JP2018004897A - Image formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the convenience of printing following processing of covering a colored toner image with a transparent toner image.SOLUTION: An image formation apparatus includes: a printing unit which transfers a colored toner image on a sheet; a control unit which controls the operation of the printing unit; and a storage unit. The printing unit stores transparent toner for forming a transparent toner image. The storage unit stores at least one of the shape and color of a previously-registered image as a feature point. The control unit determines whether or not an object image being the image having the feature point exists in the colored toner image formed on the basis of the image data, causes the printing unit to perform covering processing of covering the object image with the transparent toner image when determining that the object image exists, and causes the printing unit not to perform covering processing when determining that the object image does not exist.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image forming apparatus that prints an image on a sheet.

  2. Description of the Related Art Conventionally, an image forming apparatus capable of forming a transparent toner image made of a transparent toner in addition to a colored toner image made of a colored toner such as cyan, magenta, yellow, and black is known (see, for example, Patent Document 1). . The transparent toner is a colorless and transparent toner (clear toner) that does not contain a color material.

  In an image forming apparatus such as Patent Document 1, when an image is printed on a sheet, the image (colored toner image) printed on the sheet can be covered with a transparent toner image. In other words, the toner images can be superimposed on the sheet in the order of the colored toner image and the transparent toner image.

  The covering process for covering the colored toner image with the transparent toner image is performed for the purpose of protecting the image printed on the paper, for example. Alternatively, by performing the covering process, it is possible to give a surface effect such as imparting gloss to the image printed on the paper or suppressing the gloss.

JP 2004-151269 A

  Some conventional image forming apparatuses capable of forming a transparent toner image are configured to accept from a user a selection as to whether or not to enable the gloss mode. When the image forming apparatus configured as described above executes a print job in a state where the gloss mode is set to be valid, the image forming apparatus performs a covering process on all sheets to be printed in the print job.

  Here, depending on the user, there is a case where it is desired to perform only a covering process for an image (colored toner image) having a desired shape and color. However, in the conventional image forming apparatus, when the print job is executed in the gloss mode, the covering process is performed not only on the paper on which the user-desired image is printed but also on the paper on which the user-desired image is not printed. Is called. Therefore, it is not convenient for a user who wants only to perform a covering process for a desired image.

  The present invention has been made to solve the above-described problems, and provides an image forming apparatus capable of improving the convenience of printing with a coating process for coating a colored toner image with a transparent toner image. Objective.

  In order to achieve the above object, an image forming apparatus of the present invention accommodates colored toner, forms a colored toner image using colored toner based on image data of an image to be printed, and forms the colored toner image on a sheet. The printing unit includes a transfer unit, a control unit that controls the operation of the printing unit, and a storage unit that stores information. The printing unit stores transparent toner for forming a transparent toner image. The storage unit stores at least one of the shape and color of an image registered in advance as a feature point. Then, the control unit determines whether or not the target image that is the image having the feature point exists in the colored toner image formed based on the image data, and determines that the target image exists. Covering the target image with the transparent toner image is performed by the printing unit, and when it is determined that the target image does not exist, the coating unit is not performed by the coating process.

  In the configuration of the present invention, only when the control unit determines that the target image (image having pre-registered feature points) is present in the colored toner image formed based on the image data, the printing unit performs the covering process. Done. That is, if the feature points of the user-desired image are registered in advance, the covering process is not performed on the paper on which the user-desired image is not printed, but only on the sheet on which the user-desired image is printed. Is done. Thereby, the convenience of printing with a covering process is improved.

  With the configuration of the present invention, it is possible to improve the convenience of printing that involves a coating process for coating a colored toner image with a transparent toner image.

1 is a schematic diagram illustrating an image forming apparatus according to an embodiment of the present invention. 1 is a block diagram showing an image forming apparatus according to an embodiment of the present invention. FIG. 6 is a diagram showing a registration screen displayed on the image forming apparatus according to the embodiment of the invention. 4 is a diagram showing a gloss setting screen displayed on the image forming apparatus according to the embodiment of the invention. FIG. 6 is a flowchart showing a flow of coating processing performed in the image forming apparatus according to the embodiment of the present invention.

