Image formation apparatus

Abstract

To solve such a problem that, when jobs with large toner adhesion amounts through borderless printing are repeated, residual toner accumulates, device failure or image contamination on subsequent sheets due to toner re-transfer may occur.SOLUTION: An image formation apparatus according to the present invention is the image formation apparatus capable of executing a borderless printing job in which a toner image is formed on an edge portion of a recording material and a bordered printing job in which no toner image is formed on the edge portion of the recording material, and includes execution means (21) for executing a cleaning operation in which the interior of the image formation apparatus is cleaned by a sheet conveyed during non-image formation, and display control means for controlling display on a display unit (112) that displays a screen. When a borderless printing job is accepted, the display control means displays a warning screen (700) prompting execution of the cleaning means on the basis of job information of the printing job.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus that forms an image on a recording material. [Background technology]

[0002] In recent years, in order to increase the added value of finished products, image forming devices using electrophotography and other technologies have been required to produce not only typical bordered prints, which have margins around the edges of the recording material, but also borderless prints, in which an image is formed on the entire surface of the recording material without any margins. Borderless printing refers to prints that have no margins around at least a portion of the edges of the recording material. To print borderless, an image must be formed on a size larger than the recording material and transferred to the recording material. However, when an image is formed on a size larger than the recording material and transferred to the recording material, toner adheres to the edges, which are the thicker portions of the recording material. Toner adhered to the edges of the recording material is difficult to fix to the recording material and easily peels off when touched, resulting in toner adhering to areas other than the recording material and causing smearing.

[0003] Patent Document 1 proposes a technique in which a cleaning unit capable of contacting and separating from a fixing member is provided to clean the fixing member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-139881 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in jobs that require borderless printing and involve a large number of sheets, large volumes of recording material pass through the fixing nip and conveyance path in succession. Cleaning devices such as those described in Patent Document 1 are unable to completely remove toner that has adhered near the edges of the recording material, and the toner remains on the fixing member, conveyance path, and other areas within the device. Repeated borderless printing jobs with large amounts of toner adhesion can cause the remaining toner to accumulate, leading to device malfunctions and image contamination due to toner retransfer to subsequent sheets. [Means for solving the problem]

[0006] In consideration of the above problems, the image forming apparatus of the present invention is an image forming apparatus capable of executing a borderless print job that forms a toner image on the edge of a recording material, and a bordered print job that does not form a toner image on the edge of a recording material, and is characterized by comprising: an execution means that performs a cleaning operation that cleans the inside of the image forming apparatus using paper that is transported when no image is being formed; a display control means that controls the display on a display unit that displays a screen; and when a borderless print job is accepted, the display control means displays a warning screen that prompts the execution of the cleaning operation based on the printing information of the print job. [Effects of the Invention]

[0007] According to the present invention, even in the case of a job in which a large amount of toner adheres due to borderless printing, the user can be notified before a device malfunction or image stains on subsequent sheets become apparent, and the toner that has adhered and accumulated inside the main device can be properly removed. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of an image forming apparatus according to an embodiment of the present invention; [Figure 2] Control block diagram of an image forming apparatus according to the present embodiment [Figure 3] 1 is a diagram illustrating the configuration of a fixing device 100 according to the present embodiment. [Figure 4] Flowchart explaining the operation of the first embodiment [Figure 5] An example of an operation panel screen for explaining the operation of the first embodiment [Figure 6] An example of an operation panel screen for explaining the operation of the first embodiment [Figure 7] Flowchart explaining the operation of the second embodiment [Figure 8] Flowchart explaining the operation of the third embodiment [Figure 9] Illustration of borderless printing [Figure 10] Flowchart explaining the operation of the fourth embodiment DETAILED DESCRIPTION OF THE INVENTION

[0009] An image forming apparatus and fixing temperature control according to the present invention will be described below.

[0010] It should be noted that the numerical values ​​and structural conditions shown in the following embodiments are for reference only and do not limit the present invention. [Example]

[0011] 1 is a cross-sectional view of an image forming apparatus. In this example, an image forming apparatus that forms an image using an electrophotographic process will be described.

[0012] Inside the image forming apparatus, a sheet feeding mechanism 7, an image forming section 5, and a fixing device 100 are arranged in this order from the upstream side to the downstream side of the recording material conveying path.

[0013] 2, the image forming apparatus is provided with an operation panel 112 that serves as an interface for communication between a control unit 21, represented by a CPU, and a user or external device, and for accessing the apparatus. The operation panel is configured so that a display unit that displays a screen and a reception unit that receives user instructions are overlapped, and it is possible to receive user instructions on the screen displayed on the operation panel. The display of the screen on the display unit is controlled by the control unit 21, which functions as a display control unit.

