JP2023004387A - Image formation device - Google Patents

Abstract

To suppress generation of image defects caused by contaminations of toners generated by a mass of water droplets on a brush.SOLUTION: In a rotation operation of rotating a photoconductor drum after a stop time between a first image formation operation of performing an image formation on a transfer target body and a second image formation operation performed after the first image formation operation has passed, the number of rotations of the photoconductor drum is controlled on the basis of information on the use history of the photoconductor drum and the stop time.SELECTED DRAWING: Figure 4

Description

The present invention relates to image forming apparatuses such as laser printers, copiers, facsimiles, etc. that use an electrophotographic recording method.

2. Description of the Related Art In an electrophotographic image forming apparatus, an electrostatic latent image is formed on a photosensitive drum by uniformly charging a photosensitive drum as an image carrier and then performing exposure according to an image pattern. Thereafter, the electrostatic latent image on the photosensitive drum is developed with toner to become visible, and transferred to a recording material such as paper. Then, the untransferred toner remaining on the photosensitive drum is removed from the photosensitive drum and collected. There are several cleaning methods for removing transfer residual toner, and a configuration using a brush is widely known as one of the effective methods.

Patent Document 1 discloses a configuration in which a brush for cleaning the toner on the photosensitive drum is arranged upstream of the charging means in the moving direction of the photosensitive drum and downstream of the transferring means in the moving direction of the photosensitive drum. there is According to this document, for example, when the image formation is interrupted due to a paper jam or the like, by charging the brush to a predetermined polarity, the accumulation of untransferred toner on the photosensitive drum on the brush is suppressed, and the cleaning performance is improved. is maintained.

JP-A-2007-65580

However, Patent Document 1 has the following problems. In the image forming apparatus with the brushes disclosed in Japanese Patent Application Laid-Open No. 2002-200310, water vapor in the apparatus adheres to the brushes when the recording material is passed through. The water vapor accumulated in the brush condenses on the surface of the photosensitive drum as the stop time elapses and exists as a mass of water droplets. In this state, when the next image forming operation is performed, a lump of water droplets adhering to the brush may transfer onto the photosensitive drum, changing the surface condition of the photosensitive drum and causing an image defect. rice field. For example, at the developing contact portion, which is the contact portion between the photosensitive drum and the developing member, a mass of water droplets adhering to the photosensitive drum attracts toner, thereby causing toner contamination.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above technical problems, and to suppress image defects caused by toner stains caused by water droplets adhering to a brush.

As described above, the present invention provides a rotatable photosensitive drum, a charging member that charges the surface of the photosensitive drum in a charging section, and a toner image by supplying toner onto the surface of the photosensitive drum charged by the charging member. a developing member that contacts the photosensitive drum to form a transfer portion and transfers the toner image formed on the photosensitive drum in the transfer portion to a transfer material; Use of a brush member in contact with the surface of the photosensitive drum downstream of the transfer unit and upstream of the charging unit in the rotational direction, a driving unit that rotates the photosensitive drum, and the photosensitive drum A first image forming operation for forming an image on a transfer receiving body and a first image forming operation which is performed subsequent to the first image forming operation. In the image forming apparatus capable of executing a rotating operation of rotating the photosensitive drum before the second image forming operation is executed after a stop time between the second image forming operation and the second image forming operation is executed, the control The unit controls the number of rotations of the photosensitive drum in the rotating operation based on the information and the stop time.

As described above, according to the present invention, it is possible to suppress image defects caused by toner contamination caused by water droplets adhering to the brush.

1 is an explanatory diagram of an image forming apparatus according to Embodiment 1; FIG. 1 is a schematic diagram of a brush member in Example 1. FIG. 4 is a control block diagram in Embodiment 1. FIG. 4 is a diagram showing water vapor adhering to a brush member in Example 1. FIG. 4A and 4B are diagrams showing a state around a photosensitive drum during an image output operation in Embodiment 1; FIG. 4 is a diagram showing the extension time of the pre-rotation process in Example 1. FIG. 5 is a diagram showing the results of toner contamination in Example 1. FIG. 4 is a diagram showing a timing chart of a pre-rotation process in Example 1. FIG. 4 is a diagram showing toner and water vapor on a brush member in Example 1. FIG. FIG. 10 is a diagram showing the extension time of the pre-rotation process in Example 2;

BEST MODE FOR CARRYING OUT THE INVENTION A mode for carrying out the present invention will be exemplarily described in detail below based on an embodiment with reference to the drawings. However, the dimensions, materials, shapes and relative arrangement of the components described in this embodiment should be appropriately changed according to the configuration of the device to which the invention is applied and various conditions. That is, it is not intended to limit the scope of the present invention to the following embodiments.

1. 1. Image Forming Apparatus FIG. 1 is a schematic configuration diagram of an image forming apparatus 100 according to a first embodiment of the present invention.

The image forming apparatus 100 of this embodiment is a monochrome laser beam printer that employs a cleanerless method and a contact charging method. The image forming apparatus 100 has a photosensitive drum 1 which is a drum-shaped (cylindrical) electrophotographic photosensitive member as a rotatable image carrier. When the image output operation is started, the photosensitive drum 1 is rotationally driven in the arrow R1 direction in the figure by a driving motor (driving section) (FIG. 3) as the driving means 110 . The photosensitive drum 1 has an outer diameter of 24 mm and a peripheral speed (surface speed) of 140 mm/sec.

The surface of the rotating photosensitive drum 1 is charged with a normal polarity (in this embodiment, negative It is uniformly electrified to a predetermined potential. More specifically, the charging roller 2 is at least one of minute gaps between the photosensitive drum 1 and the photosensitive drum 1 formed upstream and downstream of the contact portion with the photosensitive drum 1 in the rotational direction of the photosensitive drum 1 . The surface of the photosensitive drum 1 is charged by the generated discharge. However, here, the contact portion between the charging roller 2 and the photosensitive drum 1 with respect to the rotation direction of the photosensitive drum 1 is hypothetically assumed to be the charging portion. The charging roller 2 is an elastic roller in which a conductive elastic layer is provided around a metal core. Although the charging roller 2 is driven to rotate in this embodiment, it may be configured to rotate following the rotation of the photosensitive drum 1 . A predetermined charging voltage, which is a negative DC voltage, is applied to the charging roller 2 from a charging power supply E1 (FIG. 3) as charging voltage applying means. In this embodiment, a negative DC voltage is applied to the charging roller 2 as the charging voltage during the charging process. The charging voltage in this embodiment was -1200V as an example. Thus, in this embodiment, the surface of the photosensitive drum 1 is uniformly charged to the dark potential Vd of -600V.