  Hereinafter, an embodiment of the present invention will be described by taking an image forming apparatus (multifunction machine) having a plurality of functions such as a scan function and a print function as an example.

<Overall configuration of image forming apparatus>
As shown in FIG. 1, the image forming apparatus 100 of the present embodiment includes an image reading unit 1 and a printing unit 2. The image reading unit 1 optically reads a document and generates image data of the document. The printing unit 2 transports the paper P along the paper transport path 20. The printing unit 2 forms a toner image based on the image data of the image to be printed. Then, the printing unit 2 prints (transfers) the toner image on the paper P being conveyed. The printing unit 2 includes a paper feed unit 3, a paper transport unit 4, an image forming unit 5, an intermediate transfer unit 6, and a fixing unit 7.

  The paper feed unit 3 feeds the paper P stored in the paper cassette 21 to the paper transport path 20. The paper transport unit 4 transports the paper P fed to the paper transport path 20 in the order of the transfer position TP (transfer nip) and the fixing position FP (fixing nip).

  The image forming unit 5 includes a plurality (five) of image forming units 50. Each of the plurality of image forming units 50 includes one photosensitive drum 51, one charging device 52, one developing device 53, and one cleaning device 54. The image forming unit 5 includes an exposure device 55 that is shared by a plurality of image forming units 50. Each of the plurality of image forming units 50 forms a toner image on the corresponding photosensitive drum 51.

  Here, the plurality of image forming units 50 are four image forming units 50K, 50Y, 50C and 50M for forming a colored toner image, and 1 for forming a transparent toner image (colorless and transparent toner image). And image forming units 50CL. Note that unused toner of each color (four colored toners and transparent toner) is stored in the toner container 60 and supplied to the corresponding image forming unit 50 (developing device 53).

  The image forming unit 50K stores black toner in the corresponding developing device 53, and forms a black toner image using the black toner. The image forming unit 50Y accommodates yellow toner in the corresponding developing device 53 and forms a yellow toner image using the yellow toner. The image forming unit 50C accommodates cyan toner in the corresponding developing device 53, and forms a cyan toner image using the cyan toner. The image forming unit 50M stores magenta toner in the corresponding developing device 53, and forms a magenta toner image using the magenta toner.

  The image forming unit 50CL accommodates transparent toner (clear toner not including color material) in the corresponding developing device 53, and forms a transparent toner image using the transparent toner. For example, the transparent toner is a nonmagnetic developer made of a nonmagnetic toner (for example, a finely pulverized pulverized toner for developing an electrostatic latent image).

  The transparent toner contains at least one of an antifouling agent and an ultraviolet absorber (for example, the transparent toner contains an antifouling agent). As the antifouling agent, a polysiloxane resin containing polymethoxysiloxane, methanol (less than 10%), ethanol (40 to 50%) and water can be used. Further, Tinuvin 326 (trade name, manufactured by Ciba Specialty Chemicals Inc., maximum absorption wavelength 353 nm) and Tinuvin 1577 (trade name, manufactured by Ciba Specialty Chemicals Inc., maximum absorption wavelength 274 nm) can be used as the ultraviolet absorber.

  The intermediate transfer unit 6 includes an intermediate transfer belt 61, a primary transfer roller 62, and a secondary transfer roller 63. The primary transfer roller 62 sandwiches the intermediate transfer belt 61 with the photosensitive drum 51. The secondary transfer roller 63 forms a transfer nip (the position of the transfer nip is the transfer position TP) with the intermediate transfer belt 61. The intermediate transfer unit 6 firstly primarily transfers the toner image formed by the image forming unit 5 to the intermediate transfer belt 61, and then secondarily transfers the toner image to the paper P that has entered the transfer position TP.

