JP2016194569A - Image forming apparatus, developer recovery method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute any one recovery processing of a plurality of types of recovery processing according to a condition.SOLUTION: A printer 1 comprises photoreceptor drums 31, a conveyance belt 53, photoreceptor blades 36, a transfer part 50, and a belt blade 56. When the printer detects paper jam and stops printing or prints a predetermined number or more of sheets after execution of correction processing, a control part 80 controls a transfer voltage and causes a part of a toner carried on the photoreceptor drums 31 to be transferred onto the transfer belt 53, so as to recover the toner with both the photoreceptor blades 36 and the belt blade 56. When the printer does not print the predetermined number or more of sheets after the execution of the correction processing, the control part 80 does not apply a transfer voltage, so as to recover the toner with the photoreceptor blades 36.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus, a developer collecting method, and a program, and more particularly to an image forming apparatus including a device for cleaning developer remaining on the surface of an image carrier, a developer collecting method, and a program. .

  2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus includes a first cleaning device that removes a primary transfer residual developer from an image carrier, and a second cleaning device that removes a secondary transfer residual developer from an intermediate transfer member. (Patent Document 1). Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for collecting the developer transferred to the image carrier in the developing device refresh operation in both the first cleaning device and the second cleaning device.

JP 2008-292734 A

  Incidentally, there is a configuration in which the developer is collected by either the image carrier or the intermediate transfer member, but the developer is shared by both the first cleaning device and the second cleaning device of Patent Document 1. It is not considered how to separate it from the structure to be collected.

  The present application has been proposed in view of the above-described problems, and an object thereof is to provide an image forming apparatus, a developer recovery method, and a program that execute any one of a plurality of recovery processes.

  An image forming apparatus according to the present application is carried on a photoconductor, a belt in contact with the photoconductor, a first cleaning member that contacts the photoconductor and cleans the photoconductor, and a transfer voltage is applied. A transfer unit that transfers the developer to the belt; a second cleaning member that contacts the belt and cleans the belt; and a control unit. The control unit performs the first transfer in response to receiving the print job. A printing process in which a voltage is applied to the transfer unit, a first transfer process in which a transfer voltage is not applied to the transfer unit with respect to an area in which the developer is carried on the photoconductor, and an area in which the developer is carried on the photoconductor On the other hand, a second transfer process in which a transfer voltage is applied to the transfer part, a third transfer process in which a second transfer voltage smaller than the voltage value of the first transfer voltage in the printing process is applied to the transfer part, and a photoconductor by the transfer part Developer At least any two of the fourth transfer processes for applying a transfer voltage to the transfer unit for a part of the held area as an option, and any of the processes included in the option depending on the condition An execution process for executing one process is executed.

  The control unit performs a first transfer process in which a transfer voltage is not applied to the transfer unit with respect to the region where the developer is carried on the photosensitive member, and applies a transfer voltage to the transfer unit with respect to the region where the developer is carried on the photosensitive member. A second transfer process to be applied; a third transfer process in which a second transfer voltage smaller than the voltage value of the first transfer voltage in the printing process is applied to the transfer unit; and a region where the developer is carried on the photosensitive member by the transfer unit. At least two of the fourth transfer processes in which a transfer voltage is applied to the transfer portion with respect to a part of the transfer part are options. In other words, the options may include combining any two of the first transfer process, the second transfer process, the third transfer process, and the fourth transfer process, any three processes, and all four processes. . The control unit can perform an execution process for executing any one process included in the options according to the condition.

  According to the image forming apparatus and the like according to the present application, any one of a plurality of collection processes can be executed.

It is sectional drawing which shows schematic structure of the laser printer of embodiment. It is a block diagram which shows the electric constitution of a laser printer. It is a flowchart which shows the processing content of the 1st printing process which concerns on 1st Embodiment. It is the schematic diagram which expanded the part in connection with the photosensitive drum of a laser printer. 6 is a flowchart illustrating processing contents of toner distribution processing. It is a schematic diagram for demonstrating the toner image for lubrication. It is a flowchart which shows the processing content of the 2nd printing process which concerns on 2nd Embodiment. It is a flowchart which shows the processing content of the 3rd printing process which concerns on 3rd Embodiment.

  A configuration of a laser printer (hereinafter abbreviated as a printer) 1 according to the present application will be described with reference to FIG. The printer 1 is a so-called tandem laser printer that uses four color toners.

  In the following description, the direction will be described with reference to the user who uses the printer 1. That is, in FIG. 1, the right side is “front”, the left side is “rear”, the front side is “left”, and the back side is “right”. Also, the vertical direction in FIG.

  As shown in FIG. 1, the printer 1 has a substantially box-shaped main body housing 2, and a paper feeding unit 10, an image forming unit 20, and the like are housed inside the main body housing 2. A discharge tray 5 is formed on the upper surface of the main body housing 2, and the sheets P on which images are formed are stored in a stacked state.

  The sheet feeding unit 10 includes a sheet feeding tray 11 in which sheets P are accommodated, a sheet feeding roller 12, and various rollers. The sheets P are separated one by one by the paper feed roller 12 and conveyed to the image forming unit 20 by various rollers. The paper feed tray 11 is configured to be detachable from the lower portion of the main body housing 2.

  The image forming unit 20 is disposed at a substantially central portion inside the main body housing 2 and includes process cartridges 30C, 30M, 30Y, and 30K, an exposure unit 40, a transfer unit 50, and a fixing unit 60.

  The process cartridges 30C, 30M, 30Y, and 30K contain cyan, magenta, yellow, and black toners, respectively. The four process cartridges 30C to 30K are provided in the order of the process cartridges 30K, 30Y, 30M, and 30C from the front to the rear of the printer 1. Further, the process cartridges 30C to 30K are detachably installed with the front cover 2a provided in the main body housing 2 opened.

  The process cartridge 30C includes a photosensitive drum 31, a charger 32, a toner cartridge 33C, and the like. The other process cartridges 30M, 30Y, and 30K have different toner colors, but the other configurations are the same as those of the process cartridge 30C. For this reason, in the following description, the process cartridge 30C will be described as a representative, and description of the other process cartridges 30M, 30Y, and 30K will be omitted as appropriate.

  The charger 32 is a scorotron charger having a charging wire 32a and a grid portion 32b. The charger 32 uniformly positively charges the surface of the photosensitive drum 31 prior to forming an electrostatic latent image on the surface of the photosensitive drum 31 during image formation.

  The toner cartridge 33C has a toner storage chamber 33a, a developing roller 33f, and the like. The toner storage chamber 33a stores cyan toner. The developing roller 33 f is disposed on the downstream side of the charger 32 along the rotation direction of the photosensitive drum 31. A positive voltage is applied to the roller shaft of the developing roller 33f. As a result, a potential difference is formed between the developing roller 33 f and the potential of the electrostatic latent image formed on the photosensitive drum 31, and the toner moves to the photosensitive drum 31.

  The exposure unit 40 is disposed at the uppermost position inside the main body housing 2 and includes a laser light source, a polygon mirror, and the like (not shown). The laser beam emitted from the laser light source is deflected by the polygon mirror and applied to the surface of the photosensitive drum 31. Thereby, an electrostatic latent image is formed.

