Image forming apparatus

Abstract

To improve working efficiency.SOLUTION: An image forming apparatus 1 comprises: an image forming unit 6 that forms a toner based on image data on an intermediate transfer belt 21; a secondary transfer section 28 that transfers the toner formed on the intermediate transfer belt 21 to a continuous form medium P; a waste toner box 32 that recovers the toner removed from the intermediate transfer belt 21; and a main control section 4 that, in a case where the continuous paper is in a paper feed state, and the main control section causes the image forming unit 6 to form a color shift detection pattern not based on the image data on the intermediate transfer belt 21, when the amount of toner stored in the waste toner box 32 is equal to or more than a predetermined amount, recovers the color shift detection pattern on the continuous paper, and when the amount of toner stored in the waste toner box 32 is less than the predetermined amount, recovers the color shift detection pattern in the waste toner box 32.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus, and is suitable for use in an image forming apparatus that performs printing on a long medium using, for example, continuous paper. [Background technology]

[0002] Conventionally, as an image forming apparatus (also called a printer), an apparatus that performs a printing process by forming a developer image (also called a toner image) by an image forming unit using a developer (also called a toner image) based on an image supplied from a computer device or the like, transferring the developer image (also called a toner image) to a medium such as paper, and fixing the image by applying heat and pressure, has been widely used. Among such image forming apparatuses, there is one that performs a printing process on a long continuous paper that is long in the conveying direction (for example, see Patent Document 1). In addition, among image forming apparatuses, there is one that cleans the intermediate transfer belt by scraping off waste toner adhering to the surface of the intermediate transfer belt and collecting it in a waste toner box as a waste developer storage section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP2019-172421A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in such an image forming device, when the waste toner adhering to the surface of the intermediate transfer belt is collected in the waste developer storage section, the waste developer storage section may become full, which may result in the waste developer storage section having to be replaced while printing continuous paper, potentially reducing work efficiency.

[0005] The present invention has been made in consideration of the above points, and aims to propose an image forming apparatus capable of improving work efficiency. [Means for solving the problem]

[0006] In order to solve such problems, the image forming apparatus of the present invention is provided with an image forming unit that forms developer based on image data on the belt, a transfer section that transfers the developer formed on the belt to continuous paper, a waste developer storage section that recovers developer removed from the belt, and a control section that, when the continuous paper is in a paper-passing state and non-printing developer not based on image data is formed on the belt from the image forming unit, if the amount of developer stored in the waste developer storage section is equal to or greater than a predetermined amount, recovers the non-printing developer onto the continuous paper, while if the amount of developer stored in the waste developer storage section is less than the predetermined amount, recovers the non-printing developer in the waste developer storage section.

[0007] To prevent a situation in which a waste developer storage section becomes full when non-printing developer is collected in the waste developer storage section, and the waste developer storage section has to be replaced during printing of continuous paper. Effect of the Invention

[0008] According to the present invention, it is possible to prevent a situation in which the waste developer storage section becomes full when non-printing developer is collected in the waste developer storage section and the waste developer storage section has to be replaced while printing continuous paper, thereby realizing an image forming device that can improve work efficiency. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a left side view showing the overall configuration of the image forming apparatus. [Diagram 2] FIG. 2 is a block diagram showing a control configuration of the image forming apparatus. [Diagram 3] 13 is a flowchart showing a printing process procedure. [Figure 4] FIG. 11 is a diagram showing a lifespan management state of a waste toner box. [Diagram 5] FIG. 13 is a diagram showing a pattern for checking the presence or absence of color misregistration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, modes for carrying out the invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

[0011] [1. Overall configuration of image forming device] As shown in Fig. 1, the image forming apparatus 1 is, for example, a printer using an electrophotographic method, and forms a color image on a medium P such as paper or film by performing an image forming operation using a developer such as toner. In this embodiment, the medium P is a long roll of paper that is long in the transport direction. When such roll paper is to be subjected to post-printing processes such as a laminate coating process or a label die-cutting process for adhesive label sheets, the image forming apparatus 1 may perform continuous operations (also called one-pass operations) with both ends of the roll paper in the transport direction wound into a roll (roll-to-roll), and may perform continuous printing on a medium P several tens of meters long at a time.

[0012] Various parts are arranged inside a housing 2 formed in a substantially box shape in the image forming apparatus 1. In the following description, the right end portion in Fig. 1 is regarded as the front of the image forming apparatus 1, and the up-down direction, left-right direction, and front-rear direction are defined when viewed from the front.

[0013] The image forming apparatus 1 is controlled by a main control unit 4. The main control unit 4 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and executes various processes by reading and executing predetermined programs.

[0014] Four image forming units 6K, 6C, 6M, and 6Y are arranged in order from the front to the rear at the upper side inside the housing 2. The image forming units 6K, 6C, 6M, and 6Y correspond to the colors black (K), cyan (C), magenta (M), and yellow (Y), respectively, but differ only in color and are all configured the same. Hereinafter, the image forming units 6K, 6C, 6M, and 6Y are also collectively referred to as image forming units 6.

