Image forming apparatus and program

Abstract

This helps to mitigate the decrease in productivity caused by users uniformly interrupting image formation. [Solution] The image forming apparatus 1 includes an image carrier (intermediate transfer belt 342) that carries a toner image on its surface, a transfer unit (secondary transfer roller 343) that transfers the toner image carried on the surface of the image carrier to paper, an adjustment unit (third control unit 36) that adjusts the pressing force of the transfer unit or the driving conditions of the transfer unit according to paper information about the paper, an acquisition unit (third control unit 36) that acquires the detection result of speed fluctuation of the image carrier or the transfer unit after the adjustment of the pressing force of the transfer unit or the driving conditions of the transfer unit, and a notification unit (third control unit 36) that notifies information regarding image defects based on the detection result of speed fluctuation of the image carrier or the transfer unit acquired by the acquisition unit.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus and a program.

Background Art

[0002] Conventionally, an image forming apparatus including a transfer unit that transfers a toner image carried on the surface of an image carrier to a sheet while sandwiching the sheet at a position facing the image carrier is known. In such an image forming apparatus, when a sheet passes (enters or exits) between the image carrier and the transfer unit, the load applied to the image carrier changes greatly, causing impact vibrations. As a result, an instantaneous speed variation (shock noise) occurs in the driving speed of the image carrier, and the speed variation of the image carrier may adversely affect the image being formed, resulting in streaks, unevenness, etc. in the image.

[0003] Regarding this, Patent Document 1 describes the following image forming apparatus. Specifically, the image forming apparatus generates a variation having a reverse phase to the speed variation in the driving speed of the image carrier when a sheet passes between the image carrier and the transfer unit. Thereby, the image forming apparatus suppresses the occurrence of image streaks, image unevenness, etc. by reducing the speed variation in the driving speed of the image carrier when a sheet passes between the image carrier and the transfer unit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the conventional image forming apparatus, the speed variation in the driving speed of the image carrier when a sheet passes between the image carrier and the transfer unit cannot be completely suppressed, and there is a possibility that image streaks, image unevenness, etc. at a level unacceptable to the user may occur. In the invention described in Patent Document 1, a warning is issued if the speed fluctuations in the driving speed of the image carrier cannot be sufficiently reduced. However, when the user receives this warning, they may not be able to recognize what effect it will have on the image being formed and may indiscriminately interrupt the image formation process. As a result, this can lead to prolonged downtime of the image forming apparatus, resulting in a decrease in productivity.

[0006] This invention has been made in view of the above circumstances. The problem that this invention aims to solve is to provide an image forming apparatus and program that can suppress the decrease in productivity caused by users uniformly interrupting image formation. [Means for solving the problem]

[0007] To solve the above problems, the image forming apparatus described in claim 1 is An image carrier that supports a toner image on its surface, A transfer unit that transfers the toner image supported on the surface of the image carrier to paper, An adjustment unit that adjusts the pressing force of the transfer unit or the driving conditions of the transfer unit according to the paper information relating to the aforementioned paper, An acquisition unit that acquires the detection result of speed fluctuations of the image carrier or the transfer unit after adjusting the pressing force of the transfer unit or the driving conditions of the transfer unit, A notification unit that notifies information regarding image defects based on the detection results obtained by the acquisition unit, It is equipped with.

[0008] The invention described in claim 2 is an image forming apparatus according to claim 1, The notification unit notifies information regarding the image defect when the speed fluctuation in the detection result exceeds a predetermined threshold.

[0009] The invention described in claim 3 relates to the image forming apparatus described in claim 1 or 2, The aforementioned information regarding image defects is an example of an image defect.

[0010] The invention described in claim 4 is an image forming apparatus according to claim 3, The aforementioned image defects are at least one of either white streaks or black streaks in the image.

[0011] The invention described in claim 5 is an image forming apparatus according to claim 1, The system includes a receiving unit that accepts a choice from the notification unit after notification is received, whether to stop the print job that is currently running or to continue the print job.

[0012] The invention described in claim 6 is an image forming apparatus according to claim 5, When the reception unit receives a request to stop the print job, the control unit modifies the image forming parameters after the print job has been stopped and then restarts the print job using the modified image forming parameters.

[0013] The invention described in claim 7 is an image forming apparatus according to claim 6, The image forming parameters include at least one of the following: secondary transfer speed, fixing speed, primary transfer pressure, secondary transfer pressure, fixing nip pressure, paper transport speed, and the number of contacts between the image carrier and the transfer section.

[0014] The invention described in claim 8 is an image forming apparatus according to claim 6, The control unit presents recommended values ​​for the image forming parameters and changes the image forming parameters by receiving an instruction operation to apply the recommended values ​​or an input operation for the values ​​of the image forming parameters.

[0015] The invention described in claim 9 is an image forming apparatus according to claim 8, The control unit determines the recommended value based on the location information of the abnormality in the formed image.

[0016] The invention described in claim 10 is an image forming apparatus according to claim 1, When the speed fluctuations exceeding a predetermined threshold value are detected a predetermined number of times in the detection result, a notification unit is provided that notifies the administrator of the image forming apparatus.

[0017] The invention according to claim 11 is the image forming apparatus according to claim 5, When the reception unit receives the continuation of the print job, a control unit is provided that continues the print job without changing the image forming parameters and controls so as not to perform notification by the notification unit in the print job being executed.

[0018] The invention according to claim 12 is the image forming apparatus according to claim 1, The image carrier is an intermediate transfer body on which a plurality of images are formed.

[0019] The invention according to claim 13 is the image forming apparatus according to claim 1, The paper information includes at least one of the thickness, basis weight, and stiffness of the paper.