  For example, in full-color printing, toner images of magenta, cyan, yellow, and black are sequentially formed in the image forming units 50M, 50C, 50Y, and 50K. Then, the toner images of the respective colors are transferred to the intermediate transfer belt 61 so as to overlap each other. That is, the full color toner image is transferred to the intermediate transfer belt 61. Thereafter, the full color toner image transferred to the intermediate transfer belt 61 is transferred to the paper P. In this case, the full color toner image corresponds to a “colored toner image”.

  In monochrome printing, a black toner image is formed in the image forming unit 50 </ b> K, and the black toner image is transferred to the intermediate transfer belt 61. Then, the black toner image transferred to the intermediate transfer belt 61 is transferred to the paper P. In this case, the black toner image corresponds to a “colored toner image”. In monochrome printing, the photosensitive drums 51 of the image forming units 50Y, 50C, and 50M are separated from the intermediate transfer belt 61.

  The fixing unit 7 includes a pair of fixing rollers (a heating roller and a pressure roller). The fixing roller pair is pressed against each other to form a fixing nip (the position of the fixing nip is the fixing position FP). The fixing unit 7 heats and pressurizes the paper P that passes through the fixing position FP, and fixes the toner image on the paper P. Thereafter, the fixed paper P is discharged to the in-body tray 22.

  Here, the paper transport path 20 includes a first transport path 2A and a second transport path 2B. The first transport path 2A reaches the in-body tray 22 from the paper cassette 21 via the transfer position TP and the fixing position FP in this order. The second transport path 2B branches from the first transport path 2A at a position downstream of the fixing position FP in the paper transport direction (that is, a position downstream of the transfer position TP in the paper transport direction), and is more than the transfer position TP. It joins the first transport path 2A at a position upstream in the paper transport direction. The second transport path 2B is used when performing double-sided printing.

  In addition, the image forming apparatus 100 includes an operation panel 8 (corresponding to an “operation display unit”). The operation panel 8 includes a touch panel display 81. The touch panel display 81 displays a screen for accepting various settings from the user. The operation panel 8 is provided with a plurality of hardware keys 82 such as a start key for receiving a job execution instruction from the user.

<Hardware configuration of image forming apparatus>
As illustrated in FIG. 2, the image forming apparatus 100 includes a control unit 110 that performs overall control of the image forming apparatus 100. The control unit 110 includes a processing device 111, an image processing unit 112, and a memory 113. The processing device 111 includes a processor such as a CPU or MPU. The image processing unit 112 includes a circuit dedicated to image processing, an ASIC, and the like, and performs various image processing (enlargement / reduction, density conversion, data format conversion, etc.) on the image data. The memory 113 includes a ROM, a RAM, and the like, and stores a control program and data. The control unit 110 controls the operation of each unit of the image forming apparatus 100 based on the control program and data.

  Specifically, the control unit 110 is connected to the image reading unit 1. The control unit 110 controls a document reading operation performed by the image reading unit 1.

  The control unit 110 is connected to the printing unit 2. Then, the control unit 110 performs an operation setting process for setting the operation condition of the printing unit 2 at the time of execution of the print job, and controls the printing operation of the printing unit 2 based on the setting content set by the setting process. .

  For example, the control unit 110 performs a process for setting the fixing temperature of the fixing unit 7 as an operation setting process for the printing unit 2. Note that the control unit 110 adjusts the fixing temperature of the fixing unit 7 to be a set temperature by switching on / off the energization of the heater 201 for heating the fixing unit 7. In addition, the control unit 110 performs a process of setting the rotation speed of the motor 202 for driving various rollers of the printing unit 2 that is responsible for feeding and transporting the paper P.

  Further, the control unit 110 is connected to the operation panel 8. Then, the control unit 110 controls the display operation of the touch panel display 81. In addition, the control unit 110 detects a touch operation on the touch panel display 81 and a press operation on the hardware key 82.

  The image forming apparatus 100 also includes a storage unit 120 for storing information. The storage unit 120 includes a nonvolatile storage device such as a ROM (such as an EEPROM) or an HDD. In the storage unit 120, for example, information indicating the feature points of the image desired by the user is stored. Details will be described later.