[0015] The image forming unit 6 is roughly composed of an image forming section 8 and a toner cartridge 9. The image forming section 8 has a charging roller 10, an image exposure section 11, a developing roller 12, a supply roller 13, a photoconductor drum 14, and a toner-low detection bar 15.

[0016] The charging roller 10 charges the surface of the photoconductor drum 14. The image exposure unit 11 has an LED head 16 and selectively exposes the charged surface of the photoconductor drum 14 to form an electrostatic latent image. The developing roller 12 electrostatically attaches a thin layer of toner to the electrostatic latent image formed on the surface of the photoconductor drum 14, thereby forming a toner image. The supply roller 13 supplies toner to the surface of the developing roller 12 while rubbing the toner between the supply roller 13 and the developing roller 12 to cause frictional charging. The photoconductor drum 14 rotates in the direction indicated by the arrow, thereby transferring the toner image formed on the surface to the intermediate transfer belt 21 (also referred to as primary transfer). These rotating bodies of the image forming unit 8 are rotated by power transmitted from the photoconductor drum motor 71 (FIG. 2) via gears and the like.

[0017] The toner-low detection bar 15 detects the amount of toner remaining in the image forming section 8 by performing different operations depending on the amount of toner remaining in the image forming unit 6 .

[0018] The toner cartridge 9 contains toner as a developer therein, and is configured to be detachable from the image forming unit 6 .

[0019] An intermediate transfer unit 20 is disposed below each image forming unit 6 within the housing 2. The intermediate transfer unit 20 includes an intermediate transfer belt 21, a drive roller 22, a driven roller 23, a backup roller 24, four primary transfer rollers 25, and a secondary transfer roller 26.

[0020] The intermediate transfer belt 21 is configured as an endless belt made of a high-resistance non-conductive plastic film, and is stretched so as to go around a drive roller 22, a driven roller 23, and a backup roller 24, and runs so as to rotate in the direction of the arrow E1.

[0021] The drive roller 22 rotates in the direction of the arrow when a driving force is supplied from the intermediate transfer belt motor 72 (FIG. 2). The driven roller 23 rotates in the direction of the arrow together with the intermediate transfer belt 21. The backup roller 24 is disposed below and in front of the drive roller 22 and below and in the rear of the driven roller 23.

[0022] The four primary transfer rollers 25 are disposed below the portion of the intermediate transfer belt 21 stretched between the drive roller 22 and the driven roller 23, i.e., directly below each of the four image forming units 6, at positions facing each of the photoconductor drums 14 across the intermediate transfer belt 21. A predetermined voltage is applied to the primary transfer rollers 25 under the control of the main control unit 4.

[0023] The secondary transfer roller 26 is located directly below the backup roller 24 and is biased toward the backup roller 24. That is, the intermediate transfer unit 20 sandwiches the intermediate transfer belt 21 between the secondary transfer roller 26 and the backup roller 24. A predetermined voltage is applied to the secondary transfer roller 26 based on the control of the main control unit 4. Hereinafter, the secondary transfer roller 26 and the backup roller 24 are collectively referred to as the secondary transfer unit 28. The secondary transfer roller 26 is configured to be separated downward from the intermediate transfer belt 21 by a secondary transfer separation motor 74 (FIG. 2). By separating the secondary transfer roller 26 from the intermediate transfer belt 21, the secondary transfer nip portion between the secondary transfer roller 26 and the backup roller 24 is not formed, and it is possible to prevent the toner image from adhering to the medium P being passed.

[0024] A mark sensor 30 is provided near the intermediate transfer belt 21 to detect the image formed on the intermediate transfer belt 21. The mark sensor 30 is a reflective optical sensor composed of a light emitting element and a light receiving element, and optically detects the image on the intermediate transfer belt 21. When the mark sensor 30 detects a color shift detection pattern during, for example, a color shift correction operation, it supplies the detection result to the main control unit 4. The main control unit 4 carries out the color shift correction operation based on the detection result obtained from the mark sensor 30.

[0025] Here, the toner of each color of image forming units 6K, 6C, 6M, and 6Y needs to be transferred to the same position on the medium P, and if the transfer positions of each color are different, differences in color and color shifts will occur, resulting in poor print quality. Here, differences in color are mainly caused by the toner charging characteristics of the replaced toner cartridge 9, and color shifts are mainly caused by a shift in the mounting position of the replaced photoconductor drum 14. For this reason, the image forming device 1 performs a color shift correction operation when the toner cartridge 9 or photoconductor drum 14 is replaced.

[0026] A cleaning blade 31 is provided near the intermediate transfer belt 21. The cleaning blade 31 has a tip portion in contact with the surface of the intermediate transfer belt 21, and cleans the intermediate transfer belt 21 by scraping off toner, including waste toner of the color shift detection pattern, adhering to the surface of the intermediate transfer belt 21 and dropping the toner into a waste toner box 32 for collection.