[0020] The invention according to claim 14 is the image forming apparatus according to claim 1, A media detection unit for detecting physical property values of the paper is provided, The paper information includes the detection result by the media detection unit.

[0021] The invention according to claim 15 is the image forming apparatus according to claim 13, The adjustment unit increases the separation amount between the image carrier and the transfer unit when the paper enters the transfer nip formed by the image carrier and the transfer unit as the value of at least one of the thickness, basis weight, and stiffness of the paper is larger.

[0022] The invention according to claim 16 is the image forming apparatus according to claim 13, The adjustment unit slows down the paper conveyance speed in the transfer nip formed by the image carrier and the transfer unit as the value of at least one of the thickness, basis weight, and stiffness of the paper is larger.

[0023] The program described in claim 17 is An image carrier that supports a toner image on its surface, A transfer unit that transfers the toner image supported on the surface of the image carrier to paper, A computer for an image forming apparatus equipped with, An adjustment unit that adjusts the pressing force of the transfer unit or the driving conditions of the transfer unit according to the paper information relating to the aforementioned paper, An acquisition unit that acquires the detection result of speed fluctuations of the image carrier or the transfer unit after adjusting the pressing force of the transfer unit or the driving conditions of the transfer unit. A notification unit provides information regarding image defects based on the detection results obtained by the acquisition unit. To make it function as such. [Effects of the Invention]

[0024] According to the present invention, it is possible to suppress the decrease in productivity caused by users uniformly interrupting image formation. [Brief explanation of the drawing]

[0025] [Figure 1] This figure shows a schematic configuration of the image forming apparatus according to this embodiment. [Figure 2] This is a functional block diagram showing the control structure of the image forming apparatus according to this embodiment. [Figure 3] This is a flowchart showing the flow of the print control process performed by the image forming apparatus. [Figure 4] This is a flowchart showing the flow of the velocity fluctuation detection process performed by the image forming apparatus. [Figure 5] This figure shows an example of the detection result from the peripheral speed detection unit. [Figure 6] This figure shows an example of a notification screen. [Figure 7] This figure shows an example of a notification screen with selection buttons displayed. [Figure 8] This figure shows an example of the direction of recommended values ​​for image formation parameters. [Modes for carrying out the invention]

[0026] Embodiments of the present invention will be described below with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

[0027] <1. Configuration of the image forming apparatus> As shown in Figures 1 and 2, the image forming apparatus 1 according to this embodiment comprises a paper feeder 10, a detection device 20, a main body 30, and a post-processing device 40. In the image forming apparatus 1, the paper feeder 10, detection device 20, main unit 30, and post-processing device 40 are arranged in the following order from upstream along the paper transport direction.

[0028] (1-1. Configuration of the paper feed device) The paper feeding device 10 includes a first control unit 11, a transport unit 12, a paper feeding unit 13, and the like.

[0029] The first control unit 11 includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and the like. The CPU of the first control unit 11 reads the program stored in ROM, loads it into RAM, and then controls each part of the paper feed device 10 according to the loaded program. For example, the first control unit 11 transports paper from the paper trays 131 to 133 of any of the paper feeding units 13 to the detection device 20 according to the print job.

[0030] The transport unit 12 is equipped with a transport path 121 that connects the paper feeding unit 13 to the detection device 20, and transports paper. The paper feeding unit 13 has paper trays 131 to 133 for storing paper according to predetermined paper types, sizes, etc. For example, paper tray 131 stores paper larger than the paper stored in paper tray 132. Paper tray 133 stores paper thicker than the paper stored in paper trays 131 and 132.

[0031] (1-2. Configuration of the detection device) The detection device 20 is located downstream of the paper feed device 10 in the paper transport direction, and upstream of the main body 30 in the paper transport direction. The detection device 20 detects the physical properties of the paper transported from the paper feed device 10 and outputs the physical property values ​​obtained as detection results to the third control unit 36, which will be described later. The detection device 20 detects values ​​(physical property values) related to the physical properties of multiple types of paper, including paper thickness, basis weight, and stiffness. The physical property values ​​may also be information that can be converted into physical properties.

[0032] The detection device 20 includes a second control unit 21, a transport unit 22, a media detection unit 23, a purge tray 24, and the like.

[0033] The second control unit 21 includes a CPU, ROM, RAM, etc. The CPU of the second control unit 21 reads the program stored in ROM, loads it into RAM, and then controls each part of the detection device 20 according to the loaded program. For example, the second control unit 21 causes the media detection unit 23 to detect the paper transported from the paper feed device 10, and outputs the obtained physical property values ​​to the third control unit 36.

[0034] The transport unit 22 is equipped with multiple roller pairs and transports the paper transported from the paper feed device 10 to the media detection unit 23. Next, the transport unit 22 transports the detected paper to the main unit 30 or the purge tray 24. The transport unit 22 includes a rigidity detection path R22 that branches off from the transport path R21 connected to the main unit 30 and connects to the purge tray 24.

[0035] The media detection unit 23 detects the physical properties of the paper. The media detection unit 23 includes a paper thickness sensor 231, a basis weight sensor 232, and a stiffness sensor 233. The paper thickness sensor 231 and the basis weight sensor 232 are positioned on the transport path R21 connected to the main unit 30. The transport unit 22 transports paper to the main unit 30, where the paper thickness is detected by the paper thickness sensor 231 and the basis weight is detected by the basis weight sensor 232. The stiffness sensor 233 is positioned on the stiffness detection path R22 connected to the purge tray 24. The transport unit 22 ejects the paper whose stiffness has been detected by the stiffness sensor 233 into the purge tray 24.

