Image forming system

Abstract

To provide an image forming system that, even when "magnification deviation" and "movement deviation" occur simultaneously in a toner image and a varnish image, can create a recording material without the occurrence of such positional deviation.SOLUTION: A main control unit determines a movement deviation amount and a magnification deviation amount as a positional deviation amount between a toner image and a varnish image formed on a recording material (S4). The main control unit calculates a positional deviation amount between image master data and inspection image data (S5). Only ground image master data or the ground image master data and varnish image master data are corrected based on the magnification deviation and the movement deviation (S11). With this, the toner image and the varnish image are formed on the recording material, while the positional deviation between the toner image and the varnish image is automatically corrected during an image forming job. Consequently, even when "magnification deviation" and "movement deviation" occur simultaneously in forming the toner image and the varnish image on the recording material, a recording material without the occurrence of the positional deviation between the toner image and the varnish image can be created.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an image forming system including an image forming device that forms a toner image on a recording material, a varnish application device capable of forming a varnish image, and an image inspection device that inspects for misalignment between the toner image and the varnish image. [Background technology]

[0002] Recently, surface processing has been performed in which a toner image is formed as a base image on a recording material using a developer for the purpose of providing gloss, surface protection, decoration, etc., and a varnish image is then formed using varnish on the recording material on which the toner image has been formed. In this specification, the toner image on which the varnish image is overlaid is called a base image. For example, an inkjet type varnish application device (called a varnish coater) is used as a device for forming a varnish image on a recording material. A varnish coater can form a varnish image by overlaying the toner image of the base image by partially applying varnish to the recording material (Patent Document 1).

[0003] Also, an image inspection device has been proposed that inspects the misalignment of a toner image actually formed on a recording material by an image forming device and a varnish image actually formed on a recording material by a varnish coater (Patent Document 2). The image forming device and the varnish coater form a toner image and a varnish image, respectively, based on data related to the toner image and data related to the varnish image contained in input image data. Patent Document 2 describes that when misalignment occurs in the toner image or varnish image actually formed on the recording material, the formation positions of the toner image and the varnish image are respectively corrected based on the input image data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-111813 A [Patent Document 2] JP 2021-156844 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, when a toner image is formed on a recording material and a varnish image is formed by superimposing the toner image on the toner image, a "magnification deviation" in which the toner image and the varnish image are misaligned due to the toner image being reduced. In addition, a "movement deviation" in which the toner image and the varnish image are misaligned in at least one of the conveying direction of the recording material and the width direction intersecting the conveying direction may occur. However, in the past, when a situation in which "magnification deviation" and "movement deviation" could occur simultaneously occurred, there was a risk that a recording material in which the toner image and the varnish image were misaligned was created.

[0006] The present invention has been made in consideration of the above problems, and aims to provide an image forming system that can create recording material in which there is no positional misalignment between a toner image and a varnish image, even in cases where "magnification misalignment" and "movement misalignment" can occur simultaneously when forming a toner image and a varnish image on the recording material. [Means for solving the problem]

[0007] An image forming system according to one embodiment of the present invention includes an image forming device that forms a toner image on a recording material based on first image data related to a toner image, a fixing device that fixes the toner image to the recording material by applying heat and pressure to the recording material on which the toner image has been formed by the image forming device, a varnish application device that forms a varnish image by discharging varnish onto the recording material on which the toner image has been fixed by the fixing device based on second image data related to a varnish image, an image reading unit that reads the toner image and varnish image formed on the recording material, and a recording material on which a toner image and a varnish image superimposed on the toner image have been formed, the recording material being subjected to a magnification shift between a toner image that is reduced compared to a toner image read by the image reading unit and based on the first image data, and the varnish image read by the image reading unit, a first movement shift that is a shift amount in at least one of the transport direction and the width direction intersecting the transport direction of the recording material with respect to the toner image based on the first image data, and a second movement shift that is a shift amount in at least one of the transport direction and the width direction of the varnish image read by the image reading unit with respect to a varnish image based on the second image data, and a magnification shift between the toner image read by the image reading unit and the varnish image that is reduced compared to the toner image based on the first image data, the toner image read by the image reading unit and the varnish image that is superimposed on the toner image, the first movement shift that is a shift amount in at least one of the transport direction and the width direction of the recording material, the varnish image read by the image reading unit and the varnish image based on the second image data, and the varnish image read by the image reading unit. a calculation unit that calculates a third movement deviation, which is a deviation amount in at least one of the transport direction and the width direction, of a varnish image read by the image reading unit relative to a toner image captured by the first image data, and a control unit that controls the image forming device and the varnish application device, and the control unit is configured to calculate a third movement deviation, which is a deviation amount in at least one of the transport direction and the width direction, of a varnish image read by the image reading unit relative to a toner image captured by the first image data, when the third movement deviation calculated by the calculation unit is greater than a predetermined first deviation amount and the magnification deviation calculated by the calculation unit is greater than a predetermined second deviation amount, When the first movement deviation calculated by the calculation unit is larger than the second movement deviation, the first image data is corrected in accordance with the third movement deviation and a magnification deviation amount of the magnification deviation, and a toner image and a varnish image are formed on a second recording material other than the first recording material, and when the second movement deviation calculated by the calculation unit is larger than the first movement deviation, the second image data is corrected in accordance with the third movement deviation, and the first image data is corrected in accordance with the magnification deviation amount of the magnification deviation, and a toner image and a varnish image are formed on a second recording material other than the first recording material. Effect of the Invention

[0008] According to the present invention, even in cases where "magnification deviation" and "movement deviation" can occur simultaneously when forming a toner image and a varnish image on a recording material, it is possible to create a recording material in which such position deviation does not occur between the toner image and the varnish image. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing a configuration of an image forming system. [Diagram 2] 6 is a graph showing the relationship between the control voltage and the film thickness in forming a varnish image. [Diagram 3] FIG. 2 is a control block diagram showing a control configuration in the image forming system according to the first embodiment. [Figure 4] 1A to 1C are diagrams illustrating conventional examples of positional misalignment correction between a toner image and a varnish image, where (a) there is no positional misalignment, (b) there is image positional misalignment due to magnification misalignment and movement misalignment, and (c) there is a conventional example of correcting the positional misalignment. [Diagram 5] 5 is a flowchart showing a recording material output process according to the first embodiment. [Figure 6] 1A is a diagram showing position reference points on image master data, and FIG. 1B is a diagram showing position reference points on inspection image data. [Figure 7] 13A and 13B are diagrams showing position reference points for character information on image master data: (a) base image master data [Dg] and varnish image master data [Dv]; (b) base image master data [Dg]; and (c) varnish image master data [Dv]. [Figure 8] FIG. 1A is a diagram for explaining calculation of a shift amount on inspection image data, and FIG. 1B is a diagram for explaining correction of the shift amount on inspection image data. [Figure 9] FIG. 1A is a diagram for explaining calculation of the amount of magnification deviation on inspection image data, and FIG. 1B is a diagram for explaining correction of the amount of magnification deviation on inspection image data. [Figure 10] 13 is a flowchart showing a determination process. [Figure 11]11 is a flowchart showing a correction means determination process. [Figure 12] 11 is a graph showing a magnification fluctuation in the recording material conveying direction relative to toner coverage. [Figure 13] 10 is a flowchart showing a recording material output process according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [First embodiment] First, the image forming system of this embodiment will be described with reference to FIG. 1. The image forming system 1X shown in FIG. 1 includes an image forming apparatus 100 that forms a toner image on a recording material S, a varnish application device (200, called a varnish coater) that forms a varnish image on the recording material S, and an image inspection device 400 that inspects the toner image and varnish image formed on the recording material S. The varnish coater 200 and the image inspection device 400 are post-process units that can be freely added to the image forming apparatus 100 for functional expansion. The image forming apparatus 100 and the varnish coater 200, and the varnish coater 200 and the image inspection device 400 are connected to each other so that the recording material S can be transferred. In addition, the image forming apparatus 100, the varnish coater 200, and the image inspection device 400 are connected by a data input / output interface (not shown) so that control signals, data, and the like can be transmitted and received between them. Note that the image forming apparatus 100, the varnish coater 200, and the image inspection device 400 do not have to be separate entities, and may be configured as an integrated unit.

[0011] The recording material S on which the toner image has been formed by the image forming apparatus 100 is transported to a varnish coater 200 for the purpose of improving the gloss, water resistance, abrasion resistance, etc. of the toner image, and a varnish image can be formed by the varnish coater 200 by superimposing the varnish image on the toner image of the base image. Thereafter, the recording material S on which the varnish image has been formed by the varnish coater 200 is transported to an image inspection device 400, which inspects the positional deviation between the toner image and the varnish image. Examples of the recording material S include sheet materials such as plain paper, cardboard, rough paper, textured paper, and coated paper.