[0014] An operation panel 112 functions as an interface for a user to access the apparatus. A control unit 21 monitors and controls the status of various parts of the apparatus, including the image forming unit 5, the sheet feeding mechanism 7, the sheet transport path 10, and the fixing device 100, and also controls the command system between each device, thereby coordinating the operation of the entire image forming apparatus.

[0015] The operation panel 112 has a sheet information acquisition means 143, an image information acquisition means 144, and a job information acquisition means 145. The sheet information acquisition means 143 acquires sheet information such as basis weight, surface properties, size, etc. input by the user as print job information. The image information acquisition means 144 acquires basic setting information for image information such as density. The job information acquisition means 145 acquires job information such as the number of prints for the job, double-sided / single-sided information, and a "borderless printing mode" in which an image is formed and printed on the entire surface of the sheet without leaving any margins around the edges.

[0016] In this embodiment, a job refers to printing data that has been converted into a format that can be processed by the control unit 21, and as described above, includes not only print commands and print data for the control unit 21, but also information such as the number of sheets to be printed and the paper type of the sheets.

[0017] An example of borderless printing will now be described using FIG. 9. The image forming apparatus in this embodiment is capable of both bordered and borderless printing, and switches between bordered and borderless printing based on job information. First, bordered printing is printing in which an image is formed with margins on all four sides of the recording material. In contrast, borderless printing refers to a printed matter in which no margins are provided on at least some of the edges of the recording material. There are multiple variations of borderless printing, including one in which the image is formed all the way to the edges of the entire surface (all four sides) of the recording material. Other variations include one in which the image is formed all the way to the edges of the short sides of the recording material, one in which the image is formed all the way to the edges of the long sides of the recording material, and one in which the image is formed all the way to the edges of three sides of the recording paper.

[0018] (Image forming section) The photosensitive drum 101 is an image carrier and is rotated counterclockwise as indicated by the arrow at a predetermined process speed (peripheral speed). During the rotation of the photosensitive drum 101, the photosensitive drum 101 is charged to a predetermined polarity by a charging device 102 such as a charging roller.

[0019] Next, the charged surface of the photosensitive drum 101 is exposed based on the input image information by a laser beam 103 output from a laser optical system 110. The laser optical system 110 outputs the laser beam 103 modulated (on / off) in response to time-series electric digital pixel signals of target image information from an image signal generating device such as an image reading device (not shown), thereby scanning and exposing the surface of the photosensitive drum 101. As a result, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 101 by this scanning and exposure. A deflection mirror 109 deflects the laser beam 103 output from the laser optical system 110 to an exposure position on the photosensitive drum 101.

[0020] The electrostatic latent image formed on the photosensitive drum 101y is visualized with yellow toner by a yellow developing device in the developing device 104. This yellow toner image is transferred onto the surface of the intermediate transfer body 105 at a primary transfer portion 111y, which is the contact portion between the photosensitive drum 101y and the intermediate transfer body 105. Note that the toner remaining on the surface of the photosensitive drum 101y is cleaned by a drum cleaner 107y.

[0021] During bordered printing, an electrostatic latent image narrower than the sheet is formed on the surface of the photosensitive drum 101, and during borderless printing, an electrostatic latent image wider than the recording material is formed on the surface of the photosensitive drum 101. This allows for the formation of a typical bordered sheet with a margin provided at the edge of the sheet, and a borderless sheet with an image formed on the entire surface of the sheet.

[0022] Note that Py is a yellow image forming unit, Pm is a magenta image forming unit, Pc is a cyan image forming unit, and Pk is a black image forming unit, which form images of the corresponding colors.

[0023] When printer job information is input to the control unit 21 from the operation panel 112 and an image forming process is instructed, the separation roller (feed roller) 8a or 8b of the cassette 7a or 7b containing sheets of the specified size is driven. As a result, the sheets P are separated one by one from the cassette 7a or 7b and introduced into the secondary transfer unit 106 of the image forming unit 5 through the sheet conveying path 10 having conveying rollers 9a or 9b and 9a.

[0024] The multicolor toner images formed in succession on the intermediate transfer body 105 are secondarily transferred all at once onto the introduced recording material in the secondary transfer section 106. The toner remaining on the intermediate transfer body 105 is cleaned by an intermediate transfer body cleaner 108.

[0025] The sheet that has passed through the secondary transfer unit 106 is introduced into the fixing device 100, which serves as an image heating device, and undergoes a fixing process (image heating process) for the unfixed toner image carried thereon. Then, the sheet that has undergone the fixing process is discharged outside the machine, and a series of image forming operations is completed.

[0026] (fixing device) FIG. 3 is a cross-sectional view of the fixing device 100. As shown in FIG.

