JP5810738B2 - Control device, image forming apparatus, and program - Google Patents

Description

  The present invention relates to a control device, an image forming apparatus, and a program.

  In Patent Document 1, the cleaning unit for the photoconductor or the cleaning unit for the paper transport unit has a cleaning blade, and a part of the toner image area formed on the photoconductor is transferred onto the paper transport unit. In addition, a technique for cleaning toner images on the photosensitive member and on the sheet conveying unit by each cleaning unit is described.

Japanese Patent No. 3248217

  An object of the present invention is to suppress a reduction in the removal capability of a removal member that comes into contact with the surface of the photosensitive member when the surface roughness is relatively small.

According to a first aspect of the present invention, there is provided a control device for removing a deposit on a first photosensitive member, a charging device for charging the first photosensitive member, and the first photosensitive member in contact with the first photosensitive member. A removing member that rotates with a driving force from a driving source, supplies toner to the electrostatic latent image formed on the first photoconductor, and performs development, a second photoconductor, A removing member that contacts the second photoconductor to remove the deposits on the second photoconductor, and rotates with the driving force from the driving source, and the electrostatic latent image formed on the second photoconductor is toner. In an electrophotographic image forming apparatus having a second developing roll that performs development by supplying the first photosensitive member, the cumulative number of rotations of the first photosensitive member from the start of use of the first photosensitive member, and the first specifying means for specifying a cumulative rotational speed of the second photoconductor from when use of the second photosensitive member is started, When at least one of said accumulated rotation number of the identified first photoconductor and said second photoconductor by serial identification means is less than the threshold value is formed on the medium the toner image by the image forming apparatus in preparation process performed before the first photoconductor and the second photoconductor is charged by the charging device, and the state in which the toner image corresponding to the image data is not formed first photoconductor and the While the second photosensitive member is rotating , the first developing roller and the second developing roller are rotated by the driving force from the driving source, respectively , and toner is applied to the first photosensitive member and the second photosensitive member . And supply control means for performing control to supply.

Control device according to claim 2 of the present invention, in the structure according to claim 1, wherein the supply control means checks whether to supply the toner to said first photosensitive body is permitted by the user When it is confirmed that the toner is permitted, control is performed to supply the toner to the first photoconductor.

According to a third aspect of the present invention, there is provided an image forming apparatus comprising: a first photosensitive member; a charging device that charges the first photosensitive member; and an attachment to the first photosensitive member in contact with the first photosensitive member. and a removing member for removing an image forming means for forming a toner image on the medium by the electrophotographic method, a detecting means for detecting that said first photosensitive body is rotated, the control according to claim 1 or 2 A control device comprising the specifying means for specifying the cumulative number of rotations of the first photoconductor from the start of use of the first photoconductor based on the detection result of the detection means. It is characterized by doing.

According to a fourth aspect of the present invention, there is provided a program comprising: a computer; a first photosensitive member; a charging device that charges the first photosensitive member; and a deposit on the first photosensitive member in contact with the first photosensitive member. A first developing roll that rotates with a driving force from a driving source, supplies toner to the electrostatic latent image formed on the first photosensitive member, and develops the second photosensitive member. A removing member that comes into contact with the second photoconductor to remove deposits on the second photoconductor, and an electrostatic latent image formed on the second photoconductor that is rotated by a driving force from the driving source. and accumulated rotation speed of the first photosensitive member from when the image forming apparatus of an electrophotographic system, the use of the first photosensitive member is started and a second developing roll for developing by supplying toner to the, Japanese and accumulated rotation speed of the second photoconductor from when use of the second photosensitive member is started To specifying means, when at least one of said accumulated rotation number of the identified first photoconductor and said second photoconductor by the specifying means is less than the threshold value, the toner image by the image forming apparatus In the preparatory process performed before forming the image on the medium, the first photoconductor and the second photoconductor are charged by the charging device, and the toner image corresponding to the image data is not formed. The first developing roller and the second developing roller are rotated by the driving force from the driving source while the first photosensitive member and the second photosensitive member are rotating , respectively . 2 Functions as supply control means for controlling supply of toner to the photoreceptor .

According to the first, third , and fourth aspects of the present invention, compared to a case where there is no configuration in which toner is supplied to the photoconductor during the target period in this configuration until the cumulative number of rotations of the photoconductor reaches a threshold value. When the surface roughness of the body is relatively small, it is possible to suppress a reduction in the removal capability of the removal member that comes into contact with the surface.
According to the first, third, and fourth aspects of the present invention, when at least one of the accumulated rotational speeds of the plurality of photoconductors is less than the threshold value, the developing roll having a common drive source in the target period in this configuration. In any of these photoconductors, when the surface roughness of the photoconductor is relatively small, the contact with the surface of the photoconductor is removed as compared with the case where the structure for supplying toner to these photoconductors is not provided. It can suppress that the removal capability of a member falls.
According to the second aspect of the present invention, it is possible to suppress the consumption of toner compared to a case where it is not configured to supply the toner to the photosensitive member when it is confirmed that the toner supply is permitted.

1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment. It is a figure which shows the structure of an image formation part. It is a figure which shows the structure of a photoconductor unit. It is a figure for demonstrating the fall of the removal capability of a cleaning blade. It is a flowchart of the process which measures the accumulated rotation speed of a photoconductive drum. 5 is a flowchart of processing for supplying toner by a control unit. It is a block diagram which shows the function which a control part implement | achieves. It is a flowchart of the process in which the control part which concerns on a modification supplies a toner. It is a flowchart of the process in which the control part which concerns on a modification supplies a toner.

[Embodiment]
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration of an electrophotographic image forming apparatus 10 according to an embodiment. The image forming apparatus 10 according to the present embodiment includes a control unit 100, an operation unit 101, a display unit 102, a storage unit 103, and an image forming unit 200. The control unit 100 is a computer including an arithmetic device including a CPU (Central Processing Unit) and a memory. The arithmetic unit of the control unit 100 executes a program stored in the memory and controls each unit of the image forming apparatus 10. The control unit 100 is an example of the “control device” according to the present invention. The operation unit 101 includes an operation element such as a button, and supplies operation information representing the operation content to the control unit 100 according to a user operation. The display unit 102 includes a liquid crystal display screen and a liquid crystal driving circuit, and displays the progress of processing, information for guiding operations to the user, and the like based on information supplied from the control unit 100.