[0012] <Image forming device> The image forming apparatus 100 will be described. The image forming apparatus 100 is a tandem-type full-color printer of an electrophotographic system. The image forming apparatus 100 is an apparatus for forming a toner image on a recording material S based on background image master data described below. The image forming apparatus 100 has image forming units Pa, Pb, Pc, and Pd for forming yellow, magenta, cyan, and black images, respectively.

[0013] The conveying process of the recording material S in the image forming apparatus 100 will be described. The recording material S is stored in a cassette 10 in a stacked form, and is sent out from the cassette 10 by a supply roller 13 in accordance with the image formation timing. The recording material S sent out by the supply roller 13 is conveyed to a registration roller 12 arranged in the middle of a conveying path 114. Then, after the registration roller 12 performs skew correction and timing correction on the recording material S, the recording material S is sent to a secondary transfer portion T2. ​​The secondary transfer portion T2 is a transfer nip portion formed by a secondary transfer inner roller 14 and a secondary transfer outer roller 11, and a toner image is transferred onto the recording material in response to the application of a secondary transfer voltage to the secondary transfer outer roller 11.

[0014] The process of forming an image sent to the secondary transfer portion T2 at the same timing as the process of conveying the recording material S to the secondary transfer portion T2 described above will be described. First, the image forming portions will be described. The image forming portions Pa, Pb, Pc, and Pd for each color are configured almost the same except that the colors of toner used in the developing devices 1a, 1b, 1c, and 1d are yellow (Y), magenta (M), cyan (C), and black (K). Therefore, the following description will be given of the black image forming portion Pd as a representative, and the description of the other image forming portions Pa, Pb, and Pc will be omitted.

[0015] The image forming section Pd is mainly composed of a developing device 1d, a charging device 2d, a photosensitive drum 3d, a photosensitive drum cleaner 4d, and an exposure device 5d. The surface of the rotating photosensitive drum 3d is uniformly charged in advance by the charging device 2d, and then an electrostatic latent image is formed on the surface of the photosensitive drum 3d by the exposure device 5d, which is driven based on a signal of image information. Next, the electrostatic latent image formed on the photosensitive drum 3d is developed into a toner image by the developing device 1d using a developer. Then, the toner image formed on the photosensitive drum 3d is primarily transferred onto the intermediate transfer belt 80 in response to a primary transfer voltage being applied to a primary transfer roller 6d, which is disposed with the image forming section Pd and the intermediate transfer belt 80 sandwiched therebetween. A small amount of primary transfer residual toner remaining on the photosensitive drum 3d is collected by the photosensitive drum cleaner 4d.

[0016] The intermediate transfer belt 80 is stretched by the inner secondary transfer roller 14 and tension rollers 15 and 16, and is driven in the direction of the arrow R2. In this embodiment, the tension roller 16 also serves as a drive roller for driving the intermediate transfer belt 80. The image forming processes of each color, which are processed in parallel by the image forming units Pa to Pd, are performed at a timing when the images are sequentially superimposed on the toner images of the upstream colors that have been primarily transferred onto the intermediate transfer belt 80. As a result, a full-color toner image is finally formed on the intermediate transfer belt 80, and is conveyed to the secondary transfer unit T2. Note that the secondary transfer residual toner after passing through the secondary transfer unit T2 is removed from the intermediate transfer belt 80 by the transfer cleaner 22.

[0017] Through the conveying process and image forming process described above, the timing of the recording material S and the full-color toner image coincides at the secondary transfer portion T2, and secondary transfer is performed. The recording material S is then conveyed to the fixing device 50, where heat and pressure are applied to fix the toner image onto the recording material. The fixing device 50 pinches and conveys the recording material S on which the toner image has been formed, thereby heating and pressurizing the conveyed recording material S to fix the toner image onto the recording material S. That is, the toner of the toner image formed on the recording material S is melted and mixed, and is fixed onto the recording material S as a full-color image.

[0018] The image forming apparatus 100 is capable of printing on both sides of the recording material S. In a single-sided printing mode, the recording material S on one side of which a toner image is fixed by the fixing device 50 is conveyed to the varnish coater 200. In a double-sided printing mode, the recording material S on one side of which a toner image is fixed by the fixing device 50 is conveyed to the double-sided conveying section 90. In the double-sided conveying section 90, the recording material S is inverted while being conveyed, and the front side (first side) and the back side (second side) of the recording material S are swapped. The inverted recording material S is conveyed again through the double-sided conveying section 90 toward the registration roller 12. Then, the recording material S is conveyed toward the secondary transfer section T2 by the registration roller 12 with the back side (second side) that is not printed facing the intermediate transfer belt 80. In the secondary transfer section T2, the full-color toner image formed on the intermediate transfer belt 80 is secondarily transferred collectively to the back side of the recording material S. Thereafter, the toner image is fixed onto the recording material S by the fixing device 50 , and the recording material S on which the toner image has been fixed is conveyed to the varnish coater 200 .

[0019] <Developer> In this embodiment, a two-component developer containing a toner and a carrier is used. The toner contains a binder resin, a colorant, and a release agent (wax). The binder resin may be a known one. For example, a vinyl copolymer such as a styrene-(meth)acrylic copolymer, a polyester resin, a hybrid resin in which a vinyl copolymer and a polyester are chemically bonded, an epoxy resin, a styrene-butadiene copolymer, or other resin may be used. The colorants may be known for yellow (Y), magenta (M), cyan (C), and black (K).

[0020] Examples of the release agent include aliphatic hydrocarbon waxes such as low molecular weight polyethylene, low molecular weight olefin copolymer wax, microcrystalline wax, Fischer-Tropsch wax, and paraffin wax, oxides of aliphatic hydrocarbon waxes such as oxidized polyethylene wax, and block copolymers thereof; waxes mainly composed of fatty acid esters such as carnauba wax and montan acid ester wax, ester waxes which are synthetic reaction products of higher fatty acids and higher alcohols such as behenyl behenate and behenyl stearate, and partially or completely deoxidized fatty acid esters such as deoxidized carnauba wax.

[0021] <Varnish coater> Next, the varnish coater 200 will be described with reference to Figures 1 and 2. The varnish coater 200 is a device that forms a varnish image on a recording material S based on varnish image master data described below. When the varnish coater 200 is of an inkjet type, the varnish is applied to the recording material S by ejecting droplets of varnish onto the recording material S, and a varnish image such as a user-desired character, line drawing, or figure is formed separately from the toner image. Note that various types of varnish may be used, such as water-based varnish, oil-based varnish, or UV varnish, and the following description will be given taking as an example the varnish coater 200 that forms a varnish image using an ultraviolet-curing UV varnish that solidifies when irradiated with ultraviolet rays.

[0022] The varnish coater 200 includes a sheet conveying section 241, a position detection section 245, a varnish discharge section 246, and a varnish solidification section 247. The sheet conveying section 241 conveys the recording material S while adsorbing it to the belt conveying surface by an air suction device (not shown) through holes formed in the conveying belt. Along the sheet conveying path of the sheet conveying section 241, the position detection section 245, the varnish discharge section 246, and the varnish solidification section 247 are arranged in this order from the upstream side to the downstream side in the conveying direction (arrow X direction) of the recording material S. The position detection section 245 is a detection section using, for example, a CCD, and can detect the position of the leading end of the recording material S in the conveying direction and the positions of both ends in the width direction intersecting with the conveying direction with respect to the recording material S adsorbed to the belt conveying surface and conveyed.

[0023] The varnish ejection section 246 ejects UV varnish onto one side of the recording material S conveyed by the sheet conveying section 241, thereby forming a varnish image on the recording material S. The varnish ejection section 246 has a plurality of print heads (not shown). The print head is, for example, a line-type head, and a plurality of ejection openings (not shown) are arranged in a line in a width direction intersecting the conveying direction of the recording material S so as to cover a range covering the maximum width of the recording material S on which an image can be formed by the varnish coater 200. The varnish ejection method of the print head may be a method using a heating element, a method using a piezoelectric element, a method using an electrostatic element, a method using a MEMS element, or the like. Although not shown, the UV varnish is supplied to the print head from a tank via a tube.