The charged surface of the photosensitive drum 1 is scanned and exposed with a laser beam L modulated according to image data by an exposure device (laser exposure unit) 4 as exposure means (electrostatic image forming means). The exposure device 4 repeatedly exposes the photosensitive drum 1 with the laser beam L in the main scanning direction (rotational axis direction) and also exposes the photosensitive drum 1 in the sub-scanning direction (surface movement direction). form a latent image. In the present embodiment, the dark area potential Vd on the surface of the photosensitive drum 1 formed by the uniform charging process is exposed by the exposure device 4, and the absolute value thereof is reduced to a bright area potential Vl of -100V. Become. The exposure position of the exposure device 4 on the photosensitive drum 1 in the rotation direction of the photosensitive drum 1 is the image exposure portion b. Note that the exposure device 4 is not limited to a laser scanner device, and for example, an LED array in which a plurality of LEDs are arranged along the longitudinal direction of the photosensitive drum 1 may be employed.

The electrostatic latent image formed on the photosensitive drum 1 is developed (visualized) into a toner image by a developing device 3 as developing means using toner as a developer. The toner used as the developer in this embodiment is spherical non-magnetic toner having an average particle diameter of 6.4 μm and an average circularity of 0.98. The average circularity of the non-magnetic toner used in this embodiment is preferably as high as possible, specifically 0.96 or more. The average circularity in this example was used as a simple method for quantitatively expressing the particle shape, and the particle shape was measured using a flow-type particle image analyzer FPIA-2100 manufactured by Toa Medical Electronics Co., Ltd. Circularity is obtained by the following formula 1.

Furthermore, as shown in the following formula 2, the value obtained by dividing the sum of measured circularities of all particles by the total number of particles is defined as average circularity.

The developing device 3 includes a developing roller 31 as a developer bearing member, a toner supply roller 32 as developer supply means, a developer containing chamber 33 containing toner, and a developing blade 34 . The toner stored in the developer storage chamber 33 is stirred by the stirring member 35 and supplied to the surface of the developing roller 31 by the toner supply roller 32 . The toner supplied to the surface of the developing roller 31 is uniformly formed into a thin layer by passing through the contact portion between the developing roller 31 and the developing blade 34, and is negatively charged by abrasion charging. Although the one-component non-magnetic contact developing method is used in this embodiment, the present invention is not limited to this, and a two-component non-magnetic contact developing method or a non-contact developing method may be used. A magnetic development method may also be employed. In addition, although the normal polarity of the toner is negative in this embodiment, it is not limited to the negative polarity. The normal polarity may be the positive polarity, and in that case, the voltage relationship and the like described later may be appropriately reversed. The developing roller 31 is moved by the drive motor 110 so that the surface of the photosensitive drum 1 and the surface of the developing roller 31 move in the same direction at the developing portion c where the photosensitive drum 1 and the developing roller 31 are in contact with each other. It is rotationally driven counterclockwise in the R3 direction. The driving motor as the driving means 110 for driving the developing roller 31 may be a main motor common to the driving means 110 for the photosensitive drum 1, or separate driving motors may rotate the photosensitive drum 1 and the developing roller 31 respectively. You may let During development, a predetermined development voltage (development bias) is applied to the development roller 31 by a development power source E2 (FIG. 3) as development voltage applying means. In this embodiment, during development, a negative DC voltage is applied to the developing roller 31 as a developing voltage, and the developing voltage is -300V. In this embodiment, the charging polarity of the photosensitive drum 1 and the charging polarity of the photosensitive drum 1 are applied to the exposure surface (image portion), which is the image forming portion of the photosensitive drum 1, where the absolute value of the potential is lowered by exposure after being uniformly charged. Toner charged to the same polarity (negative polarity in this embodiment) adheres. This developing method is called a reversal developing method.

In this embodiment, the developing roller 31 is always in contact with the photosensitive drum 1 at the developing portion c. may be In this case, a separate development contact/separation mechanism may be provided. The photosensitive drum 1 may be rotated while the developing roller 31 is separated from the photosensitive drum 1 during the rotation operation, which is a pre-rotation step to be described later.

The toner image formed on the photosensitive drum 1 is sent to a transfer portion d, which is a contact portion between the photosensitive drum 1 and a transfer roller 5, which is a roller-type transfer member as transfer means. The transfer roller 5 in this embodiment employs a roller made of conductive NBR (nitrile-butadiene rubber)/hydrin-based sponge rubber with an outer diameter of 12 mm and a hardness of 30° (Asker-C, 500 gf load). , is pressed against the photosensitive drum 1 with a predetermined pressure. On the other hand, in synchronization with the toner image on the photosensitive drum 1, the recording material P, which is the material to be transferred, is conveyed from the storage section 6 by the conveying roller 8 and the like to the transfer section d. Then, the toner image on the photosensitive drum 1 is transferred onto the recording material P conveyed while being nipped between the photosensitive drum 1 and the transfer roller 5 by the action of the transfer roller 5 at the transfer portion d. At this time, a predetermined transfer voltage, which is a DC voltage having a polarity opposite to the normal polarity of the toner (positive polarity in this embodiment), is applied to the transfer roller 5 from the transfer power source E3 (FIG. 3). As a result, an electric field is formed between the transfer roller 5 and the photosensitive drum 1, and the toner image is electrostatically transferred from the photosensitive drum 1 to the recording material P. As shown in FIG. In this embodiment, the transfer voltage at the time of transfer is +1000 V, for example. Then, the toner image is electrostatically transferred from the photosensitive drum 1 to the recording material S by the action of the electric field formed between the transfer roller 5 and the photosensitive drum 1 .

The recording material P onto which the toner image has been transferred is sent to a fixing device 9 as fixing means. In the fixing device 9 , heat and pressure are applied to the recording material P, and the toner image is fixed on the recording material P. FIG.

On the other hand, untransferred toner remaining on the photosensitive drum 1 without being transferred onto the recording material P is sent to a brush member 10 disposed downstream of the transfer roller 5 in the rotational direction of the photosensitive drum 1 . The brush member 10 used in this embodiment will be described below.