  The transfer unit 50 is disposed above the sheet feeding unit 10 and below the process cartridge 30. The transfer unit 50 forms a color image on the sheet P while conveying the sheet P fed by the sheet feeding unit 10 toward the discharge tray 5. The transfer unit 50 includes a driving roller 51, a driven roller 52, a conveyor belt 53, a plurality of transfer rollers 54, and the like.

  The conveyor belt 53 is an endless belt configured by an annular belt. Between the driving roller 51 positioned below the rear end of the process cartridge 30C and the driven roller 52 positioned below the front end of the process cartridge 30K. It is stretched over.

  Each transfer roller 54 is in contact with the conveyance belt 53 from the back side of the sheet conveyance surface 53A at a position facing each photosensitive drum 31 with the sheet conveyance surface 53A of the conveyance belt 53 interposed therebetween. Each transfer roller 54 is applied with a transfer voltage at a predetermined timing, thereby transferring the toner image carried on the surface of the photosensitive drum 31 onto the sheet P conveyed on the paper conveyance surface 53A. The rotation axis direction of the conveyor belt 53 is the main scanning direction. Further, the conveyance direction of the sheet P is the sub-scanning direction.

  The fixing unit 60 is disposed downstream of the transfer unit 50 in the transport direction. The fixing unit 60 includes a heating roller 61 and a pressure roller 62 and fixes the toner image transferred to the sheet P.

  The printer 1 also includes an optical sensor 71, a toner recovery unit 35, and a belt cleaner unit 55.

  Two optical sensors 71 are provided on the lower rear side of the conveyor belt 53, and these two optical sensors 71 are arranged side by side in the left-right direction. Each optical sensor 71 is a reflective sensor including a light emitting element such as an LED and a light receiving element such as a phototransistor. Specifically, the light emitting element irradiates light on the surface of the conveyor belt 53 from an oblique direction, and the light receiving element receives reflected light from the surface of the conveyor belt 53. As a result, the density and position of a known patch formed on the conveyor belt 53 are measured.

  The toner recovery unit 35 is provided on the rear side of each of the photosensitive drums 31 and below the charger 32. The toner recovery unit 35 includes a photoreceptor cleaning blade (hereinafter abbreviated as “photoreceptor blade”) 36, a recovery case 37, and the like. The photoconductor blade 36 is formed in a substantially flat plate shape, and is fixed in the toner collecting unit 35 so that the tip end portion is in sliding contact with the surface of the photoconductor drum 31. The collection case 37 is formed in a substantially cylindrical shape that is long in the left-right direction, and a portion facing the photosensitive drum 31 is opened. When the photosensitive drum 31 rotates, paper dust, toner, and the like attached to the surface of the photosensitive drum 31 are scraped off by the photosensitive blade 36 and fall into the collection case 37.

  The belt cleaner 55 is disposed below the conveyor belt 53. The belt cleaner 55 includes a belt cleaning blade (hereinafter abbreviated as belt blade) 56, a cleaning box 57, a tension roller 58, and the like. The belt blade 56 is disposed in contact with the surface of the conveyor belt 53. The cleaning box 57 is disposed below the belt blade 56. The tension roller 58 is disposed to face the front end portion of the belt blade 56 with the conveyance belt 53 interposed therebetween.

  When the conveyor belt 53 is moved around, the tip of the belt blade 56 comes into sliding contact with the surface of the conveyor belt 53, and the toner, paper dust, and the like attached to the surface of the conveyor belt 53 are scraped off. The toner scraped off by the belt blade 56 is stored in the cleaning box 57.

  Next, the operation at the time of image formation in the printer 1 will be described. The surface of each photosensitive drum 31 is uniformly positively charged by each charger 32 and exposed by the exposure unit 40 based on the print data. Thereby, an electrostatic latent image corresponding to each toner color is formed on the surface of each photosensitive drum 31. Next, toner is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 31 by the developing roller 33f. As a result, the electrostatic latent image on the surface of the photosensitive drum 31 is developed, and a toner image is carried on the surface of the photosensitive drum 31.

  On the other hand, the sheet P is conveyed to the image forming unit 20 by the sheet feeding unit 10 at a predetermined timing. The toner image carried on the surface of the photosensitive drum 31 is transferred to the sheet P by a transfer voltage applied to the transfer roller 54. Then, the toner is conveyed to the fixing unit 60 and the toner is thermally fixed to the sheet P. Thereafter, the sheet P is discharged to the discharge tray 5 by the discharge roller 65.

  After the transfer to the sheet P is completed, the photosensitive drum 31 is cleaned by the photosensitive blade 36 to prepare for the next printing process. Further, the transfer belt 53 that has been transferred to the sheet P is cleaned by the belt blade 56.

  Next, the electrical configuration of the printer 1 will be described with reference to FIG. The printer 1 includes a control unit 80, a transfer voltage application circuit 101, an optical sensor 71, a sheet sensor 72, a display operation unit 73, and the like in addition to the paper feeding unit 10 and the image forming unit 20 shown in FIG. The control unit 80 includes a CPU 81, a ROM 82, a RAM 83, a first timer 84, a second timer 85, a third timer 86, a first counter 87, a second counter 88, an NVRAM (nonvolatile RAM) 89, and the like. The CPU 81 executes various programs stored in the ROM 82, whereby the paper feeding unit 10, the image forming unit 20, the transfer voltage application circuit 101, the optical sensor 71, the sheet sensor 72, and the like connected via the bus 90. And the display operation unit 73 and the like. The ROM 82 stores a control program and various data. The RAM 83 is used as a main storage device for the CPU 81 to execute various processes. The first timer 84 measures the elapsed time after the end of the residual toner T (described later) and the lubricating toner image TI (described later) passes through the developing position 110 (described later). The second timer 85 measures an elapsed time after the start ends of the remaining toner T (described later) and a lubricating toner image TI (described later) pass through a transfer position 111 (described later). The third timer 86 measures the elapsed time from the end of the remaining toner T (described later) and the lubricating toner image TI (described later) passing through the transfer position 111 (described later). The first counter 87 counts the number of printed sheets after toner distribution processing (described later). The second counter 88 counts the number of printed sheets after correction processing (described later). The number of printed sheets is a value converted from the number of rotations of the photosensitive drum 31, and is converted as one sheet is printed at every predetermined number of rotations. The NVRAM 89 stores program processing results and the like.

  The transfer voltage application circuit 101 is electrically connected to the roller shaft of the transfer roller 54. The controller 80 controls the transfer voltage application circuit 101 to control the transfer voltage applied to the roller shaft of the transfer roller 54. The sheet sensor 72 is for detecting the sheet P being conveyed on the conveyance path R, and a plurality of sheet sensors 72 are provided on the conveyance path R. The sheet sensor 72 includes, for example, an irradiating unit that irradiates the conveyor belt 53 with light and a light receiving unit that receives reflected light from the conveyor belt 53, and determines whether or not the sheet P is present on the conveyor belt 53 according to the amount of received light. It is a photoelectric switch to detect. The display operation unit 73 includes, for example, a liquid crystal display and a plurality of buttons. The control unit 80 can display a setting screen for printing, the operation state of the printer 1 and the like on the liquid crystal display. In addition, the user can perform various operations by selecting a button or the like displayed on the liquid crystal display.