[0024] The thickness of the varnish image depends on the amount of UV varnish applied per unit area of ​​the recording material. The amount of varnish applied can be varied by adjusting the amount of varnish discharged from the print head. For example, in the case of a method using a piezoelectric element, as shown in FIG. 2, the amount of varnish discharged changes according to the adjustment of the control voltage, and the thickness of the varnish image is adjusted by increasing or decreasing the amount of varnish discharged per unit area. In this embodiment, the thickness of the varnish image is adjusted to a range of, for example, "5 to 100 μm," preferably "10 to 70 μm."

[0025] Furthermore, the resolution of the varnish image that can be formed by the varnish coater 200 is, for example, "600 dpi," in which case the line width of the varnish image is adjusted in units of "600 dpi." Note that the above-mentioned range of varnish image thickness, and the adjustment range of the resolution and line width of the varnish image may be changed as appropriate depending on the varnish ejection method of the print head in the varnish coater 200, the type of varnish, etc.

[0026] Returning to FIG. 1, the recording material S on which the varnish image has been formed on one side by the varnish discharge unit 246 is sent by the sheet conveying unit 241 to the varnish solidifying unit 247 on the downstream side in the conveying direction, where the UV varnish on the recording material S is solidified by the varnish solidifying unit 247. The varnish solidifying unit 247 has an ultraviolet lamp, which irradiates ultraviolet light (ultraviolet light) with a wavelength corresponding to the UV varnish to solidify the varnish image formed on the recording material S. The ultraviolet lamp is disposed so as to be able to irradiate ultraviolet light over almost the entire width of the recording material S, and is turned on only when the recording material S passes through. In this manner, the varnish image can be overprinted on the toner image formed on the recording material S. The recording material S is then conveyed to the image inspection device 400.

[0027] <Image inspection equipment> Next, the image inspection device 400 will be described. The image inspection device 400 is a device that inspects the toner image and varnish image formed on the recording material S. As shown in Fig. 1, the image inspection device 400 includes a transport roller 401, an image reading unit 402, a discharge roller 403, an image analysis unit 404, and a control unit (not shown) that controls the driving of each of these units. Each of these units is driven based on information from the main control unit 101 of the image forming apparatus 100, so that the image inspection device 400 can inspect the toner image and varnish image formed on the recording material S.

[0028] The conveying rollers 401 convey the recording material S discharged from the varnish coater 200 into the image inspection device 400. The image reading unit 402 reads the toner image and varnish image formed on the recording material S as an inspection image, and has a light irradiator 402a, a diffuse light detector 402b, and a regular reflection light detector 402c. The light irradiator 402a irradiates the surface of the recording material S conveyed by the conveying rollers 401 with inspection light, such as white light, across the width direction intersecting with the conveying direction.

[0029] The diffused light detector 402b detects the diffused light diffusely reflected on the surface of the recording material S across the width in response to the irradiation of the inspection light from the light irradiator 402a. The detected diffused light is converted into an electrical signal, and sent to the image analysis unit 404 as diffused light image data [Dh1]. The specular reflection light detector 402c detects the specular reflection light specularly reflected on the surface of the recording material S across the width in response to the irradiation of the inspection light from the light irradiator 402a. The detected specular reflection light is converted into an electrical signal, and sent to the image analysis unit 404 as specular reflection light image data [Dh2]. Note that the image inspection device 400 may be provided with at least one of the diffused light detector 402b and the specular reflection light detector 402c, but here, a case where both are provided is taken as an example.

[0030] The discharge rollers 403 discharge the recording material S, which has been conveyed by the conveying rollers 401 and passed through the image reading unit 402, to the outside of the image inspection device 400. The recording material S can be discharged to either the OK tray 400a or the NG tray 400b by the discharge rollers 403 based on the positional deviation result by the image analysis unit 404 described later. For example, the recording material S in which there is no positional deviation between the toner image and the varnish image is discharged to the OK tray 400a as the second tray, and the recording material S in which there is a positional deviation between the toner image and the varnish image is discharged to the NG tray 400b as the first tray. The OK tray 400a and the NG tray 400b can each hold a large number of recording materials S.

[0031] Next, the control configuration of the image forming system 1X will be described using Fig. 3 while referring to Fig. 1. In this embodiment, an example will be described in which the image forming apparatus 100 centrally manages and controls operation commands for the varnish coater 200 and the image inspection apparatus 400. Note that various devices other than those shown in Fig. 3 may be connected to the main control unit 101, but illustration and description of those devices will be omitted here as they are not the main focus of the invention.

[0032] In the image forming system 1X of this embodiment, the operation unit 110, the varnish coater 200, and the image inspection device 400 are connected to the main control unit 101 so as to be able to communicate operation commands, various data, etc. The main control unit 101 operates the image forming device 100 while transmitting operation commands and various data to the varnish coater 200 and the image inspection device 400 to operate them, thereby controlling the entire image forming system 1X.

[0033] The main control unit 101 has a calculation unit 103 capable of calculating the positional deviation between the toner image and the varnish image formed on the recording material S. The calculation of the positional deviation between the toner image and the varnish image will be described later. The main control unit 101 also has a memory 102 such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The memory 102 as a storage unit stores various programs such as a "recording material output process" (see FIG. 5) described later, and various data such as a correction table (see Table 1). The CPU can execute various programs using various data stored in the memory 102. The RAM stores various data such as image master data received from the external device 1000. The RAM can also temporarily store the results of calculation processing associated with the execution of various programs. The image master data includes base image master data [Dg] as the first image data and varnish image master data [Dv] as the second image data.

[0034] The base image master data [Dg] and the varnish image master data [Dv] are data created using, for example, graphic design software (such as Adobe Illustrator (trademark)) and are transmitted from the external device 1000 via a network interface. The base image master data [Dg] is data relating to a toner image that can be formed by the image forming apparatus 100, and the varnish image master data [Dv] is data relating to a varnish image that can be formed by the varnish coater 200.

[0035] The main control unit 101 can execute processes to convert the base image master data [Dg] and the varnish image master data [Dv] into data that can be handled by the image forming apparatus 100 and the varnish coater 200. The main control unit 101 can also execute various processes such as settings required for the formation of a toner image by the image forming apparatus 100, the formation of a varnish image by the varnish coater 200, and image inspection by the image inspection device 400.

[0036] The base image master data [Dg] and the varnish image master data [Dv] have information on the relative positional relationship as the formation position of the toner image and the formation position of the varnish image formed on the recording material S. The relative positional relationship here is, for example, information that the pixels of the base image master data [Dg] and the pixels of the varnish image master data [Dv] correspond one-to-one to the image information having the same resolution. This relative positional relationship may not only be the one-to-one correspondence as the image information listed above, but may also be image information having different resolutions and having margin information of the image formation position on the recording material S (for example, distance information from the four sides of the recording material S). In this case, the main control unit 101 converts the resolution of either the base image master data [Dg] or the varnish image master data [Dv] based on the ratio of the resolutions of the base image master data [Dg] and the varnish image master data [Dv] and the margin information, and performs positioning based on the margin information. This places a one-to-one correspondence between the pixels of the base image master data [Dg] and the pixels of the varnish image master data [Dv].

[0037] Furthermore, the varnish image master data [Dv] includes information about the varnish in addition to the formation position of the varnish image. The information about the varnish includes, for example, the type and gloss of the varnish, the light intensity of the diffuse light that is diffusely reflected when white light is irradiated, and the light intensity of the specularly reflected light. Note that the varnish image master data [Dv] transmitted from the external device 1000 does not need to include the above-mentioned information about the varnish. In that case, the information about the varnish may be stored in advance in the varnish coater 200.

[0038] The image forming system 1X includes an operation unit 110 having, for example, a liquid crystal display unit 111, and the operation unit 110 is connected to the main control unit 101. The operation unit 110 is, for example, a touch panel. The operation unit 110 can display various screens presenting various programs and various data on the liquid crystal display unit 111, and accepts inputs for starting various programs and inputting various data in response to a user's touch operation on the screen. Note that the touch panel may display a screen including various buttons, switches, and the like as software keys.

[0039] A user can input the start of an image formation job from the operation unit 110. When the start of an image formation job is input, the main control unit 101 executes the "recording material output process" (see FIG. 5) stored in the memory 102. In response to this, the image forming device 100 and the varnish coater 200 are operated to form a toner image and a varnish image on the recording material S. In addition, the image inspection device 400 is operated to perform image inspection of the toner image and the varnish image formed on the recording material S.

