface reference pattern 56F formed of white toner on the surface P1 and the target density. And the execution of the in-plane unevenness adjustment processing program is terminated.

  The in-plane unevenness adjustment information is information indicating a correction amount for each position to cancel the difference between the density and the target density in each region 56G of the surface reference pattern 56F formed with white toner on the surface P1. is there. In the present embodiment, the purpose is to level out the density variation due to the position in the image formed with the white toner on the surface P1, and as an example, as shown in FIG. It becomes constant. Therefore, the correction value of the laser light quantity for canceling the difference between the detected density value 90 for each position and the target density 88 for each position in each region 56G of the surface reference pattern 56F formed on the surface P1 with white toner. Is stored as in-plane unevenness adjustment information for each position. That is, when the laser light quantity is set to the laser light quantity 91 shown in FIG. 17B as an example, in-plane unevenness may occur as in the density detection value 90 shown in FIG. 17A. In consideration of this in-plane unevenness, a correction value 92 obtained by correcting the laser light quantity is stored as in-plane unevenness information so that the detected density value becomes the target density 88. Then, as shown in FIG. 17B, for example, the in-plane unevenness adjustment information is used when forming an image with white toner. For example, the correction value 92 is obtained by correcting the laser light amount for each position according to the in-plane unevenness adjustment information. And Thereby, in-plane unevenness on the image forming medium P when an image is formed with white toner is adjusted.

  As described above, in this embodiment, the first image is preliminarily applied to the surface P1 that is the first surface of the transparent film that is the translucent image forming medium P with the white toner that is the first color material. It is formed with a predetermined target density. Further, in the corresponding area corresponding to the area where the first image is formed on the back surface P2 which is the second surface of the transparent film, the black toner which is the second color whose color difference from the first color is equal to or more than a predetermined threshold value. Thus, a second image is formed. Also, the density at a plurality of positions in the first image formed on the surface P1 is acquired, and the in-plane unevenness adjustment information of the white toner is created using the acquired densities at the plurality of positions. Then, when performing image formation with white toner, the in-plane unevenness of the image formed with the white toner on the image forming medium P is corrected by correcting the output characteristics using the in-plane unevenness adjustment information of the white toner. Is corrected.

  As described above, according to the first to third embodiments, an image is formed with white toner on the front surface P1 of the transparent film, and an image is formed with black toner on the back surface P2. As a result, it is not necessary to form an image multiple times on the same surface, and calibration and the like can be performed without being affected by the unevenness of the black toner used as a base, thereby adjusting the image quality of the white toner. Accuracy is improved.

  In particular, when the image forming apparatus that adjusts the image quality of white toner is an image forming apparatus for continuous paper, the process of forming an image multiple times on the same surface is complicated for the operator. Takes time. However, according to the first to third embodiments, the image formation mode is the double-sided mode, and the image formation on the front surface P1 and the image formation on the back surface P2 are performed in a series of operations, and efficiency is measured. However, when cut paper (including a transparent film) is used as the image forming medium P, image formation on the front surface P1 and image formation on the back surface P2 may be performed separately.

  In addition, before the white toner calibration, the black toner calibration may be performed. As a result, the black region in the back surface reference pattern 58 is accurately imaged with 100% print coverage, so that the accuracy of white toner calibration is improved.

  In the first to third embodiments, the case where the image forming apparatus 10 is a so-called laser printer has been described. However, the present invention is not limited to this. For example, even if the image forming apparatus 10 is a so-called inkjet printer, the above-described calibration processing, registration deviation adjustment processing, and in-plane unevenness adjustment processing are performed in the same manner, and the same effect can be obtained.

  Further, the configuration of the image forming apparatus 10 described in the above embodiments (see FIGS. 1, 2, and 10) is an example. That is, it goes without saying that unnecessary portions may be deleted or new portions may be added within a range not departing from the gist of the present invention.