[0027] Reference numeral 20 denotes a cylindrical fixing belt (endless belt) equipped with an elastic layer, and pressure roller 22 is a pressure roller serving as a rotating pressure member that forms a fixing nip between itself and the fixing belt. Reference numeral 16 denotes a fixing heater serving as a heating element, and reference numeral 17 denotes a heat-resistant heater holder having a generally trough-shaped cross section. The fixing belt 20 is adhesively fixed to the underside of heater holder 17 along its length, allowing it to slide against the fixing belt. The fixing belt 20 is fitted around the heater holder 17.

[0028] The fixing belt 20 has a cylindrical substrate made of cylindrical stainless steel with a thickness of approximately 30 μm, on which a silicone rubber layer (elastic layer) with a thickness of approximately 300 μm is formed, and the surface is covered with a PFA resin tube (outermost layer) with a thickness of approximately 30 μm.

[0029] The pressure roller 22 has a structure in which an approximately 2.5 mm thick silicone rubber layer and an approximately 50 μm thick PFA resin tube are laminated on the surface of an Fe core metal. Both ends of the core metal of the pressure roller 22 are rotatably held between both side plates of the fixing device 100.

[0030] A fixing unit including a fixing heater 16, a heater holder 17, and a fixing belt 20 is installed above the pressure roller 22. This fixing unit is installed parallel to the pressure roller 22 so that the fixing heater 16 side is in contact with the pressure roller 22.

[0031] The heater holder 17 is made of a highly heat-resistant liquid crystal polymer resin and serves to hold the fixing heater 16 and guide the orbit of the fixing belt 20. Both ends of the heater holder 17 are urged in the axial direction of the pressure roller 22 with a force of 157 N on each side and a total pressure of 314 N by a pressure mechanism (not shown). As a result, the surface of the fixing heater 16 is pressed against the elastic layer of the pressure roller 22 via the fixing belt 20 with a predetermined pressing force, forming a fixing nip 27 of a predetermined width required for fixing. In this embodiment, the fixing belt 20 is a heating rotor that applies heat to the recording material transported through the fixing nip 27.

[0032] The fixing heater 16 has a resistance heating element B, which is made by applying a conductive paste containing a silver-palladium alloy to a ceramic substrate made of alumina or aluminum nitride in the form of a uniform film about 10 μm thick by screen printing. Furthermore, a glass coating is applied to the heating element to ensure pressure resistance.

[0033] A thermistor 19 is a temperature detection means. The thermistor 19 is arranged near the center of the belt width direction, where recording materials of all sizes pass, and detects the temperature of the heater 16. The thermistor controls the power supplied to the heater 16 so that the temperature detected by the central thermistor becomes the target temperature.

[0034] (Cleaning section) The fixing belt cleaning device 30 removes toner (offset toner) transferred to the fixing belt 20 by rubbing a cleaning web 31 against the fixing belt 20. The cleaning web 31 is pressed against a pressure roller 32 and rubs against the circumferential surface of the fixing belt 20, thereby collecting offset toner from the fixing belt 20 onto the cleaning web 31. The cleaning web 31 is pulled from the supply roller and gradually wound around a take-up roller 33, with a new web surface contacting the surface of the fixing belt 20. Because of its function of collecting offset toner, the cleaning web 31 is preferably made of thin, soft fiber paper that is less likely to scratch the fixing member surface. In this embodiment, paper made of aramid fiber is used as the cleaning web 31. While this embodiment describes a configuration in which the cleaning web 31 contacts the fixing belt 20, this is not a limitation. A metallic rotating member that contacts the fixing belt and rotates in accordance with the rotation of the fixing belt may be provided, and the cleaning web 31 may contact this rotating member. The cleaning web 31 wipes off the offset toner adhering to the rotating member, thereby recovering the offset toner. This prevents damage to the fixing belt 20 due to friction with the cleaning web. The timing of the cleaning operation by the cleaning web 31 can be controlled by controlling the contact of the cleaning web, and the cleaning operation by the cleaning web 31 is performed at least while paper is passing through the fixing nip.

[0035] In the case of a job that requires borderless printing and requires a large number of sheets, a large number of sheets pass through the fixing nip and the conveyance path in succession, and the offset toner near the edges exceeds the capacity that can be retained on the surface of the cleaning web 31, and passes over the surface of the cleaning web 31. As a result, the offset toner that was not completely removed on the surface of the cleaning web 31 is re-transferred to the surface of the fixing belt 20 and remains there.

[0036] Therefore, in this embodiment, the edge offset toner amount X per unit width perpendicular to the sheet conveyance direction, which is assumed in advance based on the surface property, basis weight, size information, and image information of the sheet, is calculated. Then, for a job in which the sum of the cumulative offset toner amount Xt and the edge offset toner amount exceeds a threshold value T, a warning process is performed to prompt a paper cleaning operation, which will be described later.