  Next, the first printing process according to the first embodiment will be described with reference to FIGS. In the first embodiment, the toner carried on the surface of the photoconductive drum 31 is collected by the photoconductive blade 36 while being carried on the photoconductive drum 31 without being transferred to the conveying belt 53, and a part of the toner is collected. In this example, the process of transferring to the conveyor belt 53 and collecting it by both the photoreceptor blade 36 and the belt blade 56 is an option. In the following description, a case where a jam occurs will be described as an example of “when the printing process is stopped”.

  The control unit 80 executes the first print processing program stored in the ROM 82 at predetermined time intervals, and starts processing according to the flowcharts shown in FIGS. First, the control unit 80 determines whether or not a print job is received from an external device such as a personal computer via a network (S1). In response to determining that a print job has not been received (S1: NO), the process is terminated. On the other hand, in response to determining that the print job has been received (S1: YES), the printing process is started according to the contents of the print job (S3). That is, the control unit 80 starts the operation at the time of image formation described above. At this time, the transfer voltage application circuit 101 starts application of the transfer voltage.

  Next, based on the detection signal from the sheet sensor 72, it is determined whether or not a jam has been detected (S5). In response to determining that the occurrence of a jam has been detected (S5: YES), the printing process is stopped (S7). At this time, the controller 80 causes the transfer voltage application circuit 101 to stop applying the transfer voltage. In addition, charging, exposure, and development operations of the charger 32, the exposure unit 40, and the developing roller 33f are stopped, and the rotation of the photosensitive drum 31 and the conveyance belt 53 is stopped. Further, an error message is displayed on the display operation unit 73 to notify the user of the occurrence of a jam. In this way, the user removes the jammed paper and releases the jam. Next, the control unit 80 determines whether or not an input of jam release completion has been made (S9). Specifically, the control unit 80 displays a message “Did you release the jam?” And a “OK” selection button on the display operation unit 73, and cancel the jam in response to the user selecting the “OK” button. It is determined that there is an input for completion. In response to determining that there is no jam clear completion input (S9: NO), the control unit 80 returns to step S9 and waits for a jam clear completion input. On the other hand, in response to determining that there has been an input of jam release completion (S9: YES), rotation of the photosensitive drum 31 and the conveyor belt 53 is started (S11). Next, toner distribution processing is executed (S13).

  By the way, when printing is stopped in step S7, the toner is still carried on the photosensitive drum 31. This will be described in detail with reference to FIG. The surface of each photosensitive drum 31 is charged by the charger 32 and then exposed by the exposure unit 40. Next, toner is supplied to the surface of the photosensitive drum 31 by the developing roller 33f. If printing is stopped in step S7, the sheet P is not conveyed, so the processing is stopped here. Accordingly, the toner remains on the photosensitive drum 31. There may be a case where a larger amount of toner is carried on the surface of the photosensitive drum 31 as compared with a state where the transfer to the sheet P has been completed. For this reason, when all the toner carried on the photosensitive drum 31 is collected by the photosensitive blade 36, a part of the toner leaks from between the tip of the photosensitive blade 36 and the surface of the photosensitive drum 31, There is a risk of poor cleaning. Therefore, a toner distribution process is executed and collected by the photoconductor blade 36 and the belt blade 56, thereby suppressing poor cleaning. Here, description will be made assuming that toner is supplied in a range from the development position 110 to the transfer position 111 on the surface of the photosensitive drum 31. The toner image formed in the range from the development position 110 to the transfer position 111 on the surface of the photosensitive drum 31 is hereinafter referred to as residual toner T.

  The toner distribution process described below is a process for collecting the residual toner T on both the photoreceptor blade 36 and the belt blade 56. Here, by switching whether the transfer voltage is applied to the transfer roller 54 or not, it is controlled whether the residual toner T is transferred to the conveying belt 53 or is held on the photosensitive drum 31. Thereby, the residual toner T can be distributed to both the photosensitive drum 31 and the conveyance belt 53. The toner transferred to the conveyance belt 53 is collected by the belt blade 56, and the toner carried on the photosensitive drum 31 is collected by the photosensitive blade 36.

  The toner distribution process (S13) will be described with reference to FIG. First, the control unit 80 obtains the elapsed time from the second timer 85, and determines whether or not a predetermined time has elapsed after the start end of the residual toner T passes the transfer position 111 (S31). Since the application of the transfer voltage to the roller shaft of the transfer roller 54 is stopped during a period from when the printing process is stopped (S7) until a predetermined time elapses, the residual toner T remains carried on the photosensitive drum 31. It becomes. Here, the predetermined time is to determine the width in the sub-scanning direction of the residual toner T that is held on the photosensitive drum 31, and is stored in advance in the ROM 82, for example. When it is determined that the predetermined time has not elapsed (S31: NO), the process returns to step S31 and waits until the predetermined time elapses. On the other hand, when it is determined that the predetermined time has elapsed (S31: YES), the elapsed time is acquired from the first timer 84, and the fixed point on the surface of the photosensitive drum 31 passes the developing position 110 and then moves to the transfer position 111. It is determined whether or not the photosensitive drum 31 has been rotated for the time required to reach it (hereinafter referred to as transfer position arrival time) (S33). In response to determining that the photosensitive drum 31 has been rotated during the transfer position arrival time (S33: YES), since it is determined that all the residual toner T has passed the transfer position 111, the process proceeds to step S43.

  On the other hand, in response to the determination that the photosensitive drum 31 is not rotating during the transfer position arrival time (S33: NO), there is still residual toner T that has not passed the transfer position 111 on the photosensitive drum 31. Then, the transfer voltage application circuit 101 starts application of the transfer voltage (S35). As a result, the residual toner T is transferred to the transport belt 53. Further, the control unit 80 causes the second timer 85 to measure the elapsed time after resetting the second timer 85. Next, the control unit 80 acquires the elapsed time from the second timer 85, and determines whether or not a predetermined time has elapsed since the transfer voltage was applied (S37). Here, the predetermined time is to determine the width of the residual toner T transferred to the conveyor belt 53 in the sub-scanning direction, and is stored in advance in the ROM 82, for example. When it is determined that the predetermined time has not elapsed (S37: NO), the process returns to step S37 and waits until the predetermined time elapses. On the other hand, in response to determining that the predetermined time has elapsed (S37: YES), the elapsed time is acquired from the first timer 84, and it is determined whether or not the transfer position arrival time and the photosensitive drum 31 have been rotated (S39). ). When it is determined that the photosensitive drum 31 has been rotated during the transfer position arrival time (S39: YES), it is determined that all the remaining toner T has passed the transfer position 111, and thus the process proceeds to step S43. On the other hand, in response to determining that the photosensitive drum 31 is not rotated during the transfer position arrival time (S39: NO), the transfer voltage application circuit 101 stops application of the transfer voltage (S41). Further, the control unit 80 causes the second timer 85 to measure the elapsed time after resetting the second timer 85. Next, since the residual toner T that has not yet passed through the transfer position 111 exists on the photosensitive drum 31, the process returns to step S31.

