JP2011145600A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus that fills a developer-storing unit with a developer to make the developer go through the storing unit in a state of mounting a developing device on an apparatus body, wherein the damage of a latent image carrier and a cleaning blade is prevented while curbing wasteful toner consumption. <P>SOLUTION: An agitation conveying path 10 and a supplying/collecting conveying path 13 serve as the developer-storing unit of the developing device. The image forming apparatus has a developer-filling mode for filling the agitation conveying path and the supplying/collecting conveying path with the developer from a developer bottle 180 in a state that a photoreceptor 1 and the developing device 4 are mounted in the apparatus. The image forming apparatus continuously drives the developing device in the developer-filling mode and intermittently drives the photoreceptor. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.

  2. Description of the Related Art Conventionally, image forming apparatuses that perform development using a two-component developer obtained by mixing a toner and a carrier are widely used. In this image forming apparatus, when the developer container of the developing device is filled with a developer in advance and shipped, development is performed to partially expose the developing roller due to vibration during transportation or tilting of the entire device. The developer is scattered from the opening of the apparatus. For this reason, after the image forming apparatus is transported to the user, the developer is filled into the empty developer accommodating portion by the service person.

  Further, when the two-component developer is used repeatedly, the carrier gradually deteriorates and the developing ability is lowered. For this reason, the developer in the developing device including the deteriorated carrier is replaced. As a method for replacing the developer, a service person visits the user every predetermined cycle, collects the old developer, and fills the empty developer container with new developer.

  When filling the developer, it is desired that the developer is filled so as to reach the developer accommodating portion with a simple operation. Patent Document 1 discloses a developer that drives a developing motor of a developing device after setting a developer containing bottle in a developer inlet that communicates with a developer containing portion while the developing device is mounted on the image forming apparatus main body. An image forming apparatus that implements a filling mode is described. In the developer filling mode, by driving the developing motor, the developer conveying screw in the developer accommodating portion can be driven, and the developer can be filled in the empty developer accommodating portion.

  In the image forming apparatus of Patent Document 1, when the driving of the photosensitive member as the latent image carrier is stopped when the developer filling mode is performed, the new developer attached to the developing roller by the driving of the developing motor is transferred to the photosensitive member. Since there is a long time contact with only a specific part of the photosensitive member, there is a risk of scratching the photoreceptor. Therefore, the photosensitive member is also driven in the developer filling mode.

  However, when the photosensitive member is driven in the developer filling mode, the photosensitive member and the cleaning blade keep rubbing for a long time in a state where toner is not supplied to the cleaning blade as the photosensitive member cleaning means, so that the blade is turned up. May occur. In general, when the image forming apparatus is shipped, a friction reducing material is attached to the surface of the photosensitive member or the cleaning blade to suppress the occurrence of blade turning at the start of driving of the photosensitive member. Further, when the developer is replaced, since the toner from the previous image formation is in the vicinity of the cleaning blade, the occurrence of blade turning can be suppressed to some extent. However, if the photoconductor is driven for a long time in the developer filling mode, the friction reducing material and toner are collected from the rubbing portion between the photoconductor and the cleaning blade, and the photoconductor is slid in a state where there is no interposition. The blade turns over as it continues to rub.

  For this reason, after a certain amount of developer is filled in the developer filling mode, a belt-like toner image is formed on the photoreceptor, and this toner is input to the cleaning blade to suppress blade turning. However, as the photosensitive member is driven for a long time, if a belt-like toner image is formed and input to the cleaning blade, there is a problem that wasteful toner consumption increases.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a wasteful image forming apparatus in which a developer is filled in a developer container while the developing device is mounted on the apparatus main body. It is an object of the present invention to provide an image forming apparatus capable of suppressing breakage of a latent image carrier and a cleaning blade while suppressing excessive toner consumption.