[0037] Here, we will explain the amount of toner formed on the sheet. The image data input to the image forming unit is 600 dpi data of 0 to 255 separated into the C, M, Y, and K colors of the image that will become the original. This data per pixel is called the image data amount. The maximum image data amount for each color is expressed as 100%. The amount of toner to be used in forming the image is calculated according to this image data amount of 0 to 100%. The toner amount is the amount of toner per pixel that will form the image on the recording material. Like the image data amount, the toner amount is also expressed as 0 to 100%. Area 1 cm 2 The total weight of the toner image formed in the area is expressed as the applied amount [mg / cm 2 When the toner amount for a single color is 100%, that color has the maximum toner amount and the maximum density. In this embodiment, the maximum toner amount for each color is 0.4 mg / cm. 2 In addition, if the total of all colors exceeds the maximum of 250%, the toner amount of each color is adjusted to 250% or less. Therefore, the maximum total amount of all color toner is 1.0 mg / cm 2 This becomes:

[0038] In this embodiment, the maximum toner amount Cmax [mg / mm] per unit width length formed on the sheet edge portion is calculated based on the image data amount distribution information, sheet information, and job information. The sheet edge portion here refers to the image data area equivalent to ±5 mm from the sheet edge position in the direction perpendicular to the sheet conveyance direction. In this embodiment, ±5 mm was set in consideration of the registration accuracy position of the image forming device used. Specifically, the toner amount is calculated in an area of ​​each division width x 10 x two locations on both ends, divided in 1 mm increments in the direction perpendicular to the sheet conveyance direction, and the maximum value is taken as Cmax. If the calculation coefficient for the offset toner amount in each sheet information is A, the offset toner amount X is

[0039]

number

[0040] [Table 1]

[0041] Table 1 shows the coefficient A for calculating the amount of offset toner for each sheet information. The lower the surface roughness of the sheet, i.e., the higher the glossiness of the sheet, the larger the coefficient A. This is because the lower the surface roughness of the sheet, i.e., the higher the glossiness, the more toner is used to form the image, and the greater the amount of offset toner. When borderless printing is performed, the amount of offset toner near the edges of the recording paper also increases for the same reason.

[0042] Furthermore, the greater the basis weight of the sheet, the larger the coefficient A. This is because when the basis weight of a sheet is large, the sheet itself has a high heat capacity, making it difficult for heat to be transferred during fixing, which increases the amount of offset toner. When borderless printing is performed, the edge area of ​​the sheet, which is the thickness of the sheet, increases, so the amount of offset toner near the edge increases.

[0043] In the borderless print job of the image formation flow described later in this embodiment, 100 sheets of A3 size "OK Topcoat +127.9" (manufactured by Oji Paper Co., Ltd.) were passed through. Also, the image data amount of 250% or 1.0 [mg / cm 2 ] was set to the entire area of ​​the sheet. 2 In this setting, Cmax is maximum in the division width region corresponding to the side edge portion.

[0044] The length of A3 size paper in the transport direction is 420 mm, and from Table 1, A = 1.3, so in the above print job

[0045]

number

[0046] Furthermore, the cumulative offset toner amount Xt at the time the borderless print job was received was 100. Furthermore, based on the allowable amount that can be held on the surface of the cleaning web in the fixing device of this embodiment, the threshold value T was set to 600. From the above, since Xt + X = 646 > T, it can be determined that the paper passing cleaning operation described below is necessary.

[0047] (Image formation flow) FIG. 4 shows a flowchart of the paper passing cleaning operation warning mode in this embodiment.

[0048] First, in step S101, the control unit 21 acquires printer job information, sheet information, and image information input from the operation panel 112.

[0049] In step S102, it is determined whether borderless printing has been specified based on the job information acquired in step S101, and if borderless printing has been specified, the process proceeds to step S103; otherwise, the process proceeds to step S110.

[0050] In step S103, the control unit 21 executes borderless printing processing.

[0051] In step S104, the control unit 21 calculates the edge offset toner amount X based on the sheet information and image information. Then, it calculates the cumulative offset toner amount Xt + edge offset toner amount X. Here, the cumulative offset toner amount Xt is the cumulative amount of offset toner in jobs executed before the current job since the previous reset. In this embodiment, borderless print jobs executed before the current job since the previous reset are assumed, but this is not limiting. The reason why bordered print jobs are not included in the calculation is that it is assumed that the offset toner calculated for bordered print jobs will be removed each time by cleaning using the cleaning web 31.