  The storage unit 103 includes a storage device such as an HDD (Hard Disk Drive), and stores, for example, image data for forming an image. The image forming unit 200 forms an image on a recording medium by an electrophotographic process using four color toners of yellow (Y), magenta (M), cyan (C), and black (K). The recording medium is, for example, a recording sheet, but may be a plastic such as an OHP sheet or a sheet of other materials, and may be any medium that can record an image on the surface.

  FIG. 2 is a diagram illustrating a configuration of the image forming unit 200. Among the reference numerals of the image forming unit 200 shown in FIG. 2, the alphabet attached to the end corresponds to the color of toner handled by the image forming apparatus. The configurations having different alphabets at the end of the codes are different in the color of the toner to be handled, but the configurations are common to each other. In the following description, when it is not necessary to distinguish between these components, the description will be made with the alphabet at the end of the reference numerals omitted. In the image forming unit 200, an image is formed on a recording sheet conveyed in the direction of the broken arrow A3 shown in FIG. The image forming unit 200 includes a photosensitive unit 210, an exposure device 220, a developing device 230, an intermediate transfer belt 240, a rotating roll 241, an edge sensor 243, a density sensor 244, a steering roll 245, and a primary transfer. A roll 250, a secondary transfer roll 260, an eccentric cam 262, a backup roll 264, a transport roll 270, and a fixing device 280 are included.

  The photoconductor unit 210 has a photoconductor drum 211. The photosensitive drum 211 is a cylindrical member that rotates around an axis with a photoconductive film laminated on the surface, and holds an electrostatic latent image formed on the surface. When the photosensitive drum 211 is in contact with the intermediate transfer belt 240, the photosensitive drum 211 rotates in the direction of the arrow A1 in the drawing with the center of the cylinder as an axis as the intermediate transfer belt 240 rotates. Hereinafter, this direction is referred to as a drum rotation direction A1. The photoconductor drum 211 is an example of the “first photoconductor” according to the present invention. The exposure device 220 exposes the photosensitive drum 211 according to image data to form an electrostatic latent image on the photosensitive drum 211. The developing device 230 contains a developer containing toner of any color of Y, M, C, and K and a magnetic material such as ferrite powder. These toners have an external additive such as silica or titanium attached to the surface, thereby improving the fluidity and controlling the charging characteristics more easily than when the external additive is not attached. It has become. The developing device 230 performs development by supplying toner to the electrostatic latent image formed on the photosensitive drum 211 using the developer.

  The intermediate transfer belt 240 is an endless belt-like member, and rotates in a direction indicated by an arrow A2 in the drawing while being in contact with the rotary roll 241, the steering roll 245, the primary transfer roll 250, and the backup roll 264. Hereinafter, this direction is referred to as a belt rotation direction A2. The photoconductor units 210Y, 210M, 210C, and 210K are arranged in a line from the upstream side to the downstream side in the belt rotation direction A2 along the outer peripheral surface of the intermediate transfer belt 240. The rotating roll 241 and the steering roll 245 are cylindrical members that support the intermediate transfer belt 240 and rotate around the center of the cylinder. The steering roll 245 is supported so as to be movable in the width direction of the intermediate transfer belt 240 (that is, the axial direction of the steering roll 245), and when the intermediate transfer belt 240 rotates by being moved in the width direction. The so-called meandering is suppressed by adjusting the traveling direction. The edge sensor 243 is provided at a position in contact with the side end (edge) of the intermediate transfer belt 240 and detects the position of the side end in the width direction of the intermediate transfer belt 240. The edge sensor 243 is provided at a position on the upstream side of the photosensitive drum 211Y and the downstream side of the steering roll 245 in the belt rotation direction A2. The density sensor 244 has a pair of light-emitting elements and light-receiving elements. The light-receiving elements receive reflected light from the intermediate transfer belt 240 irradiated with light from the light-emitting elements and detect the amount of light, whereby the intermediate transfer belt. The density of the toner image formed on 240 is detected. The density sensor 244 is provided at a position upstream of the secondary transfer roll 260 and downstream of the rotary roll 241 in the belt rotation direction A2.

  The primary transfer roll 250 is a cylindrical member that faces the photosensitive drum 211 with the intermediate transfer belt 240 interposed therebetween. Due to the potential difference between the primary transfer roll 250 and the photosensitive drum 211, the toner on the surface of the photosensitive drum 211 is transferred to the surface of the intermediate transfer belt 240. The secondary transfer roll 260 transfers the toner image obtained by the development of the developing device 230 onto the recording paper. The secondary transfer roll 260 is a cylindrical member that faces the backup roll 264 with the intermediate transfer belt 240 interposed therebetween, and forms a region that contacts the intermediate transfer belt 240 (referred to as a contact region). In this contact area, a potential difference is generated between the secondary transfer roll 260 and the backup roll 264, whereby the toner on the surface of the intermediate transfer belt 240 is transferred to the surface of the recording paper.

  The eccentric cam 262 is a cylindrical member having an elliptical cross section perpendicular to the rotation axis, and is provided at both axial ends of the rotation shaft 261 of the secondary transfer roll 260. The eccentric cam 262 is disposed such that the outer peripheral surface thereof is in contact with the outer peripheral surface of the rotating shaft 261. The rotation shaft of the eccentric cam 262 is provided at a position eccentric in the elliptical cross section. The amount by which the secondary transfer roll 260 and the intermediate transfer belt 240 are in contact with each other when the eccentric cam 262 is rotated about the rotation shaft 263 by the control of the control unit 100 so that the secondary transfer roll 260 moves in the vertical direction. (Referred to as contact amount) changes. The transport roll 270 is a cylindrical member that is driven by a drive device (not shown), and transports the recording paper in the direction of the broken arrow A3 shown in FIG. The fixing device 280 performs a fixing process of applying heat and pressure to the recording paper on which the toner image is transferred, and fixes the toner image on the recording paper.