[0027] The waste toner box 32 is provided with a waste toner near-full sensor 33 that detects a state in which the waste toner stored therein is nearly full (hereinafter also referred to as a near-full state). When the waste toner near-full sensor 33 detects the waste toner stored in the waste toner box 32, it supplies the detection result to the main control unit 4. The main control unit 4 determines that the waste toner box 32 has reached a near-full state based on the detection result acquired from the waste toner near-full sensor 33. When the waste toner box 32 becomes full, it is removed from the image forming apparatus 1 by the user and replaced with a new one. In the present embodiment, the waste toner box 32 is integrally formed with the intermediate transfer belt 21. Therefore, when the waste toner box 32 is replaced, the intermediate transfer belt 21 is also replaced together with the waste toner box 32.

[0028] The intermediate transfer unit 20 rotates the drive roller 22 in the direction of the arrow by the driving force supplied from the intermediate transfer belt motor 72 (FIG. 2), thereby moving the intermediate transfer belt 21 in the direction of the arrow E1. In addition, each primary transfer roller 25 rotates in a clockwise direction with a predetermined bias voltage applied thereto. As a result, each image forming unit 6 transfers the toner image that has reached the vicinity of the lower end of the circumferential side surface of the photosensitive drum 14 to the intermediate transfer belt 21, and sequentially superimposes the toner images of each color. At this time, the toner images of each color are sequentially superimposed on the surface of the intermediate transfer belt 21, starting from black (K) on the upstream side. The intermediate transfer unit 20 moves the intermediate transfer belt 21, thereby causing the toner images transferred from each image forming unit 6 to reach the vicinity of the backup roller 24.

[0029] Meanwhile, a transport path W, which is a path for transporting the medium P, is formed inside the housing 2. This transport path W extends horizontally from the front end of the housing 2 toward the rear, proceeds rearward below the intermediate transfer unit 20, and reaches the rear end of the housing 2.

[0030] The pair of conveying rollers 35 is positioned toward the front of the conveying path W and is driven by a conveying motor 70 (Figure 2). The conveying rollers 35 rotate while clamping the medium P fed from a paper feed unit (not shown) outside the housing 2, thereby causing the medium P to move backward along the conveying path W.

[0031] A fixing unit 37 is disposed behind the secondary transfer unit 28. The fixing unit 37 is composed of a fixing roller 38 and a pressure roller 39 disposed to face each other across the conveying path W. The fixing roller 38 is driven by a fixing motor 73 (FIG. 2), and is provided with a heat-generating fixing heater 40 and a plurality of rollers disposed inside a heating belt formed of a hollow endless belt. The pressure roller 39 is cylindrical with a central axis aligned in the left-right direction, and presses its upper surface against the lower surface of the fixing roller 38 to form a nip portion. A temperature sensor 41 is disposed above the fixing roller 38 to detect the surface temperature of the fixing roller 38. The temperature sensor 41 is, for example, a thermistor, and supplies the temperature detection result to the main control unit 4. The main control unit 4 determines the surface temperature of the fixing roller 38 based on the detection result obtained from the temperature sensor 41.

[0032] Based on the control of the main control unit 4, the fixing unit 37 heats the fixing heater 40 of the fixing roller 38 to a predetermined temperature and rotates it appropriately, and also rotates the pressure roller 39. Then, when the fixing unit 37 receives the medium P onto which the toner image has been transferred by the secondary transfer unit 28, it sandwiches (i.e. nips) it between the fixing roller 38 and the pressure roller 39 and applies heat and pressure to fix the toner image to the medium P, and sends it out rearward. The medium P is transported along the transport path W until it reaches the rear end of the housing 2, and is discharged to the outside of the housing 2.

[0033] [2. Control configuration of image forming device] 2, the image forming apparatus 1 is controlled as a whole by a main control unit 4. The main control unit 4 has a CPU, ROM, RAM, input / output ports, a timer, etc., and executes various processes by reading and executing a predetermined program. The main control unit 4 is also connected to a higher-level device 50 such as a computer device by wireless or wired connection, and when it receives a print command 51, which is a print command consisting of control data, print data, and a control signal, from the higher-level device 50 via a data receiving unit 52, it interprets the print command 51 and performs program control of the entire sequence of the image forming apparatus 1 to perform a print operation.

[0034] To the main control unit 4, a memory circuit unit 54, an operation panel unit 56, a detection circuit unit 58, a transport control unit 60, a fixing unit 37, an image exposure unit 11, an image forming unit 8, and a transfer control unit 62 are connected.

[0035] The memory circuit unit 54 has a non-volatile memory that stores various setting information for the image forming apparatus 1, and a buffer memory for expanding the print data transmitted from the higher-level device 50 into a temporary storage area that temporarily stores the print data.

[0036] The operation panel unit 56 has operation keys 56a for accepting various operations, a liquid crystal (LCD) panel 56b for displaying the operation status, and an LED lamp 56c for displaying the power on / off state, etc., and allows the user to set operation mode information, etc. during printing processing of the image forming device 1.

[0037] The detection circuit unit 58 has a waste toner near-full sensor 33, a mark sensor 30, and a temperature sensor 41. The transport control unit 60 controls the operations of the transport motor 70, the photoconductor drum motor 71, the intermediate transfer belt motor 72, the fixing motor 73, and the secondary transfer separation motor 74. The fixing unit 37 has a fixing heater 40, and by controlling the fixing heater 40, heats the fixing roller 38 (FIG. 1) to a predetermined temperature.