[0052] In step S105, the control unit 21 determines whether a warning is necessary to prompt a sheet cleaning operation based on the cumulative offset toner amount Xt+X calculated from the sheet surface property, basis weight, and size information and a preset threshold value T. If a warning is necessary, the process proceeds to step S106; if a warning is not necessary, the process ends. In this embodiment, the determination of whether to issue a warning to prompt a sheet cleaning operation is based on the relationship between the calculated toner amount and the preset threshold value T, but this is not limited to this. For example, a sheet cleaning warning may be issued when the number of borderless printed sheets reaches a predetermined number. Furthermore, even if the offset toner amount is not calculated, a sheet cleaning warning may be issued when at least one of the conditions, such as the sheet surface property, basis weight, size information, and image information, meets a predetermined condition.

[0053] In step S106, the control unit 21 performs a warning process to prompt the user to perform paper-passing cleaning. Specifically, the control unit 21 displays a paper-passing cleaning warning display or a paper-passing cleaning execution selection screen shown in FIG. 5 on the operation panel 112. Here, the paper-passing cleaning execution selection screen is also referred to as a cleaning execution screen. For example, the paper-passing cleaning warning display shown in FIG. 5(a) may be displayed while printing is in progress, without waiting for the completion of borderless printing. Then, the control unit 21 may display the paper-passing cleaning execution selection screen shown in FIG. 5(b) when the close button 701 in FIG. 5(a) is pressed, or when borderless printing is completed.

[0054] In step S107, the control unit 21 determines whether or not to perform the paper-passing cleaning operation based on the user selection information input from the operation panel 112. If the paper-passing cleaning operation is to be performed, the process proceeds to step S108; otherwise, the process ends.

[0055] In step S108, the control unit 21 executes the paper passing cleaning operation, which is executed after the job executed in S103 is completed.

[0056] In step S109, the control unit 21 clears the cumulative toner offset amount counter.

[0057] In step S110, the control unit 21 performs a bordered printing process.

[0058] 5 is an explanatory diagram showing an example of warning processing in this embodiment. In step S105, as shown in FIG. 5(a), the control unit 21 displays a warning screen 700 on the operation panel 112 or the device 300. The wording written on the warning screen 700 is an example and is not limited to this. When the close button 701 is selected, the warning screen 700 is closed. In step S108, as shown in FIG. 5(b), the control unit 21 displays a warning screen 710 on the operation panel 112 or the device 300. When an operation key 711 is selected, the control unit 21 displays a paper passing cleaning operation processing screen, which will be described later. When an operation key 712 is selected, the control unit 21 closes the warning screen 711 without performing the paper passing cleaning operation.

[0059] 6 is an explanatory diagram showing an example of the paper passing cleaning operation processing in this embodiment. In step S110, as shown in FIG. 6, the control unit 21 displays a paper passing cleaning operation processing screen 730 on the operation panel 112 or the device 300. When an operation key 731 is selected, the control unit 21 executes the paper passing cleaning operation.

[0060] (Paper passing cleaning operation) When a command to execute the paper cleaning operation is input to the control unit 21, the first cleaning paper is fed from the sheet feeding mechanism 7. Here, for example, a single sheet of paper 13 inches wide is used as the cleaning paper. The type and number of cleaning paper sheets are not limited to this, as long as it is possible to remove offset toner inside the device. In cases where there are multiple paper feeders, such as 7a and 7b, as in the present device 1, the user may be able to select one at the time of execution, or the selection may be made automatically based on priority.

[0061] The supplied cleaning paper passes through sheet transport path 10 and is introduced into fixing device 100 without a toner image formed on the front or back side of the cleaning paper. When cleaning paper of the maximum width passes through the fixing nip, any offset toner remaining on the surface of the fixing belt is transferred to the cleaning paper, thereby removing the offset toner.

[0062] In this embodiment, cleaning paper is used without forming a toner image, but a toner image may be formed if it improves cleaning performance. Also, although the offset toner is removed by paper-pass cleaning, a toner removal cleaning means other than the paper-pass cleaning operation may be performed. Also, although the fixing device in this embodiment is configured to have a cleaning unit, it may be configured not to have a cleaning unit. Note that cleaning with a cleaning web is also performed during paper-pass cleaning.

[0063] As described above, for jobs that involve borderless printing and result in a large amount of toner adhering, a warning or prompt to perform a job is displayed after the job is completed. This notifies the user before image smearing on subsequent sheets becomes apparent, and allows the toner that has adhered and accumulated inside the device to be properly removed. [Example]

[0064] In this first embodiment, a cleaning operation was performed after borderless printing was performed, but if the number of borderless printing sheets is greater, there is a possibility that smearing may occur on the image on the sheet during borderless printing. Therefore, in this embodiment, a cleaning operation is performed before borderless printing is performed, with the aim of suppressing smearing on the image on the sheet that occurs during borderless printing. Note that the configuration, warning processing, and cleaning operation are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0065] In the borderless print job of the image formation flow described later in this embodiment, 1,000 sheets of A3 size OK topcoat + 128 gsm (Oji Paper Co., Ltd.) were used as sheets. Also, the image data amount of 250% or 1.0 mg / cm was set to the entire area of ​​the sheet. 2 In this setting, Cmax is maximum in the division width region corresponding to the side edge portion.