  FIG. 3 is a view showing the structure of the photoreceptor unit 210. The photoconductor unit 210 includes a charging device 212, a cleaning blade 213, a rotation detection device 290, and a memory 291 in addition to the above-described photoconductor drum 211. The charging device 212 charges the photoconductive film 211S of the photosensitive drum 211 to a predetermined potential. The charging device 212 is an example of the “charging unit” according to the present invention. The cleaning blade 213 is a long plate-like member formed of, for example, rubber or resin, and one side in the longitudinal direction thereof is in contact with the photosensitive drum 211 and further pressed against the photosensitive drum 211 side. As a result, the deposits attached to the photoconductive film 211S of the photosensitive drum 211 are removed. This adhering material is toner or an external additive remaining on the photoconductive film 211S of the photosensitive drum 211 without being transferred to the intermediate transfer belt 240. The cleaning blade 213 is an example of the “removal member” according to the present invention.

  The rotation detection device 290 is an optical sensor and detects a sensor mark provided on the peripheral surface of the photosensitive drum 211. The rotation detection device 290 detects the sensor mark every time the photosensitive drum 211 makes one rotation, and outputs a signal indicating the detection result (hereinafter referred to as “detection signal”) to the control unit 100. As described above, the rotation detection device 290 functions as a unit that detects that the photosensitive drum 211 has rotated, and is an example of the “detection unit” according to the present invention. The memory 291 is a non-volatile memory and stores the cumulative number of rotations of the photosensitive drum 211. Here, the cumulative number of revolutions refers to the number of revolutions of the photosensitive drum 211 accumulated since the use of the photosensitive drum 211 is started. The use of the photosensitive drum 211 here includes not only forming an image using the photosensitive drum 211 but also simply rotating the photosensitive drum 211. The use of the photosensitive drum 211 is started when the photosensitive drum 211 is first attached to the image forming apparatus 10, that is, when the photosensitive unit 210 is first attached to the image forming apparatus 10. Each time the detection signal is output from the rotation detection device 290, the control unit 100 stores a number obtained by adding 1 to the accumulated number of revolutions stored in the memory 291 as a new accumulated number of revolutions.

For example, after the use of the photosensitive drum 211 is started, the photosensitive unit 210 is replaced as one component for each color when a failure occurs or when the lifetime of the photosensitive drum 211 is reached. The life of the photoconductor drum 211 is exhausted when the photoconductive film 211S is worn and the initial charging performance cannot be maintained. In the image forming apparatus 10, it is assumed that the photosensitive drum 211 that reaches the end of its life at about 400,000 rotations is used.
Further, even if the photoconductor unit 210 is removed once, it may be attached again without being replaced. Even in this case, the memory 291 of the photoconductor unit 210 stores the cumulative number of rotations of the photoconductor drum 211 of the photoconductor unit 210. In other words, this cumulative rotational speed represents the rotational speed of the photosensitive drum 211 accumulated since the photosensitive drum 211 was first attached to the image forming apparatus 10.

  The developing device 230 includes a developing roll 231 having a built-in magnetic roll and a voltage applying unit 232 that applies a voltage to the developing roll 231 and accommodates a two-component developer including toner and a carrier. The developing roller 231 rotates in the direction of the arrow A4, and the accommodated two-component developer is attracted to the surface by a magnetic force and conveyed. The developing roll 231 is an example of the “first developing roll” according to the present invention. The voltage application unit 232 applies a voltage to the developing roll 231 so that the surface thereof has a predetermined potential. A region (hereinafter referred to as “toner supply region”) sandwiched between the surface of the developing roll 231 having this potential and the photoconductive film 211S charged to the potential determined by the charging device 212 as described above. An electric field is generated by these potential differences, and the toner adsorbed on the surface of the developing roll 231 moves to the photoconductive film 211S. As described above, when the developing roll 231 and the voltage applying unit 232 operate, the developing device 230 supplies toner to the photoconductive film 211S in the toner supply region, and forms a toner image. The toner image formed at this time is a developed electrostatic latent image and is in accordance with the image data described above. The motor 233 rotates the developing roll 231 in the direction of arrow A4 via the gear 234. The charging device 212, the developing device 230, the rotation detecting device 290, the primary transfer roll 250, and the cleaning blade 213 are arranged around the photosensitive drum 211 in this order along the drum rotation direction A1. Each of the image forming units 200 described above with reference to FIGS. 2 and 3 excluding the optical sensor (detecting unit) of the rotation detecting device 290 is an example of the “image forming unit” according to the present invention.

  Subsequently, when the control unit 100 returns from a power saving mode (a state where the display unit 102 is stopped without supplying power) at a predetermined time before image formation, for example, when the power is turned on. Alternatively, a process (hereinafter referred to as “setup process”) executed when returning from a sleep mode (a state where the image forming unit 200 is stopped without supplying power to the display unit 102) will be described. Here, the setup process is a process performed as preparation for image formation before forming an image on a recording medium in order to maintain high quality of an image formed in the image forming apparatus 10. This is a process in which each part of 10 is operated on a trial basis and a setting value used for the operation of each part or an arrangement of each part is adjusted. The setup process is an example of the “preparation process” according to the present invention. Specifically, the control unit 100 adjusts the image density by changing the light amount value output from the exposure device 220, the charging bias voltage value supplied to the charging device 212, the developing bias voltage value supplied to the developing roll 231, and the like. The image density adjustment process is performed. Further, the control unit 100 changes the exposure start timing of the exposure apparatus 220 based on the amount of misregistration (so-called color misregistration) of each color toner image formed by each photoconductor unit 210 to adjust the color misregistration. Perform the adjustment process. The control unit 100 also performs an edge position adjustment process for adjusting the position of the intermediate transfer belt 240 in the width direction, and a contact amount adjustment process for adjusting the amount of contact between the secondary transfer roll 260 and the intermediate transfer belt 240 (contact amount). Then, when the photoconductor unit 210K is replaced, a K toner supply process for supplying K color toner to the cleaning blade 213K, and a K color belt-like toner image (also referred to as K band) is formed on the photoconductor drum 211K. As a result, a K band forming process is performed in which the developer with damaged K color is discharged to refresh the toner.

  The control unit 100 executes these setup processes when a predetermined condition (hereinafter referred to as “execution condition”) is satisfied. If the execution condition is an image density adjustment process, for example, if the number of recording media on which an image has been formed has exceeded a threshold (for example, 50 sheets) since the previous execution of this process, and the previous execution of this process. For example, the value of the temperature that has changed since then exceeds a threshold value (for example, 2 degrees). These execution conditions may be common for each setup process or may be different. For this reason, when a certain condition is satisfied, a plurality of setup processes may be executed, or only one setup process may be executed. When executing a plurality of setup processes, the control unit 100 executes the processes in a predetermined order. The order is, for example, an image density adjustment process, a color misregistration adjustment process, an edge position adjustment process, a contact amount adjustment process, a K toner supply process, and a K band formation process, and the control unit 100 does not execute them. If there is a process, the process is skipped and the process in the next order is executed.