  In addition, the image forming apparatus 100 includes a communication unit 130 for connecting the image forming apparatus 100 and an external device so that they can communicate with each other. The communication unit 130 includes a communication circuit and a memory. For example, the communication unit 130 communicates with a personal computer (PC) 300 that is a user terminal used by a user of the image forming apparatus 100.

<Printing with coating>
In this embodiment, it is possible to execute a process (covering process) for protecting an image desired by the user (colored toner image) by covering the image with a transparent toner image. In printing involving coating, a user-desired image (colored toner image) is coated with a transparent toner image. For example, a logo mark image or a text image can be covered with a transparent toner image.

  In order to execute printing with covering processing, registration reception of feature points (at least one of image shape and color) desired by the user is performed in advance. Also, setting reception of glossiness (whether low glossiness or high glossiness) is performed in advance.

  For example, when an operation for shifting to the registration mode is performed on the operation panel 8, the control unit 110 shifts the image forming apparatus 100 to the registration mode. Then, the control unit 110 causes the operation panel 8 to display a message (not shown) for prompting reading of a document including an image having the same feature point as the user-desired image.

  Thereafter, when an operation for instructing reading of the document is performed on the operation panel 8 in the state of shifting to the registration mode, the control unit 110 causes the image reading unit 1 to read the document. Then, the control unit 110 displays a registration screen 810 as shown in FIG. On this registration screen 810, a registration operation for registering a feature point of an image desired by the user is accepted.

  The registration screen 810 is provided with a display area 811 for displaying an image based on the image data input as registration data to the image forming apparatus 100 in the registration mode. That is, when the original is read in the registration mode, the image of the original is displayed in the display area 811. In addition, a registration key 812 (software key) is arranged on the registration screen 810.

  The operation panel 8 accepts a designation operation for designating a user-desired image from images displayed in the display area 811 as one operation of the registration operation. For example, the operation panel 8 surrounds an image designated by the designation operation with a frame 811a (in FIG. 3, it is assumed that a text image “Kyocera” is designated). Although not particularly limited, a touch operation for moving the touch position so as to surround the image displayed in the display area 811 is accepted as the designation operation.

  Thereafter, when it is detected that an operation of touching the registration key 812 has been performed, the control unit 110 causes the storage unit 120 to store the feature points of the image designated by the immediately preceding designation operation. At this time, both the shape and color of the image specified by the specifying operation may be registered as feature points. Alternatively, only one of the shape and color of the image specified by the specifying operation may be registered as the feature point.

  Note that user-desired image data (registration data) may be transmitted from the PC 300 to the image forming apparatus 100. In this case, an image based on the image data transmitted from the PC 300 to the image forming apparatus 100 is displayed on the registration screen 810 (registration operation can be performed on the image).

  Further, the control unit 110 causes the operation panel 8 to display a gloss setting screen 820 as shown in FIG. For example, the glossiness setting screen 820 is displayed by operating the registration key 812 (see FIG. 3) on the registration screen 810. On this gloss level setting screen 820, a gloss level setting operation for setting the gloss level of an image desired by the user is accepted. In other words, the glossiness setting screen 820 is a screen for inputting glossiness information indicating whether to set the glossiness to a low glossiness or a high glossiness.

  On the gloss setting screen 820, setting keys K1 and K2 are arranged. The setting key K1 is a software key for accepting that the glossiness is set to a low glossiness, and the setting key K2 is a software key for accepting that the glossiness is set to a high glossiness. Note that a return key BK (software key) is arranged on the gloss setting screen 820. When an operation is performed on the return key BK, the display screen returns from the gloss setting screen 820 to the registration screen 810. Therefore, the operation for registering the feature points of the image desired by the user can be redone.

  The controller 110 sets the glossiness to a low glossiness when an operation is performed on the setting key K1, and sets the glossiness to a high glossiness when an operation is performed on the setting key K2. In this configuration, glossiness information is input to the image forming apparatus 100 via the operation panel 8. Therefore, the operation panel 8 corresponds to an “input unit”.

  Note that glossiness may be set by transmitting glossiness information from the PC 300 to the image forming apparatus 100 (communication unit 130). In this case, since glossiness information is input to the communication unit 130, the communication unit 130 corresponds to an “input unit”.