  The toner held on the photosensitive drum 31 passes through the transfer position 111 and is collected by the photosensitive blade 36. Further, the toner transferred to the conveyance belt 53 is collected by the belt blade 56. This is because the photosensitive drum 31 and the conveyance belt 53 are driven by the control unit 80 and continue to rotate.

  In step S43, the elapsed time is acquired from the first timer 84, and the time required for the fixed point on the surface of the photosensitive drum 31 to reach the photosensitive blade position 112 (see FIG. 4) after passing through the developing position 110 (hereinafter, FIG. 4). It is determined whether or not the photosensitive drum 31 has been rotated. In response to determining that the photosensitive drum 31 is not rotating during the photosensitive blade arrival time (S43: NO), the process returns to step S43 and waits until it elapses. On the other hand, in response to determining that the photosensitive drum 31 has been rotated for the photosensitive blade arrival time (S43: YES), the processing is terminated. This is because it is determined that all the toner carried on the photosensitive drum 31 passes through the photosensitive blade 36 and is collected.

  By changing the predetermined time in steps S31 and S37, the division number of the remaining toner T can be changed. That is, when it is desired to increase the number of divisions, the predetermined time may be shortened. If the number of divisions is small, the control becomes simple. On the other hand, the larger the number of divisions, the smaller the amount of toner collected at one time by the photoconductor blade 36 and the belt blade 56, so that the cleaning failure can be further suppressed.

  Note that the control unit 80 resets the first counter 87 at the end of the toner distribution process, and starts counting the number of printed sheets again from the end.

  Returning to FIG. 3, the description of the first printing process will be continued. After the toner distribution process (S13) is completed, the process proceeds to step S29. In step S29, the rotation of the photosensitive drum 31 and the conveyance belt 53 is stopped, and the process ends. After that, the printer 1 shifts to a ready mode waiting for reception of a print job.

  On the other hand, in response to determining that a jam has not been detected (S5: NO), the control unit 80 determines whether the print job has ended (S15). In response to determining that the print job has not ended (S15: NO), the process returns to step S5. On the other hand, in response to determining that the print job is completed (S15: YES), the transfer voltage application circuit 101 stops application of the transfer voltage (S17). In the first printing process, a process for collecting the toner carried on the photoconductive drum 31 by the photoconductive blade 36 or a toner distributing process is executed. This is because in either process, it is not necessary to apply a transfer voltage at the start of the process.

  Next, the control unit 80 refers to the count value of the first counter 87, that is, the accumulated number of printed sheets, and determines whether or not a predetermined number of sheets have been printed since the previous toner distribution process (S19).

  By the way, for example, when the toner in a portion where the tip of the photosensitive blade 36 contacts the photosensitive drum 31 is depleted, the frictional resistance between the photosensitive blade 36 and the photosensitive drum 31 increases, and an audible noise is generated. The phenomenon may occur. Alternatively, the frictional resistance may increase and the leading end portion of the photoreceptor blade 36 may be pushed and bent in the rotation direction of the photoreceptor drum 31. A similar phenomenon may occur for the belt blade 56. In order to suppress these occurrences, it is effective to supply toner and lubricate the photoreceptor blade 36 and the belt blade 56 with the toner. In the toner distribution process described above, the toner is collected by the photoconductor blade 36 and the belt blade 56, and therefore the toner is supplied to the photoconductor blade 36 and the belt blade 56. That is, the photosensitive blade 36 and the belt blade 56 can be lubricated with toner. However, when the printing process is performed, the toner on the photosensitive drum 31 and the conveyance belt 53 is gradually lost. Therefore, it is determined whether or not it is necessary to supply toner based on the number of printed sheets since the previous toner distribution process was executed. When the number of printed sheets is less than the predetermined number, it is determined that there is no need to supply toner to the photosensitive blade 36 and the belt blade 56 because the toner is lubricated. On the other hand, when the number of printed sheets is equal to or larger than the predetermined number, it is determined that the toner needs to be supplied to the photosensitive blade 36 and the belt blade 56 because the toner is exhausted.

  Further, depending on the use state of the printer 1, the amount of toner remaining on each of the photosensitive drum 31 and the conveyance belt 53 may be different, and the timing at which the photosensitive blade 36 and the belt blade 56 provided in each of them should be lubricated. Different. For example, when the correction process is executed, a larger amount of toner is supplied to the belt blade 56 than the photoconductor blade 36. Here, the correction process is a process of collecting the patch with the belt blade 56 after forming the patch on the conveyance belt 53, measuring the density and position of the formed patch with the optical sensor 71. In order to collect the patch by the belt blade 56, the belt blade 56 is supplied with toner according to the shape and density of the formed patch. On the other hand, only a small amount of untransferred toner held on the photosensitive drum 31 without being transferred to the conveyor belt 53 is supplied to the photosensitive blade 36. That is, only the belt blade 56 is lubricated with toner by the correction process. When the printing process is performed, the toner on the conveyance belt 53 is gradually lost. Therefore, it is determined whether or not it is necessary to supply toner to the belt blade 56 based on the number of printed sheets after the correction process is executed. When the number of printed sheets is less than the predetermined number, it is determined that there is no need to supply toner to the belt blade 56 because the toner is lubricated. On the other hand, when the number of printed sheets is equal to or larger than the predetermined number, it is determined that the toner needs to be supplied to the belt blade 56 because the toner is exhausted.

  In response to determining that a predetermined number of sheets have been printed from the toner distribution process (S19: YES), in order to determine whether or not it is necessary to supply toner to the belt blade 56, the count value of the second counter 88, that is, With reference to the accumulated number of printed sheets, it is determined whether or not a predetermined number of sheets have been printed or not after executing the correction process (S21). Since it is necessary to supply toner to both the photosensitive blade 36 and the belt blade 56 in response to determining that a predetermined number of sheets have been printed from the execution of the correction process (S21: YES), a lubricating toner image TI is formed. (S23). The lubricating toner image TI is formed in the same manner as the printing process. The shape when the lubricating toner image TI is transferred to the conveying belt 53 is, for example, a belt shape as shown in FIG. The length of the lubricating toner image TI in the main scanning direction is the maximum width that the printer 1 can print. Thus, the toner can be uniformly supplied to the photosensitive blade 36 and the belt blade 56 in the next toner distribution process. Next, toner distribution processing is executed while the photosensitive drum 31 and the conveyor belt 53 are rotated (S13). By performing the toner distribution process, both the photosensitive blade 36 and the belt blade 56 can be lubricated.

  On the other hand, when it is determined that the predetermined number of sheets have not been printed since the correction process is executed (S21: NO), the toner image TI for lubrication is formed to supply the toner to the photosensitive blade 36 (S25). This is because it is determined that the belt blade 56 is lubricated and it is not necessary to supply toner. Since the photosensitive drum 31 is driven by the control unit 80 and continues to rotate, the lubricating toner image TI is collected by the photosensitive blade 36. Thereby, the photoreceptor blade 36 can be lubricated. Next, the elapsed time is obtained from the first timer 84, and it is determined whether the photosensitive drum 31 has been rotated by the photosensitive blade arrival time (S27). When it is determined that the photoreceptor blade arrival time and the photoreceptor drum 31 are not rotating (S27: NO), the process returns to step S27 and waits until the photoreceptor blade arrival time elapses. On the other hand, in response to determining that the photosensitive drum 31 has rotated the photosensitive blade arrival time (S27: YES), since it is determined that all the lubricating toner images TI have been collected, the process proceeds to step S29.