  The control unit 100 forms a toner image for detecting the density and position of each toner image in the image density adjustment process and the color misregistration adjustment process among the above setup processes. That is, in these processes, the control unit 100 controls the developing device 230 to supply toner to the photoconductive film 211S of the photosensitive drum 211, and forms a toner image on the photoconductive film 211S. The toner image formed on the photoconductive film 211S is transferred to the intermediate transfer belt 240 by the primary transfer roll 250, but the toner remaining without being transferred is in contact with the surface of the photoconductive film 211S. It reaches one side of 213 and stays in the surrounding area.

When the photosensitive drum 211 rotates without toner staying in the peripheral area, the cleaning blade 213 turns over or breaks down, and the ability to remove deposits (hereinafter referred to as “removing ability”) decreases. There are things to do.
FIG. 4 is a diagram for explaining a decrease in the removal capability of the cleaning blade 213. FIG. 4A shows the cleaning blade 213 before the removal capability is lowered. In the cleaning blade 213, the side 213U, which is one side in the longitudinal direction described above, is in contact with the surface of the photoconductive film 211S. The toner T adheres to the surface of the photoconductive film 211S, and the toner T is conveyed toward the side 213U while the photosensitive drum 211 rotates in the drum rotation direction A1. The toner T that has reached the side 213U stays in the peripheral region described above, that is, the region V sandwiched between the cleaning blade 213 and the photoconductive film 211S on the upstream side of the side 213U in the drum rotation direction A1. . In the state where the toner T is not staying in the region V (hereinafter referred to as “non-staying state”), the cleaning blade is compared with the state where the toner T is staying in the region V (hereinafter referred to as “staying state”). The frictional force acting on the portion where the side 213U of 213 is in contact with the surface of the photoconductive film 211S increases. For this reason, in the non-staying state, compared to the staying state, the side 213U is easily pulled in the drum rotation direction A1 by the frictional force received from the photoconductive film 211S, and the end W on the side 213U side of the cleaning blade 213 is displaced, Damages such as missing are likely to occur.

  FIG. 4B shows a state in which the end of the cleaning blade 213 pulled by this frictional force is cut and the end 213W is further pulled by the photoconductive film 211S and deformed to widen the cut. Yes. If this state continues, as shown in FIG. 4C, the end portion 213W may be broken and lost. When the end portion 213W is lost, the toner T passes through the space where the end portion 213W existed. Then, the slipped toner T is transferred to the medium, and a phenomenon occurs in which white stripes (white stripes) or colored stripes (color stripes) enter the image. This phenomenon also occurs when a so-called “turn-up” occurs in which the cleaning blade 213 is deformed in a state where it is not damaged by being pulled in the drum rotation direction A1. On the other hand, in the staying state shown in FIG. 4A, the frictional force acting on the portion where the side 213U of the cleaning blade 213 and the photoconductive film 211S are in contact with each other is smaller than that in the non-staying state. For this reason, the end portion 213W of the cleaning blade 213 is hardly pulled in the drum rotation direction A1 by the frictional force received from the photoconductive film 211S, and a reduction in the removal capability such as breakage or turning of the end portion 213W is suppressed. Along with this, in the staying state, a phenomenon in which a streak enters the image is less likely to occur than in the non-staying state.

  The control unit 100 forms the toner image as described above in the image density adjustment process and the color misregistration adjustment process. However, in the edge position adjustment process and the contact amount adjustment process, the control unit 100 forms a toner image. I won't let you. On the other hand, in these processes, the control unit 100 controls each unit so that the photosensitive drum 211 is rotated and the surface of the photosensitive drum 211 is charged by the charging device 212. In the edge position adjustment process, the control unit 100 moves the steering roll 245 in the width direction of the intermediate transfer belt 240 so that the position detected by the edge sensor 243 approaches a predetermined position. The control unit 100 may use a known technique such as the technique described in Japanese Patent Application Laid-Open No. 2010-282124 for the process of adjusting the position of the intermediate transfer belt 240. Further, in the contact amount adjustment process, the control unit 100 rotates the eccentric cam 262 and moves the secondary transfer roll 260 to adjust the contact amount. In the control unit 100, for example, the electrical resistance value from the rotation shaft 261 of the secondary transfer roll 260 to the rotation shaft of the backup roll 264 detected by a resistance detection sensor (not shown) is secondarily transferred with good image quality. Sometimes the contact amount is adjusted so as to approach the electrical resistance value (referred to as a reference resistance value) detected by the resistance detection sensor. The control unit 100 may use a known technique such as the technique described in Japanese Patent Application Laid-Open No. 2010-60734 for the process of adjusting the contact amount.

  In the edge position adjustment process and the contact amount adjustment process, the control unit 100 performs different operations depending on the cumulative number of rotations of the photosensitive drums 211. Specifically, when the accumulated number of rotations is less than a threshold value (200000 rotations in the present embodiment), the control unit 100 controls the developing device 230 to rotate the developing roll 231 so that the photosensitive drum 211 is rotated. Toner is supplied to the photoconductive film 211S. At this time, the electrostatic latent image corresponding to the above-described image data is not formed on the surface of the photoconductive film 211S, and the entire surface is at a potential charged by the charging device 212. For this reason, the toner is supplied to the entire surface of the photoconductive film 211S. Note that a toner image corresponding to the image data is not formed on the photosensitive drum 211 by the toner thus supplied. As a result, in the photosensitive unit 210 having an accumulated rotational speed less than the threshold value, the toner is supplied to the entire side 213U of the cleaning blade 213, and the side 213U of the cleaning blade 213 contacts the photoconductive film 211S of the photosensitive drum 211. The frictional force that acts on the portion where the toner is applied is smaller than when the toner is not retained. As a result, compared with the case where the toner does not stay, the above-described reduction in the removal capability of the cleaning blade is suppressed, and the occurrence of a phenomenon in which a streak enters the image is also suppressed.