2. Configuration of Brush Member Next, the paper dust removing mechanism in this embodiment will be described. As shown in FIG. 1, the image forming apparatus 100 in this embodiment has a brush member 10 (recovery member) which is a contact member as a paper dust removing mechanism. In this embodiment, the image forming apparatus 100 contacts the surface of the photosensitive drum 1 downstream of the transfer section and upstream of the charging section with respect to the rotation direction of the photosensitive drum 1 to form a brush contact portion (brush contact position). It has a brush member 10 forming. Here, it is assumed that the contact portion between the brush member 10 and the photosensitive drum 1 in the rotation direction of the photosensitive drum 1 is the brush contact portion.

FIG. 2(a) is a schematic view of the brush member 10 in a single state, viewed along its longitudinal direction (substantially parallel to the rotation axis direction of the photosensitive drum 1). FIG. 2(b) is a schematic view of the brush member 10 in contact with the photosensitive drum 1 along its longitudinal direction.

The brush member 10 has a brush portion composed of a conductive fixed brush 11 that is fixedly arranged. As shown in FIG. 2, the brush member 10 is composed of pile yarns 11a made of conductive 6 nylon, which are a plurality of bristles that rub against the surface of the photosensitive drum 1, and a base fabric 11b that supports the pile yarns 11a. be. As described above, the brush member 10 is arranged in contact with the photosensitive drum 1 downstream of the transfer section and upstream of the charging section in the movement direction (rotational direction) of the photosensitive drum 1 . there is

The brush member 10 is arranged such that its longitudinal direction is substantially parallel to the rotation axis direction of the photosensitive drum 1 . In this embodiment, the fixed brush 11 is constructed by weaving a conductive yarn 11a formed of nylon fibers mixed with a conductive substance into a base cloth 11b formed of synthetic fibers containing carbon as a conductive agent. ing. As the material of the conductive thread 11a, rayon, acrylic, polyester, etc. may be used in addition to nylon.

As shown in FIG. 2A, when the brush member 10 is in a single state, that is, in a state where no external force is applied to bend the conductive threads 11a, the conductive threads 11a exposed from the base cloth 11b are exposed. Let L1 be the distance to the tip of . In this example, L1 is 6.5 mm. The base cloth 11b of the brush member 10 is fixed to a support member (not shown) installed at a predetermined position of the image forming apparatus 100 by fixing means such as double-sided tape, and the tip of the conductive thread 11a is attached to the photosensitive drum 1. is placed in such a way as to encroach on In this embodiment, the clearance between the supporting member and the photosensitive drum 1 is fixed. The shortest distance from the base cloth 11b of the brush member 10 fixed to the support member to the photosensitive drum 1 is L2. In this embodiment, the difference between L2 and L1 is defined as the penetration amount of the brush member 10 with respect to the photosensitive drum 1 . In this embodiment, the amount of penetration of the brush member 10 into the photosensitive drum 1 is 1 mm. In this embodiment, as shown in FIG. 2A, the length of the brush member 10 in the circumferential direction of the photosensitive drum 1 (hereinafter referred to as the "transverse direction") when the brush member 10 is in a single state. L3 is 5 mm. Further, in this embodiment, the length of the brush member 10 in the longitudinal direction is 216 mm. As a result, the brush member 10 can come into contact with the entire image forming area (area where a toner image can be formed) on the photosensitive drum 1 in the rotation axis direction of the photosensitive drum 1 . In this embodiment, the conductive yarn 11a has a thickness of 2 denier and a density of 280 kF/inch ² (kF/inch ² is the unit of brush density and indicates the number of filaments per square inch). . As described above, the brush member 10 is supported by a support member (not shown), is arranged at a fixed position with respect to the photosensitive drum 1, and rubs the surface of the photosensitive drum 1 as the photosensitive drum 1 moves.

The brush member 10 collects (collects) adherents such as paper dust transferred from the recording material S onto the photosensitive drum 1 at the transfer portion, and collects (recovers) the attached matter such as paper dust. , and reduce the amount of paper dust that travels to the development station.

In this embodiment, the length of the brush member 10 in the circumferential direction (hereinafter referred to as the width direction) of the photosensitive drum 1 is set to L3=5 mm, but the length is not limited to this. For example, it may be changed as appropriate according to the life of the image forming apparatus or process cartridge. Needless to say, the longer the length of the brush member 10 in the lateral direction, the longer the paper dust can be collected.

Although the longitudinal length of the brush member 10 in this embodiment is set to 216 mm, it is not limited to this. For example, it may be changed as appropriate according to the maximum sheet passing width of the image forming apparatus.

The fineness of the brush member 10 in this embodiment is 220T/96F (meaning 96 bundles of 220g thick threads per 10,000m), which should be determined in consideration of the ability of paper dust to pass through. is desirable. If the fineness of the brush member 10 is small, the force of blocking paper dust is weak and the paper dust easily slips through. Further, if the fineness of the brush member 10 is too large, toner and fine paper dust cannot be collected, resulting in density unevenness due to uneven adhesion of toner along the length of the charging roller 2, and image defects due to charging failure at the paper dust adhering portion. Sometimes.

The density of the brush member 10 in this embodiment is 280 kF/inch ² (kF/inch ² is a unit of brush density and indicates the number of filaments per square inch). It is desirable to determine it in consideration of powder collecting performance. That is, if the density of the brush member 10 is too high, the toner passing property is deteriorated and the toner is stuck, and the stuck toner may scatter and contaminate the inside of the machine. Also, if the density of the brush member 10 is too low, the ability to collect paper dust will be weakened. Therefore, the thickness and density of the conductive yarn 11a are preferably 1 to 6 denier and 150 to 350 kF/inch ² , respectively, from the viewpoint of paper dust collecting properties. The length of the brush member 10 in the short direction is preferably 3 mm or more from the viewpoint of long life. A brush power source E4 (FIG. 3) is connected to the brush member 10 as a brush voltage applying means.

