JP2012220930A - Image forming system, image forming method, and program for image forming system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem in which an image with a greater glossiness difference cannot be obtained in a case where two types of transparent toners are used to form an image according to a conventional method, surface layer parts of a gloss transparent toner layer and a semi-gloss transparent toner layer fixed on paper are shaped to be uneven, and thus gloss of respective transparent toners are prevented from being generated due to the unevenness.SOLUTION: Plasticization means of an image forming system heats a recording medium on which a first toner image and a second toner image are fixed to selectively plasticize respective toners of the second toner image. Also, cooling means cools the toners in a state where it contacts with the plasticized toner image so as to solidify the respective toners of the second toner image. Accordingly, an advantage is obtained in which a difference of glossiness between the first toner image and the second toner image can be enlarged.

Description

  The present invention relates to an image forming system that forms an image using colored toner and clear toner.

  2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus that forms an image using clear toner in addition to colored toners such as yellow, magenta, cyan, and black is known. This image forming apparatus can form a glossy image by overlaying clear toner on colored toner. In addition, this image forming apparatus can output a partially glossy image by overlaying clear toner on a part of an image formed with colored toner.

  On the other hand, from the user of the image forming apparatus, when forming an image including characters and photos, the glossiness is increased from the point of decoration in the range including the photos, and from the point of readability in the range including the characters. There is a demand for forming an image with low glossiness.

  In response to such a demand, an image forming apparatus using two types of transparent toners having different glossiness levels has been proposed (see Patent Document 1). According to this proposal, the image forming apparatus forms a glossy transparent toner layer corresponding to a photographic region and a semi-glossy transparent toner layer over the entire image, and collectively forms the transparent toner layer and the color toner layer. Then, it is transferred to a sheet to form an image. As a result, the recorded photographic region can be a glossy image with a good appearance, and the character region can be a semi-glossy image without glare.

  However, when an image is formed using two types of transparent toners by the proposed method, the surface layer portions of the glossy transparent toner layer and the semi-glossy transparent toner layer fixed on the paper have an uneven shape. Accordingly, each transparent toner has a problem in that an image having a large difference in glossiness cannot be obtained because the occurrence of gloss is suppressed by the unevenness.

  The invention according to claim 1 includes the first clear toner and the color toner, and the surface layer portion includes the first toner image made of the first clear toner, the second clear toner and the color toner, and the surface layer. An image forming unit that forms on the recording medium a second toner image of the second clear toner and the colored toner, and the first toner image and the first toner image formed by the image forming unit. A fixing unit that fixes the second toner image on the recording medium; and the fixing unit that heats the recording medium on which the first toner image and the second toner image are fixed, and thereby the second toner image. The second clear toner and the color toner are selectively plasticized, and the second clear toner and the color toner plasticized by the plasticizer are in contact with the second clear toner and the color toner. By cooling the recording medium, an image forming system characterized by having a cooling means for solidifying the second clear toner and the color toner.

  The invention according to claim 4 includes the first clear toner and the color toner, and the surface layer portion includes the first toner image made of the first clear toner, the second clear toner and the color toner, and the surface layer. An image forming unit that forms a second toner image made of the second clear toner on a recording medium, and the first toner image and the second toner image formed by the image forming unit. Is fixed on the recording medium, and the recording medium on which the first toner image and the second toner image are fixed is heated by the fixing unit, and the second toner image is heated. The second clear toner by cooling the recording medium in a state of contact with the second clear toner plasticized by the plasticizing means and the plasticizing means for selectively plasticizing the clear toner. The Image forming system characterized by having a cooling means for reduction.

  As described above, according to the present invention, the plasticizing means of the image forming system heats the recording medium on which the first toner image and the second toner image are fixed, and each toner of the second toner image. Is selectively plasticized. The cooling unit cools the recording medium in contact with the plasticized toner image to solidify each toner of the second toner image. Thereby, there is an effect that the difference in glossiness between the first toner image and the second toner image can be increased.

1 is a schematic diagram of an image forming system according to an embodiment of the present invention. 1 is a hardware configuration diagram of an image forming system according to an embodiment of the present invention. 1 is a functional block diagram of an image forming system according to an embodiment of the present invention. It is explanatory drawing for demonstrating an example of the image formed by an image forming system. It is explanatory drawing for demonstrating the gloss range and non-gloss range of the image formed with an image forming system. FIG. 6 is a process flow diagram illustrating a processing method in the image forming system. FIG. 3 is a schematic diagram illustrating an example of a cross section of a sheet on which toner is fixed. FIG. 6 is a schematic diagram illustrating an example of a cross section of a sheet subjected to gloss generation processing.

<< Overall Configuration of Embodiment >>
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an image forming system according to an embodiment of the present invention. First, the overall configuration of the present embodiment will be described with reference to FIG.

  As shown in FIG. 1, the image forming system 1 of this embodiment includes an image forming apparatus 10 and a gloss generating device 20. The image forming apparatus 10 forms an image by fixing a toner image on a sheet as an example of a recording medium. The gloss generating device 20 heats the paper on which the toner image is fixed by the image forming device 10 and then cools the paper in contact with the toner image, thereby generating a gloss corresponding to the contact surface on the toner image. .