  Further, the control unit 100 supplies toner per unit area when supplying toner as described above, compared with when supplying toner to an area where an electrostatic latent image is formed (that is, when forming a toner image). Reduce the amount of toner. Specifically, the control unit 100 controls the voltage application unit 232 so that the potential difference between the photoconductive film 211S and the surface of the developing roll 231 is such that the electrostatic latent image and the surface of the developing roll 231 when the toner is developed. A voltage is applied to the developing roll 231 so as to be smaller than the potential difference between the two. In this case, the electric field generated in the toner supply region described above is weaker and the amount of toner supplied is smaller than when developing a toner image. Further, the amount of toner supplied at this time reduces the above-described reduction in the removal capability by reducing the frictional force acting at the portion where the side 213U of the cleaning blade 213 and the photoconductive film 211S are in contact with each other. The amount is determined so that the phenomenon of streaking is less likely to occur.

  When the toner is supplied as described above, the amount of toner stored in the developing device 230 again without being supplied to the surface of the photoconductive film 211S becomes larger than when the toner image is formed. As the number of times these toners circulate in the developing device 230 increases, the external additive attached to the surface is buried inside. As a result, in these toners, the fluidity improved by the external additive is lowered, and it becomes difficult to control the charging characteristics. That is, the toner deteriorates.

  On the other hand, in the photoconductor unit 210 whose cumulative rotation number is equal to or greater than the threshold, the photoconductive film 211S of the photoconductor drum 211 is compared with the case where the photoconductor drum 211 is first used after being attached to the image forming apparatus 10 for the first time. The surface roughness is increasing. Surface roughness here is arithmetic mean roughness, for example, and is surface roughness prescribed | regulated to JISB0601 (2001). Therefore, in this photosensitive unit 210, if the amount of toner staying in the region V does not change, it acts on the portion where the surface of the photoconductive film 211S and the cleaning blade 213 are in contact with each other than when the use is started. The frictional force is reduced. As a result, in the photoconductor unit 210, the control unit 100 does not perform the process of supplying toner to the surface of the photoconductive film 211S at the time of the specific process, but compared to when the use is started. The reduction in removal capability is suppressed, and the occurrence of the phenomenon described above is suppressed.

  Therefore, the control unit 100 does not perform the above-described control for supplying the toner to the surface of the photosensitive drum 211 whose cumulative rotation number is equal to or greater than the threshold value. In other words, in a state where the surface of the photoconductive film 211S is used and the surface becomes rough, the control unit 100 gives priority to making the toner less likely to deteriorate rather than reducing the frictional force. The toner is not supplied to the photoconductive film 211S of the drum 211.

In addition, in the K toner supply process and the K band formation process, the control unit 100 forms a K color toner image, but does not form Y, M, and C color toner images. Further, in these processes, the control unit 100 controls the respective units so that the Y, M, and C photoconductive drums 211 are rotated and the surface of the photoconductive drum 211 is charged by the charging device 212. To do. For this reason, in the Y, M, and C photoconductor units 210, the toner is not supplied to the side 213U of the cleaning blade 213, so that the removal capability is likely to be reduced and the above-described phenomenon is likely to occur. Therefore, the control unit 100 controls the developing device 230 for each color of Y, M, and C to control the photoconductive film of the photosensitive drum 211 when the cumulative number of rotations of the photosensitive drum 211 for each color is less than the above threshold. When the toner is supplied to 211S and the value is equal to or greater than the threshold value, the control is not performed. Thereby, also in the K toner supply process and the K band forming process, the decrease in the removal capability is suppressed as in the edge position adjustment process and the contact amount adjustment process, and the occurrence of the above-described phenomenon is suppressed.
As described above, when the control unit 100 performs specific processing (edge position adjustment processing, contact amount adjustment processing, K toner supply processing, and K band formation processing), the cumulative number of rotations of the photosensitive drum 211 is less than the above threshold value. In this case, the developing device 230 is controlled to supply toner to the photoconductive film 211S of the photosensitive drum 211.

  Next, the procedure of the process in which the control unit 100 measures the cumulative rotation speed will be described with reference to FIG. 5 which is a flowchart showing this procedure. The control unit 100 starts this process when the image forming apparatus 10 is manufactured and used for the first time by the user. In addition, the control unit 100 executes this process for each photoconductor unit 210 of each color. First, the control unit 100 measures the number of rotations of the photosensitive drum 211 (step S11). Specifically, every time a detection signal output from the rotation detection device 290 is received, the control unit 100 increments the rotation number of the photosensitive drum 211 by one, and the rotation number is determined in the storage unit 103. Stored in the storage area. Next, the control unit 100 measures the measured rotation when the photosensitive drum 211 does not rotate for a predetermined period (that is, when the number of rotations is not added), or when the power is turned off and turned on again. The number is added to the cumulative rotational speed (step S12). The control unit 100 stores the accumulated rotation number in a predetermined storage area of the storage unit 103. Then, the control unit 100 determines whether or not the photoconductor unit 210 has been replaced (step S13). If it is determined that the photoconductor unit 210 has not been replaced (step S13; NO), the processes of steps S11 and S12 are executed again. . Moreover, if the control part 100 judges that it replaced | exchanged (step S13; YES), an accumulation speed will be set to 0 (step S14) and it will return to the process of step S11. Through the above processing, the control unit 100 measures the cumulative number of rotations of the photosensitive drum 211 for each color.

  Subsequently, a procedure of processing in which the control unit 100 supplies toner to the photoconductive film 211S of the photosensitive drum 211 in the specific processing described above will be described with reference to FIG. 6 which is a flowchart showing this procedure. The control unit 100 starts this procedure when the image forming apparatus 10 is turned on, when it returns from the power saving mode, or when it returns from the sleep mode. First, the control unit 100 starts the setup process described above (step S21). Specifically, the control unit 100 executes, in the order described above, the setup processes described above that satisfy the respective execution conditions. For example, if the setup process that satisfies the execution conditions is an image density adjustment process, an edge position adjustment process, a contact amount adjustment process, a K toner supply process, and a K band formation process, the control unit 100 performs these setup processes in this order. Run.