3. Image Output Operation In this embodiment, the image forming apparatus 100 performs a series of operations for forming an image on a single or multiple recording materials P in response to one start instruction from an external device (not shown) such as a personal computer. Execute the image output operation (job). A job generally includes an image forming process (printing process), a pre-rotation process, an inter-paper process when forming images on a plurality of recording materials P, and a post-rotation process. The image forming process is a period of actually forming an electrostatic image on the photosensitive drum 1, developing the electrostatic image (forming a toner image), transferring the toner image, and fixing the toner image. refers to this period. More specifically, the timing of image formation differs depending on the position where the electrostatic image is formed, the toner image is formed, the toner image is transferred, and the toner image is fixed. Therefore, the image forming operation may be defined as up to transfer of the toner image, or up to fixing of the toner image. Even if the image forming operation performed on the photosensitive drum 1 is finished and the operation of the photosensitive drum 1 is switched from the image forming operation to the non-image forming operation, the image already transferred to the recording material P is , may be defined as above, since they have no effect. The pre-rotation process is a period for preparatory operations before the image forming process. The paper interval process is a period corresponding to the interval between the recording materials P when the image forming process is continuously performed on a plurality of recording materials P (at the time of continuous image formation). The post-rotation process is a period during which an arrangement operation (preparation operation) is performed after the image forming process. The non-image forming time is a period other than the image forming time, and includes the pre-rotation process, the paper interval process, the post-rotation process, and the preparatory operation when the image forming apparatus 100 is powered on or returned from the sleep state. and a pre-multi-rotation step.

4. Control Mode FIG. 3 is a schematic block diagram showing a control mode of the main part of the image forming apparatus 100 of this embodiment. A control unit 150 is provided in the image forming apparatus 100 . The control unit 150 includes a CPU 151 as an arithmetic control means which is a central element for arithmetic processing, a memory (storage element) 152 such as ROM and RAM as a storage unit, and various elements connected to the control unit 150. It has an input/output unit (not shown) for controlling transmission and reception of signals. The RAM stores sensor detection results, calculation results, and the like, and the ROM stores control programs, pre-determined data tables, and the like. In this embodiment, the memory 152 stores the number of revolutions of the photosensitive drum 1, which is the usage history information of the photosensitive drum 1. FIG. The usage history information of the photosensitive drum 1 includes the rotation time of the photosensitive drum 1, the number of printed sheets of recording material P, information on the film thickness of the photosensitive drum 1, and other information that changes depending on the use of the photosensitive drum 1. Not limited. It also has a measurement unit 153 for measuring the stop time for determining the conditions for performing the pre-rotation process, which will be described later.

The control unit 150 is a control unit that controls the operation of the image forming apparatus 100 in an integrated manner. The control unit 150 controls transmission and reception of various electrical information signals, driving timing, and the like, and executes a predetermined image forming sequence. Each unit of the image forming apparatus 100 is connected to the control unit 150 . For example, in relation to the present embodiment, the control section 150 is connected to a charging power source E1, a developing power source E2, a transfer power source E3, a brush power source E4, a drive motor 110, an exposure unit 4, and the like. In particular, in relation to the present embodiment, the control unit 150 controls the ON/OFF and output values of various power sources E1, E2, E3, and E4, and executes the extension operation of the pre-rotation process, which will be described later. . In this example, the normal pre-rotation process time was set to 2 seconds. The time for this pre-rotation step is appropriately set.

5. Extension operation of the pre-rotation step After performing a job of continuously passing the recording material P using the image forming apparatus 100 described above, when performing the next job after stopping for a predetermined time, normal pre-rotation is performed. When the process is carried out, toner contamination may occur. This is due to water vapor adhering to the brush member 10 during the passage of the previous job. Specifically, the water vapor adhering to the brush member 10 shown in FIG. 4(a) condenses with the lapse of time immediately after stopping (FIG. 4(b)), forming a mass of water droplets on the surface of the photosensitive drum 1. (Fig. 4(c)). The size of water droplets varies depending on the usage environment of image forming apparatus 100 and the number of sheets passed in the previous job. For example, in a high-temperature and high-humidity environment, the recording material P contains a large amount of water, so the larger the number of sheets passed in the previous job, the larger the size of water droplets. Further, after a predetermined time has passed, the water droplets evaporate due to the ambient temperature in the image forming apparatus as time elapses. That is, immediately after the recording material P is passed through and stopped, the water vapor condenses with the lapse of time to form a mass of water droplets, and evaporates and disappears with the lapse of time after a predetermined time. When the brush member 10 of this embodiment is used, the largest water droplets are present on the surface of the photosensitive drum 1 30 seconds after the driving of the photosensitive drum 1 is stopped. The stop time varies depending on the length (L1), thickness, and density of the brush member 10. FIG. This is because the speed at which water droplets are formed, the speed at which water droplets evaporate, the size of formed water droplets, and the like differ depending on the length (L1), thickness, and density of the brush member 10 .

FIG. 5 shows the state around the photosensitive drum 1 when the next job is performed with a lump of water droplets on the surface of the photosensitive drum 1 . 5A moves in the direction of arrow R1 as the photosensitive drum 1 rotates, and partly adheres to the charging roller 2 at the charging portion a. Furthermore, the water droplets that have passed through the charging portion a attract the toner on the developing roller 31 at the developing portion c (FIG. 5B). Due to this phenomenon, image defects due to charging failure and toner attracted to the photosensitive drum 1 are transferred to the conveyed recording material P at the transfer portion d, resulting in conspicuous toner stains (Fig. 5(c)). )).

Therefore, in this embodiment, after a job of continuously passing the recording material P is performed, when the next job is performed after stopping for a predetermined time, the pre-rotation process is extended. and That is, based on the stop time between the first image forming operation for forming an image on the recording material P and the second image forming operation that is performed subsequent to the first image forming operation, the exposure time in the pre-rotation process is determined. It controls the number of revolutions of the drum 1 .

Hereinafter, the conditions for extending the pre-rotation process and the extension time will be described.

FIG. 6 shows the extended time of the pre-rotation process in this embodiment. As shown in the figure, in the first embodiment, the conditions for the pre-rotation process are determined according to the number of sheets passed in the previous job, and the extension time of the pre-rotation process is increased as the number of sheets passed increases. That is, control is performed so that the number of rotations of the photosensitive drum 1 increases as the number of sheets passed increases. Also, it can be seen that the extended time of the pre-rotation process is the longest when the stop time from the previous job is 30 seconds, and the extended time after that is shorter. The reason will be described later. The stop time and the number of sheets passed shown in FIG. 6 are assumed to be the maximum values of the stop time and number of sheets passed. That is, when the stop time is described as 5 seconds, it means 0 to 5 seconds, and when it is described as 10 seconds, it is more than 5 seconds and 10 seconds or less. Also, the value of the rotation time between stop times and between the number of sheets passed may be linearly interpolated. Also, although not shown, during the pre-rotation process, the same fixing temperature control as in the image forming process is applied to the fixing device 9 . The controlled temperature during the pre-rotation and during the image forming process in this embodiment is 180.degree. Incidentally, the fixing temperature control during the pre-rotation process may be appropriately changed with respect to the fixing temperature control during image formation.