[0036] The paper thickness sensor 231 measures the paper thickness by detecting the axis of a driven roller that displaces according to the paper thickness as the paper is transported by the nip of the transport roller pair. The media detection unit 23 outputs the paper thickness as a physical property value to the second control unit 21. The basis weight sensor 232 includes a light-emitting unit and a light-receiving unit, and measures the basis weight of the paper by measuring the amount of attenuation of light transmitted through the paper. The media detection unit 23 outputs the basis weight as a physical property value to the second control unit 21. The stiffness sensor 233 detects physical properties corresponding to the rigidity of the paper. For example, when paper is transported along a curved transport path, the sensor mechanically measures the force or displacement exerted by the paper on one of the outer guide plates constituting the transport path. The media detection unit 23 outputs the stiffness as a physical property value based on the force or displacement exerted by the paper to the second control unit 21.

[0037] (1-3. Main body configuration) The main body 30 is located downstream of the detection device 20 in the paper transport direction and upstream of the post-processing device 40 in the paper transport direction. The main unit 30 forms a color image by electrophotography based on image data obtained by reading an image from a document, or job image data of a print job received from an external device (not shown). Next, the main unit 30 transports the image-formed paper to the post-processing device 40. As shown in Figures 1 and 2, the main unit 30 includes an operation unit 31, a display unit 32, a document reading unit 33, an image forming unit 34, a third control unit 36, a storage unit 37, a communication unit 38, and a peripheral speed detection unit 39.

[0038] The operation unit 31 includes a touch panel formed to cover the display screen of the display unit 32, and various operation buttons such as number buttons and a start button. The operation unit 31 outputs an operation signal based on the user's operation to the third control unit 36.

[0039] The display unit 32 includes an LCD (Liquid Crystal Display) or the like. The display unit 32 displays various screens according to the instructions of the display signals input from the third control unit 36.

[0040] The document reading unit 33 is equipped with an automatic document feeder (ADF), a scanner, and the like. The document reading unit 33 reads the image of the document and outputs the resulting image data to the third control unit 36.

[0041] The image forming unit 34 forms an image on the paper transported from the detection device 20 using an intermediate transfer method, based on the image data that has undergone image processing. In this embodiment, the paper is a single sheet. The image forming unit 34 includes photosensitive drums 341Y, 341M, 341C, and 341K corresponding to yellow (Y), magenta (M), cyan (C), and black (K), an intermediate transfer belt 342, a secondary transfer roller 343, a fixing unit 344, an inversion path 345, a resist unit 346, and the like.

[0042] The image forming unit 34 uniformly charges the photoreceptor drum 341Y, then scans and exposes it with a laser beam based on yellow image data to form an electrostatic latent image. Next, the image forming unit 34 deposits yellow toner onto the electrostatic latent image on the photoreceptor drum 341Y and performs development. The photoconductor drums 341M, 341C, and 341K are the same as the photoconductor drum 341Y, except for the different colors they handle, so we will omit their explanation.

[0043] The image forming unit 34 sequentially transfers the toner images of each color formed on the photoreceptor drums 341Y, 341M, 341C, and 341K onto the rotating intermediate transfer belt 342 (primary transfer). In other words, the image forming unit 34 forms a color toner image on the intermediate transfer belt 342 by superimposing the four toner images. The intermediate transfer belt 342 is an intermediate transfer body and an image carrier that supports the toner image on its surface. The image forming unit 34 transfers the color toner image on the intermediate transfer belt 342 onto the paper in one go using the secondary transfer roller 343 (secondary transfer). The secondary transfer roller 343 functions as a transfer unit that transfers the toner image carried on the surface of the intermediate transfer belt 342 onto the paper. The intermediate transfer belt 342 and the secondary transfer roller 343 form a transfer nip 34a.

[0044] The fixing unit 344 includes a heating roller 344a for heating the paper onto which the color toner image has been transferred, a pressure roller 344b for applying pressure to the paper, and the like. The fixing unit 344 fixes the color toner image to the paper by heating and pressurizing in the fixing nip 344c formed by the heating roller 344a and the pressure roller 344b.

[0045] In the case of single-sided printing, where an image is formed on one side of the paper in the main unit 30, the third control unit 36 ​​transports the paper from the fuser unit 344 to the post-processing device 40. On the other hand, in the case of double-sided printing, where an image is formed on both sides of the paper, the third control unit 36 ​​transports the paper from the fuser unit 344 to the reversal path 345 to reverse the paper surface. Next, the third control unit 36 ​​feeds the paper again upstream of the resist unit 346 in the paper transport direction.

[0046] The resist section 346 is equipped with resist rollers and transports the paper to the transfer nip 34a. The resist unit 346 corrects the tilt of the paper transported from the detection device 20 and adjusts the timing of paper transport.

[0047] The third control unit 36 ​​includes a CPU, RAM, ROM, etc. The CPU of the third control unit 36 ​​reads various processing programs stored in ROM and loads them into RAM. The third control unit 36 ​​then comprehensively controls the operation of the main unit 30 in cooperation with the various programs loaded into RAM. For example, if the third control unit 36 ​​is to perform post-processing on the output paper, it issues an instruction to the post-processing device 40 to perform the predetermined post-processing.

[0048] The memory unit 37 is a non-volatile storage device such as an HDD (Hard Disk Drive) or semiconductor memory that stores various types of data, such as programs and image data. The memory unit 37 stores data such as program data and various setting data so that it can be read and written by the third control unit 36.