  Next, the control unit 100 determines whether or not the setup process to be executed is a specific process (step S22). When the specific process is to be executed (step S22; YES), the control unit 100 determines whether or not the cumulative rotation number of the photosensitive drum 211 is less than the threshold value (200000 rotations) (step S22). S23). The specific processing here is edge position adjustment processing, contact amount adjustment processing, K toner supply processing, or K band formation processing. In these processes, the control unit 100 performs an operation of charging the photoconductive film 211S to a predetermined potential by controlling the charging device 212 while rotating the photosensitive drum 211, while the photoconductive film 211S is charged. The operation of forming a toner image by exposure is not performed. When the specific process is the edge position adjustment process or the contact amount adjustment process, the control unit 100 performs the process of step S23 on the photosensitive drum 211 of each color (Y, M, C, K), and the specific process is K toner. In the case of the supply process and the K band forming process, the process of step S23 is performed on the Y, M, and C photoconductive drums 211. If the control unit 100 determines that it is less than the threshold value (step S23; YES), it controls the developing device 230 for that color during the execution of the specific process, and the photoconductive film 211S of the photosensitive drum 211 for that color. The toner is supplied to the toner (step S24). On the other hand, when the control unit 100 determines that the value is equal to or greater than the threshold (step S23; NO), the control unit 100 proceeds to the process of step S25. Moreover, also when it is judged that the control part 100 is not a specific process in step S22 (step S22; NO), it progresses to the process of step S25.

  In step S25, the control unit 100 determines whether or not there is a setup process to be executed. If it is determined that there is any remaining data (step S25; YES), the control unit 100 executes the process of step S22. On the other hand, when determining that there is no remaining (step S25; NO), the control unit 100 ends the process.

  FIG. 7 is a block diagram illustrating functions realized by the control unit 100 executing a program. The control unit 100 includes an image formation processing unit 110, a specifying unit 120, and a supply control unit 130. The image forming processing unit 110 controls each unit of the image forming unit 200 to form an image on a recording medium. Further, the image formation processing unit 110 controls each part of the image forming unit 200 to execute the above-described setup process. The specifying unit 120 executes the processes of steps S11 and S12 illustrated in FIG. 5 and starts using the photosensitive drum 211 based on the detection result (that is, the detection signal) output from the rotation detection device 290. The cumulative number of rotations of the photosensitive drum 211 is specified. The identification unit 120 is an example of the “identification unit” according to the present invention. The specifying unit 120 supplies data representing the specified accumulated rotational speed to the supply control unit 130. The supply control unit 130 performs the processes of steps S22, S23, and S24 illustrated in FIG. 6, and when the cumulative number of rotations specified by the specifying unit 120 is less than the threshold value, The period during which the photosensitive drum 211 is rotated in a state where the drum 211 is charged by the charging device 212 and the toner image is not formed on the photosensitive drum 211 (this period in the specific processing is referred to as “specific processing” below. During the period, the toner is supplied to the photosensitive drum 211. The supply control unit 130 is an example of the “supply control unit” according to the present invention.

  As described above, the control unit 100 performs control to supply toner to the photosensitive drum 211 during the specific period when the cumulative rotation number of the photosensitive drum 211 is less than the threshold value. The time when this control is performed is a time when the surface roughness of the photoconductive drum 211 is smaller than the time when the cumulative number of revolutions of the photoconductive drum 211 is equal to or greater than the threshold, in other words, the photoconductive drum 211 is used. It is a time when the surface roughness is relatively small during the entire period. That is, according to the present embodiment, a configuration in which the control unit does not perform control to supply toner to the photosensitive drum during the specific period when the cumulative number of rotations of the photosensitive drum is less than the threshold (Comparative Configuration 1). In contrast, when the surface roughness of the photosensitive drum is relatively small, the frictional force acting on the portion where the cleaning blade and the surface of the photosensitive drum are in contact with each other decreases. Therefore, according to the present embodiment, compared with the comparative configuration 1, a reduction in the removal capability of the cleaning blade is suppressed, and the above-described phenomenon that a streak enters the image is suppressed from occurring at this time.

[Modification]
The above-described embodiment is merely an example of the present invention, and various modifications may be made as follows. Moreover, you may combine embodiment mentioned above and each following modification as needed.

(Modification 1)
In the image forming apparatus 10, the setup process that the control unit 100 controls and executes the image forming unit 200 is not limited to the one shown in the above-described embodiment. For example, the control unit 100 detects the remaining amount of each color toner stored in a toner container (not shown) that cleans the photosensitive drum 211 and the intermediate transfer belt 240 or supplies toner to the developing device 230. Or the like may be executed by the image forming unit 200. In the case of the latter processing, the toner container is provided with a sensor for detecting the remaining amount of toner stored in the toner container, and the control unit 100 acquires data indicating the remaining amount detected by the sensor, Information indicating the degree of the remaining amount (for example, character information such as “remaining 1/2” or “remaining 1/4”) is displayed on the display unit 102. In short, the control unit 100 may execute the setup process as long as it is performed in order to maintain the quality of the formed image at a high level.

  At this time, the specific process of the setup process is not limited to the edge position adjustment process, the contact amount adjustment process, the K toner supply process, and the K band formation process as in the above-described embodiment. For example, it is a process of detecting the remaining amount of each color toner. Also in this process, the control unit 100 controls the developing device 230 to supply toner to the photoconductive film 211S of the photosensitive drum 211 when the cumulative number of rotations of the photosensitive drum 211 is less than the threshold value. If it is above the threshold, the control is not performed. In short, the control unit 100 specifies a setup process in which the photosensitive drum 211 rotates, the charging device 212 charges the photoconductive film 211S of the photosensitive drum 211, and no toner image is formed on the photoconductive film 211S. This process is sufficient. When the charging device 212 charges the photoconductive film 211S, the surface of the photoconductive film 211S and the cleaning blade 213 are compared with the case where the photoconductive film 211S is not charged by the discharge product generated in the photoconductive film 211S. The frictional force acting on the portion where the contact is made increases. Further, when the toner image is not formed, the toner that has not been transferred does not stay on the cleaning blade 213. Therefore, in this specific process, the cleaning blade 213 and the surface of the photoconductive film 211S are in contact with each other as compared with the case where the charging device 212 does not charge the photoconductive film 211S or a toner image is formed. The working frictional force is increased, the above-described removal ability of the cleaning blade 213 is easily lowered, and the above-described phenomenon is likely to occur. According to the present modification, even in these specific processes, the surface is brought into contact with the cleaning blade 213 as compared with the comparative configuration 1 by supplying toner to the surface of the photoconductive film 211S. The frictional force acting on the portion is reduced, the reduction in removal capability is suppressed, and the occurrence of the above-described phenomenon is suppressed.