<Configuration of image forming apparatus>
As shown in FIG. 1, the image forming apparatus 10 includes a paper feeding unit 110, a conveyance unit 120, an image forming unit 130, a transfer unit 140, a fixing unit 150, and a control unit 160. ing.

  As shown in FIG. 1, the paper feeding unit 110 includes a paper feeding cassette 111 on which papers to be fed are stacked, and a paper feeding roller 112 that feeds the papers stacked on the paper feeding cassette 111 one by one. It has.

  The conveyance unit 120 waits by sandwiching a plurality of rollers 121 that convey the sheet fed by the sheet feeding roller 112 in the direction of the transfer unit 140 and the leading end of the sheet conveyed by the roller 121, and A pair of timing rollers 122 that are sent to the transfer unit 140 at a timing and a conveyance belt 123 that conveys the sheet sent from the transfer unit 140 to the fixing unit are provided. Further, the transport unit 120 includes a guide member (not shown) that guides the transported paper along a predetermined transport path.

  The image forming unit 130 includes, in order from the left to the right in FIG. 1 at a predetermined interval, an image forming unit A that uses a developer having a first clear toner, and a yellow toner (colored toner). Image forming unit B using a developer having a toner), image forming unit C using a developer having a cyan toner (colored toner), and image formation using a developer having a magenta toner (colored toner). A unit D, an image forming unit E using a developer having black toner (colored toner), and an image forming unit F using a developer having a second clear toner.

  In this embodiment, the developer is not particularly limited, but is a two-component developer having a carrier and a toner, respectively. In the present embodiment, the colored toner means resin particles that are charged or contain a coloring material such as a pigment or a dye and have a charging property. Further, the clear toner means resin particles configured so that a base recording medium or an image formed on the recording medium can be visually recognized after fixing. Accordingly, the clear toner may contain a coloring material such as a fluorescent pigment or a colored pigment as long as the amount is such that the base recording medium or the like can be visually recognized after fixing.

  In this embodiment, the lower limit fixing temperature of the second clear toner and the lower limit fixing temperature of the colored toner are set lower than the transition temperature of the first clear toner by adjusting the molecular weight of the polymer constituting the toner. ing. That is, the molecular weight of the second clear toner and the molecular weight of the colored toner are smaller than the molecular weight of the first clear toner.

  In the present exemplary embodiment, the fixing lower limit temperature means a lower limit temperature at which toner is fixed. Hereinafter, a method for measuring the minimum fixing temperature will be described. However, the method is not particularly limited to the following method as long as the difference in the relative minimum fixing temperature of the toner can be determined.

  When measuring the minimum fixing temperature, first, a fixing device for measurement is prepared. As this fixing device, a fixing device provided in a commercially available copying machine as an example of an image forming apparatus, which has been modified so that it can be driven independently, is easily used. When measuring the lower limit fixing temperature, the fixing temperature, the pressure applied to the paper during fixing, or the contact width generated by applying the pressure is managed. This is because the lower limit fixing temperature is determined by the pressure and thermal energy received by the paper. Therefore, in addition to the above, it is needless to say that when there is a characteristic that affects the thermal energy and pressure received by the paper, it is necessary to control it so as to keep it constant. As the conditions such as temperature and pressure, conditions set by default in a fixing device of a commercially available copying machine may be used.

  Next, a certain amount of toner is adhered to the paper. As the paper, it is only necessary to standardize the measurement, but paper that is widely distributed in the market is preferably used. The toner adhesion amount varies depending on the use conditions of each apparatus, but it is sufficient that the toner is unified to a constant amount in the measurement. Subsequently, the paper on which a certain amount of toner is adhered is passed through the fixing device for measurement while changing the fixing temperature, and the toner on the paper is fused to the paper. As the fixing temperature is lowered, the toner on the paper is less likely to be melted, and the degree of adhesion to the paper, that is, the fixability is lowered. Thus, by fixing the fixing temperature and fusing the toner to the paper, it is possible to obtain samples having different fixing properties at each fixing temperature.

  Finally, the fixing property is evaluated for the obtained sample, and the fixing temperature of the sample having the lowest fixing temperature among the samples having acceptable fixing properties is set as the minimum fixing temperature. Although the evaluation of the fixing property is not particularly limited, in the present embodiment, the evaluation was made by scratching a fixed toner image with a needle applied with a certain amount of load and removing the toner on the mark. The acceptable fixing degree may be set to a certain level. Specifically, a sample showing an acceptable limit of fixability can be prepared, and the sample and the sample obtained in the test can be compared with the degree of toner removal of the scratches scratched by the needle.

  In the present embodiment, the glossiness Gs (60 °) after fixing the first clear toner is preferably 30% or less in order to increase the difference in glossiness between images. Here, the glossiness Gs (60 °) means a 60 ° specular glossiness defined by JIS Z 8741. Further, the glossiness Gs (60 °) after fixing of the colored toner and the second clear toner is usually smaller than 70%. This is because the contact surface of the fixing belt 151 (described later) with the paper is uneven, or the surface of the paper 40 is uneven, so that the smoothness of the surface is lowered and the glossiness is lowered in the process of solidifying the toner. It is to do.