[0049] The communication unit 38 includes, for example, a communication control card such as a LAN (Local Area Network) card. The communication unit 38 transmits and receives various types of data with external devices (such as personal computers) connected to communication networks such as LANs and WANs (Wide Area Networks).

[0050] The peripheral speed detection unit 39 is an encoder that detects the peripheral speed of the intermediate transfer belt 342 by detecting the amount of mechanical displacement of the rotation of the drive roller that drives the intermediate transfer belt 342. The peripheral speed detection unit 39 outputs the detection result to the third control unit 36. Alternatively, the peripheral speed detection unit 39 may be an encoder that detects the peripheral speed of the secondary transfer roller 343 by detecting the amount of mechanical displacement of the rotation of the drive roller that drives the secondary transfer roller 343.

[0051] (1-4. Configuration of the post-processing device) The post-processing device 40 is located downstream of the main unit 30 in the paper transport direction and performs post-processing on the paper transported from the main unit 30. The post-processing device 40 includes a fourth control unit 41, a post-processing unit 42, a transport unit 43, and a paper output tray 44.

[0052] The fourth control unit 41 includes a CPU, RAM, ROM, etc. The CPU of the fourth control unit 41 reads various processing programs stored in ROM and loads them into RAM. The fourth control unit 41 then comprehensively controls the operation of the post-processing unit 40 in cooperation with the various programs loaded into RAM.

[0053] The post-processing unit 42 performs post-processing on the paper transported from the main unit 30. This post-processing includes, for example, cutting, folding, perforating, creasing, foil stamping, varnishing, and various binding methods.

[0054] The transport unit 43 is equipped with multiple roller pairs and transports the paper transported from the main unit 30 to the post-processing unit 42. Next, the transport unit 43 discharges the paper that has been post-processed by the post-processing unit 42 into the output tray 44.

[0055] In this embodiment, the third control unit 36 ​​of the main unit 30 comprehensively controls the entire image forming apparatus 1, but this is not limited to this configuration. The first control unit 11 of the paper feed device 10, the second control unit 21 of the detection device 20, or the fourth control unit 41 of the post-processing device 40 may also comprehensively control the entire image forming apparatus 1.

[0056] <2. Operation of the image forming apparatus> Next, the print control process performed in the image forming apparatus 1 will be described. The third control unit 36 ​​works in cooperation with the program stored in the memory unit 37 to execute print control processing. The third control unit 36 ​​executes print control processing, for example, when the main unit 30 receives print job information from an external device via the communication unit 38. The external device is, for example, a personal computer. Figure 3 shows a flowchart of the print control process.

[0057] (Print control processing) The third control unit 36 ​​acquires the stiffness of the target paper, which is the detection result of the stiffness sensor 233 of the detection device 20 for the target paper of the print job (step A1). The paper information of the target paper includes the stiffness of the target paper.

[0058] Next, the third control unit 36 ​​starts the print job based on the received job information (step A2).

[0059] Next, the third control unit 36 ​​acquires the thickness of the target paper, which is the detection result of the paper thickness sensor 231 of the detection device 20. Furthermore, the third control unit 36 ​​acquires the basis weight of the target paper, which is the detection result of the basis weight sensor 232 (step A3). The paper information of the target paper includes the thickness and basis weight of the target paper. In steps A1 and A3, the third control unit 36 ​​functions as an acquisition unit. The paper attribute information may include at least one of the following: the thickness, basis weight, and stiffness of the paper used in the print job.

[0060] Next, the third control unit 36 ​​adjusts the secondary transfer pressure based on the paper information of the target paper acquired in steps A1 and A3, in order to suppress speed fluctuations in the peripheral speed of the intermediate transfer belt 342 or the peripheral speed of the secondary transfer roller 343. The secondary transfer pressure is the pressure applied when the secondary transfer roller 343 is pressed against the intermediate transfer belt 342. Alternatively, the third control unit 36 ​​adjusts the rotational speed, which is the driving condition for the secondary transfer roller 343, based on the paper information of the target paper acquired in steps A1 and A3, in order to suppress speed fluctuations in the peripheral speed of the intermediate transfer belt 342 or the peripheral speed of the secondary transfer roller 343 (step A4). In step A4, the third control unit 36 ​​functions as an adjustment unit. In step A4, the third control unit 36 ​​reduces the secondary transfer pressure as the value of at least one of the target paper's thickness, basis weight, and stiffness increases. In other words, the third control unit 36 ​​increases the amount of separation between the intermediate transfer belt 342 and the secondary transfer roller 343 when the target paper enters the transfer nip 34a as the value of at least one of the target paper's thickness, basis weight, and stiffness increases. Alternatively, in step A4, the third control unit 36 ​​slows down the rotation speed of the secondary transfer roller 343 as the value of at least one of the target paper thickness, basis weight, and stiffness increases. In other words, the third control unit 36 ​​slows down the paper transport speed at the transfer nip 34a as the value of at least one of the target paper thickness, basis weight, and stiffness increases.

[0061] Next, the third control unit 36 ​​determines whether the speed fluctuation detection process shown in Figure 4 is enabled (step A5). If the speed fluctuation detection process is enabled (step A5; YES), the third control unit 36 ​​executes the speed fluctuation detection process (step A6).

[0062] (Speed ​​fluctuation detection processing) The third control unit 36 ​​acquires the detection result of speed fluctuations in the peripheral speed of the intermediate transfer belt 342 from the peripheral speed detection unit 39 (step B1). In step B1, the third control unit 36 ​​may obtain the detection result of speed fluctuations in the peripheral speed of the secondary transfer roller 343 from the peripheral speed detection unit 39, but in the following description, the third control unit 36 ​​will be described as obtaining the detection result of speed fluctuations in the peripheral speed of the intermediate transfer belt 342. In step B1, the third control unit 36 ​​acquires the detection result of speed fluctuations of the intermediate transfer belt 342 or the secondary transfer roller 343 after adjusting the pressing force or driving conditions of the secondary transfer roller 343. The third control unit 36 ​​functions as an acquisition unit.