(Modification 2)
In the above-described embodiment, each color developing roll 231 is rotated by a motor 233 provided for each color, but a plurality of developing rolls 231 may share one motor. In other words, the image forming apparatus 10 may include a motor that rotates two or more developing rolls 231 together. For example, the image forming apparatus according to this modification includes a motor that rotates the Y, M, and C developing rolls 231 together. This motor is configured such that a driving force is transmitted through each developing roll 231 and a gear, and the motor and each gear cooperate to function as a driving source for rotating each developing roll 231. In this case, in the specific process, the control unit 100 determines that each developing roll is driven by the driving force from the driving source when the accumulated rotational speed of any of the Y, M, and C photoconductive drums 211 is less than the threshold value. 231 is rotated to supply toner to the photoconductive film 211S of the Y, M, and C photoconductive drums 211, respectively. The photoconductor drums 211Y, 211M, and 211C in this modification are examples of the “first photoconductor” and the “second photoconductor” according to the present invention, respectively. The developing rolls 231Y, 231M, and 231C in the present modification are examples of the “first developing roll” and the “second developing roll” according to the present invention.

  FIG. 8 is a flowchart illustrating a processing procedure in which the control unit 100 supplies toner to the photoconductive film 211S in the present modification. This procedure differs from the procedure shown in FIG. 6 in the processing steps of steps S23 and S24. When the setup process to be executed is a specific process (step S22; YES), the control unit 100 first determines whether or not the accumulated rotational speed of the photosensitive drum 211Y is less than a threshold value (step S31). If it is determined that the value is greater than or equal to the threshold value (step S31; NO), the control unit 100 determines whether or not the cumulative rotation number of the photosensitive drum 211M is less than the threshold value (step S32). (NO), it is determined whether or not the accumulated rotational speed of the photosensitive drum 211C is less than a threshold value (step S33). When the control unit 100 determines that the accumulated rotational speed is less than the threshold (YES) in any of steps S31, S32, and S33, the control unit 100 controls the developing devices 230Y, 230M, and 230C, and executes the specific processing. In the middle, the toner of each color is supplied to the photosensitive drums 211Y, 211M, and 211C (step S34).

  As described above, in the control unit 100 according to this modification, in a configuration in which one motor rotates two or more developing rolls 231, toner is supplied from each of two or more developing rolls 231 rotated by the motor. When any one of the accumulated rotational speeds of the photosensitive drum 211 is less than the threshold value, toner is supplied to each of the photoconductive films 211S by two or more developing rolls. According to this modification, in a configuration including one motor that rotates two or more developing rolls, the photosensitive drums to which toner is supplied by these developing rolls (in the example of FIG. 8, the photosensitive drums 211Y and 211M). , 211C), in any of these photosensitive drums, compared to the case where the configuration in which toner is supplied to these photosensitive drums when the cumulative number of revolutions is less than the threshold value is not included. The reduction of the cleaning blade removal capability due to friction with the slag is suppressed.

(Modification 3)
The threshold value of the cumulative rotation number is 200000 rotations in the above-described embodiment, but is not limited thereto. This threshold value may be, for example, a value smaller than that of the embodiment (for example, 50000 rotations) or a value larger than that of the embodiment (for example, 300000 rotations). This threshold value may be a value that is at least smaller than the cumulative number of rotations (400,000 in the above embodiment) that is expected to end the life of the photosensitive drum 211. Desirably, when a toner image is formed at the beginning of use of the photosensitive drum 211, the cumulative rotation is greater than the frictional force acting on the portion where the surface of the photosensitive drum 211 contacts the cleaning blade 213. When the number reaches the threshold value, the threshold value may be set so that the surface of the photosensitive drum 211 is charged and the frictional force is smaller when the toner image is not formed. Thereby, a friction force larger than the former friction force does not act on the contact portion.

(Modification 4)
In the embodiment described above, when the cumulative number of rotations of the photosensitive drum 211 is less than the threshold value (step S23 in FIG. 6; YES), the control unit 100 supplies toner to the photoconductive film 211S of the photosensitive drum 211. However, whether or not to supply toner may be determined according to the mode selected by the user.

  FIG. 9 is a flowchart showing a procedure of processing in which the control unit 100 supplies toner to the photoconductive film 211S in the present modification. This procedure is different from the procedure shown in FIG. 6 in that the process of determining whether or not to supply toner is executed before the process of step S22. After the setup process is started, the control unit 100 determines whether or not the toner supply in the specific process is permitted (step S41). Specifically, the control unit 100 first determines an area for storing data representing “permitted mode” or “non-permitted mode” in the storage unit 103. Subsequently, when the user who operates the operation unit 101 selects one of these modes, the control unit 100 stores data representing the selected mode in the area. Then, in step S41, the control unit 100 refers to this area of the storage unit 103, and determines that toner supply is permitted (YES) if data indicating “permitted mode” is stored. Then, the process of step S22 is executed. On the other hand, if data representing “non-permission mode” is stored in this area, the control unit 100 determines that toner supply is not permitted (NO), and executes the process of step S25. In this case, since the control unit 100 does not execute the process of step S24, the toner is not supplied to the photoconductive film 211S of the photosensitive drum 211 when the specific process is executed. If the control unit 100 determines in step S25 that the setup process to be executed remains (YES), the control unit 100 next executes the process of step S41.

  The supply control unit 130 of the control unit 100 according to the present modification executes the process of step S41 in FIG. 9, and the developing device 230 supplies toner to the photoconductive film 211S of the photosensitive drum 211 in a specific process. To see if it is allowed. Specifically, the supply control unit 130 refers to the storage unit 103 to confirm whether the “permitted mode” or the “non-permitted mode” is selected by the user, and whether or not the above-described permission has been made. To check. If the confirmed result is “permitted”, the supply control unit 130 controls the developing device 230 to supply toner to the photoconductive film 211S of the photosensitive drum 211, and the confirmed result is “ If “not permitted”, the process of supplying toner to the photoconductive film 211S of the photosensitive drum 211 is not executed.