  In the present embodiment, the glossiness Gs (60 °) of the first clear toner after the gloss generation processing is equivalent to the glossiness Gs (60 °) of the first clear toner before fixing. This is because the first clear toner is not plasticized by the gloss generation process, and the shape of the surface layer portion of the first clear toner is not greatly changed. On the other hand, the glossiness Gs (20 °) after the gloss generation processing of the color toner and the second clear toner is about 64%. This is because, in the gloss generation process, the colored toner and the second clear toner are cooled and solidified in contact with a smooth surface, so that the surface layer portion of the colored toner becomes smooth and the glossiness increases. is there. The glossiness Gs (60 °) after the gloss generation processing of the color toner and the second clear toner is 70% or more, but the sensitivity of the measuring device may be lowered in a region with high glossiness. Therefore, in the above description, the glossiness after the gloss generation process is indicated by Gs (20 °).

  In FIG. 1, the six image forming units have substantially the same mechanical configuration except that the developers used are different. Each of the image forming units is provided to be rotatable counterclockwise, and a photosensitive drum (131a, 131b, 131c, 131d, 131e, 131f) on which a latent image and a toner image are formed, and a photosensitive drum (131a, 131b, 131f). 131c, 131d, 131e, 131f) are charged by a charger (132a, 132b, 132c, 132d, 132e, 132f) that uniformly charges the surface and a charger (132a, 132b, 132c, 132d, 132e, 132f). Exposure units (133a, 133b, 133c, 133d, 133e, 133f) that irradiate light on the surfaces of the photosensitive drums (131a, 131b, 131c, 131d, 131e, 131f) based on the respective image data to form latent images. ) And exposure units (133a, 133b, 133c, 133) , 133e, 133f) and magnetic brush type developing devices (134a, 134b, 134c, 134d) for developing a latent image formed on the surface of the photosensitive drum (131a, 131b, 131c, 131d, 131e, 131f) into a toner image. 134e, 134f) and static eliminators (135a, 135b, 135c, 135d) for neutralizing the surfaces of the photosensitive drums (131a, 131b, 131c, 131d, 131e, 131f) after the toner image is primarily transferred to the transfer medium. 135e, 135f) and the transfer residual toner remaining on the surface of the photosensitive drum (131a, 131b, 131c, 131d, 131e, 131f) that has been neutralized by the static eliminator (135a, 135b, 135c, 135d, 135e, 135f). Cleaning devices (136a, 136b, 136c, 136d, 1 6e, it is equipped with a 136f) and.

  In the present embodiment, the “photosensitive drum 131” is used when any photosensitive drum among the photosensitive drums (131a, 131b, 131c, 131d, 131e, 131f) is shown. The “charger 132” is used when an arbitrary charger is shown among the chargers (132a, 132b, 132c, 132d, 132e, 132f). Further, when an arbitrary exposure device is shown among the exposure devices (133a, 133b, 133c, 133d, 133e, 133f), the “exposure device 133” is used. Further, the “developing unit 134” is used to indicate an arbitrary developing unit among the developing units (134a, 134b, 134c, 134d, 134e, 134f). Further, in the case of indicating any static eliminator among the static eliminators (135a, 135b, 135c, 135d, 135e, 135f), the “static eliminator 135” is used. Further, in the case where any cleaning device among the cleaning devices (136a, 136b, 136c, 136d, 136e, 136f) is indicated, the “cleaning device 136” is used.

  The transfer unit 140 includes a driving roller 141 and a driven roller 142, a secondary opposing roller 143 provided below the rollers, and a tension roller 144 provided between the driven roller 142 and the secondary opposing roller 143. And an intermediate transfer belt 145 that is wound around these rollers and can rotate clockwise as the driving roller 141 is driven.

  In addition, the transfer unit 140 includes primary transfer rollers (146a, 146b, 146c, 146c, 146c, 146c, 146c, which are provided between the driving roller 141 and the driven roller 142, with the intermediate transfer belt 145 interposed therebetween. 146d, 146e, 146f). When an arbitrary primary transfer roller among the primary transfer rollers (146a, 146b, 146c, 146d, 146e, 146f) is indicated, the “primary transfer roller 146” is used. The toner image formed on the surface of the photosensitive drum 131 is sequentially transferred to the intermediate transfer belt 145 by applying a primary transfer bias by the primary transfer roller 146.

  Further, the transfer unit 140 includes a secondary transfer roller 147 provided to face the secondary opposing roller 143 with the intermediate transfer belt 145 interposed therebetween. As a result, a secondary transfer bias is applied to the sheet being conveyed sandwiched between the secondary transfer roller 147 and the transfer belt 145, whereby the toner image transferred to the intermediate transfer belt 145 is transferred to the sheet.

  The fixing unit 150 includes a conveyance upstream roller 151 provided so as to be positioned above the rear end of the conveyance belt 123 and a conveyance downstream roller 152 provided so as to be substantially at the same level as the conveyance belt 123. . The fixing unit 150 is stretched over the roller portions of the above-described rollers, and can be rotated clockwise by a driving motor (not shown), a heater 154 for heating the sheet via the fixing belt 153, and a fixing belt. And a pressure roller 155 that forms a contact surface by pressing and pressing the roller 153 against the conveyance downstream roller 152 with the roller 153 interposed therebetween.

  The control unit 160 controls the overall operation of the image forming system 1. Therefore, the control unit 160 includes a storage device such as a CPU (Central Processing Unit) described later, a ROM (Read Only Memory), and a RAM (Random Access Memory).