[0038] The image exposure unit 11 controls the operation of the LED head 16 that forms an electrostatic latent image on the surface of the photoconductor drum 14 in each of the four image forming units 6. The image forming unit 8 controls the voltages applied to the charging roller 10, the supply roller 13, and the developing roller 12 in each of the four image forming units 6. The transfer control unit 62 controls the voltages applied to the primary transfer roller 25 and the secondary transfer roller 26 in each of the four image forming units 6.

[0039] In this manner, the image forming apparatus 1 is provided with an image forming unit 6 that forms a toner image on the intermediate transfer belt 21 based on image data (i.e., performs primary transfer), a secondary transfer roller 26 that transfers the toner image on the intermediate transfer belt 21 to a medium P (i.e., performs secondary transfer), a cleaning blade 31 that removes and cleans the toner image remaining on the intermediate transfer belt 21 without being transferred to the medium P, and a fixing unit 37 that fixes the toner image to the medium P, and the main control unit 4 determines whether the waste toner box 32 is near full based on the detection result of the waste toner near-full sensor 33.

[0040] [3. Color shift correction processing] A specific procedure of the color misregistration correction process by the image forming apparatus 1 will be described with reference to the flowchart of FIG. 3. In step SP1, the main control unit 4 recognizes that the toner cartridge 9 has been replaced by reading information from an RFID (Radio Frequency Identification) tag attached to the toner cartridge 9, and proceeds to step SP2. In step SP2, the main control unit 4 determines whether the medium P is being conveyed along the conveying path W (i.e., paper passing state) based on the detection result of a collision sensor (not shown) provided near the conveying roller pair 35. If a negative result is obtained here, this indicates that the medium P is not present on the conveying path W (i.e., paper non-passing state), and therefore the toner of the color misregistration detection pattern that has adhered to the intermediate transfer belt 21 in the color misregistration correction operation is scraped off by the cleaning blade 31, and the color misregistration detection pattern waste toner, which is the waste toner, is collected in the waste toner box 32 instead of the medium P, and the main control unit 4 proceeds to step SP7.

[0041] In step SP7, the main control unit 4 drives the secondary transfer separation motor 74 to move the secondary transfer roller 26 away from the intermediate transfer belt 21, thereby controlling the intermediate transfer belt 21 not to contact the medium P, and then proceeds to step SP8. In step SP8, the main control unit 4 starts the color misregistration correction operation caused by replacement of the toner cartridge 9, and then proceeds to step SP9.

[0042] In the color misregistration correction operation, the main control unit 4 transfers a predetermined color misregistration detection pattern from the image forming unit 6 onto the intermediate transfer belt 21, and causes the transferred color misregistration detection pattern to be read by the mark sensor 30. Next, the main control unit 4 performs the color misregistration correction operation based on the reading result by the mark sensor 30. The color misregistration detection pattern is an image for detecting the amount of color misregistration of other colors (cyan, magenta, or yellow) using a black image as a reference.

[0043] In step SP9, the main control unit 4 waits until the color misregistration correction operation is completed, and when it is completed, the process proceeds to step SP18, where the printing process procedure RT1 is terminated. During this color misregistration correction operation, the toner of the color misregistration detection pattern that has adhered to the intermediate transfer belt 21 is scraped off by the cleaning blade 31 and becomes color misregistration detection pattern waste toner, which is then collected in the waste toner box 32.

[0044] On the other hand, if a positive result is obtained in step SP2, this indicates that the medium P is in a paper passing state being transported along the transport path W, and at this time the main control unit 4 proceeds to step SP3. In step SP3, the main control unit 4 determines whether the waste toner box 32 is in a near-full state based on the detection result from the waste toner near-full sensor 33. If a negative result is obtained here, this indicates that the waste toner box 32 has not reached a near-full state and therefore the color misregistration detection pattern waste toner can be sufficiently collected in the waste toner box 32, and at this time the main control unit 4 proceeds to step SP7 and executes the color misregistration correction operation with the waste toner box 32 as the collection destination for the color misregistration detection pattern waste toner, as described above.

[0045] On the other hand, if a positive result is obtained in step SP3, this indicates that the waste toner box 32 has reached a near-full state and there is a possibility that the color shift detection pattern waste toner cannot be sufficiently collected in the waste toner box 32, and in this case the main control unit 4 proceeds to step SP4.

[0046] In step SP4, the main control unit 4 refers to the menu setting previously set by the user via the operation panel unit 56, and determines whether the collection method for the color misregistration detection pattern waste toner is set to collection into the waste toner box 32 or collection into the medium P. For example, if the user wants to reduce waste paper, which is an area of ​​the medium P where normal printing is not performed due to the color misregistration detection pattern being transferred to the medium P, the user sets the collection method for the color misregistration detection pattern waste toner to collection into the waste toner box 32. On the other hand, if the user wants to avoid the color misregistration correction operation filling up the waste toner box 32 and preventing printing from being unable to continue in the image forming apparatus 1, even if there is a possibility that waste paper may increase, the user sets the collection method for the color misregistration detection pattern waste toner to collection into the medium P.