  Even when the above-described specific processing is executed, for example, an image is formed on several tens of recording media before that, and the toner remaining without being transferred as the image is the region V shown in FIG. May stay. In that case, even if the toner is not supplied to the photoconductive film 211S of the photosensitive drum 211, damage to the cleaning blade 213 due to friction with the photosensitive drum 211 is less likely to occur than in the non-staying state. According to this modification, toner consumption is suppressed by the user selecting the “non-permission mode” in this case.

(Modification 5)
The present invention is not limited to the control device and the image forming apparatus provided with the control device, but can be grasped as a method for realizing them and a program for causing a computer to realize the functions shown in FIG. . Such a program may be provided in the form of a recording medium such as an optical disk storing the program, or may be provided in the form of being downloaded to a computer via a communication line such as the Internet, and installed and used. Is.

(Modification 6)
In the embodiment described above, the rotation detection device 290 includes the optical sensor that detects the sensor mark. However, the rotation detection device 290 is not limited thereto, and may include a magnetic sensor, for example. In this case, a magnetic body that rotates together with the photosensitive drum 211 is provided, and is arranged so that the magnetic body passes through a region that is detected by the magnetic sensor. Each time the magnetic material passes, the magnetic sensor outputs a detection signal indicating that the photosensitive drum 211 has rotated once to the control unit 100. In short, the sensor included in the rotation detection device 290 may be any sensor that detects that the photosensitive drum 211 has rotated.

(Modification 7)
In the embodiment described above, the control unit 100 stores the accumulated rotational speed in the memory 291. However, the control unit 100 is not limited thereto, and may be stored in the storage unit 103. In this case, for example, when the photoreceptor unit 210 is attached to the image forming apparatus 10, the user selects whether or not it is the first attachment by operating the operation unit 101. If the selected result is the former, the control unit 100 may reset the cumulative rotational speed, and if the selected result is the latter, the control section 100 may not reset the cumulative rotational speed. Alternatively, a memory storing an identifier for identifying the photoreceptor unit 210 is provided in the photoreceptor unit 210, and the identifier stored in the memory when the photoreceptor unit 210 is attached to the image forming apparatus 10 is used as the control unit 100. It is sufficient to determine whether or not the photoconductor unit 210 is attached to the image forming apparatus 10 for the first time.

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus, 100 ... Control part, 101 ... Operation part, 102 ... Display part, 103 ... Memory | storage part, 200 ... Image forming part, 210 ... Photoconductor unit, 211 ... Photoconductor drum, 212 ... Charging device, 213 DESCRIPTION OF SYMBOLS Cleaning blade, 220 ... Exposure apparatus, 230 ... Developing apparatus, 231 ... Developing roll, 232 ... Voltage application part, 233 ... Motor, 234 ... Gear, 240 ... Intermediate transfer belt, 241 ... Rotating roll, 243 ... Edge sensor, 244 ... density sensor, 245 ... steering roll, 250 ... primary transfer roll, 260 ... secondary transfer roll, 261 ... rotating shaft, 262 ... eccentric cam, 263 ... rotating shaft, 264 ... backup roll, 270 ... transport roll, 280 ... fixing Device, 290 ... rotation detection device, 291 ... memory

Claims (4)

A first photosensitive member, a charging device that charges the first photosensitive member, a removing member that comes into contact with the first photosensitive member to remove deposits on the first photosensitive member, and a driving force from a driving source. A second developing roller that rotates and supplies toner to the electrostatic latent image formed on the first photosensitive member for development, a second photosensitive member, and the second photosensitive member in contact with the second photosensitive member. A removing member that removes deposits on the body, a second developing roll that rotates with a driving force from the driving source and supplies toner to the electrostatic latent image formed on the second photosensitive member for development. In the electrophotographic image forming apparatus having the above, the cumulative number of rotations of the first photoconductor from the start of use of the first photoconductor and the time from the start of use of the second photoconductor A specifying means for specifying the cumulative rotational speed of the second photoconductor;
When at least one of said accumulated rotation number of the identified first photoconductor and said second photoconductor by the specifying means is less than the threshold value is formed on the medium the toner image by the image forming apparatus in preparation process performed before the first photoconductor and the second photoconductor is charged by the charging device, and the state in which the toner image corresponding to the image data is not formed first photoconductor and the While the second photosensitive member is rotating , the first developing roller and the second developing roller are rotated by the driving force from the driving source, respectively , and toner is applied to the first photosensitive member and the second photosensitive member . And a supply control means for performing control to supply the control device. The supply control unit confirms whether or not the user is permitted to supply the toner to the first photoconductor, and when it is confirmed that the toner is permitted, The control apparatus according to claim 1, wherein control for supplying toner is performed. An electrophotographic method includes a first photosensitive member, a charging device that charges the first photosensitive member, and a removing member that comes into contact with the first photosensitive member and removes deposits on the first photosensitive member. Image forming means for forming a toner image on a medium;
Detecting means for detecting that the first photosensitive member is rotated;
3. The control device according to claim 1, wherein, based on a detection result of the detection unit, the cumulative rotation speed of the first photoconductor from when the use of the first photoconductor is started is specified. An image forming apparatus comprising: a control device including a specifying unit. Computer
A first photosensitive member, a charging device that charges the first photosensitive member, a removing member that comes into contact with the first photosensitive member to remove deposits on the first photosensitive member, and a driving force from a driving source. A second developing roller that rotates and supplies toner to the electrostatic latent image formed on the first photosensitive member for development, a second photosensitive member, and the second photosensitive member in contact with the second photosensitive member. A removing member that removes deposits on the body, a second developing roll that rotates with a driving force from the driving source and supplies toner to the electrostatic latent image formed on the second photosensitive member for development. In the electrophotographic image forming apparatus having the above, the cumulative number of rotations of the first photoconductor from the start of use of the first photoconductor and the time from the start of use of the second photoconductor A specifying means for specifying the cumulative rotational speed of the second photoconductor;
When at least one of said accumulated rotation number of the identified first photoconductor and said second photoconductor by the specifying means is less than the threshold value is formed on the medium the toner image by the image forming apparatus in preparation process performed before the first photoconductor and the second photoconductor is charged by the charging device, and the state in which the toner image corresponding to the image data is not formed first photoconductor and the While the second photosensitive member is rotating , the first developing roller and the second developing roller are rotated by the driving force from the driving source, respectively , and toner is applied to the first photosensitive member and the second photosensitive member . A program for functioning as a supply control means for performing control to supply.

Images