FIG. 7 shows the results of toner contamination when paper containing a large amount of moisture is passed through the control of Example 1 and the case of not extending the pre-rotation process (comparative example). In FIG. 7, ◯ indicates no image deterioration due to toner adhesion to the surface of the photosensitive drum 1, Δ indicates slight toner adhesion on the surface of the photosensitive drum 1 but no image deterioration occurs, and × indicates image deterioration. occurred remarkably. The recording medium used in the paper threading experiment was Xerox Vitality Multipurpose paper, letter size, basis weight of 75 g/m ² , and left unwrapped for two days in an environment of temperature 30°C and humidity 80%. be. The moisture content of the paper was 9.2% as measured by a moisture meter Moistrex MX-8000 manufactured by NDC Infrared Engineering. For comparison, the moisture content immediately after opening was measured and found to be 5.7%. As shown in the figure, in the comparative example, the greater the number of sheets passed in the previous job, the worse the level of toner contamination. Also, it can be seen that the level is the worst when the stop time is 30 seconds, and the level is improved thereafter. This is because the water droplets form lumps as the stop time increases, but after a certain period of time elapses, 30 seconds or more in this embodiment, the water droplets start to evaporate. Therefore, as the elapsed time increases, the influence of water droplets decreases. Therefore, the time zone in which the level of toner contamination is the lowest is around 30 seconds after the paper has passed. Further, the reason why the level of toner contamination does not change after 100 sheets of paper is passed is that water vapor is generated by the passage of paper, and the water vapor is evaporated due to the ambient temperature in the image forming apparatus. On the other hand, in Example 1, when the number of sheets passed in the previous job was 50 or more and the stop time was about 30 seconds, slight toner contamination occurred, but other than that, it did not occur. This is because the extension time of the pre-rotation process is provided according to the number of sheets passed and the stop time of the previous job.

6. Effect of Present Embodiment As described above, according to the present embodiment, the pre-rotation process is extended by a necessary time according to the number of sheets passed in the previous job and the stop time from the previous job. As a result, the water droplets on the surface of the photosensitive drum 1 can be easily evaporated, and a stable image free from image defects such as toner contamination can be provided.

In this embodiment, an example of application to a DC charging type image forming apparatus has been described. The present invention can also be applied to charging type image forming apparatuses.

In this embodiment, only the DC component of the developing voltage has been described, but the developing voltage may be an oscillating voltage in which a DC voltage (DC component) and an AC voltage (AC component) are superimposed.

Further, in this embodiment, toner, which is a non-magnetic one-component developer, is used as the developer, but a magnetic one-component developer may be used.

In this embodiment, the "cleaner-less system" that does not have means for cleaning the photosensitive drum 1 is used, but the present invention is not limited to this. For example, a “blade cleaning method” using a blade as a cleaning means on the downstream side of the brush member 10 and the upstream side of the charging roller 2 with respect to the conveying direction of the photosensitive drum 1 may be used.

In this embodiment, the extension time is variable based on the number of sheets passed in the previous job, but the invention is not limited to this. For example, it may be variable based on the time or distance that the recording material P passes through the photosensitive drum 1 .

From the above results, the present embodiment has the following configuration.
It has a rotatable photosensitive drum 1 and a charging roller 2 that charges the surface of the photosensitive drum 1 in a charging section a. It has a developing roller 31 that supplies toner onto the surface of the photosensitive drum 1 charged by the charging roller 2 to form a toner image. It has a transfer roller 5 which forms a transfer portion d in contact with the photosensitive drum 1 and transfers the toner image formed on the photosensitive drum 1 to the recording material P at the transfer portion d. A brush member 10 that contacts the surface of the photosensitive drum 1 downstream of the transfer portion d and upstream of the charging portion a in the rotation direction of the photosensitive drum 1 and a driving motor 110 that rotates the photosensitive drum 1 are provided. have. It has a memory 152 that stores information about the usage history of the photosensitive drum 1 and a control section 150 that controls the drive motor 110 . It has a measurement unit 153 that measures a stop time between a first image forming operation for forming an image on the recording material P and a second image forming operation that is performed subsequent to the first image forming operation.

Then, after the stop time between the first image forming operation for forming an image on the recording material P and the second image forming operation performed subsequent to the first image forming operation has passed, the second image forming operation is performed. A rotation operation for rotating the photosensitive drum 1 is controlled to be executable before an image forming operation is performed. The number of rotations of the photosensitive drum 1 in the rotation operation performed before the second image forming operation is controlled based on the information about the usage history of the photosensitive drum 1 and the stop time. The object to be controlled is not limited to the number of rotations of the photosensitive drum 1, but may be the rotation time of the photosensitive drum 1. FIG.

Further, in the case where the number of recording materials P that have passed between the transfer portion d in the first image forming operation is the first number, the number of the recording materials P is the second number that is greater than the first number. The number of rotations of the photosensitive drum 1 during the rotation operation is controlled to be smaller than in the case of .

The stop time is set to start the second image forming operation after the driving state in which the photosensitive drum 1 is rotated after the first image forming operation is switched to the stopped state in which the rotation of the photosensitive drum 1 is stopped. It is the time until the photosensitive drum 1 is switched from the stopped state to the driven state. The stop time in the present embodiment is not limited to the above content as long as it is a time correlated with the phenomenon of water droplets accumulating on the brush member 10 . For example, it may be the time from immediately after the first image forming operation ends to just before the second image forming operation starts. Here, the stop time may include the time during which the photosensitive drum 1 is stopped.

Further, the stop time is not limited to being measured by the measurement unit 153, and may be predicted from the attenuation state of the surface potential of the photosensitive drum 1, the temperature transition of the image forming apparatus 100, the temperature change of the fixing device 9, and the like. .

In this embodiment, as shown in FIG. 6, the extension time of the pre-rotation process is stored in the memory 152 as a table. , may be a ratio that extends with respect to the time of the pre-rotation step. Alternatively, the extension time may be calculated each time by storing coefficients corresponding to the number of sheets of recording material P to be printed and the stop time without preparing a table.