  A hardware configuration of the control unit 160 of the image forming system 1 will be described with reference to FIG. FIG. 2 is a hardware configuration diagram of the control unit 160 of the image forming system 1. The control unit 160 is used as a work area for the CPU 161 that controls the overall operation of the image forming system 1, a ROM 162 that stores an image forming system program for causing the image forming system 1 to implement various functions or various means, and the CPU 161. RAM 163, HD (Hard Disk) 164 for storing various data, HDD (Hard Disk Drive) 165 for controlling reading or writing of various data to / from the HD 164 according to the control of the CPU 161, and display for displaying the operating status of the image forming system 1 A display operation panel 166 that also functions as a panel and an operation panel that receives an operation input from a user, a network I / F (Interface) 167 for data transmission with an external device such as an information processing apparatus, and the above-described components Electrically connected as shown in Figure 2 It has an order of address bus, a data bus, and the like of the bus line 168.

<Configuration of gloss generator>
As shown in FIG. 1, the gloss generating device 20 includes a heater 21 provided inside, a heating roller 22 that heats the paper, and a plurality of rollers 23 provided downstream of the heating roller 22 on the conveyance side, A toner image side contact surface having a higher surface smoothness (lower surface roughness) than the toner image side contact surface of the fixing belt 153 is formed on the heating roller 22 and the plurality of rollers 23, and is rotated by a drive motor (not shown). An endless glosser belt 24 that can be configured, a second pressure roller 25 that presses against the heating roller 22 to form a contact surface with the glosser belt 24 interposed therebetween, and a second pressure roller 25 A plurality of cooling fans 26 are provided on the downstream side of the conveyance of the sheet from the pressure roller 25 and cool the sheet.

  The output of the heater 21 of the gloss generating device 20 is heated to a temperature that is equal to or higher than the fixing lower limit temperature of the second clear toner and the fixing lower limit temperature of the colored toner and lower than the fixing lower limit temperature of the first clear toner. The control unit 160 controls the operation. In this case, the control unit 160 may control the output of the heater 21 with a thermistor or a thermopile (infrared temperature sensor) (not shown).

  Accordingly, the surface layer portion of the second toner image composed of the second clear toner and the color toner is selectively selected from the toner images formed on the sheet passing through the contact surface between the glosser belt 24 and the pressurizing unit 25. Plasticize. Further, the output of the cooling fan 26 of the gloss generating device 20 or the conveyance speed by the glosser belt 24 is controlled by the control unit 160. As a result, the surface layer portion of the second toner image composed of the second clear toner and the color toner plasticized on the contact surface is cooled and solidified within the conveyance time in which the second toner image is conveyed in contact with the glosser belt 24. .

<< Functional Configuration of Embodiment >>
Next, the functional configuration of this embodiment will be described with reference to FIGS. 3, 4-1, and 4-2. FIG. 3 is a functional block diagram of the image forming system 1 according to the embodiment of the present invention. FIG. 4A is an explanatory diagram for explaining an example of an image formed by the image forming system. FIG. 4B is an explanatory diagram for explaining a glossy range and a non-glossy range of an image formed by the image forming system.

  The image forming system 1 includes a receiving unit 1601, a CMYK image data generation unit 1602, a calculation unit 1603, and a clear toner image data generation unit 1604. Each of these units is a function or means realized by any one of the constituent elements shown in FIG. 2 operating according to a command from the CPU 161 according to a program stored in the ROM 162.

  The receiving unit 1601 is realized by the network I / F 167 illustrated in FIG. 2, and receives various data (information) transmitted by an image output terminal, device, or system via a communication network. The received data includes image data of the image to be formed, gloss range information indicating the gloss range in the image, non-gloss range information indicating the non-gloss range in the image, and the like.

  As the image data, for example, the color image 3 (see FIG. 4A) including characters, photographs, and the like is color-separated into R (Red) image data, G (Green) image data, and B (Blue) image data. The RGB image data obtained by this is mentioned. The gloss range information includes position information indicating the position set in the gloss range 32 (see FIG. 4B) that generates gloss in the image 3. The non-gloss range information includes position information indicating the position set in the non-gloss range 31 (see FIG. 4B) where no gloss is generated in the image 3.

  The CMYK image data generation unit 1602 is formed with colored toners of yellow (Y), black (K), cyan (C), and magenta (M) in accordance with an instruction from the CPU 161 according to a program stored in the ROM 162. Image data (colored image data) of the image to be processed is generated.

  The calculation unit 1603 calculates the image area ratio of the image formed by the color toner based on the CMYK image data generated by the CMYK image data generation unit 1602 according to the instruction from the CPU 161 according to the program stored in the ROM 162. calculate.

  The CL1 image data generation unit 1604, based on the non-gloss range information received by the reception unit 1601 in accordance with an instruction from the CPU 161 according to the program stored in the ROM 162, the image of the image formed by the first clear toner. Image data (non-gloss image data) is generated.

  The CL2 image data generation unit 1605 is an image of an image formed by the second clear toner based on the image area ratio calculated by the calculation unit 1603 according to an instruction from the CPU 161 according to a program stored in the ROM 162. Data (gloss image data) is generated.

<< Processing and Operation of Embodiment >>
Next, a processing method in the image forming system 1 according to the present embodiment will be described with reference to FIG. FIG. 5 is a processing flowchart showing a processing method in the image forming system 1.