In order to achieve the above object, the invention of claim 1 includes a developer accommodating portion that accommodates a developer composed of a carrier and a toner, a developer conveying member that conveys the developer in the developer accommodating portion, and the developing device. A developing device having a developer carrying member that transports the developer to a portion facing the latent image carrier and develops the latent image on the latent image carrier; and a surface of the latent image carrier A cleaning blade for removing deposits, and driving the developing device and the latent image carrier in a state where the latent image carrier and the developing device are mounted in the device, and developing the developer from a developer-filled container. In the image forming apparatus having a developer filling mode for filling the developer container with the developer, the developing device is continuously driven and the latent image carrier is intermittently driven during the developer filling mode. It is characterized by the fact that
According to a second aspect of the present invention, in the image forming apparatus of the first aspect, when the latent image carrier is intermittently stopped during the developer filling mode, the same portion of the latent image carrier is located on the developer carrier. The latent image carrier is driven so that it does not face the surface.
According to a third aspect of the present invention, in the image forming apparatus of the second aspect, the intermittent stop time of the latent image carrier is longer than the intermittent drive time.
According to a fourth aspect of the present invention, in the image forming apparatus of any one of the first, second, and third aspects, the toner for supplying the latent image carrier to the cleaning blade when the latent image carrier is intermittently driven. An image is formed.
According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first, second, third, and fourth aspects, the latent image carrier is driven one or more times during one intermittent drive of the latent image carrier. It is characterized by doing.
According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first, second, third, and fifth aspects, when the latent image carrier is intermittently driven, the background potential of the latent image carrier is formed. It is characterized by being made larger than the background potential of the surface.
Further, the invention of claim 7 is the image forming apparatus according to any one of claims 1, 2, 3, 4, 5 or 6, wherein the developer accommodating portion includes a developer stirring conveyance path, a developer supply conveyance path, It consists of a developer recovery transport path, and a developer transport member is provided in each transport path.

  In the present invention, the developing device is continuously driven in the developer filling mode to fill the developer while continuously operating the developer conveying member in the developer containing portion. It can be filled to spread. For this reason, the developer filling mode itself can be shortened. Further, when the latent image carrier is driven in the developer filling mode, the developer attached to the developer carrier is in contact with a specific portion of the latent image carrier for a long time and may damage the latent image carrier. To prevent. At this time, by driving the latent image carrier intermittently, the latent image carrier and the cleaning blade are prevented from rubbing for a long time, so that it is difficult to turn the blade. For this reason, blade turning can be suppressed without relying on toner input to the cleaning blade which has been conventionally performed for suppressing blade turning, and wasteful toner consumption can be suppressed.

  According to the present invention, in an image forming apparatus that fills a developer container so that the developer spreads while the developing device is mounted on the apparatus main body, the latent image carrier and the cleaning blade are suppressed while suppressing wasteful toner consumption. There is an excellent effect that can prevent the damage.

1 is a schematic configuration diagram of a copier according to an embodiment. FIG. 3 is an enlarged configuration diagram showing a developing device and a photoreceptor provided in a process cartridge. Sectional drawing which shows an example of a developing device. FIG. 4 is a schematic diagram for explaining a flow of a developer in a developer container of the developing device in FIG. 3. Sectional drawing which shows the other example of a developing device. FIG. 6 is a schematic diagram illustrating the flow of a developer in a developer container of the developing device in FIG. 5. FIG. 3 is an external perspective view illustrating a toner supply port of a developing device. FIG. 3 is a front view showing a toner supply port exposed from a side plate when a developer is replaced. The front view which shows the state which set the developer bottle at the time of developer replacement | exchange. FIG. 3 is a schematic configuration diagram of a process cartridge in which a developer bottle is set when the developer is replaced. The graph which shows the surface potential of the photoreceptor in which the electrostatic latent image was formed. The graph showing the relationship between the development potential | VB−VL | and the toner adhesion amount M / A. 6 is a motor drive timing chart in the developer filling mode of Embodiment 1. FIG. 7 is a motor drive timing chart in a developer filling mode of Comparative Example 1. The figure which showed the photoreceptor position and developer contact range which oppose a developing roller in developer filling implementation mode.