[0063] Next, the third control unit 36 ​​determines, based on the speed fluctuation detection result obtained in step B1, whether or not it has detected a speed fluctuation that exceeds a predetermined threshold in the peripheral speed of the intermediate transfer belt 342 (step B2). Figure 5 shows an example of the detection results for the peripheral speed of the intermediate transfer belt 342. In Figure 5, the horizontal axis represents the time since paper feeding started at the transfer nip 34a, and the vertical axis represents the speed fluctuation amount of the peripheral speed of the intermediate transfer belt 342. The third control unit 36 ​​determines that it has detected a speed fluctuation exceeding a predetermined threshold for the peripheral speed of the intermediate transfer belt 342 when the speed fluctuation amount exceeds the upper limit C1 or the lower limit C2 of a predetermined threshold.

[0064] The following describes the case where a speed fluctuation exceeding a predetermined threshold in the peripheral speed of the intermediate transfer belt 342 is detected (Step B2; YES). In this case, the third control unit 36 ​​notifies the user by displaying on the notification screen 321 (see Figure 6) displayed on the display unit 32 that a speed fluctuation exceeding a predetermined threshold in the peripheral speed of the intermediate transfer belt 342 has been detected. Furthermore, the third control unit 36 ​​notifies the user by displaying on the notification screen 321 information regarding image defects that occur as a result of the speed fluctuation exceeding a predetermined threshold in the peripheral speed of the intermediate transfer belt 342 (Step B3). In step B3, the third control unit 36 ​​notifies information regarding image defects based on the detection result of speed fluctuations of the intermediate transfer belt 342 or the secondary transfer roller 343. The third control unit 36 ​​functions as a notification unit.

[0065] In the example shown in Figure 6, the third control unit 36 ​​displays text 321a on the notification screen 321 indicating that it has detected a speed fluctuation exceeding a predetermined threshold in the peripheral speed of the intermediate transfer belt 342. Furthermore, the third control unit 36 ​​displays image 321b on the notification screen 321 as information regarding image defects that occur as a result of the speed fluctuation exceeding a predetermined threshold in the peripheral speed of the intermediate transfer belt 342. The image defect is at least one of white streaks and black streaks.

[0066] Next, the third control unit 36 ​​determines whether it has detected a predetermined number of speed fluctuations in the peripheral speed of the intermediate transfer belt 342 that exceed a predetermined threshold in the print job that is currently being executed (step B4). The case where a speed fluctuation exceeding a predetermined threshold in the peripheral speed of the intermediate transfer belt 342 has not been detected a predetermined number of times (Step B4; NO) will be described. In this case, as shown in Figure 7, the third control unit 36 ​​displays a selection button 321c on the notification screen 321 for selecting whether to stop or continue the running print job. Next, the third control unit 36 ​​accepts a press operation of the selection button 321c by the user via the operation unit 31 (Step B5). In step B5, the third control unit 36 ​​accepts a request from the notification unit to either stop the ongoing print job or continue the print job. The third control unit 36 ​​functions as a reception unit.

[0067] Next, the third control unit 36 ​​determines whether stopping the print job was selected based on the operation of pressing the selection button 321c in step B5 (step B6). If stopping the print job is selected (step B6; YES), the third control unit 36 ​​stops the running print job (step B7). When a print job is stopped, the user checks the output paper ejected from the image forming apparatus 1 and measures the distance from the leading edge of the paper to the location of the abnormality on the paper in question.

[0068] Next, the third control unit 36 ​​acquires location information of the location of the abnormality on the paper in which the image abnormality occurred (step B8). Specifically, the third control unit 36 ​​receives an input operation from the user via the operation unit 31, which specifies the distance from the leading edge of the paper to the location of the abnormality on the paper in which an image abnormality has occurred.

[0069] Next, the third control unit 36 ​​determines recommended values ​​for image forming parameters based on the location information of the abnormality location acquired in step B8, in order to suppress speed fluctuations in the peripheral speed of the intermediate transfer belt 342 or the peripheral speed of the secondary transfer roller 343. Image forming parameters are parameters used in the image forming process by the image forming unit 34. Next, the third control unit 36 ​​displays the determined recommended values ​​on the display unit 32 (step B9). The image forming parameters include at least one of the following: secondary transfer speed, fixing speed, primary transfer pressure, secondary transfer pressure, fixing nip pressure, paper transport speed, and the number of pressures applied between the intermediate transfer belt 342 and the secondary transfer roller 343.

[0070] Figure 8 shows an example of the directionality of recommended values ​​for image formation parameters. As shown in Figure 8, if the distance from the leading edge of the paper to the location of the anomaly is, for example, 78 mm, the timing of the anomaly is when the leading edge of the preceding paper of the paper in which the image anomaly occurred enters the transfer nip 34a. In this case, the third control unit 36 ​​determines the recommended value by changing the current secondary transfer pressure in a direction that weakens it, and also by changing the current primary transfer pressure in a direction that weakens it. If the distance from the leading edge of the paper to the location of the anomaly is, for example, 150 mm, the timing of the anomaly is when the leading edge of the paper where the anomaly occurred enters the fuser nip 344c. In this case, the third control unit 36 ​​determines the recommended value by increasing the current secondary transfer pressure and decreasing the current fuser nip pressure. If the distance from the leading edge of the paper to the location of the anomaly is, for example, 324 mm, the timing of the anomaly is when the trailing edge of the preceding sheet of paper with the image anomaly has come off the transfer nip 34a. In this case, the third control unit 36 ​​determines the recommended value by adjusting the current secondary transfer speed or fixing speed and changing the current paper transport speed to a slower speed. If the distance from the leading edge of the paper to the location of the anomaly is, for example, 397 mm, the timing of the anomaly is when the leading edge of the paper where the anomaly occurred enters the transfer nip 34a. In this case, the third control unit 36 ​​determines the recommended value by changing the current secondary transfer pressure in a direction that weakens it.