[0040] The image inspection device 400 has an image analysis unit 404 that is composed of a CPU, a ROM, a RAM, etc. (not shown). The image analysis unit 404 obtains the inspection base image data [Dpg] and the inspection varnish image data [Dpv] based on the diffuse light image data [Dh1] detected by the diffuse light detector 402b and the specular reflected light image data [Dh2] detected by the specular reflected light detector 402c. The image analysis unit 404 stores, for example, the light intensity of the diffuse light and the specular reflected light for each type of varnish, type of base image, and type of recording material as a reflected light table. The image analysis unit 404 obtains each of the inspection image data of the inspection base image data [Dpg] and the inspection varnish image data [Dpv] by processing the diffuse light image data [Dh1] and the specular reflected light image data [Dh2] with reference to the reflected light table. In this embodiment, the data that associates the detected toner image with the coordinates of the image forming area on the recording material S is called inspection base image data [Dpg], and the data that associates the detected varnish image with the coordinates of the image forming area on the recording material S is called inspection varnish image data [Dpv].

[0041] Both the inspection base image data [Dpg] and the inspection varnish image data [Dpv] are data associated with the coordinates of the image formation area on the recording material S. Therefore, if the resolution of the toner image and the varnish image are the same, the pixel positions of the inspection base image data [Dpg] and the pixel positions of the inspection varnish image data [Dpv] can be associated. On the other hand, if the resolution of the toner image and the varnish image are different, the resolution of either the base image master data [Dg] or the varnish image master data [Dv] is converted based on the ratio of the resolutions of the inspection base image data [Dpg] and the inspection varnish image data [Dpv] and the coordinate information of the image formation position on the recording material S, and then the alignment is performed. In this way, the pixel positions of the base image data [Dpg] and the pixel positions of the inspection varnish image data [Dpv] can be associated with each other.

[0042] <Movement deviation> In the image forming apparatus 100, for example, when forming an electrostatic latent image on the photosensitive drum 3d, when a toner image is primarily transferred from the photosensitive drum 3d to the intermediate transfer belt 80, or when a toner image is secondarily transferred from the intermediate transfer belt 80 to the recording material S, a toner image that has been "shifted" may be formed on the recording material S. The toner image that has been "shifted" is detected as the inspection base image data [Dpg] that has a translation component that is shifted in at least one of the conveying direction of the recording material S and the width direction that intersects the conveying direction compared to the base image master data [Dg]. On the other hand, in the varnish coater 200, for example, when the recording material S is conveyed in the sheet conveying section 241, a varnish image that has been "shifted" may be formed on the recording material S. The varnish image that has been "shifted" is detected as the inspection varnish image data [Dpv] that has a translation component compared to the varnish image master data [Dv].

[0043] <Magnification deviation> In the image forming apparatus 100, if the recording material S slips during transport at the secondary transfer portion T2 or if the recording material S shrinks due to heating by the fixing device 50, a "magnification deviation" may occur in the toner image on the recording material S. This is because the moisture content of the recording material S is reduced by heating by the fixing device 50, causing the recording material S itself to shrink, which may result in the toner image formed on the recording material S shrinking. If a varnish image is formed by the varnish coater 200 while the toner image formed on the recording material S is in a state in which there is a magnification variation compared to the base image master data [Dg], a "magnification deviation" in which the toner image and the varnish image are misaligned may occur.

[0044] <Conventional example> Next, a conventional example of misalignment correction between a toner image and a varnish image will be briefly explained using Figures 4(a) to 4(c). Figure 4(a) shows a case where there is no misalignment between the toner image and the varnish image, Figure 4(b) shows a case where there is a magnification misalignment and a movement misalignment between the toner image and the varnish image, and Figure 4(c) shows a conventional example of misalignment correction.

[0045] For example, the base image master data [Dg] and the varnish image master data [Dv] are specified so that a toner image V and a varnish image W of the same size and shape (rectangle) are formed overlapping each other in their entirety. If there is no misalignment between the toner image V and the varnish image W, the toner image V and the varnish image W will overlap each other in their entirety on the recording material S, as shown in Fig. 4(a). In this case, the length of the toner image V and the varnish image W in the transport direction is 100 mm.

[0046] However, when forming the toner image V and the varnish image W on the recording material S, the above-mentioned "magnification deviation" and "movement deviation" may occur at the same time. In the example shown in FIG. 4(b), as the recording material S shrinks toward the upstream side in the transport direction due to heat, a "magnification deviation" of a magnification variation of "0.98 times" occurs in the toner image V, and the length of the toner image V in the transport direction is shortened from "100 mm" to "98 mm". In addition, the toner image V also has a "movement deviation" of "3 mm" shifted toward the downstream side in the transport direction from the original position defined in the base image master data [Dg] based on the upstream end of the transport direction of the recording material S. In this case, if the position deviation correction of the toner image and the varnish image is not performed, the toner image V and the varnish image W will remain misaligned as shown in FIG. 4(b).

[0047] Conventionally, the "magnification deviation" of the toner image V is corrected by comparing the base image master data [Dg] with the inspection base image data [Dpg]. In the "magnification deviation" correction of the toner image V, the base image master data [Dg] is corrected so that the length of the toner image V in the transport direction is changed from "100 mm" to "102 mm". As a result, as shown in FIG. 4(c), even if the recording material S is reduced, a toner image V with a transport direction length of "100 mm" is formed on the recording material S. Then, the "movement deviation" of the toner image V is corrected. For example, in the example shown in FIG. 4(b), the position deviation of the toner image V from the varnish image W based on the varnish image master data [Dv] is calculated to be "3 mm" based on the upstream end of the recording material S in the transport direction. Therefore, in the "movement deviation" correction, the base image master data [Dg] is corrected so that the formation position of the toner image V is moved "3 mm" downstream in the transport direction.

[0048] Furthermore, in the past, if a "magnification deviation" occurs in the toner image V, the "magnification deviation" of the varnish image W is corrected. In the "magnification deviation" correction of the varnish image W, the varnish image master data [Dv] is corrected so that the length of the varnish image W in the transport direction is changed from "100 mm" to "98 mm" as shown in FIG. 4(c). However, because of this, in the past, as shown in FIG. 4(c), a positional deviation remained between the toner image V and the varnish image W at the downstream end in the transport direction. Therefore, in this embodiment, even if "magnification deviation" and "movement deviation" can occur simultaneously in the toner image and the varnish image, which could not be dealt with in the past, it is possible to form the toner image and the varnish image on the recording material S without causing "magnification deviation" and "movement deviation". The following will explain.

[0049] <Recording material output processing> Next, the "recording material output process" of the first embodiment will be described with reference to Fig. 3 and Fig. 5 to Fig. 11. The "recording material output process" is started by the main control unit 101 in response to an input to start an image forming job, for example, and is repeated until the image forming job is completed.

[0050] As shown in Fig. 5, the main control unit 101 initializes a counter "N" that holds the number of sheets of recording material S on which an image has been formed during the execution of the image forming job to an initial value "1" each time an image forming job is started (S1). In the case of this embodiment, as described later, the number of sheets of recording material S on which there is no misalignment between the toner image and the varnish image is counted and held in the counter "N". Then, the main control unit 101 acquires the base image master data [Dg] and the varnish image master data [Dv], and causes the image forming apparatus 100 to form a toner image on the Nth sheet of recording material S, and causes the varnish coater 200 to form a varnish image on the Nth sheet of recording material S (S2).

[0051] In addition, when this is the first (first) image formation on the Nth recording material S, the toner image and varnish image are formed without correcting the base image master data [Dg] and varnish image master data [Dv]. On the other hand, when this is the second or subsequent image formation on the Nth recording material S, the toner image and varnish image are formed by correcting the base image master data [Dg] and varnish image master data [Dv].

[0052] The main control unit 101 acquires (S3) the inspection base image data [Dpg] and the inspection varnish image data [Dpv] from the image inspection device 400. The main control unit 101 determines (S4) the amount of movement deviation and the amount of magnification deviation as the amount of positional deviation between the toner image and the varnish image actually formed on the Nth sheet of recording material S, from the coordinate information of the position reference point based on the acquired inspection base image data [Dpg] and the inspection varnish image data [Dpv].

[0053] <Amount of misalignment between toner image and varnish image> The following describes how to determine the amount of misalignment between the toner image and the varnish image formed on the recording material S. The main control unit 101 sets a "position reference point" in the base image master data [Dg] and the varnish image master data [Dv] that is used to detect the misalignment of the images.

[0054] The position reference point is set, for example, by the user specifying any toner image and varnish image from the operation unit 110. In the example shown in Fig. 6(a), it is assumed that a toner image and a varnish image of the same size and shape (rectangle) that are formed by overlapping in the entire area, as specified in the base image master data [Dg] and the varnish image master data [Dv], are specified. Then, as shown in Fig. 6(a), a rectangular area that is the specified toner image and varnish image is specified, and the four points P1, P2, P3, and P4 that are the vertices of this rectangular area are set as "position reference points".