  First, the receiving unit 1601 of the image forming system 1 receives image formation request information that is transmitted by the image output terminal via the communication network and includes image data, gloss range information, non-gloss range information, and the like (step S1). ). In the present embodiment, a case where the image data is RGB image data will be described.

  When the reception unit 1601 receives the image formation request information, the CMYK image data generation unit 1602 displays an image formed by each color toner of yellow (Y), black (K), cyan (C), and magenta (M). Image data is generated (step S2). In this case, the CMYK image data generation unit 1602 performs color conversion processing on the RGB image data included in the image formation request information, and CMYK including color separation data corresponding to each color (C, M, Y, K) of the colored toner. Generate image data. The CMYK image data generation unit 1602 may execute known image processing such as color correction processing and spatial frequency correction processing in addition to color conversion processing on image data.

  Next, the calculation unit 1603 calculates the image area ratio of an image formed with colored toner based on the CMYK image data generated by the CMYK image data generation unit 1602. (Step S3). In this case, the calculation unit 1603 calculates the sum of the numerical values of the color separation data corresponding to each color (C, M, Y, K) of the colored toner for each dot of the image indicated by the CMYK image data. The area ratio can be calculated. In this embodiment, in order to shorten the calculation time, the calculation unit 1603 calculates the image area ratio only for each dot in the gloss range 32 (see FIG. 4B) of the image indicated by the CMYK image data. To do.

  The CL1 image data generation unit 1604 generates image data (non-gloss image data) of an image formed by the first clear toner (CL1) based on the non-gloss range information included in the image formation request information (step S1). S4). In this case, the CL1 image data generation unit 1604 generates non-gloss image data of an image (solid image) having an image area ratio of 100% corresponding to the non-gloss range 31.

  On the other hand, the CL2 image data generation unit 1605 generates image data (glossy image data) of an image formed by the second clear toner (CL2) based on the image area ratio calculated by the calculation unit 1603 (Step S1). S5). In this case, for each dot in the gloss range 32, the CL2 image data generation unit 1605 calculates the sum of the image area ratio of the image formed with the second clear toner and the image area ratio of the image formed with the colored toner. Glossy image data is generated so as to be 100%. That is, the CL2 image data generation unit 1605 subtracts the image area ratio (%) calculated by the calculation unit 1603 for each dot from an image (solid image) corresponding to the gloss range 32 with an image area ratio of 100%. Glossy image data is generated.

  When the generation of the color image data, the non-glossy image data, and the glossy image data is completed, the paper feed roller 112 of the paper feed unit 110 feeds the paper stored in the paper feed cassette 111 one by one in the image forming apparatus 10. (Step S6). Subsequently, the roller 121 of the transport unit 120 transports the fed paper in the direction of the transfer unit 140. The timing roller 122 sandwiches the leading end portion of the sheet conveyed by the roller 121 and waits until the timing at which the transfer unit 140 transfers the sheet.

  On the other hand, each image forming unit of the image forming unit 130 uses toner of each toner (C, M, Y, K, CL1, CL2) based on the generated color image data, non-gloss image data, and gloss image data. An image is created (step S7). In this case, the charger 132 uniformly charges the surface of the photosensitive drum 131 that rotates counterclockwise.

  Subsequently, the exposure unit 133 irradiates light on the surface of the photosensitive drum charged by the charger 132 based on each image data to form a latent image. In this case, the exposure unit 133a irradiates the surface of the charged photosensitive drum 133a with a laser based on the non-gloss image data. As a result, an electrostatic latent image corresponding to the image indicated by the non-glossy image data is formed on the photosensitive drum 131a after charging.

  Similarly, the exposure units (133b, 133c, 133d, 133e) are charged photosensitive drums (131b, 131c) based on color separation data (Y, C, M, K) included in the color image data. , 131d, 131e) is irradiated with a laser. Thereby, an electrostatic latent image corresponding to the image indicated by each color separation data (Y, C, M, K) is formed on the charged photosensitive drums (131b, 131c, 131d, 131e).

  Similarly, the exposure device 133f irradiates a laser on the surface of the charged photosensitive drum 133f based on the gloss image data. As a result, an electrostatic latent image corresponding to the image indicated by the glossy image data is formed on the charged photosensitive drum 131f.

  When each electrostatic latent image is formed, the developing unit 134 converts the electrostatic latent images on the photosensitive drums (131a, 131b, 131c, 131d, 131e, and 131f) into toners (CL1, Y, C, M, K, CL2). ) To develop toner images (CL1, Y, C, M, K, CL2).

  The developed toner image is applied with a primary transfer bias by a primary transfer roller 146, so that the toner image is sequentially transferred to the intermediate transfer belt 145 that circulates clockwise in FIG. 1 (primary transfer). After the toner image is primarily transferred to the intermediate transfer belt 145, the surface of the photosensitive drum 131 is neutralized by the neutralizer 135. Further, the transfer residual toner remaining on the surface of the photosensitive drum 131 that has been neutralized is removed by the cleaner 136.

  The primarily transferred toner image moves while attached to the intermediate transfer belt 145, and is transferred onto the sheet by applying a secondary transfer bias by the secondary transfer roller 147 (secondary transfer) (step S8). This sheet is fed by the timing roller 122 in accordance with the timing at which the toner image on the intermediate transfer belt 145 moves. When the secondary transfer is completed, the conveyance belt 123 conveys the sheet sent from the transfer unit 140 to the fixing unit 150.