[0071] Next, the third control unit 36 ​​displays a change button on the display unit 32 to instruct the user to change the image formation parameters to the recommended values ​​displayed in step B9. Next, the third control unit 36 ​​accepts an instruction operation to change the image formation parameters by receiving a press operation of the change button via the operation unit 31 by the user (step B10). In other words, the third control unit 36 ​​presents recommended values ​​for the image formation parameters in step B9 and accepts an instruction operation to apply those recommended values ​​in step B10. Alternatively, in step B10, the third control unit 36 ​​may accept input operations for image formation parameter values ​​from the user via the operation unit 31.

[0072] Next, the third control unit 36 ​​changes the image formation parameters to the recommended values ​​displayed in step B9. Alternatively, the third control unit 36 ​​changes the image formation parameters to the values ​​entered by the user in step B10 (step B11).

[0073] Next, the third control unit 36 ​​executes the image forming process using the image forming parameters changed in step B11, restarts the print job (step B12), and terminates the speed fluctuation detection process. As described above, when the third control unit 36 ​​receives a request to stop the print job, it changes the image formation parameters after the print job has been stopped and then restarts the print job using the changed image formation parameters. The third control unit 36 ​​functions as a control unit.

[0074] If stopping the print job is not selected (step B6; NO), the third control unit 36 ​​determines whether continuing the print job was selected based on the operation of pressing the selection button 321c in step B5 (step B13). If the option to continue the print job is selected (step B13; YES), the third control unit 36 ​​disables the speed fluctuation detection process for the currently running print job (step B14) and terminates the speed fluctuation detection process. As described above, when the third control unit 36 ​​receives a request to continue the print job, it continues the print job without changing the image formation parameters and controls the system so that the notification unit does not send notifications for the print job that is currently running.

[0075] On the other hand, if the option to continue the print job is not selected (step B13; NO), the third control unit 36 ​​proceeds to step B6 for speed fluctuation detection processing.

[0076] If the third control unit 36 ​​detects a predetermined number of speed fluctuations in the peripheral speed of the intermediate transfer belt 342 that exceed a predetermined threshold (step B4; YES), it stops the print job that is currently running (step B15). Next, the third control unit 36 ​​sends a notification via the communication unit 38 to an external device used by the administrator of the image forming apparatus 1 (step B16), and terminates the speed fluctuation detection process. The notification includes information such as that a speed fluctuation exceeding a predetermined threshold in the peripheral speed of the intermediate transfer belt 342 has been detected a predetermined number of times, and that the print job has been stopped. In step B16, the third control unit 36 ​​notifies the administrator of the image forming apparatus 1 if a predetermined number of speed fluctuations exceeding a predetermined threshold are detected in the speed fluctuation detection results of the intermediate transfer belt 342 or the secondary transfer roller 343. The third control unit 36 ​​functions as a notification unit.

[0077] If no speed fluctuation exceeding a predetermined threshold is detected in the peripheral speed of the intermediate transfer belt 342 (step B2; NO), the third control unit 36 ​​terminates the speed fluctuation detection process.

[0078] Returning to Figure 3, the third control unit 36 ​​determines whether the running print job has been completed or not (step A7). If the print job is completed (step A7; YES), the third control unit 36 ​​terminates the print control process.

[0079] On the other hand, if the print job is not completed (step A7; NO), the third control unit 36 ​​determines whether or not the print job was stopped in the speed fluctuation detection process of step A6 (step A8). If the print job is stopped during the speed fluctuation detection process in step A6 (step A8; YES), the third control unit 36 ​​terminates the print control process.

[0080] On the other hand, if the print job is not stopped in the speed fluctuation detection process in step A6 (step A8; NO), the third control unit 36 ​​proceeds to step A3 for print control processing and continues the print job.

[0081] <3. Effects> As described above, the image forming apparatus 1 according to this embodiment includes an image carrier (intermediate transfer belt 342) that supports a toner image on its surface. The image forming apparatus 1 according to this embodiment includes a transfer unit (secondary transfer roller 343) that transfers a toner image supported on the surface of an image carrier to paper. The image forming apparatus 1 according to this embodiment includes an adjustment unit (third control unit 36) that adjusts the pressing force of the transfer unit or the driving conditions of the transfer unit according to the paper information relating to the paper. The image forming apparatus 1 according to this embodiment includes an acquisition unit (third control unit 36) that acquires the detection result of a speed fluctuation of the image carrier or the transfer unit after adjusting the pressing force of the transfer unit or the driving conditions of the transfer unit. The image forming apparatus 1 according to this embodiment includes a notification unit (third control unit 36) that notifies information regarding image defects based on the detection result of speed fluctuations of the image carrier or transfer unit acquired by the acquisition unit. Therefore, users can obtain information about image defects that occur due to speed fluctuations in the image carrier or transfer unit. This allows users to decide whether or not to stop the print job based on information regarding the image defect, thereby preventing productivity losses caused by users uniformly interrupting image formation.