[0066] The length of A3 size paper in the transport direction is 420 mm, and from Table 1, A = 1.3, so in the above print job

[0067]

number

[0068] Furthermore, the cumulative offset toner amount Xt at the time the borderless printing job was received was 500. Based on the allowable amount that can be held on the surface of the cleaning web in the fixing device of this embodiment, a threshold value T of 600 was set. From the above, since Xt + X = 1319 > T, it can be determined that a paper-passing cleaning operation is necessary. However, after 19 borderless sheets have been printed, the cumulative offset toner amount X is 603, exceeding the previously set threshold value T. Therefore, on sheets from the 20th onward, any offset toner that was not completely removed may be re-transferred to the surface of the fixing belt 20 and may then be transferred onto the sheet, causing stains.

[0069] Therefore, in this embodiment, a cleaning operation is performed not only after borderless printing is performed, but also before printing.

[0070] FIG. 7 shows a flowchart of the paper passing cleaning operation warning mode in this embodiment.

[0071] First, in step S201, the control unit 21 acquires the printer job information, sheet information, and image information input from the operation panel 112.

[0072] In step S202, it is determined whether borderless printing has been specified based on the job information acquired in step S201, and if borderless printing has been specified, the process proceeds to step S203; otherwise, the process proceeds to step S215.

[0073] In step S203, the control unit 21 calculates the cumulative offset toner amount Xt+X based on the sheet information and image information.

[0074] In step S204, the control unit 21 determines whether or not a warning is necessary to prompt the user to perform the sheet cleaning operation based on the cumulative offset toner amount Xt+X calculated from the surface property, basis weight, and size information of the sheet and a preset threshold value T2. If it is determined that a warning is necessary, the process proceeds to step S205, and if it is determined that a warning is not necessary, the process proceeds to step S209.

[0075] In step S205, the control unit 21 performs a warning process to prompt the user to perform the paper passing cleaning operation.

[0076] In step S206, the control unit 21 determines whether or not to perform the paper-passing cleaning operation based on the user selection information input from the operation panel 112. If the paper-passing cleaning operation is to be performed, the process proceeds to step S207; otherwise, the process proceeds to step S209.

[0077] In step S207, the control unit 21 executes the paper passing cleaning operation.

[0078] In step S208, the control unit 21 clears the cumulative toner offset amount counter X.

[0079] In step S209, the control unit 21 performs borderless printing processing.

[0080] In step S210, the control unit 21 determines whether or not a warning is necessary to prompt a paper cleaning operation based on the cumulative offset toner amount Xt+X calculated from the surface property, basis weight, and size information of the sheet and a preset threshold value T. If it is determined that a warning is necessary, the process proceeds to step S211, and if it is determined that a warning is not necessary, the process ends.

[0081] In step S211, the control unit 21 executes a selection screen process for selecting whether or not to execute the paper passing cleaning operation.

[0082] In step S212, the control unit 21 determines whether or not to perform the paper-passing cleaning operation based on the user selection information input from the operation panel 112. If the paper-passing cleaning operation is to be performed, the process proceeds to step S213; otherwise, the process ends.

[0083] In step S213, the control unit 21 executes the paper passing cleaning operation.

[0084] In step S214, the control unit 21 clears the cumulative toner offset amount counter.

[0085] In step S215, the control unit 21 performs bordered printing processing.

[0086] 5B, in steps S205 and S212, the control unit 21 displays a warning screen 710 on the operation panel 112 or the device 300. When operation key 711 is selected, the control unit 21 displays a paper passing cleaning operation processing screen. When operation key 712 is selected, the control unit 21 closes the warning screen 711 without executing the paper passing cleaning operation.

[0087] As described above, even in the case of a job in which a large amount of toner adheres due to borderless printing, the user can be notified before the device malfunctions or image stains on subsequent sheets become apparent, and the toner that has adhered and accumulated inside the main device can be properly removed.

[0088] In this embodiment, a warning is displayed before printing, but it is also possible to add X for each sheet and display a warning when the value exceeds the threshold T during continuous printing. Also, in this embodiment, the judgment threshold T for displaying a warning before and after printing is the same value, but the threshold T may be changed before and after printing. [Example]

[0089] This embodiment aims to prevent smearing of images on print sheets for a subsequent job after borderless printing. The offset toner that accumulates during borderless printing is concentrated mainly at the side edge positions of the borderless-printed sheet, in a direction perpendicular to the sheet transport direction. Therefore, if the width of the sheet used for the subsequent job is larger than the width of the sheet used for the borderless printing of the preceding job, the offset toner from the preceding job may transfer to the sheet for the subsequent job, causing smearing.