  On the other hand, if it is determined that the predetermined number of sheets or more are not printed from the toner distribution process (S19: NO), the photosensitive blade 36 and the belt blade 56 are lubricated and it is not necessary to supply toner, so the process proceeds to step S29. move on.

  Here, the photosensitive drum 31 is an example of a photosensitive member. The conveyor belt 53 is an example of a belt. The photoreceptor blade 36 is an example of a first cleaning member, and the belt blade 56 is an example of a second cleaning member. Step S17 is an example of a first transfer process, and steps S31 to S41 in the toner distribution process (S13) are an example of a fourth transfer process. Step S19 is an example of a rotational speed determination process, and step S21 is an example of a corrected rotational speed determination process. The sheet P is an example of a printing sheet.

As described above, according to the first embodiment described above, the following effects are provided.
The control unit 80 collects the toner with the photoconductor blade 36 without applying a transfer voltage to the transfer unit 50 with respect to the region where the toner is carried on the photoconductive drum 31, and carries the toner on the photoconductive drum 31. A process for applying a transfer voltage to the transfer unit 50 is selected as an option for a part of the region that is being processed, and one of the processes included in the option is executed according to the condition. Further, after the toner image TI for lubrication is formed (S25), the photosensitive drum 31 is driven until the toner image TI for lubrication contacts the photoconductor blade 36 without applying a transfer voltage to the transfer unit 50 (S27). . In the toner distribution process, the photosensitive drum 31 is driven until the toner carried on the photosensitive drum 31 is collected by the photosensitive blade 36 (S43). Thus, the toner carried on the photosensitive drum 31 is conveyed to the photosensitive blade 36 while being carried on the photosensitive drum 31, or a part of the toner carried on the photosensitive drum 31 is conveyed. Depending on the conditions, the processing can be switched depending on whether the transfer to the belt 53 and the conveyance to both the photosensitive blade 36 and the belt blade 56 are options.

  When the printing process is stopped in the middle of the process (S7), the toner remains on the photosensitive drum 31 without being transferred to the sheet P, and the amount of toner carried on the photosensitive drum 31 is large. There may be. In this case, a toner distribution process (S13) is performed in which a part of the toner carried on the photosensitive drum 31 is transferred to the conveyance belt 53 and collected by each of the photosensitive blade 36 and the belt blade 56. Thereby, even when the amount of toner carried on the photosensitive drum 31 is unknown, it is possible to suppress the cleaning failure.

  In addition, after executing the toner distribution process (S13), the control unit 80 counts the number of printed sheets P and determines whether the counted number of printed sheets is equal to or greater than a predetermined number (S19). If the number of printed sheets is not equal to or greater than the predetermined number (S19: NO), it is determined that the photoreceptor blade 36 and the belt blade 56 are lubricated and there is no possibility of causing damage to the photoreceptor blade 36 and the belt blade 56. In this case, the untransferred toner is collected by the photoconductor blade 36. In the first embodiment, step S21 is executed in response to determining that the number of printed sheets is equal to or greater than a predetermined number. In another embodiment, when step S21 is omitted, processing similar to steps S23 and S13 may be executed in response to determining that the number of printed sheets is equal to or greater than the predetermined number. As a result, the photosensitive blade 36 and the belt blade 56 are lubricated, and damage to the photosensitive blade 36 and the belt blade 56 can be suppressed.

  Further, the control unit 80 performs a correction process for forming a patch. The patches formed on the conveyor belt 53 are collected by the belt blade 56. As a result, toner is supplied to the belt blade 56. The control unit 80 counts the number of printed sheets after executing the correction process, and determines whether or not the number of printed sheets is equal to or larger than a predetermined number (S21). If the number of printed sheets is equal to or greater than the predetermined number (S21: YES), it is determined that the toner of the belt blade 56 may be depleted and the belt blade 56 may be damaged. In this case, a toner distribution process (S13) is executed, and the toner is collected by both the photoreceptor blade 36 and the belt blade 56. As a result, toner is supplied to both the photosensitive blade 36 and the belt blade 56, and damage to the photosensitive blade 36 and the belt blade 56 can be suppressed. On the other hand, when the number of printed sheets is not equal to or greater than the predetermined number (S21: NO), it is determined that the belt blade 56 is lubricated with toner and there is no possibility of causing damage to the conveyor belt 53. In this case, it is not necessary to supply toner to the belt blade 56, and the lubricating toner image TI is collected by the photoconductor blade 36. As a result, toner is supplied to the photoreceptor blade 36, and damage to the photoreceptor blade 36 can be suppressed.

  Further, the processing after step S21 is executed after the print job is completed. As a result, both the photosensitive blade 36 and the belt blade 56 can be lubricated with toner without hindering the printing process and without waiting for the user.

  In the toner distribution process (S13), first, the control unit 80 does not apply a transfer voltage and keeps the toner on the photosensitive drum 31, and then applies the transfer voltage to apply the toner to the transport belt 53. Transcript. As a result, the toner can be supplied to the photoreceptor blade 36 before the belt blade 56. In the photoreceptor blade 36 and the belt blade 56, paper dust discharged from the sheet P in addition to the toner functions as a lubricant. In particular, toner and paper dust may not be sufficient in the downstream photosensitive drum 31. For this reason, the photoreceptor blade 36 is not sufficiently lubricated, and a squeal phenomenon may occur. Therefore, first, the photoreceptor blade 36 is lubricated with priority given to the toner collection by the photoreceptor blade 36. As a result, the toner is supplied to the photosensitive blade 36 first, and the occurrence of squeal development can be suppressed.

  Next, the second printing process according to the second embodiment will be described with reference to FIG. In the second embodiment, the toner carried on the surface of the photosensitive drum 31 is transferred to the conveyance belt 53 and collected by the belt blade 56, and a part of the toner is transferred to the conveyance belt 53, and the photosensitive blade This is an example in which the process of collecting by both 36 and the belt blade 56 is an option. The same steps as those in the first printing process are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

  The controller 80 performs steps S1 to S9 as in the case of the first printing process. In response to determining that there is an input for completion of jam release (S9: YES), it is determined whether or not color printing has been performed (S61). For example, the control unit 80 determines that color printing has been performed when a print job for color printing is received. When it is determined that the color printing has been performed (S61: YES), the processes of steps S11 and S13 are performed as in the case of the first printing process. When the stopped printing process is color printing, the toner remains carried on the plurality of photosensitive drums 31. In this case, when toner is transferred from all the photosensitive drums 31 to the conveyance belt 53, the amount of transferred toner becomes large, and the belt blade 56 may not be able to collect the toner satisfactorily. Therefore, the residual toner T is collected by both the photosensitive blade 36 and the belt blade 56 by toner distribution processing, thereby suppressing the cleaning failure in the belt blade 56.