Another embodiment of the present invention will now be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the image forming apparatus of the first embodiment. Accordingly, in the image forming apparatus of the present embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of the first embodiment are denoted by the same reference numerals as those of the image forming apparatus of the first embodiment. A detailed explanation is omitted.

1. Features of Embodiment 2 Embodiment 2 is characterized in that the extension time of the pre-rotation process is variable according to the usage environment of the image forming apparatus 100 . The image forming apparatus 100 used in the second embodiment is provided with the environment sensor 300, and based on the environmental information detected by the environment sensor 300, the extension time of the pre-rotation process described in the first embodiment is determined. The environment information includes information on the absolute moisture content of the environment calculated by the CPU 151 based on the detection results of the temperature sensor 301 and the humidity sensor 302 of the environment sensor 300 . In Example 2, the absolute moisture content obtained from the environment sensor 300 is stored in the memory 152 within the control unit 150 in units of 0.1 g/m ³ . Then, when image forming apparatus 100 receives an image output operation (job) signal, controller 150 determines whether the absolute moisture content is greater or less than the threshold value of 10.5 g/m ³ . At this time, if the absolute moisture content is greater than the threshold value of 10.5 g/m ³ , the same extension of the pre-rotation process as in the first embodiment is executed. The extension time of the pre-rotation process is the same as that in FIG. Further, when the absolute moisture content is less than the threshold value of 10.5 g/m ³ , the pre-rotation process is not extended. As a result, the photosensitive drum 1 is not rotated unnecessarily in an environment other than an environment where the absolute moisture content is large. Here, the absolute water content for determining whether the extension time of the pre-rotation process is variable according to the usage environment is not limited to this value, and may be changed as appropriate.

2. Effects of Second Embodiment As described above, according to the second embodiment, the following control is performed based on the absolute moisture content obtained from the detection result of the environment sensor 300 . Only when the absolute moisture content is greater than 10.5 g/m ³ , the pre-rotation process is extended for the necessary time according to the number of sheets passed in the previous job and the stop time from the previous job. As a result, the operation of effectively evaporating the water droplets on the surface of the photosensitive drum 1 can be executed in a necessary situation without rotating the photosensitive drum 1 uselessly in an environment other than the environment where the absolute water content is large.

From the above results, Example 2 has the following configuration.

It has an environment detection sensor 300 that detects the installation environment of the image forming apparatus 100, and controls the number of rotations according to the installation environment. Here, the installation environment is the temperature or humidity detected by the environment detection sensor 300, and is the absolute moisture content. The absolute moisture content may be calculated from the results of detecting the temperature and humidity. Alternatively, the absolute water content may be calculated by estimating the temperature or humidity.

In the second embodiment, the extension of the pre-rotation step is determined based on the absolute moisture content obtained from the detection result of the environment sensor 300, divided into two environments, one with a large absolute moisture content and the other. There is no limit. For example, the usage environment of the image forming apparatus 100 may be divided into a plurality of environments such as three environments based on the absolute moisture content, and the extension time of the pre-rotation process may be appropriately changed according to the environment. That is, a plurality of thresholds may be provided. Further, the extension time of the pre-rotation step may be appropriately changed based on the absolute moisture content. In other words, when the absolute moisture content is detected as the first absolute moisture content, the rotational speed of the photosensitive drum 1 is higher than when the second absolute moisture content is detected which is smaller than the first absolute moisture content. may be controlled to increase

Further, in the second embodiment, the environment sensor 300 is used as means for detecting the environment in which the image forming apparatus 100 is used, but this is not restrictive. For example, the usage environment may be determined based on the detection of the electrical resistance value of the transfer roller 5 (result of transfer ATVC control).

1. Brush Voltage Control This embodiment is characterized in that a brush voltage is applied to the brush member 10 by the brush power source E4 shown in FIG. 3 during the pre-rotation process. The control of the brush voltage in the pre-rotation process will be described below.

A predetermined brush voltage, which is a negative DC voltage, is applied from the control unit 150 to the brush member 10 in this embodiment. Here, as the brush voltage applying means E4, for example, a voltage in which a DC component and an AC component are superimposed may be applied. In this example, the brush voltage during the imaging process is -300V. On the other hand, the surface potential of the photosensitive drum 1 after passing through the transfer portion d is about -50V. Therefore, of the transfer residual toner sent from the transfer portion d, the positively charged toner is primarily collected by the brush member 10 due to the potential difference between the brush voltage and the surface potential of the photosensitive drum 1 in the brush portion e. be done. On the other hand, the negatively charged toner is attracted to the photosensitive drum 1 side in the brush portion e and passes through the brush portion e. The toner that has passed through the brush portion e has a desired negative charge due to uniform discharge in the charging portion a, and is sent to the developing portion c. Of the toner sent to the developing portion c, the non-image area (non-exposed area) is transferred to the developing roller 31 due to the potential difference between the dark portion potential (Vd) on the surface of the photosensitive drum 1 and the developing bias (Vdc). , are collected in the developing device 3 . As in Example 1, the dark area potential (Vd) in this example is about -600V, and the development bias (Vdc) is -300V. On the other hand, the image area (exposure area) is not transferred to the developing roller 31 due to the potential difference between the bright area potential (Vl) on the surface of the photosensitive drum 1 and the developing bias (Vdc), and the image area remains on the photosensitive drum 1 as an image area. As it rotates, it is sent to the transfer portion d and transferred to the recording material P. As shown in FIG. The bright area potential (Vl) in this embodiment is about -100 V, as in the first embodiment.

2. Extension Operation of Pre-Rotation Step FIG. 8 shows a timing chart of the pre-rotation step in this embodiment. Timing A in the figure is the timing at which the image forming apparatus 100 receives an image output operation (job) signal from an external device and starts the pre-rotation process. At this time, the control unit 150 determines the extension time of the pre-rotation process based on the number of sheets passed in the previous job and the stop time from the previous job. At the same timing A, the drive motor 110 is started to be driven, and the outputs of the charging voltage and the brush voltage are turned on. Further, in the fixing device 9, output is started so that the same fixing temperature control (180° C.) as in the image forming process is achieved. The ON timings of the charging voltage and the brush voltage may be appropriately changed depending on the power supply start-up time and the like. Also, the output timing of the fixing temperature adjustment may be appropriately changed depending on the responsiveness of the fixing device.