  In addition, the flow of processing of various programs described in the above embodiments (see FIGS. 11, 14, and 16) is also an example. That is, it goes without saying that unnecessary steps may be deleted, new steps may be added, and the processing order may be changed within a range not departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Photoconductor 14 Charging device 18 Developing roll 20 Developing device 21 Toner replenishment basket 22 Intermediate transfer belt 24 Primary transfer device 28 Secondary transfer device 34 Secondary transfer belt 40 Image data input unit 42 Toner detection unit 44 Image quality adjustment Determination unit 46 Paper determination unit 48 Image data generation unit 50 Image formation mode setting unit 52 Image output unit 53 Correction data generation unit 54 Storage unit 54A Toner information 54B Media information 54C Image formation mode information 60 Colorimeter 70 CPU
80 Operation display part P Image forming medium P1 Front surface P2 Back surface

Claims (11)

First forming means for forming a first image with a color material of a first color on a first surface of an image forming medium having translucency;
A color material of a second color whose color difference from the first color is greater than or equal to a predetermined threshold value in a corresponding region corresponding to a region where the first image is formed on the second surface opposite to the first surface. Second forming means for forming a second image;
Obtaining means for obtaining a density of the first image formed on the first surface;
Generating means for generating density correction information of the color material of the first color using the density of the first image acquired by the acquiring means and a predetermined target density of the first image;
An image forming apparatus. The first forming means forms a plurality of the first images with different color coverages on the first surface with a color material of a first color,
The acquisition means acquires the density of the plurality of first images formed on the first surface for each of the first images,
The generation means uses the density for each of the first images acquired by the acquisition means and a target density predetermined for each of the first images, and density correction information for the color material of the first color. The image forming apparatus according to claim 1. The second forming means forms the second image with the color material of the second color in a region including the corresponding region on the second surface and having a larger area than the corresponding region. The image forming apparatus described. First forming means for forming a first image with a color material of a first color on a first surface of an image forming medium having translucency;
A color material of a second color whose color difference from the first color is greater than or equal to a predetermined threshold value in a corresponding region corresponding to a region where the first image is formed on the second surface opposite to the first surface. Second forming means for forming a second image;
Third forming means for forming a third image with a color material of a third color different from both the first color and the second color at a position adjacent to the first image on the first surface;
Obtaining means for obtaining a shift amount between the first image and the third image formed on the first surface;
Generating means for generating position adjustment information of the color material of the first color using the deviation amount acquired by the acquisition means;
An image forming apparatus. The third forming unit forms the third image at a position adjacent to the first image and the conveyance direction of the image forming medium;
The acquisition means acquires a shift amount in the transport width direction that intersects the transport direction of the position of the first image and the third image formed on the first surface,
The image forming apparatus according to claim 4, wherein the generation unit generates position adjustment information in the transport width direction of the color material of the first color using the shift amount in the transport width direction acquired by the acquisition unit. The third forming unit forms the third image at a position adjacent to the first image and a conveyance width direction intersecting a conveyance direction of the image forming medium;
The acquisition means acquires the shift amount in the transport direction of the position of the first image and the third image formed on the first surface,
The image forming apparatus according to claim 4, wherein the generation unit generates position adjustment information in the transport direction of the color material of the first color using the shift amount in the transport direction acquired by the acquisition unit. First forming means for forming a first image with a color material of a first color on a first surface of an image forming medium having translucency;
A color material of a second color whose color difference from the first color is greater than or equal to a predetermined threshold value in a corresponding region corresponding to a region where the first image is formed on the second surface opposite to the first surface. Second forming means for forming a second image;
Obtaining means for obtaining densities at a plurality of positions in the first image formed on the first surface;
Generating means for generating unevenness adjustment information of the color material of the first color using the densities at the plurality of positions acquired by the acquiring means;
An image forming apparatus. The acquisition means acquires the density at a plurality of positions in the first image formed on the first surface at different positions in the transport direction of the image forming medium,
The generation unit generates unevenness adjustment information in the conveyance direction of the color material of the first color by using the densities at a plurality of positions different from each other in the conveyance direction acquired by the acquisition unit. The image forming apparatus described. The acquisition means acquires the density at a plurality of positions in the first image formed on the first surface, each of which has a different position in the transport width direction intersecting the transport direction of the image forming medium,
The generation unit generates unevenness adjustment information in the transport width direction of the color material of the first color by using the densities at a plurality of positions different from each other in the transport width direction acquired by the acquisition unit. Item 9. The image forming apparatus according to Item 7 or 8. The image forming apparatus according to claim 1, wherein the first color is white and the second color is black.   An image forming program for causing a computer to function as an acquisition unit and a generation unit constituting the image forming apparatus according to claim 1.