[0082] In the image forming apparatus 1 according to this embodiment, the notification unit (third control unit 36) notifies information regarding image defects when the speed fluctuation detected in the speed fluctuation of the image carrier (intermediate transfer belt 342) or the transfer unit (secondary transfer roller 343) exceeds a predetermined threshold. Therefore, users can obtain information about image defects that occur due to velocity fluctuations exceeding a predetermined threshold in the image carrier or transfer section.

[0083] In the image forming apparatus 1 according to this embodiment, the information regarding image defects is an example of an image defect. Therefore, users can identify examples of image defects that occur due to speed fluctuations in the image carrier or transfer unit.

[0084] In the image forming apparatus 1 according to this embodiment, an example of an image defect is at least one of either white streaks in the image or black streaks in the image. Therefore, the user can perceive at least one of the white or black streaks in the image that occur due to fluctuations in the speed of the image carrier or transfer area.

[0085] The image forming apparatus 1 according to this embodiment includes a receiving unit (third control unit 36) that, after notification by the notification unit (third control unit 36), accepts a selection of whether to stop the print job that is currently running or to continue the print job. Therefore, if a speed fluctuation occurs in the image carrier or transfer unit, the user can refer to information regarding image defects and choose whether or not to stop the print job.

[0086] The image forming apparatus 1 according to this embodiment includes a control unit (third control unit 36) that, upon receiving a request from the reception unit (third control unit 36) to stop a print job, changes the image forming parameters after stopping the print job and restarts the print job using the changed image forming parameters. Therefore, the print job can be restarted by modifying the image forming parameters to suppress speed fluctuations in the image carrier or transfer section.

[0087] In the image forming apparatus 1 according to this embodiment, the image forming parameters include at least one of the following: secondary transfer speed, fixing speed, primary transfer pressure, secondary transfer pressure, fixing nip pressure, paper transport speed, and the number of presses between the image carrier (intermediate transfer belt 342) and the transfer section (secondary transfer roller 343). Therefore, the print job can be restarted by modifying the image forming parameters to suppress speed fluctuations in the image carrier or transfer section.

[0088] In the image forming apparatus 1 according to this embodiment, the control unit (third control unit 36) presents recommended values ​​for the image forming parameters and changes the image forming parameters by receiving an instruction operation to apply the recommended values ​​or an input operation for the values ​​of the image forming parameters. Therefore, users can choose to modify the image formation parameters according to recommended values ​​or according to their desired values.

[0089] In the image forming apparatus 1 according to this embodiment, the control unit (third control unit 36) determines recommended values ​​for image forming parameters based on location information of abnormalities in the formed image. Therefore, recommended values ​​for image formation parameters can be easily determined based on the location information of the anomaly.

[0090] The image forming apparatus 1 according to this embodiment includes a notification unit (third control unit 36) that notifies the administrator of the image forming apparatus 1 when a speed fluctuation exceeding a predetermined threshold is detected a predetermined number of times in the detection results of speed fluctuations of the image carrier (intermediate transfer belt 342) or the transfer unit (secondary transfer roller 343). Therefore, the operator of the image forming apparatus 1 can determine that a predetermined number of speed fluctuations exceeding a predetermined threshold have been detected in the detection results of speed fluctuations in the image carrier or transfer section.

[0091] The image forming apparatus 1 according to this embodiment includes a control unit (third control unit 36) that, upon receiving a request from the reception unit (third control unit 36) to continue a print job, continues the print job without changing the image forming parameters and controls the notification unit (third control unit 36) to notify the print job in progress. Therefore, if you choose to continue the print job, you can prevent the notification unit from sending notifications for the currently running print job.

[0092] In the image forming apparatus 1 according to this embodiment, the image carrier is an intermediate transfer body (intermediate transfer belt 342) on which multiple images are formed. Therefore, users can obtain information about image defects that occur due to speed fluctuations in the intermediate transfer medium or transfer section.

[0093] In the image forming apparatus 1 according to this embodiment, the paper information includes at least one of the paper thickness, basis weight, and stiffness. Therefore, the pressing force of the transfer unit or the driving conditions of the transfer unit can be appropriately adjusted according to at least one of the paper thickness, basis weight, and stiffness.

[0094] The image forming apparatus 1 according to this embodiment includes a media detection unit 23 that detects the physical properties of the paper. The paper information includes the detection results from the media detection unit 23. Therefore, the media detection unit 23 can easily detect the physical properties of the paper.

[0095] In the image forming apparatus 1 according to this embodiment, the adjustment unit (third control unit 36) increases the amount of separation between the image carrier and the transfer unit when the paper enters the transfer nip 34a formed by the image carrier (intermediate transfer belt 342) and the transfer unit (secondary transfer roller 343), as the value of at least one of the paper thickness, basis weight, and stiffness increases. Therefore, by appropriately adjusting the secondary transfer pressure, it is possible to suppress velocity fluctuations in the image carrier or transfer area.

[0096] In the image forming apparatus 1 according to this embodiment, the adjustment unit (third control unit 36) slows down the paper transport speed at the transfer nip 34a formed by the image carrier (intermediate transfer belt 342) and the transfer unit (secondary transfer roller 343) as the value of at least one of the paper thickness, basis weight, and stiffness increases. Therefore, by appropriately adjusting the secondary transfer rate, it is possible to suppress rate fluctuations in the image carrier or transfer area.

[0097] Although the present invention has been specifically described above based on embodiments, the present invention is not limited to the above embodiments and can be modified without departing from its spirit. For example, the image forming apparatus 1 may be configured to send and receive information for mutual cooperation with a print controller (not shown) that generates and manages print jobs, other image forming systems (not shown), a business management system, etc.