[0090] Therefore, in this embodiment, the user is prompted to perform a paper cleaning operation if the print sheet width of a subsequent job after borderless printing is larger than the sheet width of the preceding borderless printing, and the accumulated offset toner amount Xt exceeds the threshold value T. The method of prompting the user to perform a paper cleaning operation is the same as in the first embodiment, including the configuration, warning processing, and cleaning operation, and therefore will not be described here.

[0091] In the print job of the image formation flow described later in this embodiment, bordered printing was set, and the sheets were set to be passed through 100 sheets of OK Topcoat + 128 gsm (manufactured by Oji Paper Co., Ltd.) A3 size, i.e., sheet width W = 210 mm.

[0092] Furthermore, the cumulative offset toner amount Xt at the time the print job was accepted was 500, and the sheet information for borderless printing in the preceding job was set to a width size Wd of 148 mm. Furthermore, based on the allowable amount that can be held on the surface of the cleaning web in the fixing device of this embodiment, the threshold value T was set to 400. From the above, since Xt > T and W > Wd, it can be determined that a paper cleaning operation is required.

[0093] (Image formation flow) FIG. 8 shows a flowchart of the paper passing cleaning operation warning mode in this embodiment.

[0094] First, in step S301, the control unit 21 acquires printer job information, sheet information, image information acquisition, and sheet information for the preceding borderless job entered from the operation panel 112. Here, the sheet information for the preceding borderless job is size and width information for the sheets used in borderless printing up to now.

[0095] In step S302, it is determined whether a sheet with a width larger than the size width of the leading borderless sheet is set based on the job information and sheet information of the leading borderless job acquired in step S301. If it is set, the process proceeds to step S303; otherwise, the process proceeds to step S312.

[0096] In step S303, the control unit 21 obtains the cumulative offset toner amount Xt.

[0097] In step S304, the control unit 21 determines whether or not a warning to prompt a paper-passing cleaning operation is necessary based on the cumulative offset toner amount Xt. If it is determined that a warning is necessary, the process proceeds to step S305, and if it is determined that a warning is not necessary, the process proceeds to step S306.

[0098] In step S305, the control unit 21 performs a warning process to prompt the user to perform the paper passing cleaning operation.

[0099] In step S306, the control unit 21 performs printing processing for the print job.

[0100] In step S107, the control unit 21 determines whether or not a warning to prompt the user to perform the paper passing cleaning operation is necessary, similar to step S204.

[0101] In step S308, the control unit 21 executes a selection screen process for selecting whether or not to execute the paper passing cleaning operation.

[0102] In step S309, the control unit 21 determines whether or not to perform the paper-passing cleaning operation based on the user selection information input from the operation panel 112. If the paper-passing cleaning operation is to be performed, the process proceeds to step S309; ​​otherwise, the process ends.

[0103] In step S310, the control unit 21 executes the paper passing cleaning operation.

[0104] In step S311, the control unit 21 clears the cumulative toner offset amount counter and the sheet information of the preceding marginless job.

[0105] In step S312, the control unit 21 performs the processes from step S102 onward in the flow of the first embodiment.

[0106] In this embodiment, the sheet information and cumulative toner offset amount information of the preceding job are acquired, but it is also possible to divide the width direction of the sheet according to size width classifications and set multiple cumulative toner offset amount counters in each divided area when printing borderless.

[0107] As described above, when the size width of the subsequent job is larger than the size width of the print sheet used in the preceding borderless printing, the user can be notified before stains on the image on the subsequent paper become apparent, and the toner can be removed appropriately. [Example]

[0108] In the first embodiment, the cleaning warning process was performed during or after the borderless printing job was completed, but it is also possible to configure the system to execute the cleaning warning process before the job is executed and then reserve cleaning to be performed after the job is completed. In this embodiment, the operation of reserving cleaning to be performed at the end of a job before the job is executed will be described. Note that the configuration, warning process, and cleaning operation are the same as those in the first embodiment, so their explanation will be omitted.

[0109] FIG. 10 shows a flowchart of the paper passing cleaning operation reservation mode in this embodiment.

[0110] First, in step S1001, the control unit 21 acquires the printer job information, sheet information, and image information input from the operation panel 112.

[0111] In step S1002, it is determined whether borderless printing has been specified based on the job information acquired in step S101. If borderless printing has been specified, the process proceeds to step S1003; otherwise, the process proceeds to step S1012.