[0055] In addition, in the inspection substrate image data [Dpg] and the inspection varnish image data [Dpv], which are the inspection results of the image inspection device 400, "position reference points" corresponding to the points P1, P2, P3, and P4, which are the "position reference points" on each image master data shown in FIG. 6(a), are set. In detail, as shown in FIG. 6(b), for example, the position reference points on the inspection substrate image data [Dpg] are set to points Pg1, Pg2, Pg3, and Pg4, and the position reference points on the inspection varnish image data [Dpv] are set to points Pv1, Pv2, Pv3, and Pv4. The X and Y coordinates of these position reference points are as shown in FIG. 6(b). The setting of the position reference points on each inspection image data corresponding to each image master data is performed based on a predetermined algorithm, such as performing corner detection within a specified area on the inspection image data and performing template matching between the image master data and the inspection image data.

[0056] Another example of the setting of the position reference point will be described. For example, as shown in Fig. 7(a), a varnish image formed as the character information "aiue" and a toner image formed as other character information are specified, as specified in the base image master data [Dg] and the varnish image master data [Dv]. That is, the base image master data [Dg] specifies a toner image other than the character information (i.e., other than white) shown in Fig. 7(b), and the varnish image master data [Dv] specifies a varnish image of the character information shown in Fig. 7(c).

[0057] In this case, in response to the specification of the character information "AIUEUE" from the operation unit 110 or the external device 1000, the four vertices (P1, P2, P3, P4) of the rectangular area specified so as to surround the specified character information are set as "position reference points". Also, in the inspection base image data [Dpg] and the inspection varnish image data [Dpv], "position reference points" are set that correspond to the points P1, P2, P3, P4, which are the "position reference points" on each image master data shown in Fig. 7(a).

[0058] After setting the above-mentioned "position reference point," the main control unit 101, via the calculation unit 103, compares the coordinates of the above-mentioned position reference point in the inspection base image data [Dpg] and the inspection varnish image data [Dpv] to calculate the amount of positional deviation between the toner image and the varnish image.

[0059] The X-component movement deviation amount QX and the Y-component movement deviation amount QX of the varnish image relative to the toner image are calculated by calculating the X-component and Y-component of the difference in the centroid coordinates of the rectangular areas that form the position reference points of the inspection base image data [Dpg] and the inspection varnish image data [Dpv]. As shown in Fig. 8(a), the movement deviation amounts QX and QY as the third movement deviation are calculated by the following formulas (1) and (2). QX={(xv1+xv2+xv3+xv4)÷4}-{(xg1+xg2+xg3+xg4)÷4} ··· Formula (1) QY={(yv1+yv2+yv3+yv4)÷4}-{(yg1+yg2+yg3+yg4)÷4} ··· Equation (2)

[0060] On the other hand, the magnification deviation is the ratio of the length of the side on the inspection base image data [Dpg] to the length of the side on the inspection varnish image data [Dpv] for two sides of the rectangular area that forms the position reference point. As shown in Fig. 9(a), the magnification deviation amount RX in the X direction and the magnification deviation amount RY in the Y direction are calculated by the following formulas (3) and (4). RX=(xg4-xg1)÷(xv4-xv1) Equation (3) RY=(yg2-yg1)÷(yv2-yv1) Equation (4)

[0061] <Amount of misalignment between image master data and inspection image data> 5, the main control unit 101 calculates (S5) the amount of positional deviation between the image master data and the test image data for the Nth sheet of recording material S using the calculation unit 103. A method for calculating the amount of positional deviation between the image master data and the test image data will be described.

[0062] The X-component shift amount SgX and the Y-component shift amount SgY between the base image master data [Dg] and the inspection base image data are calculated by the following formulas (5) and (6). The shift amounts SgX and SgY as the first shift correspond to the shift difference between the center of gravity of the position reference points (P1, P2, P3, P4) on the base image master data [Dg] and the center of gravity of the position reference points (Pg1, Pg2, Pg3, Pg4) on the inspection base image data. SgX={(xg1+xg2+xg3+xg4)÷4}-{(x1+x2+x3+x4)÷4} ··· Equation (5) SgY={(yg1+yg2+yg3+yg4)÷4}-{(y1+y2+y3+y4)÷4} ··· Equation (6)

[0063] The amount of movement deviation SvX of the X component and the amount of movement deviation SvY of the Y component between the varnish image master data [Dv] and the inspection varnish image data are calculated by the following formulas (7) and (8). The amounts of movement deviation SvX and SvY as the second movement deviation correspond to the difference between the center of gravity of the position reference points (P1, P2, P3, P4) on the varnish image master data [Dv] and the center of gravity of the position reference points (Pv1, Pv2, Pv3, Pv4) on the inspection varnish image data. SvX={(xv1+xv2+xv3+xv4)÷4}-{(x1+x2+x3+x4)÷4} ··· Equation (7) SvY={(yv1+yv2+yv3+yv4)÷4}-{(y1+y2+y3+y4)÷4} ··· Equation (8)

[0064] <Determination process, correction method decision process> Next, the main control unit 101 determines whether or not there is misalignment between the toner image and the varnish image formed on the Nth sheet of recording material S by a "determination process" described later (S6). If there is no misalignment (No in S6), the main control unit 101 jumps to the process of step S7. If there is a misalignment (Yes in S6), the main control unit 101 performs a "correction means determination process" described later (S10).

[0065] Fig. 10 shows a flowchart of the "determination process" (S6 in Fig. 9). As shown in Fig. 10, the main control unit 101 determines whether the movement deviation amount QX is greater than a threshold value QXT (first deviation amount) or whether the movement deviation amount QY is greater than a threshold value QYT (first deviation amount) (S31). If the bequest deviation amount QX is greater than the threshold value QXT or the movement deviation amount QY is greater than the threshold value QYT (Yes in S31), the main control unit 101 determines that "there is a position deviation" (S32).

[0066] If the movement deviation amount QX is not larger than the threshold value QXT and the movement deviation amount QY is not larger than the threshold value QYT (No in S31), the main control unit 101 judges whether the magnification deviation amount RX in the X direction is larger than the threshold value RXT (second deviation amount) or whether the magnification deviation amount RY in the Y direction (second deviation amount) is larger than the threshold value RYT (S33). If the magnification deviation amount RX is larger than the threshold value RXT or the magnification deviation amount RY is larger than the threshold value RYT (Yes in S33), the main control unit 101 judges that "there is a position deviation" (S32). If the magnification deviation amount RX is not larger than the threshold value RXT and the magnification deviation amount RY is not larger than the threshold value RYT (No in S33), the main control unit 101 judges that "there is no position deviation" (S34).

[0067] The above threshold values ​​QXT, QYT, RXT, and RYT may be stored in advance in the image analysis unit 404, or may be appropriately input by the user from the operation unit 110. Alternatively, they may be included in the base image master data [Dg] and the varnish image master data [Dv].

[0068] Fig. 11 shows a flowchart of the correction means determination process (S10 in Fig. 5). As shown in Fig. 11, the main control unit 101 judges whether the movement deviation amounts SgX, SgY of the toner image (inspection image) relative to the base image master data [Dg] are larger than the movement deviation amounts SvX, SvY of the varnish image (inspection image) relative to the varnish image master data [Dv] (S41). If the movement deviation amounts SgX, SgY of the toner image (inspection image) are larger than the movement deviation amounts SvX, SvY of the varnish image (inspection image) relative to the varnish image master data [Dv] (Yes in S41), the main control unit 101 selects the image forming apparatus 100 as the movement deviation amount correction means M (S42). On the other hand, if the movement deviation amounts SgX, SgY of the toner image (inspection image) are not greater than the movement deviation amounts SvX, SvY of the varnish image (inspection image) relative to the varnish image master data [Dv] (No in S41), the main control unit 101 selects the varnish coater 200 as a means for correcting the movement deviation amounts (S43).

[0069] In this way, the image forming apparatus 100 or the varnish coater 200, whichever has the larger movement deviation of the position reference point on the inspection image data relative to the position reference point on the image master data, is selected as the movement deviation correction means. That is, the movement deviation correction is performed to eliminate it in either the toner image formation or the varnish image formation. In this embodiment, as described above, the movement deviation correction is performed by the image forming apparatus 100 or the varnish coater 200, whichever causes the larger movement deviation.