[0047] Here, if collection to waste toner box 32 is set, this indicates that the user wishes to have the color shift detection pattern waste toner collected to waste toner box 32, even if waste toner box 32 has reached a near-full state and therefore the color shift detection pattern waste toner may not be able to be sufficiently collected in waste toner box 32. In this case, the main control unit 4 proceeds to step SP7 and performs color shift correction operation with the color shift detection pattern waste toner being collected to waste toner box 32 as described above.

[0048] On the other hand, if recovery to medium P is set in step SP4, this indicates that the user wishes to recover the color misregistration detection pattern waste toner to medium P, and in this case the main control unit 4 proceeds to step SP5. In step SP5, the main control unit 4 calculates the amount of color misregistration detection pattern waste toner and stores it in the memory circuit unit 54 as the color misregistration detection pattern waste toner amount, and proceeds to step SP6. The main control unit 4 counts the toner image that is not transferred to medium P by the secondary transfer roller 26 and remains on the intermediate transfer belt 21 as the amount of waste toner during printing operation as waste toner, but counts all of the toner images of the color misregistration detection pattern as waste toner for the amount of waste toner during color misregistration correction operation (color misregistration detection pattern waste toner amount) because the secondary transfer roller 26 is separated from the intermediate transfer belt 21.

[0049] In step SP6, the main control unit 4 determines whether the amount of waste toner of the color shift detection pattern is equal to or greater than the waste toner box collectable remaining amount, which is the amount of waste toner remaining in the waste toner box 32 that can be collected (i.e., waste toner box collectable remaining amount≦waste toner amount of the color shift detection pattern).

[0050] Here, as shown in FIG. 4, immediately after the waste toner box 32 is replaced with a new one, the amount of waste toner in the waste toner box 32 is an empty level LVe. When the amount of waste toner in the waste toner box 32 reaches a full level LVf, which is a life threshold, the waste toner box 32 is determined to be full. After the waste toner box 32 is replaced with a new one, waste toner accumulates in the waste toner box 32, and when the amount of waste toner in the waste toner box 32 reaches a near-full level LVn, the main control unit 4 recognizes that the waste toner box 32 is in a near-full state based on the detection result from the waste toner near-full sensor 33. From this point on, the main control unit 4 accumulates the amount of waste toner by adding the amount of waste toner collected to the current amount of waste toner in the waste toner box 32 every time waste toner is collected in the waste toner box 32. When the current amount of waste toner in the waste toner box 32 is, for example, a current level LVc, the main control unit 4 determines whether the amount of waste toner exceeds the full level LVf when the amount of waste toner of the color shift detection pattern is added to the current level LVc. Here, if the amount of waste toner does not exceed the full level LVf, the main control section 4 obtains a negative result in step SP6, whereas if the amount of waste toner exceeds the full level LVf, the main control section 4 obtains a positive result in step SP6.

[0051] If a negative result is obtained in step SP6, this indicates that the color misregistration detection pattern waste toner can be sufficiently collected in the waste toner box 32, and therefore the collection method for the color misregistration detection pattern waste toner is changed from collection onto medium P to collection into the waste toner box 32, thereby reducing paper waste. In this case, the main control unit 4 proceeds to step SP7 and performs color misregistration correction operation with the color misregistration detection pattern waste toner being collected into the waste toner box 32 as described above.

[0052] On the other hand, if a positive result is obtained in step SP6, this means that it is not possible to collect all of the color misregistration detection pattern waste toner in the waste toner box 32, and therefore, as desired by the user who set the collection method for the color misregistration detection pattern waste toner to be collected onto medium P, a color misregistration correction operation is executed with the color misregistration detection pattern waste toner being collected onto medium P, and at this time the main control unit 4 proceeds to step SP10.

[0053] In step SP10, the main control unit 4 drives the secondary transfer separation motor 74 to move the secondary transfer roller 26 away from the intermediate transfer belt 21, thereby controlling the intermediate transfer belt 21 not to contact the medium P, and then proceeds to step SP11. In step SP11, the main control unit 4 starts a color misregistration correction operation caused by replacement of the toner cartridge 9, and then proceeds to step SP12.

[0054] In the color misregistration correction operation, the main control unit 4 transfers a predetermined color misregistration detection pattern from the image forming unit 6 onto the intermediate transfer belt 21 as described above, and causes the transferred color misregistration detection pattern to be read by the mark sensor 30. Next, the main control unit 4 performs the color misregistration correction operation based on the reading result by the mark sensor 30. The color misregistration detection pattern is an image for detecting the amount of color misregistration of other colors (cyan, magenta, or yellow) using a black image as a reference.

[0055] In step SP12, the main control unit 4 causes the mark sensor 30 to read the color misregistration detection pattern, and then drives the secondary transfer separation motor 74 to move the secondary transfer roller 26 so as to abut against the intermediate transfer belt 21 at a timing immediately before the color misregistration detection pattern reaches the secondary transfer roller 26, thereby controlling the intermediate transfer belt 21 to contact the medium P, and proceeds to step SP13. In this way, the image forming apparatus 1 rotates the intermediate transfer belt 21 without rotating the pair of conveyor rollers 35, moves the color misregistration detection pattern formed on the intermediate transfer belt 21 from the image forming unit 6 as the intermediate transfer belt 21 travels in the direction of the arrow E1, and brings the secondary transfer roller 26 and the backup roller 24 into a nip state at a timing immediately before the color misregistration detection pattern reaches the secondary transfer unit 28, thereby reducing paper waste as much as possible.