  When the sheet conveyed to the fixing unit 150 passes through the contact surface formed by the fixing belt 153 and the pressure roller 155, the lower limit of fixing of the transferred toner (CL1, C, M, Y, K, CL2). Heat at a fixing temperature above the temperature is applied. As a result, all the toners (CL1, C, M, Y, K, CL2) transferred to the paper reach the fixing temperature and are plasticized. Further, pressure is applied to the plasticized toner and paper by the pressure roller 155 so that the toner adheres to the paper and is fixed by entering between the fibers of the paper (step S9). The upper limit of the fixing temperature is preferably a temperature at which no offset phenomenon occurs in the first toner, the second clear toner, and the colored toner. Here, the offset phenomenon means a phenomenon in which a part of the toner image is removed from the fixing belt.

  Here, the state of the paper on which the toner is fixed will be described with reference to FIG. FIG. 6 is a schematic diagram illustrating an example of a cross section of a sheet on which toner is fixed. As shown in FIG. 6, the paper 40 has a first toner image 51 having at least a first clear toner 41 and a colored toner 43, and a second toner having a second clear toner 42 and a colored toner 43. Toner image 52 is formed.

  The first toner image 51 is a toner image formed in the non-gloss range 31 based on the non-gloss image data generated by the CL1 image data generation unit 1604 and the image data generated by the CMYK image data generation unit 1602. is there. The surface layer portion of the first toner image 51 is composed of the first clear toner 41. This is because the non-glossy image (solid image) of the first clear toner is first transferred to the intermediate transfer belt 145 in the primary transfer (see step S8).

  The second toner image is a toner image formed in the gloss range 32 based on the gloss image data generated by the CL2 image data generation unit 1605 and the image data generated by the CMYK image data generation unit 1602. The surface layer portion of the second toner image is composed of the second clear toner 42 and the colored toner 43. In the second toner image, the toner amount of each dot is the same. This is because the CL2 image data generation unit 1605 calculates the sum of the image area ratio of the image formed by the second clear toner and the image area ratio of the image formed by the colored toner for each dot in the gloss range 32. This is because the glossy image data is generated so as to be 100%.

  The surface layer portion of the first toner image 51 and the surface layer portion of the second toner image 52 of the paper on which the toner is fixed are uniformly uneven. This is because the toner plasticized by being heated to a temperature higher than the lower limit fixing temperature is deformed and solidified based on the uneven shape on the surface of the fixing belt 153 or the uneven shape on the surface of the paper 40.

  Note that the glossiness of the first clear toner is smaller than the glossiness of the colored toner and the glossiness of the second clear toner. The gloss level can be made smaller than that of the second toner image 52. However, the surface layer portion of the first toner image and the surface layer portion of the second toner image have unevenness uniformly, and gloss is suppressed by this gloss. Therefore, an image having a large difference in glossiness between the surface layer portion of the first toner image and the surface layer portion of the second toner image cannot be obtained.

  Next, gloss generation processing by the gloss generation device 20 will be described. The sheet on which the toner is fixed is conveyed to the gloss generation device 20 and subjected to gloss generation processing (step S10). In this case, the sheet on which the toner is fixed is heated by the heater 21 when it passes through the contact surface between the glosser belt 24 and the pressure unit 25. As a result, the surface layer portion of the second toner image of the paper composed of the second clear toner and the colored toner is plasticized. On the other hand, the surface layer portion of the first toner image made of the first clear toner is not plasticized. This is because the output of the heater 21 is set so that the sheet is heated to a temperature lower than the lower limit fixing temperature of the second clear toner and the lower limit fixing temperature of the colored toner and lower than the lower limit fixing temperature of the first clear toner. Because it is.

  The sheet heated on the contact surface is cooled by the cooling fan 26 while being conveyed by the glosser belt 24. As a result, the surface layer portion of the second toner image made of the plasticized second clear toner and colored toner is cooled while being conveyed while being in contact with the glosser belt 24, and until it is separated from the glosser belt 24. Solidify. The paper on which the gloss generation processing has been performed is discharged to a predetermined storage unit of the gloss generation device 20.

  Here, the state of the sheet subjected to the gloss generation process will be described with reference to FIG. FIG. 7 is a schematic diagram illustrating an example of a cross section of a sheet subjected to gloss generation processing. As shown in FIG. 7A, the surface layer portion of the first toner image 51 of the paper 40 that has been subjected to the gloss generation process has an uneven surface. This is a gloss generation process. Even if the paper is heated to a temperature lower than the lower limit fixing temperature of the first clear toner, the first clear toner of the first toner image is not plasticized, and before the gloss generation process. This is because the concavo-convex shape of the surface is maintained.

  On the other hand, the surface layer portion of the second toner image 52 of the sheet subjected to gloss generation processing is a smooth surface compared to the surface layer portion of the first toner image 51. This is because the surface layer portion of the second toner image made of the second clear toner and the color toner plasticized by the heater 21 is solidified in contact with the surface of the smooth glosser belt 24. Thereby, a difference in smoothness of the surface layer portion can be generated between the first toner image 51 and the second toner image, so that a difference in glossiness between the toner images can be increased.