[0070] <Calculation of correction amount> Returning to the explanation of FIG. 5, the main control unit 101 calculates the correction amount (S11). The movement deviation amount correction is performed by changing the image master data so that the movement deviation amounts QX and QY calculated in the inspection image are both "0". In this embodiment, the correction according to the movement deviation correction amount is performed by the correction means selected in step S10. When the image forming device 100 is selected as the correction means, the image forming device 100 performs a correction to move the toner image in the X direction by "-QX" and in the Y direction by "-QY". That is, the image forming device 100 corrects the base image master data [Dg] using the movement deviation correction amount at the time of the next image formation (reprinting the Nth sheet) to form a toner image. By this control, as shown in FIG. 8(b) with respect to FIG. 8(a), the center of gravity of the rectangular area forming the position reference point of the toner image coincides with the center of gravity of the rectangular area forming the position reference point of the varnish image.

[0071] On the other hand, the magnification deviation correction is performed by enlarging the toner image of the base image master data [Dg] so that the magnification deviations RX and RY calculated in the inspection image are both "1", and then forming the image. For example, as shown in FIG. 9(a), the image forming apparatus 100 performs a correction to enlarge the toner image by "1 / RX times" in the X direction and "1 / RY times" in the Y direction, based on the center of gravity position of the rectangular area that forms the position reference point of the toner image. That is, the image forming apparatus 100 changes the magnification of the toner image of the base image master data [Dg] using the magnification deviation correction amount at the time of the next image formation (reprinting the Nth sheet) to form a toner image. With this control, the toner image whose movement deviation amount has been corrected as described above is corrected so as to match the varnish image, as shown in FIG. 9(b) with respect to FIG. 9(a).

[0072] On the other hand, when the varnish coater 200 is selected as the correction means, the varnish coater 200 performs a correction to move the varnish image in the X direction by "-QX" and in the Y direction by "-QY". The varnish coater 200 corrects the varnish image master data [Dv] using the movement deviation correction amount at the time of the next image formation (reprinting the Nth sheet) to form a varnish image. Note that even when the varnish coater 200 is selected as the correction means, with regard to magnification deviation, the magnification of the toner image of the base image master data [Dg] is changed using the magnification deviation correction amount (1 / RX times, 1 / RY times), and a toner image is formed by the image forming apparatus 100.

[0073] Returning to FIG. 5, when the main control unit 101 calculates the correction amount (S11), it discharges the Nth recording material S (first recording material) that has been image-inspected to the NG tray 400b (S12). In this case, it is determined that image misalignment has occurred on the recording material S, and the process returns to step S2 without updating the counter "N". In other words, the image formation on the Nth recording material S that has been image-inspected is redone (reprinted). In this way, when misalignment has occurred on the Nth recording material S, the base image master data [Dg] and the varnish image master data [Dv] are corrected by the above-mentioned movement misalignment correction amount and magnification misalignment correction amount, and are applied to the image formation on the Nth recording material S and the image formation on the subsequent recording materials S.

[0074] On the other hand, if no misalignment occurs (No in S6), the main control unit 101 discharges the Nth recording material S (second recording material) that has been image-inspected onto the OK tray 400a (S7). Then, the main control unit 101 judges whether there is a next (N+1) recording material S for which an image is to be formed continuously and the image forming job should be continued, or there is no next (N+1) recording material S for which an image is to be formed continuously and the image forming job should be ended (S8). If the image forming job is to be ended (Yes in S8), the main control unit 101 ends the "recording material output process". If the image forming job is not to be ended (No in S8), the main control unit 101 counts up the counter (N) (S9) and returns to the process of step S2.

[0075] As described above, in this embodiment, the positional deviation between the toner image and the varnish image is corrected based on the inspection results of the toner image and the varnish image on the recording material S by the image inspection device 400 and the image master data of the toner image and the varnish image formed on the recording material S. At that time, the magnification deviation (RX, RY) between the toner image and the varnish image read by the image inspection device 400, the movement deviation (SgX, SgY) of the toner image read by the image inspection device 400 relative to the toner image based on the base image master data, and the movement deviation (QX, QY) of the varnish image read by the image inspection device 400 relative to the toner image read by the image inspection device 400 are calculated. Based on these magnification deviations and movement deviations, only the base image master data, or the base image master data and the varnish image master data are corrected, and the toner image and the varnish image are formed on the recording material S while the positional deviation of the toner image and the varnish image is automatically corrected during the image forming job. In this way, even in cases where "magnification deviation" and "movement deviation" can occur simultaneously when forming a toner image and a varnish image on the recording material S, it is possible to create a recording material S in which such position deviation does not occur in the toner image and the varnish image.

[0076] [Second embodiment] Next, the second embodiment will be described with reference to Figures 12 and 13. As described above, in the first embodiment, the toner image and varnish image formed on the Nth sheet of recording material S are inspected, and the positional deviation correction for the Nth sheet is performed based on the inspection image data, and then the positional deviation amount at that time is applied to image formation on the "N+1"th sheet of recording material S (see Figure 5).

[0077] However, the toner image formed on the recording material S may vary in the magnification in the transport direction so that the larger the toner coverage, the more the toner image is reduced. For example, as shown in FIG. 12, when the toner coverage is "0%," the toner image is difficult to reduce (magnification "100%), but when the toner coverage is "50%," the toner image may be reduced to a magnification of "99%", and when the toner coverage is "100%," the toner image may be reduced to a magnification of "98%". This is because the closer the toner coverage is to "100%," the faster the rotation speed of the intermediate transfer belt 80 is, and the rotation speed of the intermediate transfer belt 80 becomes relatively faster than the transport speed of the recording material S, so that the toner image is formed on the recording material S so as to be reduced in the transport direction. In this embodiment, the toner coverage refers to the ratio (area ratio) of the toner amount of the toner image formed on the recording material S, assuming that the toner amount when the toner image is formed on the entire A4 paper is "100%".

[0078] For example, if the toner coverage of the Nth sheet is "50%" or more and the toner coverage of the "N+1"th sheet is less than "50%," a magnification difference of "2%" may occur in the toner image. Therefore, in the first embodiment, when an image forming job is performed in which image formation with a toner coverage of "50%" or more (above a threshold value) and image formation with a toner coverage of less than "50%" are performed in succession, there is a risk that a magnification deviation of "2%" will repeatedly occur for each sheet of recording material S. This is because, for example, the magnification deviation correction amount "RY=100÷98=102%" when the toner coverage of the Nth sheet is "50%" or more is also applied to image formation with a toner coverage of less than "50%" for the "N+1"th sheet.

[0079] In addition, when the number of fixing times is different in the image formation of the Nth sheet and the "N+1"th sheet, a magnification difference is likely to occur between the magnification deviation of the Nth sheet and the magnification deviation of the "N+1"th sheet. That is, in the case of double-sided printing, after a toner image is fixed on one side of the recording material S, a toner image is fixed on the other side. That is, in the case of single-sided printing, the recording material S passes through the fixing device 50 once for the number of fixing times "one time", and in the case of double-sided printing, the recording material S passes through the fixing device 50 twice for the number of fixing times "two times", that is, twice. When the recording material S passes through the fixing device 50 twice, the recording material S may be reduced more due to the influence of heating by the fixing device 50 than when it passes through the fixing device 50 once. Note that the above-mentioned information regarding toner coverage and single-sided or double-sided printing is included in the base image master data [Dg].

[0080] <Recording material output processing> Fig. 13 shows the recording material output process of the second embodiment. In the recording material output process of the second embodiment shown in Fig. 13, the same processes as those in the recording material output process of the first embodiment described above (see Fig. 5) are given the same step numbers, and the description thereof will be simplified or omitted.

[0081] As shown in FIG. 13, the main control unit 101 initializes a counter "N" that holds the number of sheets of recording material S on which images are formed during the execution of the image forming job to an initial value "1" every time an image forming job is started (S1). Then, the main control unit 101 acquires the base image master data [Dg] and the varnish image master data [Dv], and acquires the base image forming condition C[N] from the base image master data [Dg] (S21). As the base image forming condition C[N], information on the toner coverage of the toner image and single-sided printing or double-sided printing is acquired. Based on the acquired base image forming condition C[N], the main control unit 101 acquires a magnification correction value from a correction table shown in Table 1 (S22). [Table 1]

[0082] As shown in Table 1, the correction table specifies the magnification correction value. Here, the magnification correction value is specified as "2%" when the toner coverage is "50% or more" and the number of fixing times is "1", as "5%" when the toner coverage is "50% or more" and the number of fixing times is "2", as "1%" when the toner coverage is "less than 50%" and the number of fixing times is "1", and as "4%" when the toner coverage is "less than 50%" and the number of fixing times is "2". In other words, the magnification correction value (second magnification correction value) when the toner coverage is "less than 50%" is smaller than the magnification correction value (first magnification correction value) when the toner coverage is "50% or more". Also, the magnification correction value (second magnification correction value) when the number of fixing times is "2" is larger than the magnification correction value (first magnification correction value) when the number of fixing times is "1".