[0056] In step SP13, the main control unit 4 turns on the fixing heater 40, and proceeds to step SP14. In step SP14, the main control unit 4 starts driving the transport motor 70 and the fixing motor 73 to start the transport operation of the medium P, transporting the medium P, and proceeds to step SP15. By this transport operation, the toner images of the color shift detection patterns formed on the surfaces of the respective photoconductor drums 14 are transferred and fixed onto the passing medium P.

[0057] In step SP15, the main control unit 4 waits until the color misregistration correction operation is completed, and when it is completed, the process proceeds to step SP16. In step SP16, the main control unit 4 turns off the drive of the fixing heater 40, and the process proceeds to step SP17. In step SP17, the main control unit 4 stops the drive of the conveying motor 70 and the fixing motor 73 to end the conveying operation, and the process proceeds to step SP18, where the printing process procedure RT1 is ended.

[0058] [4. Effects, etc.] In the above configuration, when the image forming device 1 is in a paper passing state and forms a color misregistration detection pattern, which is a toner image not based on image data received from the higher-level device 50, on the intermediate transfer belt 21 from the image forming unit 6, if the amount of waste toner of the color misregistration detection pattern is equal to or greater than the remaining amount that can be collected in the waste toner box (in other words, the amount of toner contained in the waste toner box 32 is equal to or greater than a predetermined amount) when the toner cartridge 9 is replaced, the image forming device 1 is configured to collect the color misregistration detection pattern in the waste toner box 32 if the amount of waste toner of the color misregistration detection pattern is less than the remaining amount that can be collected in the waste toner box (in other words, the amount of toner contained in the waste toner box 32 is less than a predetermined amount).

[0059] Therefore, in the case where the waste toner box 32 becomes full when the waste toner for the color misregistration detection pattern generated during the color misregistration correction operation for replacing the toner cartridge 9 is collected in the waste toner box 32, the image forming device 1 can collect the color misregistration detection pattern in the medium P instead of the waste toner box 32. This makes it possible for the image forming device 1 to prevent a situation from occurring in which the toner cartridge 9, which is a consumable item, is replaced during printing on the medium P, which is continuous paper, and printing has to be interrupted to replace the waste toner box 32.

[0060] Here, the amount of waste toner of the color misregistration detection pattern (color misregistration detection pattern waste toner) during the color misregistration correction operation performed after replacing the toner cartridge 9 is particularly large compared to the residual waste toner adhering to the intermediate transfer belt 21 generated during printing, and the entire amount, not just a portion of the color misregistration detection pattern, is collected in the waste toner box 32. For this reason, if the waste toner box 32 is nearly full when the toner cartridge 9 is replaced, the waste toner box 32 becomes full due to the color misregistration detection pattern waste toner, and printing is interrupted in order to replace the waste toner box 32. In response to this, the image forming apparatus 1 can prevent the waste toner box 32 from becoming full during the color misregistration correction operation performed after replacing the toner cartridge 9, when the amount of waste toner collected in the waste toner box 32 increases.

[0061] As described above, since the waste toner box 32 is integrally formed with the intermediate transfer belt 21, when the waste toner box 32 is replaced, the intermediate transfer belt 21 is also replaced together with the waste toner box 32. When the intermediate transfer belt 21 is removed from the image forming apparatus 1 together with the waste toner box 32 in the paper passing state of the medium P, it is necessary to remove the medium P, which is continuous paper, from the image forming apparatus 1 in order to prevent the attitude of the medium P from changing and causing problems such as skew and jamming during subsequent printing. For this reason, when the waste toner box 32 becomes full in the paper passing state, the user is required to perform the troublesome task of removing the medium P from the image forming apparatus 1 and setting it again in addition to replacing the waste toner box 32. In contrast, in the case of the image forming apparatus 1, it is possible to prevent the user from performing the troublesome task of removing the medium P from the image forming apparatus 1 and setting it again.

[0062] According to the above configuration, the image forming device 1 includes an image forming unit 6 that forms toner as a developer based on image data on the intermediate transfer belt 21 as a belt, a secondary transfer unit 28 that transfers the toner formed on the intermediate transfer belt 21 to a continuous paper medium P, a waste toner box 32 that collects toner removed from the intermediate transfer belt 21, and a main control unit 4 that, when the continuous paper is in a paper passing state and a color misregistration detection pattern as a non-printing developer not based on image data is formed on the intermediate transfer belt 21 from the image forming unit 6, if the amount of toner contained in the waste toner box 32 is a predetermined amount or more, the color misregistration detection pattern is collected on the continuous paper, and if the amount of toner contained in the waste toner box 32 is less than the predetermined amount, the color misregistration detection pattern is collected in the waste toner box 32.