  On the other hand, when it is determined that the color printing has not been performed (S61: NO), a transfer voltage is applied to the roller shaft of the transfer roller 54 (S63). Next, the photosensitive drum 31 and the conveyor belt 53 are rotated (S65). The residual toner T is transferred to the transport belt 53 by steps S63 and S65. The elapsed time is acquired from the third timer 86, and the time required for the fixed point on the surface of the conveyance belt 53 to reach the position where it contacts the belt blade 56 after passing through the transfer position 111 (hereinafter referred to as belt blade arrival time). ), It is determined whether or not the conveyor belt 53 has been rotated (S67). When it is determined that the belt blade arrival time and the conveyor belt 53 are not rotating (S67: NO), the process returns to step S67 and waits until the belt blade arrival time elapses. On the other hand, when it is determined that the belt blade arrival time and the conveyance belt 53 have been rotated (S67: YES), the rotation of the photosensitive drum 31 and the conveyance belt 53 is stopped (S29), and the processing is terminated.

  On the other hand, in response to determining that the jam is not detected (S5: NO), the control unit 80 performs the processes of steps S15 and S19 as in the case of the first printing process. In response to determining that a predetermined number or more sheets have been printed from the previous toner distribution process (S19: YES), a lubricating toner image TI is formed (S23). Since the transfer voltage is continuously applied, the lubricating toner image TI is transferred to the conveyance belt 53. Further, since the conveyor belt 53 is rotating, it is collected by the belt blade 56. Next, the elapsed time is acquired from the third timer 86, and it is determined whether or not the belt blade arrival time and the conveyor belt 53 have been rotated (S69). In response to the belt blade arrival time and determining that the conveyor belt 53 is not rotating (S69: NO), the process returns to step S69 and waits until it elapses. On the other hand, when it is determined that the belt blade arrival time and the conveyor belt 53 have been rotated (S69: YES), the process proceeds to step S29.

  On the other hand, in response to determining that the predetermined number of sheets have not been printed since the previous toner distribution process (S19: NO), the transfer voltage application circuit 101 stops application of the transfer voltage (S71). In addition, charging, exposure, and development operations of the charger 32, the exposure unit 40, and the developing roller 33f are stopped, and the rotation of the photosensitive drum 31 and the conveyance belt 53 is stopped. Next, the process proceeds to step S29. When a predetermined number of sheets have not been printed since the previous toner distribution process, it is not necessary to supply toner to the photoreceptor blade 36 and the belt blade 56, so a toner image for lubrication is formed and the photoreceptor blade 36 and the belt blade 56 are formed. This is because it is determined that the process of supplying toner to the toner is unnecessary.

  Here, step S63 is an example of a second transfer process.

As described above, according to the above-described second embodiment, the following effects can be obtained.
The control unit 80 applies a transfer voltage to the transfer unit 50 to a region where the toner is carried on the photosensitive drum 31 and collects the toner with the belt blade 56, and the toner is carried on the photosensitive drum 31. A process of applying a transfer voltage to the transfer unit 50 is selected as an option for a part of a region that is present, and one of the processes included in the option is executed according to the condition. After forming the lubricating toner image TI (S23), a transfer voltage is applied to the transfer unit 50, and the conveying belt 53 is driven until the transferred lubricating toner image TI contacts the belt blade 56 (S69). In the toner distribution process (S13), the conveyor belt 53 is driven until the toner transferred to the conveyor belt 53 comes into contact with the belt blade 56 (S43). As a result, the toner carried on the photosensitive drum 31 is transferred to the conveyor belt 53 and conveyed to the belt blade 56, or a part of the toner carried on the photosensitive drum 31 is transferred to the conveyor belt 53. Depending on the conditions, the processing can be switched according to the choice of whether the image is transferred and conveyed to both the photosensitive blade 36 and the belt blade 56.

  When the toner to be printed on the sheet P is in a plurality of colors (S61: YES), a large amount of toner that can be satisfactorily collected by either the photoreceptor blade 36 or the belt blade 56 is carried on the photoreceptor drum 31. The case is considered. Accordingly, by performing recovery with both the photoreceptor blade 36 and the belt blade 56 in the toner distribution process, it is possible to suppress a cleaning failure. If the toner to be printed on the sheet P is a single color (S61: NO), the photosensitive member carries a toner that can be recovered satisfactorily if it is recovered by either the photosensitive blade 36 or the belt blade 56. There are cases. Accordingly, the belt blade 56 may be used for collection.

  Next, a third printing process according to the third embodiment will be described with reference to FIG. In the third printing process, step S81 is executed instead of step S69 of the second printing process. In the second printing process, steps S23 and S69 are executed to supply toner to the belt blade 56 in response to determining that a predetermined number of sheets have been printed since the previous toner distribution process (S19: YES). On the other hand, in the third printing process, toner is supplied to the belt blade 56 by executing a toner distribution process (S81) after step S23.

  In the first and second embodiments described above, a case where a jam has occurred has been described as an example of “when the printing process is stopped”. Here, a process executed when the printer 1 is turned off during printing will be described.

  When the control unit 80 receives the print job, it sets a printing flag in the NVRAM 89. In response to determining that the print job ends and the next print job is not received, the printing flag is canceled. In response to the power supply of the printer 1 being turned on, the control unit 80 determines whether or not the printing flag is set. In response to determining that the printing flag is set, it is determined that the power of the printer 1 has been turned off during the printing process, so the toner distribution process is executed. When the power of the printer 1 is turned off during the printing process, the amount of toner carried on the photosensitive drum 31 is unknown, so that the toner is collected by both the photosensitive blade 36 and the belt blade 56, thereby cleaning. Defects can be suppressed. In response to the completion of the toner distribution process, a known warm-up process is executed, and a transition is made to the ready mode. On the other hand, since it is determined that the power of the printer 1 is not turned off during the printing process in response to determining that the printing flag is not set, the toner distribution process is omitted and the warm-up process is executed. By determining whether the printing flag is set, it is possible to determine whether printing has been interrupted. Note that when the printer 1 is turned off during printing, the power supply is cut off due to a power failure or the like, or the front cover 2a is opened by the user.

Needless to say, the present invention is not limited to the above-described embodiment, and various improvements and modifications can be made without departing from the spirit of the present invention.
For example, in the embodiment, the method of directly transferring the toner image formed on the photosensitive drum 31 to the sheet P has been described, but the present invention is not limited to this. The toner image formed on the photoconductive drum 31 can also be applied to a so-called secondary transfer type image forming apparatus in which the toner image is once transferred to a belt and further transferred to a sheet P.

  In steps S19 and S21, whether or not to execute toner distribution processing is determined based on the number of printed sheets converted from the number of rotations of the photosensitive drum 31, but the present invention is not limited to this. It can also be determined by the number of printed sheets converted from the charging time of the charger 32. Alternatively, the rotational speed of the photosensitive drum 31 and the charging time of the charger 32 may be compared with a predetermined number and a predetermined time, respectively.

  Further, it has been described that in the toner distribution process, a part of the toner carried on the photosensitive drum 31 is transferred to the conveyance belt 53 by controlling whether or not the transfer voltage is applied. However, the present invention is not limited to this, and a part of the toner carried on the photosensitive drum 31 can be transferred to the conveying belt 53 by controlling the voltage value of the transfer voltage. By making the voltage value of the transfer voltage smaller than the voltage value applied in the printing process, the potential difference between the photosensitive drum 31 and the conveying belt 53 is reduced, and a part of the toner carried on the photosensitive drum 31 is conveyed. Transfer to the belt 53.