<< Supplement of Embodiment >>
In the above embodiment, the image forming apparatus 10 and the gloss generating apparatus 20 of the image forming system 1 are housed in separate housings. However, the present invention is not limited to this, and the image forming apparatus 10 and the gloss generating apparatus 20 of the image forming system 1 may be housed in the same casing.

  Further, in the above embodiment, the contact surface of the glosser belt 24 with the paper is smoother than the contact surface of the fixing belt 153 with the paper. However, the present invention is not limited to this, and the contact surface of the fixing belt 153 with the paper may be smoother than the contact surface of the glosser belt 24 with the paper. In this case, by performing the same processing as in the above-described embodiment, an image formed product in which the surface layer portion of the second toner image 52 is less smooth than the surface layer portion of the first toner image 51 is obtained (FIG. 7). (See (B)). Thereby, the difference in glossiness between the first toner image 51 and the second toner image 52 can be increased.

  Furthermore, in the above embodiment, the calculation unit 1603 calculates the image area ratio, and the CL2 image data generation unit 1605 generates gloss image data based on the calculated image area ratio (%). However, the present invention is not limited to this, and the CL2 image data generation unit 1604 may create gloss image data including an image (solid image) with an image area ratio of 100% corresponding to the gloss range 32. In this case, the same processing as in the above embodiment can be performed by replacing the positions of the image forming unit B and the image forming unit F of the image forming apparatus 10 in FIG. In this case, an image having a gloss difference between the first toner image 51 and the second toner image 52 is obtained without performing the calculation process (see FIG. 7C).

  Further, in the above-described embodiment, the heater 21 of the gloss generating device 20 has a sheet that is higher than the lower limit fixing temperature of the second clear toner and the lower limit fixing temperature of the colored toner and lower than the lower limit fixing temperature of the first clear toner. Heated to temperature. However, the present invention is not limited to this, and the output of the heater 21 is set to a predetermined temperature at which the second clear toner and the colored toner can be selectively plasticized according to the toner material, structure, and the like. Just do it. For example, the output of the heater 21 may be set based on the glass transition temperature (Tg) instead of the lower limit fixing temperature. Further, when a thermosetting resin that does not remelt is used for the first clear toner, the output of the heater 21 may be set to an arbitrary temperature at which the second clear toner and the colored toner can be plasticized. good.

<< Main effects of embodiment >>
As described above, according to the present embodiment, the heater 21 of the image forming system 1 heats the paper passing through the contact surface between the glosser belt 24 and the pressurizing unit 25 and fixes the toner by the fixing belt 153. Of the image, the surface layer portion of the second toner image composed of the second clear toner and the colored toner is selectively plasticized. Further, the cooling fan 26 cools the sheet in contact with the glosser belt 24 and solidifies the plasticized second clear toner and colored toner. Accordingly, the surface layer portion of the second toner image is solidified based on the shape of the contact surface of the glosser belt 24, and thus has a shape different from the surface layer portion of the first toner image. That is, the image forming system 1 of the present embodiment can form an image with a large difference in glossiness by making the surface layer portion of the first toner image different from the surface layer portion of the second toner image. There is an effect that can be done.

  Further, according to the present embodiment, the heater 21 of the image forming system 2 causes the sheet passing through the contact surface to be higher than the lower limit fixing temperature of the second clear toner and the lower limit fixing temperature of the colored toner, The toner is heated to a temperature lower than the fixing temperature of the clear toner. Thereby, the heater 21 can selectively plasticize the surface layer portion of the second toner image composed of the second clear toner and the colored toner based on the difference in the lower limit fixing temperature of each clear toner. Play.

  Further, according to the present embodiment, the calculation unit 1603 of the image forming system 2 calculates the image area ratio based on the CMYK image data generated by the CMYK image data generation unit 1602. The CL2 image data generation unit 1605 generates image data (gloss image data) of a gloss image formed by the second clear toner based on the image area ratio calculated by the calculation unit 1603. In addition, the image forming unit creates the second toner image 32 based on the CMYK image data generated by the CMYK image data generation unit 1602 and the glossy image data generated by the CL2 image data generation unit 1605. In this case, since gloss image data can be generated based on the color toner image area ratio, the image area ratio formed by the color toner and the second clear toner at each dot of the second toner image 32 can be made constant. Play.

  Further, according to the present embodiment, the heater 21 of the image forming system 1 heats the sheet passing through the contact surface between the glosser belt 24 and the pressurizing unit 25, and among the toner images fixed by the fixing belt 153, The surface layer portion of the second toner image made of the second clear toner is selectively plasticized. Further, the cooling fan 26 cools the sheet in contact with the glosser belt 24 and solidifies the plasticized second clear toner. Accordingly, the surface layer portion of the second toner image is solidified based on the shape of the contact surface of the glosser belt 24, and thus has a shape different from the surface layer portion of the first toner image. That is, the image forming system 1 of the present embodiment can form an image with a large difference in glossiness by making the surface layer portion of the first toner image different from the surface layer portion of the second toner image. There is an effect that can be done.

  Further, according to the present embodiment, the heater 21 of the image forming system 2 causes the sheet passing through the contact surface to be higher than the fixing lower limit temperature of the second clear toner and higher than the fixing temperature of the first clear toner. Also heat to a lower temperature. Accordingly, the heater 21 has an effect that the surface layer portion of the second toner image made of the second clear toner can be selectively plasticized based on the difference in the lower limit fixing temperature of each clear toner.