Hereinafter, as an image forming apparatus to which the present invention is applied, an embodiment of a tandem type color laser copier (hereinafter simply referred to as “copier 100”) in which a plurality of photoconductors are arranged in parallel will be described.
FIG. 1 is a schematic configuration diagram of a copying machine 100 according to the present embodiment. The copying machine 100 includes a printer unit 150, a paper feeding device 200 on which the printer unit 150 is placed, a scanner 300 fixed on the printer unit 150, and the like. An automatic document feeder 400 fixed on the scanner 300 is also provided.

  The printer unit 150 includes an image forming unit including four sets of process cartridges 18Y, 18M, 18C, and 18K for forming images of each color of yellow (Y), magenta (M), cyan (C), and black (K). 20 is provided. Y, M, C, and K attached to the numbers of the respective symbols indicate members for yellow, magenta, cyan, and black (the same applies hereinafter). In addition to the process cartridges 18Y, 18M, 18C, and 18K, an optical writing unit 21, an intermediate transfer unit 17, a secondary transfer device 22, a resist roller pair 49, a belt fixing type fixing device 25, and the like are disposed. .

  The optical writing unit 21 includes a light source (not shown), a polygon mirror, an f-θ lens, a reflection mirror, and the like, and irradiates the surface of a photoconductor described later with laser light based on image data.

Since the four process cartridges 18Y, 18M, 18C, and 18K have substantially the same configuration except that the colors of the toners to be handled are different, the process cartridge 18Y for yellow will be described below.
The process cartridge 18Y includes a drum-shaped photoreceptor 1Y as an image carrier, a charger, a developing device 4Y, a cleaning unit, a static eliminator, and the like. The surface of the photoreceptor 1Y as a latent image carrier is uniformly charged by a charger as a charging means. The surface of the photoreceptor 1 </ b> Y that has been subjected to charging processing is irradiated with laser light that has been modulated and deflected by the optical writing unit 21. Then, the potential of the irradiation part (exposure part) is attenuated. By this attenuation, an electrostatic latent image for Y is formed on the surface of the photoreceptor 1Y. The formed electrostatic latent image for Y is developed by the developing device 4Y as developing means to become a Y toner image. The Y toner image formed on the Y photoconductor 1Y is primarily transferred to an intermediate transfer belt 110 described later. The surface of the photoreceptor 1Y after the primary transfer is cleaned of the transfer residual toner by the drum cleaning unit. Further, the photoconductor 1Y cleaned by the drum cleaning unit is discharged by the charge eliminator. Then, it is uniformly charged by the charger and returns to the initial state. The series of processes as described above is the same for the other process cartridges 18M, 18C, and 18K.

Next, the intermediate transfer unit will be described.
The intermediate transfer unit 17 includes an intermediate transfer belt 110 serving as an intermediate transfer member, a belt cleaning device 90, and the like. Further, it also includes a drive roller 14, a stretching roller 15, a secondary transfer backup roller 16, four primary transfer bias rollers 62Y, M, C, and K.
The intermediate transfer belt 110 is tensioned by a plurality of rollers including the tension roller 14. Then, it is endlessly moved clockwise in the drawing by the rotation of the driving roller 15 driven by a belt driving motor (not shown).
The four primary transfer bias rollers 62Y, 62M, 62C, and 62K are disposed so as to be in contact with the inner peripheral surface side of the intermediate transfer belt 110, respectively, and receive primary transfer bias from a power source (not shown). Further, the intermediate transfer belt 110 is pressed toward the photoreceptors 1Y, 1M, 1C, and 1K from the inner peripheral surface side to form primary transfer nips. In each primary transfer nip, a primary transfer electric field is formed between the photoreceptor 1 and the primary transfer bias roller 62 due to the influence of the primary transfer bias.
The above-described Y toner image formed on the Y photoconductor 1Y is primarily transferred onto the intermediate transfer belt 110 due to the influence of the primary transfer electric field and nip pressure. On the Y toner image, the M, C, K toner images formed on the M, C, K photoconductors 1M, C, K are sequentially superposed and primarily transferred. By this primary transfer of superposition, a four-color superposed toner image (hereinafter referred to as a four-color toner image) that is a multiple toner image is formed on the intermediate transfer belt 110.
The four-color toner image superimposed and transferred on the intermediate transfer belt 110 is secondarily transferred onto a transfer sheet (not shown) as a recording medium at a secondary transfer nip described later. Transfer residual toner remaining on the surface of the intermediate transfer belt 110 after passing through the secondary transfer nip is cleaned by a belt cleaning device 90 that sandwiches the belt with the driving roller 15 on the left side in the drawing.