  For example, in the first embodiment, the control unit 80 collects toner with the photoconductor blade 36 without applying a transfer voltage to the transfer unit 50 with respect to an area where the toner is carried on the photoconductor drum 31. As an option, a process of applying a transfer voltage to the transfer unit 50 with respect to a part of the region where the toner is carried on the photosensitive drum 31 is selected, and one of the processes included in the option is executed depending on conditions. It was. A process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried on the photosensitive drum 31, and controlling the voltage value of the transfer voltage to control the toner carried on the photosensitive drum 31. The control unit 80 replaces a part of the photosensitive drum 36 with the transfer belt 50 without applying a transfer voltage to the area where the toner is carried on the photosensitive drum 31. The process of collecting toner and the process of controlling the voltage value of the transfer voltage to transfer a part of the toner carried on the photosensitive drum 31 to the transport belt 53 are included as options, and are included in the options depending on the conditions. Either of the processes to be performed may be executed.

  For example, in the first embodiment, when the printing process is stopped during the process (S7), the control unit 80 transfers a part of the toner carried on the photosensitive drum 31 to the conveyance belt 53. Thus, the toner distribution process (S13) to be collected by each of the photoreceptor blade 36 and the belt blade 56 is executed. A process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried on the photosensitive drum 31, and controlling the voltage value of the transfer voltage to control the toner carried on the photosensitive drum 31. When the printing process is stopped during the process (S7), the control unit 80 controls the voltage value of the transfer voltage to transfer the photosensitive drum 31 to the photosensitive drum 31. A process of transferring a part of the carried toner to the conveyor belt 53 may be executed.

  Further, for example, in the first embodiment, the control unit 80 counts the number of printed sheets P after executing the toner distribution process (S13), and whether the counted number of printed sheets is equal to or larger than a predetermined number. It is determined whether or not (S19). If the number of printed sheets is equal to or greater than the predetermined number (S19: YES), a part of the toner carried on the photosensitive drum 31 is transferred to the conveying belt 53, and each of the photosensitive blade 36 and the belt blade 56 is used. The toner distribution process (S13) to be collected was executed. A process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried on the photosensitive drum 31, and controlling the voltage value of the transfer voltage to control the toner carried on the photosensitive drum 31. The control unit 80 controls the voltage value of the transfer voltage when the number of printed sheets after the toner distribution process (S13) is equal to or larger than the predetermined number. Alternatively, a process of transferring a part of the toner carried on the photosensitive drum 31 to the conveyance belt 53 may be executed.

  Further, for example, in the first embodiment, the control unit 80 counts the number of printed sheets after executing the correction process, and determines whether or not the number of printed sheets is equal to or larger than a predetermined number (S21). When the number of printed sheets is equal to or larger than the predetermined number (S21: YES), a part of the toner carried on the photosensitive drum 31 is transferred to the conveying belt 53, and each of the photosensitive blade 36 and the belt blade 56 is used. The toner distribution process (S13) to be collected was executed. A process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried on the photosensitive drum 31, and controlling the voltage value of the transfer voltage to control the toner carried on the photosensitive drum 31. The control unit 80 controls the voltage value of the transfer voltage when the number of printed sheets after executing the correction process is equal to or larger than the predetermined number. A process of transferring a part of the toner carried on the drum 31 onto the conveyance belt 53 may be executed.

  In the second embodiment, the control unit 80 applies a transfer voltage to the transfer unit 50 to a region where the toner is carried on the photosensitive drum 31 and collects the toner with the belt blade 56, and the photosensitive drum. The process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried at 31 is an option, and one of the processes included in the option is executed according to the conditions. A process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried on the photosensitive drum 31, and controlling the voltage value of the transfer voltage to control the toner carried on the photosensitive drum 31. The control unit 80 applies a transfer voltage to the transfer unit 50 with respect to the area where the toner is carried on the photosensitive drum 31 and causes the belt blade 56 to transfer the toner. The process of collecting and controlling the voltage value of the transfer voltage to transfer a part of the toner carried on the photosensitive drum 31 to the conveying belt 53 are options. Either process may be executed.

  Further, for example, in the second embodiment, when the printing process is stopped during the processing (S7), the control unit 80 transfers a part of the toner carried on the photosensitive drum 31 to the conveyance belt 53. Thus, the toner distribution process (S13) to be collected by each of the photoreceptor blade 36 and the belt blade 56 is executed. A process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried on the photosensitive drum 31, and controlling the voltage value of the transfer voltage to control the toner carried on the photosensitive drum 31. When the printing process is stopped during the process (S7), the control unit 80 controls the voltage value of the transfer voltage to transfer the photosensitive drum 31 to the photosensitive drum 31. A process of transferring a part of the carried toner to the conveyor belt 53 may be executed.

  For example, in the third embodiment, the control unit 80 counts the number of printed sheets P after executing the toner distribution process (S13, S81), and the counted number of printed sheets is equal to or greater than a predetermined number. It is determined whether or not there is (S19). If the number of printed sheets is equal to or greater than the predetermined number (S19: YES), a part of the toner carried on the photosensitive drum 31 is transferred to the conveying belt 53, and each of the photosensitive blade 36 and the belt blade 56 is used. The toner distribution process (S81) to be collected was executed. A process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried on the photosensitive drum 31, and controlling the voltage value of the transfer voltage to control the toner carried on the photosensitive drum 31. The control unit 80 controls the voltage value of the transfer voltage when the number of printed sheets after the toner distribution process (S13, S81) is equal to or larger than the predetermined number. Then, a process of transferring a part of the toner carried on the photosensitive drum 31 to the conveyance belt 53 may be executed.

  For example, in the second embodiment, when the toner to be printed on the sheet P has a plurality of colors (S61: YES), the control unit 80 conveys a part of the toner carried on the photosensitive drum 31. A toner distribution process (S13) is performed in which the toner is transferred to the belt 53 and collected by each of the photosensitive blade 36 and the belt blade 56. A process of applying a transfer voltage to the transfer unit 50 for a part of the region where the toner is carried on the photosensitive drum 31, and controlling the voltage value of the transfer voltage to control the toner carried on the photosensitive drum 31. When the toner to be printed on the sheet P is a plurality of colors, the control unit 80 controls the voltage value of the transfer voltage and is carried on the photosensitive drum 31. A process of transferring a part of the toner on the conveying belt 53 may be executed.

  Further, although it has been described that the transfer voltage is applied to the roller shaft of the transfer roller 54 by the transfer voltage application circuit 101, the present invention is not limited to this. A configuration in which a transfer current is applied may be used.

  Further, although it has been described that the surface of the photosensitive drum 31 is positively charged by the charger 32 and a positive charge is applied to the roller shaft of the developing roller 33f, the present invention is not limited to this. The surface of the photosensitive drum 31 may be negatively charged, and a negative charge may be applied to the roller shaft of the developing roller 33f.

  Further, in step S43 of the toner distribution process, it has been described that it is determined whether the photosensitive drum arrival time and the photosensitive drum 31 have been rotated. However, the present invention is not limited to this. It may be determined whether the belt blade arrival time and the conveyance belt 53 have been rotated.