DESCRIPTION OF SYMBOLS 1 Image forming system 3 Paper 10 Image forming apparatus 20 Gloss generating device 21 Heater 22 Heating roller 23 Roller 24 Grosser belt 25 Second pressurizing means 26 Cooling fan 31 Non-gloss range 32 Gloss range 40 Paper 41 First clear toner 42 Second clear toner 43 Colored toner 51 First toner image 52 Second toner image 110 Paper feed unit 111 Paper feed cassette 112 Paper feed roller 120 Transport unit 121 Roller 122 Timing roller 130 Image forming unit 131 Photosensitive drum 132 Charger 133 Exposing device 134 Developing device 135 Static eliminator 136 Cleaning device 140 Transfer unit 141 Drive roller 142 Driven roller 143 Secondary opposing roller 144 Tension roller 145 Intermediate transfer belt 146 Primary transfer roller 150 Fixing unit 151 Transport upstream roller 152 Transport downstream Roller 153 Wearing belt 154 heater 155 pressure roller 160 controller 1601 receiving unit 1602 CMYK image data generating unit 1603 calculating unit 1604 CL1 image data generating unit 1605 CL2 image data generating unit

JP 2002-207334 A

Claims (8)

The first clear toner and the color toner are included, the surface layer portion includes the first toner image made of the first clear toner, the second clear toner and the color toner, and the surface layer portion is the second clear toner. And an image forming means for forming a second toner image made of the colored toner on a recording medium;
Fixing means for fixing the first toner image and the second toner image formed by the image forming means to the recording medium;
The fixing unit heats the recording medium on which the first toner image and the second toner image are fixed, and selectively selects the second clear toner and the colored toner of the second toner image. A plasticizing means for plasticizing;
Cooling means for solidifying the second clear toner and the colored toner by cooling the recording medium in contact with the second clear toner and the colored toner plasticized by the plasticizing means;
An image forming system comprising:   The plasticizing means heats the recording medium to a temperature that is equal to or higher than the lower limit fixing temperature of the second clear toner and the lower limit fixing temperature of the colored toner and lower than the lower limit fixing temperature of the first clear toner. The image forming system according to claim 1, wherein the second clear toner and the colored toner are selectively plasticized. A color image data generation unit that generates color image data of an image formed by the color toner;
A calculation unit that calculates an image area ratio of an image formed by the color toner based on the color image data generated by the color image data generation unit;
A clear image data generation unit that generates clear image data of an image formed by the second clear toner based on the image area ratio calculated by the calculation unit;
The image forming system according to claim 1, wherein the image forming unit forms the second toner image based on the colored image data and the clear image data. The first clear toner and the color toner are included, the surface layer portion includes the first toner image made of the first clear toner, the second clear toner and the color toner, and the surface layer portion is the second clear toner. An image forming means for forming a second toner image on the recording medium;
Fixing means for fixing the first toner image and the second toner image formed by the image forming means to the recording medium;
The fixing unit heats the recording medium on which the first toner image and the second toner image are fixed, so that the second clear toner of the second toner image is selectively plasticized. And
Cooling means for solidifying the second clear toner by cooling the recording medium in contact with the second clear toner plasticized by the plasticizing means;
An image forming system comprising:   The plasticizing means heats the recording medium to a temperature that is equal to or higher than the lower limit fixing temperature of the second clear toner and lower than the lower limit fixing temperature of the first clear toner. The image forming system according to claim 4, wherein the image forming system is selectively plasticized. The first clear toner and the color toner are included, the surface layer portion includes the first toner image made of the first clear toner, the second clear toner and the color toner, and the surface layer portion is the second clear toner. And an image forming step of forming a second toner image made of the colored toner on a recording medium;
A fixing step of fixing the first toner image and the second toner image formed by the image forming unit to the recording medium;
The fixing unit heats the recording medium on which the first toner image and the second toner image are fixed, and selectively selects the second clear toner and the colored toner of the second toner image. A plasticizing process for plasticizing;
A cooling step for solidifying the second clear toner and the colored toner by cooling the recording medium in contact with the second clear toner and the colored toner plasticized by the plasticizing means;
An image forming method comprising: The first clear toner and the color toner are included, the surface layer portion includes the first toner image made of the first clear toner, the second clear toner and the color toner, and the surface layer portion is the second clear toner. An image forming step of forming on the recording medium a second toner image comprising:
A fixing step of fixing the first toner image and the second toner image formed by the image forming unit to the recording medium;
The fixing unit heats the recording medium on which the first toner image and the second toner image are fixed, so that the second clear toner of the second toner image is selectively plasticized. Conversion process,
A cooling step of solidifying the second clear toner by cooling the recording medium in contact with the second clear toner plasticized by the plasticizing means;
An image forming method comprising: An image forming system program used in the image forming system according to claim 3,
In the image forming system,
A color image data generation process for generating color image data of an image formed by the color toner;
A calculation process for calculating an image area ratio of an image formed by the color toner based on the color image data generated by the color image data generation process;
A clear image data generation process for generating clear image data of an image formed by the second clear toner based on the image area ratio calculated by the calculation process;
An image forming system program for executing an image forming process for forming the second toner image based on the colored image data and the clear image data.

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