Next, the secondary transfer device 22 will be described.
Below the intermediate transfer unit 17 in the figure, a secondary transfer device 22 is disposed in which a paper conveying belt 24 is stretched by two stretching rollers 23. The paper transport belt 24 is moved endlessly in the counterclockwise direction in the drawing in accordance with the rotational drive of at least one of the stretching rollers 23. Of the two stretching rollers 23, one stretching roller 23 arranged on the right side in the drawing is between the intermediate transfer belt 110 and the paper transport belt between the secondary transfer backup roller 16 of the intermediate transfer unit 17. 24 is sandwiched. By this sandwiching, a secondary transfer nip is formed in which the intermediate transfer belt 110 of the intermediate transfer unit 17 and the paper transport belt 24 of the secondary transfer device 22 are in contact with each other. A secondary transfer bias having a polarity opposite to that of the toner is applied to the one stretching roller 23 by a power source (not shown). By applying this secondary transfer bias, the four-color toner image on the intermediate transfer belt 110 of the intermediate transfer unit 17 is electrostatically moved from the belt side toward the one stretching roller 23 side in the secondary transfer nip. A next transfer electric field is formed. The transfer paper fed into the secondary transfer nip so as to synchronize with the four-color toner image on the intermediate transfer belt 110 by a registration roller pair 49 to be described later has four colors affected by the secondary transfer electric field and nip pressure. The toner image is secondarily transferred. Instead of the secondary transfer method in which the secondary transfer bias is applied to one of the stretching rollers 23 as described above, a charger for charging the transfer paper in a non-contact manner may be provided.

  In the paper feeding device 200 provided at the lower part of the copying machine 100 main body, a plurality of paper feeding cassettes 44 in which a plurality of transfer sheets can be stacked and stored in a bundle of sheets are arranged in a stack in the vertical direction. It is installed. Each paper feed cassette 44 presses the paper feed roller 42 against the uppermost transfer paper in the paper bundle. Then, by rotating the paper feed roller 42, the uppermost transfer paper is sent out toward the paper feed path 46.

  The paper feed path 46 that receives the transfer paper fed from the paper feed cassette 44 has a plurality of conveying roller pairs 47 and a registration roller pair 49 provided near the end in the path. Then, the transfer paper is conveyed toward the registration roller pair 49. The transfer sheet conveyed toward the registration roller pair 49 is sandwiched between the rollers of the registration roller pair 49. On the other hand, in the intermediate transfer unit 17, the four-color toner image formed on the intermediate transfer belt 110 enters the secondary transfer nip as the belt moves endlessly. The registration roller pair 49 sends out the transfer paper sandwiched between the rollers at a timing at which the transfer paper can be brought into close contact with the four-color toner image at the secondary transfer nip. As a result, at the secondary transfer nip, the four-color toner image on the intermediate transfer belt 110 is in close contact with the transfer paper. Then, it is secondarily transferred onto the transfer paper and becomes a full color image on the white transfer paper. The transfer paper on which the full-color image is formed in this manner exits the secondary transfer nip as the paper transport belt 24 moves endlessly, and then is sent from the paper transport belt 24 to the fixing device 25.