  In the embodiment, the printer 1 has been described as an example, but the present invention is not limited to this. It may be a so-called multifunction machine having a scanner function, a copy function, a facsimile function, and the like.

  Moreover, although embodiment demonstrated the case where the control part 80 was provided with CPU81 as an example, it is not limited to this. A plurality of CPUs may be provided, or an ASIC may be used. Furthermore, it may be configured by a combination of the CPU 81 and the ASIC.

DESCRIPTION OF SYMBOLS 1 Laser printer 31 Photoconductor drum 32 Charger 33f Developing roller 36 Photoconductor cleaning blade 50 Transfer part 53 Conveyor belt 54 Transfer roller 56 Belt cleaning blade 80 Control part 101 Transfer voltage application circuit

Claims (13)

A photoreceptor,
A belt in contact with the photoreceptor;
A first cleaning member that contacts the photoreceptor and cleans the photoreceptor;
A transfer unit that applies a transfer voltage and transfers the developer carried on the photoconductor to the belt;
A second cleaning member that contacts the belt and cleans the belt;
A control unit,
The controller is
A printing process for applying a first transfer voltage to the transfer unit in response to receiving a print job;
A first transfer process in which the transfer voltage is not applied to the transfer unit with respect to the region where the developer is carried on the photoconductor, and the transfer unit with respect to the region where the developer is carried on the photoconductor A second transfer process in which the transfer voltage is applied, a third transfer process in which a second transfer voltage smaller than the voltage value of the first transfer voltage in the printing process is applied to the transfer unit, and the development on the photoconductor At least any two of the fourth transfer processes in which the transfer voltage is applied to the transfer unit with respect to a part of the region where the agent is carried are included as options, depending on conditions. An image forming apparatus that executes an execution process for executing any one of the processes. The options are the first transfer process and the third transfer process or the fourth transfer process.
2. The image formation according to claim 1, wherein the control unit executes any one of the first transfer process and the third transfer process or the fourth transfer process included in the option. apparatus. The controller is
3. The image formation according to claim 2, wherein the third transfer process or the fourth transfer process is executed on the condition that the printing process is stopped in a state where there is a developer on the photoconductor. apparatus. The controller is
A counting process for counting the number of rotations of the photoreceptor;
Performing a rotational speed determination process for determining whether or not the first rotational speed counted by the counting process after executing the fourth transfer process is equal to or greater than a first predetermined rotational speed;
3. The third transfer process or the fourth transfer process is executed when it is determined by the rotation speed determination process that the first rotation speed is equal to or greater than the first predetermined rotation speed. The image forming apparatus described in 1. A light emitting element that emits light;
A light receiving element for receiving light,
The controller is
A counting process for counting the number of rotations of the photoreceptor;
A correction process in which a correction mark is formed on the belt, the light emitting element emits light to the correction mark, and the light receiving element receives reflected light from the correction mark;
Performing a corrected rotation speed determination process for determining whether or not the second rotation speed counted by the counting process after execution of the correction process is equal to or greater than a second predetermined rotation speed;
The third transfer process or the fourth transfer process is executed in response to determining that the second rotational speed is greater than or equal to the second predetermined rotational speed in the post-correction rotational speed determination process, and the corrected number of sheets determination process The image forming apparatus according to claim 2, wherein the first transfer process is executed in response to determining that the second rotation speed is not equal to or greater than the second predetermined rotation speed. The options are the second transfer process, the third transfer process or the fourth transfer process,
2. The image formation according to claim 1, wherein the control unit executes any one of the second transfer process and the third transfer process or the fourth transfer process included in the option. apparatus. The controller is
The image formation according to claim 6, wherein the third transfer process or the fourth transfer process is executed on the condition that the printing process is stopped in a state where there is a developer on the photoconductor. apparatus. The controller is
A counting process for counting the number of rotations of the photoreceptor;
Performing a rotational speed determination process for determining whether or not the first rotational speed counted by the counting process after executing the fourth transfer process is equal to or greater than a first predetermined rotational speed;
7. The third transfer process or the fourth transfer process is executed when it is determined by the rotation speed determination process that the first rotation speed is equal to or greater than the first predetermined rotation speed. The image forming apparatus described in 1. There are a plurality of the photoreceptors,
When the developer to be printed on the print sheet is a single color using only one photoconductor,
The control unit executes the first transfer process included in the option, the second transfer process, or the third transfer process,
When the developer to be printed on the print sheet is a plurality of colors using a plurality of the photoreceptors,
The image forming apparatus according to claim 1, wherein the control unit executes the third transfer process or the fourth transfer process. The controller is
The image forming apparatus according to claim 1, wherein the execution process is executed after the print process is executed. A plurality of photoconductors arranged linearly in the rotation direction of the belt;
Among the photoconductors included in the photoconductor group, the photoconductors disposed in the downstream area in the rotation direction are within a predetermined time after starting the execution of the fourth transfer process in the fourth transfer process. 11. The image forming apparatus according to claim 1, wherein the transfer voltage is not applied to the transfer unit and the transfer voltage is applied after the predetermined time has elapsed. A photoconductor, a belt in contact with the photoconductor, a first cleaning member in contact with the photoconductor, and a transfer unit that applies a transfer voltage to transfer the developer carried on the photoconductor to the belt. A developer recovery method for recovering the developer carried on the photoconductor in an image forming apparatus comprising a second cleaning member that contacts the belt, and a control unit,
A printing step of applying a first transfer voltage to the transfer unit in response to receiving a print job; and applying the transfer voltage to the transfer unit with respect to a region where the developer is carried on the photoconductor From the voltage value of the first transfer voltage in the first transfer process, the second transfer process in which the transfer voltage is applied to the transfer unit with respect to the region where the developer is carried on the photoconductor, and the printing process A third transfer process in which a small second transfer voltage is applied to the transfer unit; and the transfer voltage is applied to the transfer unit with respect to a part of a region where the developer is carried on the photosensitive member by the transfer unit. Including at least any two of the fourth transfer processes to be applied as options and executing any one of the processes included in the options according to a condition. Method of recovering developer. A photoconductor, a belt in contact with the photoconductor, a first cleaning member in contact with the photoconductor, and a transfer unit that applies a transfer voltage to transfer the developer carried on the photoconductor to the belt. A program for controlling an image forming apparatus comprising: a second cleaning member in contact with the belt,
In the image forming apparatus,
A printing step of applying a first transfer voltage to the transfer unit in response to receiving a print job; and applying the transfer voltage to the transfer unit with respect to a region where the developer is carried on the photoconductor From the voltage value of the first transfer voltage in the first transfer process, the second transfer process in which the transfer voltage is applied to the transfer unit with respect to the region where the developer is carried on the photoconductor, and the printing process A third transfer process in which a small second transfer voltage is applied to the transfer unit; and the transfer voltage is applied to the transfer unit with respect to a part of a region where the developer is carried on the photosensitive member by the transfer unit. It is characterized in that at least any two of the fourth transfer processes to be applied are selected as options, and an execution process for executing any one of the processes included in the options is executed according to a condition. Programs that.

Images