[0083] Returning to the explanation of FIG. 13, the main control unit 101 causes the image forming apparatus 100 to form a toner image on the Nth recording material S, and causes the varnish coater 200 to form a varnish image on the Nth recording material S (S2). After step S2, the processes of steps S3 to S9, S10, and S11 are the same as those of the first embodiment described above. In the second embodiment, if positional deviation occurs on the Nth recording material S (Yes in S6), the base image master data [Dg] and varnish image master data [Dv] are corrected by the calculated movement deviation correction amount and magnification deviation correction amount, and are applied to image formation (reprinting) of the Nth recording material S.

[0084] However, in the second embodiment, when a positional deviation occurs in the Nth recording material S (Yes in S6), the main control unit 101 calculates the amount of magnification deviation between the base image master data and the inspection base image data (S23). The amounts of magnification deviation TgX and TgY between the base image master data and the inspection base image data are calculated by the following formulas (9) and (10). The amounts of magnification deviation TgX and TgY as the second magnification deviation correspond to the ratio between the length of one side of a rectangular area forming a positional reference point on the base image master data and the length of one side of a rectangular area forming a positional reference point on the inspection base image data (see FIG. 6(b)). TgX=(xg4-xg1)÷(x4-x1) Equation (9) TgY=(yg2-yg1)÷(y2-y1) Equation (10)

[0085] Then, the main control unit 101 updates the correction table (Table 1) based on the calculated magnification deviation between the base image master data and the inspection base image data (S24). After that, the main control unit 101 discharges the Nth recording material S that has been image-inspected to the NG tray 400b (S12), and returns to the process of step S2. For example, the correction magnification for the toner coverage is that shown in FIG. 12, but some deviation may occur due to various conditions of the image forming apparatus 100 main body. The deviation is found from the inspection result by the image inspection device 400, and the correction table is changed to one that takes into account the deviation. For example, if a deviation of "2%" is expected for a toner coverage of "100%" but is actually 1%, the magnification correction value is updated from "2%" to "1%".

[0086] In the second embodiment, the main control unit 101 returns to the process of step S21 after the process of step S9, that is, to form an image on the "N+1"th recording material S. Then, the main control unit 101 acquires information on the toner coverage of the toner image and single-sided printing or double-sided printing from the base image master data [Dg] for forming an image on the "N+1"th recording material S (S21). The main control unit 101 acquires a magnification correction value from the correction table shown in Table 1 based on the acquired information on the toner coverage and single-sided printing or double-sided printing (S22). The main control unit 101 causes the image forming apparatus 100 to form a toner image on the "N+1"th recording material S (S2), and at that time, corrects the magnification deviation amount calculated for the Nth recording material S with the magnification correction value acquired from the correction table, and enlarges the toner image of the base image master data [Dg] according to the corrected magnification deviation amount before forming the image.

[0087] As described above, in the second embodiment, by providing the correction table shown in Table 1, even when an image forming job is executed in which the magnitude of the magnification misalignment between the toner image and varnish image formed on the recording material S may change frequently, it is possible to create a recording material S in which there is no misalignment between the toner image and the varnish image while suppressing consumption of the recording material S.

[0088] The present technology can also be configured as follows. (1) an image forming apparatus for forming a toner image on a recording material based on first image data relating to the toner image; a fixing device that applies heat and pressure to a recording material on which a toner image has been formed by the image forming apparatus, thereby fixing the toner image to the recording material; a varnish application device that forms a varnish image by discharging varnish onto the recording material on which the toner image has been fixed by the fixing device, based on second image data relating to the varnish image; an image reading unit that reads the toner image and the varnish image formed on the recording material; a calculation unit that calculates, in a recording material on which a toner image and a varnish image superimposed on the toner image are formed, a magnification shift between the toner image, which is reduced compared to the toner image read by the image reading unit and based on the first image data, and the varnish image read by the image reading unit, a first movement shift that is a shift amount in at least one of the transport direction and width direction intersecting the transport direction of the recording material relative to the toner image based on the first image data of the toner image read by the image reading unit, a second movement shift that is a shift amount in at least one of the transport direction and width direction of the varnish image read by the image reading unit relative to the varnish image based on the second image data, and a third movement shift that is a shift amount in at least one of the transport direction and width direction of the varnish image read by the image reading unit relative to the toner image read by the image reading unit; A control unit for controlling the image forming device and the varnish applying device, the control unit, in a case where the third movement deviation calculated by the calculation unit is larger than a predetermined first deviation amount and the magnification deviation calculated by the calculation unit is larger than a predetermined second deviation amount, in a first recording material on which a toner image based on the first image data and a varnish image based on the second image data are formed, When the first movement deviation calculated by the calculation unit is greater than the second movement deviation, the first image data is corrected according to the third movement deviation and the magnification deviation amount of the magnification deviation, and a toner image and a varnish image are formed on a second recording material different from the first recording material, When the second movement deviation calculated by the calculation unit is larger than the first movement deviation, the second image data is corrected in accordance with the third movement deviation, and the first image data is corrected in accordance with a magnification deviation amount of the magnification deviation, and a toner image and a varnish image are formed on a second recording material different from the first recording material. 1. An image forming system comprising: (2) a first tray and a second tray capable of discharging the recording material from which the toner image and the varnish image have been read by the image reading unit; When a toner image and a varnish image are formed on a second recording material, the control unit The first recording material is discharged onto the first tray; After forming a toner image and a varnish image on the second recording material, the toner image and the varnish image formed on the second recording material are read by the image reading unit, and if the first movement deviation, the second movement deviation, and the third movement deviation do not occur, the second recording material is discharged onto the second tray. 4. The image forming system according to claim 1, (3) a storage unit that stores a correction table that defines a magnification correction value used to correct the magnification deviation, the control unit corrects the first image data according to an amount of magnification shift, and when forming a toner image on a second recording material different from the first recording material, When the area ratio of the toner image is equal to or greater than a threshold value, the first image data is corrected by a first magnification correction value of the correction table; When the area ratio of the toner image is smaller than a threshold value, the first image data is corrected by a second magnification correction value of the correction table which is smaller than the first magnification correction value. 3. The image forming system according to claim 1, wherein the first and second components are arranged in a first direction. (4) a storage unit that stores a correction table that defines a magnification correction value used to correct the magnification deviation, the control unit corrects the first image data according to an amount of magnification shift, and when forming a toner image on a second recording material different from the first recording material, In the case of single-sided printing in which an image is formed on one side of a recording material, the first image data is corrected in accordance with a first magnification correction value of the correction table; In the case of double-sided printing in which images are formed on both sides of a recording material, the first image data is corrected in accordance with a second magnification correction value of the correction table that is greater than the first magnification correction value. 3. The image forming system according to claim 1, wherein the first and second components are arranged in a first direction. (5) the calculation unit calculates a second magnification deviation between the toner image read by the image reading unit and a toner image based on the first image data; The control unit updates the magnification correction value of the correction table based on the second magnification deviation calculated by the calculation unit. 4. The image forming system according to claim 3, wherein the first and second electrodes are arranged in a first direction. (6) The varnish is an ultraviolet-curing UV varnish, The varnish application device solidifies the UV varnish dispensed onto the recording material by irradiating it with ultraviolet light. 6. The image forming system according to claim 1, wherein the image forming system comprises: [Explanation of symbols]

[0089] 1X: image forming system, 50: fixing device, 100: image forming apparatus, 101: control unit (main control unit), 102: storage unit (memory), 103: calculation unit, 200: varnish application device (varnish coater), 400a: second tray (OK tray), 400b: first tray (NG tray), 402: image reading unit, S: recording material

Claims

1. An image forming apparatus that forms a toner image on a first recording material based on first image data related to the toner image; A fixing device that fixes the toner image on the first recording material by applying heat and pressure to the first recording material on which the toner image is formed by the image forming apparatus; A varnish image forming device that forms a varnish image on the first recording material on which the toner image is fixed by the fixing device based on second image data related to the varnish image; An image reading unit that reads the toner image and the varnish image formed on the first recording material; A control unit that controls the image forming apparatus and the varnish image forming device, wherein the control unit acquires a first deviation amount related to a size deviation occurring in the toner image formed on the first recording material and a second deviation amount related to a position deviation occurring in the toner image formed on the first recording material based on the first image data and first detected image data of the toner image read by the image reading unit, corrects the first image data based on the first deviation amount and the second deviation amount, and forms a toner image on a second recording material subsequent to the first recording material based on the corrected first image data; acquires a third deviation amount related to a position deviation occurring in the varnish image formed on the first recording material based on the second image data and second detected image data of the varnish image read by the image reading unit, corrects the second image data based on the third deviation amount, and forms a varnish image on the second recording material based on the corrected second image data. An image forming system characterized by the above.