The output value of the charging voltage is -1200 V, which is the same as in the image forming process, so that the surface potential of the photosensitive drum 1 uniformly becomes the dark potential (-600 V). While the surface potential of the photosensitive drum 1 is maintained at the dark potential (-600 V), the surface of the photosensitive drum 1 passes through the developing portion c and reaches the transfer portion d. At this time, since no transfer voltage is applied to the transfer roller 5, the surface of the photosensitive drum 1 reaches the brush portion e while maintaining the dark potential (-600 V). The output value of the brush voltage is -300V, which is the same as in the image forming process. As a result, the positive toner remaining on the brush member 10 is ejected onto the surface of the photosensitive drum 1 due to the potential difference between the brush voltage and the dark portion potential (-600 V) of the photosensitive drum 1 .

Here, in this embodiment, although the cleaning operation is performed in the post-rotation process to discharge the transfer residual toner that was primarily collected on the brush member 10 during the image forming process, not a little toner remains on the brush member 10 . . Therefore, after the timing A, the positive toner among the toner remaining on the brush member 10 is discharged positively. At this time, water vapor adheres around the toner, and the toner is discharged from the brush member 10 together with the surrounding water vapor. FIG. 9 is a diagram showing the state of toner and water vapor in the brush member 10 at this time. As can be seen from the figure, water vapor adheres to the toner on the brush member 10, and the water vapor is discharged together with the toner discharged from the brush member 10. FIG. By expelling the residual toner on the brush member 10 in this way, the expelling of water vapor adhering to the brush member 10 can be facilitated.

Here, in this embodiment, although no transfer voltage is applied at timing A, the brush voltage (-300 V) is set to a value that does not lower the surface potential of the photosensitive drum 1, that is, the surface potential of the photosensitive drum. A voltage value with the same negative polarity and a small absolute value may be set.

Next, at timing B in FIG. 8, the output of the transfer voltage is turned ON. The output value of the transfer voltage at this time is +1000V. As a result, the surface potential of the photosensitive drum 1 after passing through the transfer portion d is about -50V. On the other hand, since the output value of the brush voltage is still maintained at −300 V, the negative toner remaining on the brush member 10 will be the potential difference between the brush voltage and the surface potential of the photosensitive drum 1 (−50 V). is ejected onto the surface of the photosensitive drum 1 by . Similarly, it is possible to accelerate the discharge of water vapor adhering to the brush member 10 . Here, the timing B is set to 500 ms after the timing A as long as it is possible to secure the time for discharging the positive toner in the brush member 10 .

In this way, the brush voltage is applied and the potential difference from the surface potential of the photosensitive drum 1 discharges the residual toner of positive and negative polarity in the brush member 10, thereby accelerating the discharge of water vapor.

Timing C in FIG. 8 is the image forming process start timing when the pre-rotation process is not extended. When it is determined at timing A that the pre-rotation process should be extended, the extension is started at timing C, and the image forming process is started at timing D. That is, the period from timing C to timing D in FIG. 8 is the extension time of the pre-rotation process.

FIG. 10 shows the extended time of the pre-rotation process in this embodiment. As can be seen from the figure, it is shorter than the extension time of the pre-rotation process in Example 1 (FIG. 6). This is because, in the third embodiment, the evaporation of the water droplets in the pre-rotation step is accelerated by actively discharging the water vapor together with the toner remaining on the brush member 10 by the brush voltage.

3. Effect of the present embodiment As described above, according to the present embodiment, the residual toner in the brush member 10 is discharged at the same time as the pre-rotation process is started, and the number of sheets passed in the previous job and the number of sheets passed in the previous job are increased by the brush voltage. Extend the pre-rotation process by the required amount of time depending on the stop time from the job. As a result, water droplets on the surface of the photosensitive drum 1 can be effectively evaporated by discharging water vapor together with the toner remaining on the brush member 10, and the extension time of the pre-rotation process can be shortened. As a result, it is possible to extend the life of the image forming apparatus 100 while providing a stable image in which the occurrence of image defects such as toner contamination is suppressed.

From the above results, Example 3 has the following configuration.

A brush voltage applying section E4 for applying a brush voltage to the brush member 10 is provided. The brush member 10 is a conductive brush, and the brush voltage application unit E4 is controlled so as to apply a brush voltage having the same polarity as the toner charged to the normal polarity to the brush member 10 while the brush member 10 is rotating. do.

During the rotating operation, the potential difference between the brush voltage applied to the brush member 10 and the surface potential of the photosensitive drum 1 gradually increases at the brush portion e where the surface of the photosensitive drum 1 and the brush member 10 are in contact with each other. The brush voltage applying section E4 is controlled so that

The brush voltage applying section E4 is arranged so that the brush voltage applied to the brush member 10 and the surface potential of the photosensitive drum 1 have the same polarity, and the absolute value of the brush voltage is larger than the absolute value of the surface potential of the photosensitive drum 1. Control. Alternatively, the brush voltage applied to the brush member 10 and the surface potential of the photosensitive drum 1 have the same polarity, and the brush voltage applying unit is configured such that the absolute value of the brush voltage is smaller than the absolute value of the surface potential of the photosensitive drum 1. Control E4.

Further, a transfer voltage application section E3 for applying a transfer voltage to the transfer roller 5 is provided. When the brush voltage applied to the brush member 10 and the surface potential of the photosensitive drum 1 at the transfer portion d have the same polarity, the surface potential of the photosensitive drum 1 at the transfer portion d becomes smaller than the brush voltage applied to the brush member 10. The transfer voltage applying section E3 is controlled as follows.

Although the surface potential of the photosensitive drum 1 is controlled by varying the transfer voltage and the brush voltage in this embodiment, the present invention is not limited to this. For example, the transfer voltage and the brush voltage may be applied while the photosensitive drum 1 is grounded and the surface potential is grounded (0 V). Alternatively, the potential relationship with the transfer roller 5 and the brush member 10 may be controlled by applying a voltage directly to the photosensitive drum 1 .

In this embodiment, an example of application to a DC charging type image forming apparatus has been described. The present invention can also be applied to charging type image forming apparatuses.

In this embodiment, only the DC component of the developing voltage has been described, but the developing voltage may be an oscillating voltage in which a DC voltage (DC component) and an AC voltage (AC component) are superimposed.
In addition, in this embodiment, toner, which is a magnetic one-component developer, is used as the developer, but a non-magnetic one-component developer may be used.