[0098] In this embodiment, the third control unit 36 ​​of the main unit 30 comprehensively controls the entire image forming apparatus 1, but this is not limited to this. A separate control device may be provided, and the control unit of the control device comprehensively controls the entire image forming apparatus 1.

[0099] Furthermore, the detailed configuration and detailed operation of each device constituting the image forming apparatus 1 can also be modified as appropriate without departing from the spirit of the present invention. [Explanation of Symbols]

[0100] 1. Image forming apparatus 10 Paper feeder 11 First Control Unit 12 Conveying section 121 Transport Route 13 Paper feed section 131, 132, 133 Paper feed tray 20 Detection device 21 Second Control Unit 22 Conveying section 23 Media detection unit 231 Paper thickness sensor 232 basis weight sensor 233 Stiffness Sensor 24 Purge Trays R21 Transport Route R22 Stiffness detection path 30 Main body 31 Operation section 32 Display section 33 Manuscript Reading Unit 34 Image forming unit 34a Transfer nip 341Y, 341M, 341C, 341K Photoconductor Drum 342 Intermediate transfer belt (image carrier) 343 Secondary transfer roller (transfer section) 344 Fixing section 344a Heating roller 344b Pressure Roller 344c Fixing Nip 345 Reversal Path 346 Resist section 36. Third Control Unit (Adjustment Unit, Acquisition Unit, Notification Unit, Reception Unit, Control Unit, Notification Unit) 37 Memory section 38 Communications Department 39 Peripheral speed detection unit 40 Post-processing equipment 41 Fourth Control Unit 42 Post-processing 43 Conveying section 44 Paper output tray

Claims

1. An image carrier that supports a toner image on its surface, A transfer unit that transfers the toner image supported on the surface of the image carrier to paper, An adjustment unit that adjusts the pressing force of the transfer unit or the driving conditions of the transfer unit according to the paper information relating to the aforementioned paper, An acquisition unit that acquires the detection result of speed fluctuations of the image carrier or the transfer unit after adjusting the pressing force of the transfer unit or the driving conditions of the transfer unit, A notification unit that notifies information regarding image defects based on the detection results obtained by the acquisition unit, An image forming apparatus equipped with the following features.

2. The image forming apparatus according to claim 1, wherein the notification unit notifies information regarding the image defect when the speed fluctuation in the detection result exceeds a predetermined threshold.

3. The image forming apparatus according to claim 1 or 2, wherein the information relating to the image defect is an example of an image defect.

4. The image forming apparatus according to claim 3, wherein the aforementioned image defect is at least one of white streaks or black streaks in the image.

5. The image forming apparatus according to claim 1, further comprising a receiving unit that accepts a selection whether to stop the print job in progress or to continue the print job after notification by the notification unit.

6. The image forming apparatus according to claim 5, further comprising a control unit that, when the reception unit receives a request to stop the print job, changes the image forming parameters after stopping the print job and restarts the print job using the changed image forming parameters.

7. The image forming apparatus according to claim 6, wherein the image forming parameters include at least one of the following: secondary transfer speed, fixing speed, primary transfer pressure, secondary transfer pressure, fixing nip pressure, paper transport speed, and the number of presses between the image carrier and the transfer section.

8. The image forming apparatus according to claim 6, wherein the control unit presents recommended values ​​for the image forming parameters and changes the image forming parameters by receiving an instruction operation to apply the recommended values ​​or an input operation for the values ​​of the image forming parameters.

9. The image forming apparatus according to claim 8, wherein the control unit determines the recommended value based on location information of the abnormality in the formed image.

10. The image forming apparatus according to claim 1, further comprising a notification unit that notifies the administrator of the image forming apparatus when the speed fluctuation exceeding a predetermined threshold is detected a predetermined number of times in the detection results.

11. The image forming apparatus according to claim 5, further comprising a control unit that, when the reception unit receives a request to continue the print job, continues the print job without changing the image forming parameters and controls the notification unit not to provide notification for the print job in progress.

12. The image forming apparatus according to claim 1, wherein the image carrier is an intermediate transfer body on which a plurality of images are formed.

13. The image forming apparatus according to claim 1, wherein the paper information includes at least one of the paper thickness, basis weight, and stiffness.

14. The system includes a media detection unit that detects the physical properties of the aforementioned paper, The image forming apparatus according to claim 1, wherein the aforementioned paper information includes the detection result by the media detection unit.

15. The image forming apparatus according to claim 13, wherein the adjustment unit increases the amount of separation between the image carrier and the transfer unit when the paper enters the transfer nip formed by the image carrier and the transfer unit, the greater the value of at least one of the paper thickness, basis weight, and stiffness.

16. The image forming apparatus according to claim 13, wherein the adjustment unit slows down the paper transport speed in the transfer nip formed by the image carrier and the transfer unit as the value of at least one of the paper thickness, basis weight, and stiffness increases.

17. An image carrier that supports a toner image on its surface, A transfer unit that transfers the toner image supported on the surface of the image carrier to paper, A computer for an image forming apparatus equipped with, An adjustment unit that adjusts the pressing force of the transfer unit or the driving conditions of the transfer unit according to the paper information relating to the aforementioned paper, An acquisition unit that acquires the detection result of speed fluctuations of the image carrier or the transfer unit after adjusting the pressing force of the transfer unit or the driving conditions of the transfer unit. A notification unit provides information regarding image defects based on the detection results obtained by the acquisition unit. A program that makes it function as such.

Images