2. The control unit acquires a fourth deviation amount related to a position deviation occurring between the toner image and the varnish image formed on the first recording material, and when the fourth deviation amount is greater than a threshold value, acquires the first deviation amount, the second deviation amount, and the third deviation amount. The image forming system according to claim 1, characterized by the above.

3. The varnish is an ultraviolet curable UV varnish, and the varnish image forming device cures the UV varnish by irradiating ultraviolet rays onto the UV varnish ejected onto the recording material. The image forming system according to claim 1, characterized by the above.

4. An image forming apparatus that forms a toner image on a first recording material based on first image data related to the toner image; A fixing device that fixes the toner image on the first recording material by applying heat and pressure to the first recording material on which the toner image is formed by the image forming apparatus; Based on second image data regarding the varnish image, a varnish image forming device that forms a varnish image on the first recording material on which the toner image has been fixed by the fixing device; An image reading unit that reads the toner image and the varnish image formed on the first recording material; A first tray and a second tray; A control unit that controls the image forming device and the varnish image forming device; and The control unit: Corrects the first image data based on first detection image data of the toner image read by the image reading unit, and forms a toner image on a second recording material following the first recording material based on the corrected first image data; Corrects the second image data based on second detection image data of the varnish image read by the image reading unit, and forms a varnish image on the second recording material based on the corrected second image data; Based on the first detection image data and the second detection image data, if there is a shift between the toner image and the varnish image formed on the first recording material, the first recording material is discharged to the first tray, and if there is no shift between the toner image and the varnish image formed on the first recording material, the first recording material is discharged to the second tray; An image forming system characterized by the above.

5. An image forming device that forms a toner image on a first recording material based on first image data regarding the toner image; A fixing device that fixes the toner image on the first recording material by applying heat and pressure to the first recording material on which the toner image has been formed by the image forming device; Based on second image data regarding the varnish image, a varnish image forming device that forms a varnish image on the first recording material on which the toner image has been fixed by the fixing device; An image reading unit that reads the toner image and the varnish image formed on the first recording material; A control unit that controls the image forming device and the varnish image forming device; and The control unit: Based on the first image data, the first detection image data of the toner image read by the image reading unit, and the second detection image data of the varnish image read by the image reading unit, a first deviation amount related to the size deviation occurring in the toner image formed on the first recording material, a second deviation amount related to the position deviation occurring in the toner image formed on the first recording material, and a third deviation amount related to the deviation occurring between the toner image and the varnish image formed on the first recording material are obtained, the first image data is corrected based on the first deviation amount, the second deviation amount, and the third deviation amount, and a toner image is formed on a second recording material following the first recording material based on the corrected first image data. An image forming system characterized by the above. **Claim 6**: The control unit obtains the third deviation amount, and when the third deviation amount is larger than a threshold value, obtains the first deviation amount and the second deviation amount. The image forming system according to claim 5, characterized by the above. **Claim 7**: An image forming apparatus that forms a toner image on a first recording material based on first image data related to the toner image, A fixing device that fixes the toner image on the first recording material by applying heat and pressure to the first recording material on which the toner image is formed by the image forming apparatus, A varnish image forming device that forms a varnish image on the first recording material on which the toner image is fixed by the fixing device based on second image data related to the varnish image, An image reading unit that reads the toner image and the varnish image formed on the first recording material, A first tray and a second tray, A control unit that controls the image forming apparatus and the varnish image forming device, and The control unit, corrects the first image data based on the first detection image data of the toner image read by the image reading unit and the second detection image data of the varnish image read by the image reading unit, and forms a toner image on a second recording material following the first recording material based on the corrected first image data. Based on the first detection image data and the second detection image data, when a deviation occurs between the toner image and the varnish image formed on the first recording material, the first recording material is discharged to the first tray, and when no deviation occurs between the toner image and the varnish image formed on the first recording material, the first recording material is discharged to the second tray. An image forming system characterized by the above. **Claim 8**: The varnish is an ultraviolet curable UV varnish. The varnish image forming device cures the UV varnish by irradiating the UV varnish discharged onto the recording material with ultraviolet rays. The image forming system according to any one of claims 4 to 7, characterized in that.

9. An image forming device that forms a toner image on a recording material based on first image data regarding the toner image, A fixing device that fixes the toner image to the recording material by applying heat and pressure to the recording material on which the toner image has been formed by the image forming device, A varnish image forming device that forms a varnish image by discharging varnish onto the recording material on which the toner image has been fixed by the fixing device based on second image data regarding the varnish image, An image reading unit that reads the toner image and the varnish image formed on the recording material, In the recording material on which the toner image and the varnish image overlapping the toner image are formed, the magnification deviation between the toner image read by the image reading unit and the varnish image read by the image reading unit, and the toner image read by the image reading unit and the toner image based on the first image data. A first movement deviation that is the deviation amount in at least one of the conveyance direction of the recording material and the width direction intersecting the conveyance direction, and the varnish image read by the image reading unit and the varnish image based on the second image data. A second movement deviation that is the deviation amount in at least one of the conveyance direction and the width direction, and a third movement deviation that is the deviation amount in at least one of the conveyance direction and the width direction between the toner image read by the image reading unit and the varnish image read by the image reading unit. A calculation unit that calculates, A control unit that controls the image forming device and the varnish image forming device, When the toner image based on the first image data and the varnish image based on the second image data are formed on the first recording material, the control unit calculates the third movement deviation calculated by the calculation unit. When it is larger than a predetermined first deviation amount and the magnification deviation calculated by the calculation unit is larger than a predetermined second deviation amount, When the first movement deviation calculated by the calculation unit is larger than the second movement deviation, the first image data is corrected according to the magnification deviation amounts of the third movement deviation and the magnification deviation, and a toner image and a varnish image are formed on a second recording material different from the first recording material. When the second movement deviation calculated by the calculation unit is larger than the first movement deviation, the second image data is corrected according to the third movement deviation, and the first image data is corrected according to the magnification deviation amount of the magnification deviation, and a toner image and a varnish image are formed on the second recording material. An image forming system characterized by the above.

10. The image reading unit further includes a first tray and a second tray capable of discharging a recording material on which a toner image and a varnish image are read. When a toner image and a varnish image are formed on the second recording material, the first recording material is discharged to the first tray. The toner image and varnish image formed on the second recording material are read by the image reading unit. When the first movement deviation, the second movement deviation, and the third movement deviation do not occur, the second recording material is discharged to the second tray. The image forming system according to claim 9, characterized by the above.

11. The image forming system further includes a storage unit that stores a correction table defining a magnification correction value used to correct the magnification deviation. When the control unit corrects the first image data according to the magnification deviation amount of the magnification deviation and forms a toner image on the second recording material, when the area ratio of the toner image is equal to or greater than a threshold value, the first image data is corrected by the first magnification correction value of the correction table. when the area ratio of the toner image is smaller than the threshold value, the first image data is corrected by a second magnification correction value smaller than the first magnification correction value of the correction table. The image forming system according to claim 9, characterized by the above.

12. The image forming system further includes a storage unit that stores a correction table defining a magnification correction value used to correct the magnification deviation. When the control unit corrects the first image data according to the magnification deviation amount of the magnification deviation and forms a toner image on the second recording material, in the case of single-sided printing in which an image is formed on one side of the recording material, the first image data is corrected by the first magnification correction value of the correction table. in the case of double-sided printing in which an image is formed on both sides of the recording material, the first image data is corrected by a second magnification correction value larger than the first magnification correction value of the correction table. The image forming system according to claim 9, characterized by the above.

13. The calculation unit calculates a second magnification deviation between the toner image read by the image reading unit and the toner image based on the first image data. Based on the second magnification deviation calculated by the calculation unit, the control unit updates the magnification correction value of the correction table. The image forming system according to claim 11 or 12, characterized by the above.

14. The varnish is an ultraviolet curable UV varnish, The varnish image forming apparatus cures the UV varnish by irradiating the UV varnish discharged onto the recording material with ultraviolet rays. The image forming system according to claim 9, characterized by the above.

Images