  When image data is input to the image forming apparatus 100 after registration processing (including processing for setting glossiness) for registering a feature point of a user-desired image is completed, the flowchart shown in FIG. 5 starts. In a copy job, image data of a document obtained by reading the document by the image reading unit 1 is input to the image forming apparatus 100. In a printer job, image data transmitted from the PC 300 is input to the image forming apparatus 100.

  In step S <b> 1, the control unit 110 determines whether or not a target image that is an image having a registered feature point exists in the color toner image formed based on the image data. In other words, the control unit 110 determines whether or not to cause the printing unit 2 to perform the covering process.

  When only the shape of the image is registered as the feature point, the control unit 110 recognizes an image having the same shape as the registered feature point (shape) as the target image. When only the color of the image is registered as the feature point, the control unit 110 recognizes an image having the same color as the registered feature point (color) as the target image.

  When both the shape and color of the image are registered as feature points, the control unit 110 recognizes an image having the same shape and color as the registered feature points (shape and color) as the target image. That is, even if an image having the same shape as a registered feature point exists, if the color of the image is different from the registered feature point, the image is not recognized as a target image. Conversely, even if an image having the same color as the registered feature point exists, the image is not recognized as the target image if the shape of the image is different from the registered feature point.

  If the control unit 110 determines in step S1 that the target image exists, the process proceeds to step S2. In step S2, the control unit 110 determines whether or not the glossiness indicated by the glossiness information is a low glossiness. As a result, when the control unit 110 determines that the gloss is low, the process proceeds to step S3. When the control unit 110 determines that the gloss is high (not low gloss), the process proceeds to step S4. Migrate to

  When the process proceeds to step S3, the control unit 110 sets the operation condition of the printing unit 2 to the setting for low glossiness. For example, the control unit 110 sets the fixing temperature of the fixing unit 7 to a predetermined temperature (default temperature). Further, the control unit 110 sets the conveyance speed of the paper P to a predetermined speed (default speed). In other words, the control unit 110 sets the operating conditions of the printing unit 2 to be the same as the operating conditions during normal printing. Thereafter, the process proceeds to step S5.

  On the other hand, when the process proceeds to step S4, the control unit 110 sets the operation condition of the printing unit 2 for high glossiness. For example, the control unit 110 sets the fixing temperature of the fixing unit 7 to a predetermined high gloss temperature that is higher than a predetermined temperature. Alternatively, the control unit 110 sets the conveyance speed of the paper P to a predetermined high gloss speed that is slower than a predetermined speed. When the operation condition of the printing unit 2 is set for high glossiness, only one of the fixing temperature of the fixing unit 7 and the conveyance speed of the paper P may be changed to the setting for high glossiness. However, both may be changed to a setting for high glossiness. Thereafter, the process proceeds to step S5.

  In step S5, the control unit 110 recognizes the mixing ratio of each color of CMYK when reproducing the color of the target image using cyan, magenta, yellow, and black, and the mixing ratio of the predetermined color among the colors of CMYK is determined in advance. It is determined whether or not a predetermined threshold value is exceeded. As a result, when the control unit 110 determines that the mixing ratio of the predetermined color is less than the threshold value, the process proceeds to step S6. On the other hand, when the control unit 110 determines that the mixing ratio of the predetermined color is equal to or greater than the threshold value, the process proceeds to step S7. The predetermined color is preset and stored in the storage unit 120 as color information. For example, a color that easily fades (cyan or yellow) is set as the predetermined color.

  When the process proceeds to step S6, the control unit 110 sets the thickness of the transparent toner image for covering the target image to a predetermined first thickness. On the other hand, when the process proceeds to step S7, the control unit 110 sets the thickness of the transparent toner image for covering the target image to a predetermined second thickness that is larger than the first thickness. That is, the higher the mixing ratio of the predetermined color when reproducing the color of the target image, the larger the thickness of the transparent toner image for covering the target image.