In this embodiment, the "cleaner-less system" that does not have means for cleaning the photosensitive drum 1 is used, but the present invention is not limited to this. For example, a “blade cleaning method” using a blade as a cleaning means on the downstream side of the brush member 10 and the upstream side of the charging roller 2 with respect to the conveying direction of the photosensitive drum 1 may be used.

In this embodiment, the extension time is variable based on the number of sheets passed in the previous job, but the invention is not limited to this. For example, it may be variable based on the time or distance that the paper passes through the photosensitive drum.

Further, in the present embodiment, the recording material P, which is the object to be transferred, is transported to the transfer portion for transfer, but a transport belt may be provided to transport the recording material P to the transfer portion.

In this embodiment, a pre-exposure unit may be provided for exposing the surface of the photosensitive drum 1 downstream of the transfer section d and upstream of the charging section a in the rotation direction of the photosensitive drum 1. . The pre-exposure unit may be provided upstream or downstream of the contact portion e between the brush member 10 and the photosensitive drum 1 . When the pre-exposure unit is provided upstream of the contact portion e, the surface potential of the photosensitive drum 1 may be controlled by the pre-exposure unit.

REFERENCE SIGNS LIST 1 photosensitive drum 2 charging roller 5 transfer roller 10 brush member 31 developing roller 110 driving motor 150 control section 152 memory

Claims (18)

a rotatable photosensitive drum;
a charging member that charges the surface of the photosensitive drum in a charging unit;
a developing member that supplies toner onto the surface of the photosensitive drum charged by the charging member to form a toner image;
a transfer member that forms a transfer portion in contact with the photosensitive drum, and transfers the toner image formed on the photosensitive drum to a transfer material at the transfer portion;
a brush member that contacts the surface of the photosensitive drum downstream of the transfer section and upstream of the charging section in the rotational direction of the photosensitive drum;
a driving unit that rotates the photosensitive drum;
a storage unit that stores information about the usage history of the photosensitive drum;
A control unit that controls the driving unit,
The second image is formed after a stop time between a first image forming operation for forming an image on a transfer material and a second image forming operation performed subsequent to the first image forming operation has elapsed. In an image forming apparatus capable of performing a rotating operation of rotating the photosensitive drum before performing a forming operation,
The image forming apparatus, wherein the control unit controls the number of rotations of the photosensitive drum in the rotation operation based on the information and the stop time. The stop time is for starting the second image forming operation after the driving state in which the photosensitive drum is rotated after the first image forming operation is switched to the stop state in which the rotation of the photosensitive drum is stopped. 2. The image forming apparatus according to claim 1, wherein the time is the time until the photosensitive drum is switched from the stopped state to the driven state. characterized by having a measurement unit that measures a stop time between a first image forming operation for forming an image on a transfer target and a second image forming operation that is performed subsequent to the first image forming operation. 3. The image forming apparatus according to claim 1 or 2. 4. The controller according to any one of claims 1 to 3, wherein the controller controls the number of rotations in the rotating operation performed before the second image forming operation, according to the information and the stop time. 1. The image forming apparatus according to item 1 or 1. having an environment detection sensor that detects an installation environment of the image forming apparatus;
The image forming apparatus according to any one of claims 1 to 4, wherein the control section controls the number of rotations according to the installation environment. 6. The image forming apparatus according to claim 5, wherein the installation environment is temperature or humidity detected by the environment detection sensor. 6. The image forming apparatus according to claim 5, wherein the installation environment is the absolute moisture content detected by the environment detection sensor. When the absolute moisture content is detected to be the first absolute moisture content, the control unit controls the rotational speed of the rotation relative to the case where a second absolute moisture content smaller than the first absolute moisture content is detected. 8. The image forming apparatus according to claim 7, wherein the number is increased. 9. The image forming apparatus according to any one of claims 1 to 8, wherein the information is the number of transfer-receiving materials that have passed through the transfer section in the first image forming operation. . a brush voltage applying unit that applies a brush voltage to the brush member;
The brush member is a conductive brush,
The control unit controls the brush voltage application unit to apply the brush voltage having the same polarity as the toner charged to the normal polarity to the conductive brush while the rotating operation is being performed. 10. The image forming apparatus according to any one of claims 1 to 9. While the rotation operation is being performed, the control unit controls the relationship between the brush voltage applied to the brush member and the surface potential of the photosensitive drum at a contact portion where the surface of the photosensitive drum and the brush member contact each other. 11. The image forming apparatus according to claim 10, wherein the brush voltage applying section is controlled so as to increase the potential difference stepwise. The controller controls the brush voltage applied to the brush member and the surface potential of the photosensitive drum to have the same polarity, and the absolute value of the brush voltage to be larger than the absolute value of the surface potential of the photosensitive drum. 11. The image forming apparatus according to claim 10, wherein said brush voltage applying section is controlled by said brush voltage applying section. The controller controls the brush voltage applied to the brush member and the surface potential of the photosensitive drum to have the same polarity, and the absolute value of the brush voltage to be smaller than the absolute value of the surface potential of the photosensitive drum. 11. The image forming apparatus according to claim 10, wherein said brush voltage applying section is controlled by said brush voltage applying section. a transfer voltage applying unit that applies a transfer voltage to the transfer member;
The controller controls the brush voltage applied to the brush member and the surface potential of the photosensitive drum in the transfer section to have the same polarity, and the surface potential of the photosensitive drum in the transfer section is applied to the brush member. 14. The image forming apparatus according to any one of claims 10 to 13, wherein the transfer voltage applying section is controlled to be lower than the brush voltage applied. When the number of transfer-receiving bodies that have passed between the transfer section in the first image forming operation is a first number, the control section controls a second image forming operation in which the number of transfer-receiving materials is greater than the first number. 15. The image forming apparatus according to any one of claims 1 to 14, wherein the number of rotations of the photosensitive drum in the rotating operation is reduced compared to the number of sheets. 16. The image forming apparatus according to any one of claims 1 to 15, wherein the control section controls a rotation time of the rotation operation in order to control the number of rotations of the photosensitive drum in the rotation operation. . 17. The apparatus according to any one of claims 1 to 16, wherein the transfer unit is configured such that residual toner that has not been transferred from the photosensitive drum to the transfer-receiving body is collected by the developing member. Image forming device. The image forming apparatus according to any one of claims 1 to 17, wherein the toner is a one-component developer.

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