[0063] This allows the image forming device 1 to prevent a situation in which the waste toner box 32 becomes full when the color misregistration detection pattern is collected in the waste toner box 32, and the waste toner box 32 has to be replaced during printing of continuous paper.

[0064] 5. Other embodiments In the above-described embodiment, when the image forming apparatus 1 collects the color shift detection pattern waste toner on the medium P, the color shift presence / absence check pattern PT shown in FIG. 5 may be printed on both the upstream side and downstream side of the color shift detection pattern waste toner in the transport direction of the medium P, or at least on the upstream side. As shown in FIG. 5(A), the color shift presence / absence check pattern PT includes three check block images IM, i.e., check block images IMC, IMM, and IMY (hereinafter collectively referred to as check block images IM), corresponding to cyan, magenta, and yellow, respectively, arranged along the main scanning direction (transport width direction) perpendicular to the transport direction D of the medium P. The check block image IMC is composed of a frame line FB and an inner frame image IMIC. The frame line FB is a reference black rectangular frame line drawn with a line of, for example, about 2 or 3 dots wide. The inner frame image IMIC is an image in which the area inside the frame line FB is filled with cyan. The confirmation block images IMM and IMY are configured in almost the same manner as the confirmation block image IMC, with the framed image IMIM of the confirmation block image IMM being magenta, and the framed image IMIY of the confirmation block image IMY being yellow.

[0065] The user can check the presence or absence of color misalignment for each toner color by visually checking whether the positions of the frame images IMIC, IMIM, and IMIY (hereinafter collectively referred to as the frame images IMI) within the frame lines FB of the confirmation block images IMC, IMM, and IMY in the color misalignment check pattern PT are misaligned with respect to the frame lines FB. For example, in the color misalignment check pattern PT shown in FIG. 5A, the frame images IMIC, IMIM, and IMIY for all the confirmation block images IM (confirmation block images IMC, IMM, and IMY) are contained within the frame lines FB without misalignment, and there is no misalignment of the frame images IMI with respect to the frame lines FB. Therefore, the user can check that there is no color misalignment in any of the toner colors in the color misalignment check pattern PT shown in FIG. 5A. On the other hand, for example, in the color misregistration check pattern PT shown in Fig. 5(B), the frame image IMIM for the check block image IMM does not fit within the frame line FB and is shifted toward the transport direction D, so it is possible to confirm the portion inside the frame line FB where the frame image IMIM does not exist and the medium P is exposed. For this reason, the user can confirm that color misregistration has occurred in the magenta toner color in the color misregistration check pattern PT shown in Fig. 5(B).

[0066] When collecting the color shift detection pattern waste toner onto a medium P, the image forming device 1 prints a color shift confirmation pattern PT at least on the upstream side in the transport direction of the medium P, thereby allowing the user to confirm that color shift correction has been performed appropriately.

[0067] In the above embodiment, the present invention is applied to the image forming apparatus 1 when the toner cartridge 9, which is a consumable item, is replaced. However, the present invention is not limited to this, and the present invention may be applied to the image forming apparatus 1 when the photoconductor drum 14, which is a consumable item, is replaced.

[0068] Further, in the above-described embodiment, the present invention has been described as being applied to a case where the image forming apparatus 1 selects whether to collect the color misregistration detection pattern waste toner into either the medium P or the waste toner box 32 depending on the amount of the color misregistration detection pattern waste toner generated during the color misregistration correction operation. The present invention is not limited to this, and the present invention may be applied to a case where the image forming apparatus 1 selects whether to collect the concentration detection pattern waste toner into either the medium P or the waste toner box 32 depending on the amount of the concentration detection pattern waste toner generated when the concentration detection pattern is formed on the intermediate transfer belt 21 as a non-printing developer and a concentration correction operation is performed according to the concentration detection pattern as a concentration correction image. The present invention may also be applied to a case where the image forming apparatus 1 selects whether to collect the waste toner into either the medium P or the waste toner box 32 depending on the amount of the waste toner generated during a deteriorated toner disposal operation in which deteriorated toner inside the image forming unit 6 is discharged onto the intermediate transfer belt 21 as waste toner as a non-printing developer.

[0069] Furthermore, in the above-mentioned first embodiment, the present invention has been described as being applied to an image forming apparatus 1 having four image forming units 6 and forming a color image using toner of four colors. However, the present invention is not limited to this, and the present invention may be applied to an image forming apparatus having two, three, five or more image forming units 6 and forming an image using toner of a predetermined number of colors.

[0070] Furthermore, in the above-mentioned first embodiment, the present invention has been described as being applied to the image forming apparatus 1 which is a single-function printer. However, the present invention is not limited to this, and the present invention may be applied to an image forming apparatus having various other functions, such as an MFP (Multi Function Peripheral) having the functions of a copier or facsimile machine.

[0071] Furthermore, the present invention is not limited to the above-mentioned embodiments and other embodiments. That is, the scope of application of the present invention extends to embodiments in which the above-mentioned embodiments and the other embodiments are combined in part or in whole in any manner. The scope of application of the present invention also extends to embodiments in which a part of the configuration described in any of the above-mentioned embodiments and other embodiments is extracted and replaced or diverted with a part of the configuration of any of the above-mentioned embodiments and other embodiments, or an embodiment in which a part of the extracted configuration is added to any of the embodiments.