  The exposure device 55 forms an electrostatic latent image on the photosensitive drum 51 by irradiating the photosensitive drum 51 with laser light, and the developing device 53 forms a toner image by supplying toner to the electrostatic latent image. To do. When a toner image is formed in this way, the amount of toner (the thickness of the toner image formed on the photosensitive drum 51) placed on the photosensitive drum 51 can be changed by the amount of laser light emitted from the exposure device 55. it can. Therefore, for example, the light emission amount of the laser light emitted from the exposure device 55 may be set as the thickness setting of the transparent toner image.

  After setting the thickness of the transparent toner image, the process proceeds to step S8. In step S8, the control unit 110 causes the printing unit 2 to perform printing with a covering process. At this time, when the glossiness is set to a high glossiness, the fixing temperature of the fixing unit 7 becomes higher (or the conveyance speed of the paper P is slower) than when the glossiness is set to a low glossiness. Therefore, the glossiness becomes high. In addition, when the mixing ratio of the predetermined color in the target image is equal to or greater than the threshold, the thickness of the transparent toner image is larger than when the ratio is less than the threshold.

  If the control unit 110 determines in step S1 that the target image does not exist, the process proceeds to step S9. In step S9, the control unit 110 causes the printing unit 2 to perform normal printing (printing without covering processing). That is, in this case, the coating process is not performed (a transparent toner image is not formed).

  Here, there are a first mode and a second mode as execution modes of printing accompanied by the covering process. When the control unit 110 receives a print execution instruction with a covering process, the control unit 110 selects one of the first mode and the second mode, and causes the printing unit 2 to execute printing in the selected mode. .

  When performing printing in the first mode, the printing unit 2 feeds the paper P from the paper cassette 21 to the first transport path 2A and transports the paper P along the first transport path 2A. As a result, the sheet P being conveyed passes through the transfer position TP and the fixing position FP in this order. Then, when the paper P being conveyed passes through the transfer position TP (at the first pass), the printing unit 2 first transfers the colored toner image onto one surface of the paper P.

  Thereafter, the printing unit 2 sends the paper P that has passed through the fixing position FP (the paper P on which the colored toner image is transferred on one side) to the second transport path 2B, and sends the paper P along the second transport path 2B. It returns to 2 A of 1st conveyance paths by conveying. At this time, the printing unit 2 does not perform processing for executing double-sided printing (switching back the paper P). For this reason, the front and back of the paper P returned to the first transport path 2A are not reversed.

  Subsequently, the printing unit 2 conveys the paper P returned to the first conveyance path 2A (the paper P with the colored toner image transferred on one side) along the first conveyance path 2A. As a result, the sheet P being conveyed passes through the transfer position TP and the fixing position FP again in this order. Then, when the paper P passes the transfer position TP (at the second pass), the printing unit 2 transfers the transparent toner image to one surface of the paper P, thereby covering the target image with the transparent toner image. .

  On the other hand, in the second mode, the color toner image and the transparent toner image are superimposed on the intermediate transfer belt 61, and the color toner image and the transparent toner image are simultaneously transferred onto the paper P.

  When printing in the second mode, the printing unit 2 first forms a transparent toner image and transfers the transparent toner image to the intermediate transfer belt 61. Subsequently, the printing unit 2 forms toner images of respective colors in the order of cyan, magenta, yellow, and black. In addition, the printing unit 2 sequentially transfers cyan, magenta, yellow, and black toner images to the area where the transparent toner image of the intermediate transfer belt 61 is transferred. Then, the printing unit 2 transfers the color toner image and the transparent toner image transferred to the intermediate transfer belt 61 onto the paper P at the transfer position TP. As a result, the target image is covered with the transparent toner image.

  In the configuration of the present embodiment, as described above, only when the control unit 110 determines that a target image (an image having a pre-registered feature point) exists in the colored toner image formed based on the image data. Covering processing is performed in the printing unit 2. That is, if the feature points of the user-desired image are registered in advance, the covering process is not performed on the paper P on which the user-desired image is not printed, but only on the paper P on which the user-desired image is printed. A coating process is performed. Thereby, the convenience of printing with a covering process is improved.