[0112] In step S1003, the control unit 21 calculates the cumulative offset toner amount Xt+edge offset toner amount X based on the sheet information and image information. Here, the cumulative offset toner amount Xt is the cumulative amount of offset toner in jobs executed before the current job since the previous reset.

[0113] In step S1004, the control unit 21 determines whether or not a reservation process for the sheet passing cleaning operation is required based on the cumulative offset toner amount Xt+X calculated from the surface property, basis weight, and size information of the sheet and a preset threshold value T. If it is determined that a reservation process is required, the process proceeds to step S1005, and if it is determined that a reservation process is not required, the process ends.

[0114] In step S1005, the control unit 21 performs a reservation process for the paper passing cleaning operation. Specifically, the paper passing cleaning reservation display screen shown in Fig. 5(c) is displayed on the operation panel 112. On the paper passing cleaning reservation screen, when operation key 721 is selected, the control unit 21 makes a reservation for the paper passing cleaning operation, which will be described later. When operation key 722 is selected, the control unit 21 closes the screen 720 display without making a reservation for the paper passing cleaning operation.

[0115] In step S1006, it is determined whether a paper-passing cleaning operation has been reserved. Specifically, if operation key 721 is selected, the process proceeds to S1007, and if operation key 722 is selected, the process proceeds to S1008.

[0116] In step S1007, the control unit 21 rewrites the reservation flag in the storage unit (not shown) from 0 to 1. In this embodiment, the reservation control is described as being performed using the flag in the storage unit, but the way the value is held and the reservation method are not limited.

[0117] In step S1008, the control unit 21 executes borderless printing processing. When the borderless printing processing is completed, the process proceeds to step S1009.

[0118] In step S1009, the value of the reservation flag is referenced. If a reservation has been made, the process proceeds to step S1010, and if not, the process ends.

[0119] In step S1010, the sheet passing cleaning operation is performed.

[0120] In step S1011, the control unit 21 clears the cumulative toner offset amount counter.

[0121] In step S1012, the control unit 21 performs bordered printing processing.

[0122] As a result, it is possible to issue a warning and schedule the paper cleaning operation before the execution of a job where the user is likely to be looking at the operation panel, and toner that has accumulated inside the main device can be removed more appropriately without being left unattended.

Claims

1. An image forming apparatus capable of executing a borderless print job in which a toner image is formed on the edge of a recording material, and a bordered print job in which a toner image is not formed on the edge of a recording material, a cleaning unit that performs a cleaning operation to clean the inside of the image forming apparatus by using paper that is transported when no image is being formed; a display control means for controlling display on a display unit that displays a screen; When a borderless print job is accepted, the display control means displays a warning screen that prompts the user to perform the cleaning operation based on job information of the print job. An image forming apparatus characterized by:

2. The display control means displays the warning screen before the borderless print job is executed.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. The display control means displays the warning screen after the borderless print job is executed.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. the display control means displays a cleaning execution screen different from the warning screen, When a predetermined operation is accepted on the cleaning execution screen, the execution unit executes the cleaning operation.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

5. the display control means displays the cleaning execution screen before execution of the borderless print job; When a predetermined operation is accepted on the cleaning execution screen, the execution unit executes the cleaning operation.

5. The image forming apparatus according to claim 4.

6. the display control means displays the cleaning execution screen before execution of the borderless print job; After receiving a predetermined operation on the cleaning execution screen, the execution unit executes a cleaning operation when the execution of the print job is completed.

5. The image forming apparatus according to claim 4.

7. The display control means displays the cleaning execution screen after the borderless print job is executed.

5. The image forming apparatus according to claim 4.

8. a rotatable heating rotor; a rotatable heating rotor that forms a nip portion by contacting the pressure rotor; a fixing device that fixes a toner image to a recording material by applying heat and pressure to the recording material carrying the toner image at the nip portion, The cleaning unit cleans the toner adhering to the heating rotor by using paper conveyed to the nip portion of the fixing device.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

9. a cleaning web for cleaning toner adhering to the heating rotary member during image formation in the image forming apparatus; When the cleaning operation is performed by the performing means, cleaning is performed with the cleaning web.

9. The image forming apparatus according to claim 8,

10. a calculation unit that calculates an offset toner amount based on job information of the print job when the print job is received; When the cumulative offset toner amount including the calculated offset toner amount based on the job information of the print job satisfies a predetermined value, the display control means displays a warning screen.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

11. When the cleaning operation is performed by the execution means, the value of the accumulated offset toner amount is reset.

11. The image forming apparatus according to claim 10.

12. The job information includes information about the surface properties and size of the recording material.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

13. The job information includes image data.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

14. When the preceding job information indicates first size information and the subsequent job information indicates second size information that is smaller than the first size information, the display control means does not display the warning screen.

13. The imaging device of claim 12.

Images