[0072] Furthermore, in the above-described embodiment, the image forming apparatus 1 is configured as an image forming apparatus by the image forming unit 6 as an image forming unit, the secondary transfer portion 28 as a transfer portion, the waste toner box 32 as a waste developer storage portion, and the main control portion 4 as a control portion. The present invention is not limited to this, and the image forming apparatus may be configured by an image forming unit, a transfer portion, a waste developer storage portion, and a control portion having various other configurations. [Industrial Applicability]

[0073] The present invention can be used in an image forming apparatus that performs printing on a long medium using continuous paper. [Explanation of symbols]

[0074] 1: image forming apparatus, 2: housing, 4: main control section, 6: image forming unit, 8: image forming section, 9: toner cartridge, 10: charging roller, 11: image exposure section, 12: developing roller, 13: supply roller, 14: photoconductor drum, 15: toner low detection bar, 16: LED head, 20: intermediate transfer section, 21: intermediate transfer belt, 22: driving roller, 23: driven roller, 24: backup roller, 25: primary transfer roller, 26: secondary transfer roller, 28: secondary transfer section, 30: mark sensor, 31: cleaning blade, 32: waste toner box, 33: waste toner near full sensor, W: transport path, 35: transport roller pair, 37: fixing section, 38: fixing roller roller, 39...pressure roller, 40...fixing heater, 41...temperature sensor, 50...host device, 51...print instruction, 52...data receiving section, 54...memory circuit section, 56...operation panel section, 56a...operation key, 56b...LCD panel, 56c...LED lamp, 58...detection circuit section, 60...conveyance control section, 62...transfer control section, 70...conveyance motor, 71...photoconductor drum motor, 72...intermediate transfer belt motor, 73...fixing motor, 74...secondary transfer separation motor, LVe...empty level, LVn...near full level, LVf...full level, LVc...current level, P...medium, PT...color misregistration confirmation pattern, IM...confirmation block image, FB...frame line, IMI...framed image.

Claims

1. an image forming unit that forms a developer on a belt based on image data; a transfer section that transfers the developer formed on the belt onto a continuous sheet of paper; a waste developer storage section for collecting the developer removed from the belt; a control unit that, when the continuous paper is in a paper passing state and a non-printing developer not based on the image data is formed on the belt from the image forming unit, recovers the non-printing developer onto the continuous paper if the amount of the developer stored in the waste developer storage unit is equal to or greater than a predetermined amount, and recovers the non-printing developer into the waste developer storage unit if the amount of the developer stored in the waste developer storage unit is less than the predetermined amount; An image forming apparatus comprising:

2. the non-printing developer is a correction image, A sensor for detecting the correction image and the waste developer container collects the developer of the correction image that has been removed from the belt after being detected by the sensor; The control unit performs a correction process in accordance with a detection result by the sensor. The image forming apparatus according to claim 1 .

3. The control unit is When the continuous paper is in the paper passing state and the non-printing developer is formed on the belt from the image forming unit, if a recoverable remaining volume of the developer in the waste developer storage section is smaller than the amount of developer of the correction image, the non-printing developer is recovered on the continuous paper, whereas if a recoverable remaining volume of the developer in the waste developer storage section is equal to or larger than the amount of developer of the correction image, the non-printing developer is recovered in the waste developer storage section. The image forming apparatus according to claim 2 .

4. The control unit is When a consumable item is replaced in the image forming apparatus, the continuous paper is in the paper passing state, and when the non-printing developer is formed on the belt from the image forming unit, if the amount of the developer stored in the waste developer storage unit is equal to or greater than a predetermined amount, the non-printing developer is recovered onto the continuous paper, whereas if the amount of the developer stored in the waste developer storage unit is less than the predetermined amount, the non-printing developer is recovered in the waste developer storage unit. The image forming apparatus according to claim 2 .

5. The image forming unit is provided in a plurality of units, The consumable item is a developer container that supplies the developer to the image forming unit. The image forming apparatus according to claim 4 .

6. The consumable is a photoconductor drum in the image forming unit. The image forming apparatus according to claim 4 .

7. The correction image is at least one of a color shift correction image and a density correction image. The image forming apparatus according to claim 2 .

8. The non-printing developer is The developer is deteriorated inside the image forming unit. The image forming apparatus according to claim 1 .

9. The control unit is When the continuous paper is not in the paper passing state, the non-printing developer is collected in the waste developer storage unit. The image forming apparatus according to claim 1 .

10. The control unit is Even if the recovery destination of the non-printing developer is specified as the continuous paper, if the recoverable remaining volume of the developer in the waste developer storage unit is equal to or larger than the amount of developer of the correction image, the non-printing developer is caused to be recovered in the waste developer storage unit. The image forming apparatus according to claim 3 .

11. The control unit is An image for confirming that the correction process has been performed is printed on the continuous paper. The image forming apparatus according to claim 2 .

12. The waste developer storage section is integrally formed with the belt. The image forming apparatus according to claim 1 .

Images