  Here, when comparing a coated print image (colored toner image coated with a transparent toner image) and a non-coated print image, there is almost no difference in color reproducibility immediately after printing. It becomes good. However, as time progresses (for example, after several years to several tens of years), a print image that has not been coated has poor color reproducibility and more image defects than a printed image that has been coated. . Therefore, it is effective to perform the covering process in order to protect the image desired by the user.

  Further, in the present embodiment, as described above, by simply designating a user-desired image from among the images displayed on the operation panel 8, at least one of the shape and color of the designated image is registered as a feature point. The According to this configuration, since it is not necessary to perform a complicated operation when performing printing with a covering process, convenience for the user is improved.

  In this embodiment, as described above, the thickness of the transparent toner image that covers the target image increases as the mixing ratio of the predetermined color (yellow or cyan that easily fades) when reproducing the color of the target image is higher. Is done. With this configuration, the target image can be prevented from fading.

  Here, the print image (herein referred to as the first image) that has been coated so that the thickness of the transparent toner image becomes the first thickness (for example, 5 μm) and the thickness of the transparent toner image are larger than the first thickness. When compared with a printed image (referred to herein as a second image) that has been coated so as to have a thickness (for example, 20 μm), there is almost no difference in color reproducibility immediately after printing, and both are good. However, as the aging progresses (for example, when about several to several tens of years have passed), the first image is less saturated than the second image. Therefore, it is preferable to increase the thickness of the transparent toner image when the mixing ratio of a predetermined color (yellow or cyan that easily fades) necessary for color reproduction of the target image is high. If the target image is not covered, the color reproducibility deteriorates and many image defects occur as the aging progresses (the image quality decreases to an unacceptable level).

  In the present embodiment, as described above, when the glossiness indicated by the glossiness information is high glossiness, the fixing temperature is set to a temperature higher than the predetermined temperature, and the conveyance speed is set to be higher than the predetermined speed. Also, at least one of the processes of setting at a slower speed is performed. With this configuration, the glossiness of the target image can be easily set to the glossiness desired by the user (without complicating the structure of the image forming apparatus 100). In addition, the user can select whether the glossiness of the target image is low glossiness or high glossiness, which is convenient. Note that a coated print image (colored toner image coated with a transparent toner image) has a higher gloss than a print image that has not been coated, and a decrease in gloss over time is small.

  Further, in the present embodiment, as described above, printing with a covering process is performed in any one of the first mode and the second mode. When printing in the first mode, the transfer of the colored toner image onto the paper P and the transfer of the transparent toner image onto the paper P are performed separately (the transparent toner image is mounted later), so that the output image It can be made clearer. When printing in the second mode, the transport path of the paper P is shortened (the second transport path 2B is not used), so that printing can be completed promptly.

  In the present embodiment, as described above, since the antifouling agent is contained in the transparent toner, it is possible to suppress the smearing of the printed image. Further, since the light resistance is improved by using a transparent toner containing an antifouling agent, it is possible to suppress discoloration of a printed image and damage to the paper P due to ultraviolet rays or the like. Only one of the antifouling agent and the ultraviolet absorber may be contained in the transparent toner, or both may be contained in the transparent toner.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is shown not by the description of the above-described embodiment but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, as an image forming unit for forming a transparent toner image, a unit that stores a toner for low glossiness, and a unit that stores a toner for high glossiness that has a higher glossiness than when a toner for low glossiness is used. May be provided in the image forming apparatus 100. In such a configuration, when the glossiness indicated by the glossiness information is a low glossiness, the control unit 110 causes the low glossiness toner to be used when the printing unit 2 forms a transparent toner image. On the other hand, when the glossiness indicated by the glossiness information is a high glossiness, the control unit 110 causes the high glossiness toner to be used when the printing unit 2 forms a transparent toner image.

  The developing device of the image forming unit for transparent toner may be replaceable. As a result, a transparent toner image can be formed using a transparent toner having a component (for example, glossiness) different from that of the currently accommodated transparent toner. For example, a matte toner that can suppress gloss may be used as the transparent toner.

2 Printing section 7 Fixing section 8 Operation panel (operation display section, input section)
20 Paper transport path 61 Intermediate transfer belt 110 Control unit 120 Storage unit 130 Communication unit (input unit)

Claims (8)

A printing unit that stores the color toner, forms a color toner image using the color toner based on image data of an image to be printed, and transfers the color toner image to a sheet;
A control unit for controlling the operation of the printing unit;
A storage unit for storing information,
The printing unit contains a transparent toner for forming a transparent toner image,
The storage unit stores at least one of the shape and color of an image registered in advance as a feature point,
The control unit determines whether or not a target image that is an image having the feature point exists in the colored toner image formed based on the image data, and determines that the target image exists. The covering unit is configured to cover the target image with the transparent toner image, and when it is determined that the target image does not exist, the covering unit is not allowed to perform the covering process. Image forming apparatus. It has an operation display unit that accepts operations from users,
The operation display unit displays an image based on image data input as registration data on the image forming apparatus, accepts a designation operation for designating a user-desired image from the displayed images,
The image forming apparatus according to claim 1, wherein the control unit causes the storage unit to store at least one of the shape and color of the image designated by the designation operation as the feature point. The printing unit stores a plurality of color toners including a predetermined color as the colored toner,
The control unit recognizes the mixing ratio of the plurality of colors when reproducing the color of the target image, and increases the thickness of the transparent toner image covering the target image as the mixing ratio of the predetermined color increases. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. Glossiness information indicating whether the glossiness of the target image is low glossiness or high glossiness is input,
The printing unit includes a fixing unit, and transports the paper on which the toner image is transferred to the fixing unit, thereby fixing the toner image transferred on the paper to the paper,
When the gloss level indicated by the gloss level information is the low gloss level, the control unit sets a fixing temperature of the fixing unit to a predetermined temperature, sets a sheet conveyance speed to a predetermined speed, and sets the gloss level. When the gloss level indicated by the degree information is the high gloss level, a process of setting the fixing temperature to a temperature higher than the predetermined temperature, and a process of setting the transport speed to a speed slower than the predetermined speed; The image forming apparatus according to claim 1, wherein at least one of the two is performed. Glossiness information indicating whether the glossiness of the target image is low glossiness or high glossiness is input,
The printing unit contains, as the transparent toner, a low-gloss toner and a high-gloss toner that has a higher gloss than when the low-gloss toner is used,
When the glossiness indicated by the glossiness information is the low glossiness, the control unit causes the low glossiness toner to be used when the transparent toner image is formed by the printing portion, and is indicated by the glossiness information. 4. The high glossiness toner is used when the transparent toner image is formed by the printing unit when the glossiness is the high glossiness. 5. Image forming apparatus. A first conveyance path that passes through a transfer position for transferring a toner image to a sheet, and a position branched downstream from the first conveyance path at a position downstream of the transfer position in the sheet conveyance direction, the sheet conveyance direction from the transfer position. A second transport path that merges with the first transport path at an upstream position;
The printing unit conveys the paper along the first conveyance path when the target image exists, and transfers the colored toner image onto the paper passing through the transfer position, and then the colored toner image is transferred. By transporting the printed paper along the second transport path, the paper on which the color toner image has been transferred is returned to the upstream side of the first transport path in the paper transport direction, and the transfer position is The image forming apparatus according to claim 1, wherein the transparent toner image is transferred to a sheet that passes again. The printing unit includes an intermediate transfer belt that contacts the paper at a transfer position for transferring the toner image to the paper,
When the target image is present, the printing unit transfers the transparent toner image to the intermediate transfer belt, and then transfers the colored toner image to an area of the intermediate transfer belt where the transparent toner image is transferred. The image forming apparatus according to claim 1, wherein the colored toner image and the transparent toner image transferred to the intermediate transfer belt are transferred to a sheet at the transfer position.   The image forming apparatus according to claim 1, wherein the transparent toner contains at least one of an ultraviolet absorber and an antifouling agent.

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