  The fixing device 25 includes a belt unit that moves the fixing belt 26 endlessly while being stretched by two rollers, and a pressure roller 27 that is pressed toward one roller of the belt unit. The fixing belt 26 and the pressure roller 27 are in contact with each other to form a fixing nip, and the transfer paper received from the paper transport belt 24 is sandwiched therebetween. Of the two rollers in the belt unit, the roller that is pressed from the pressure roller 27 has a heat source (not shown) inside, and pressurizes the fixing belt 26 by the generated heat. The pressed fixing belt 26 heats the transfer paper sandwiched in the fixing nip. The full color image is fixed on the transfer paper by the influence of the heating and the nip pressure.

  The transfer paper subjected to the fixing process in the fixing device 25 is stacked on the stack portion 57 provided outside the left side plate in the drawing of the printer housing, or forms a toner image on the other surface. To the secondary transfer nip described above.

  When a document (not shown) is copied, for example, a bundle of sheet documents is set on the document table 30 of the automatic document feeder 400. However, when the original is a single-sided original that is closed in a main form, it is set on the contact glass 32. Prior to this setting, the automatic document feeder 400 is opened with respect to the copying machine 100 main body, and the contact glass 32 of the scanner 300 is exposed. Thereafter, the single-bound original is pressed by the closed automatic document feeder 400.

  When a copy start switch (not shown) is pressed after the document is set in this way, the document reading operation by the scanner 300 starts. However, when a sheet document is set on the automatic document feeder 400, the automatic document feeder 400 automatically moves the sheet document to the contact glass 32 prior to the document reading operation. In the document reading operation, first, the first traveling body 33 and the second traveling body 34 start traveling together, and light is emitted from a light source provided in the first traveling body 33. Then, the reflected light from the document surface is reflected by a mirror provided in the second traveling body 34, passes through the imaging lens 35, and then enters the reading sensor 36. The reading sensor 36 constructs image information based on the incident light.

  In parallel with the document reading operation, each device in each process cartridge 18Y, M, C, K, the intermediate transfer unit 17, which is a transfer means, the secondary transfer device 22, and the fixing device 25 start driving. . Then, based on the image information constructed by the reading sensor 36, the optical writing unit 2 is driven and controlled, and Y, M, C, and K toner images are formed on the respective photoreceptors 1Y, 1M, 1C, and 1K. Is done. These toner images become four-color toner images superimposed and transferred on the intermediate transfer belt 110.

  Further, almost simultaneously with the start of the document reading operation, the paper feeding operation is started in the paper feeding device 200. In this paper feeding operation, one of the paper feeding rollers 42 is selectively rotated, and the transfer paper is sent out from one of the paper feeding cassettes 44 accommodated in the paper bank 43 in multiple stages. The fed transfer sheets are separated one by one by the separation roller 45 and enter the reverse feeding path 46, and then conveyed toward the secondary transfer nip by the conveyance roller pair 47. In some cases, paper feeding from the manual feed tray 51 is performed instead of such paper feeding from the paper feeding cassette 44. In this case, after the manual feed roller 50 is selectively rotated and the transfer paper on the manual feed tray 51 is sent out, the separation roller 52 separates the transfer paper one by one and feeds it to the manual feed path 53 of the printer unit 150. Make paper.

  When the copier 100 forms an image of another color composed of toner of two or more colors, the intermediate transfer belt 110 is stretched so that the upper stretched surface is substantially horizontal, and all the upper stretched surface is placed on the upper stretched surface. Photoconductors 1Y, 1M, 1C, and 1K are brought into contact with each other. On the other hand, when forming a monochrome image consisting of only K toner, the intermediate transfer belt 110 is tilted to the lower left in the drawing by a mechanism (not shown) and the upper stretched surface is set to Y, M, C. The photoconductors 1Y, 1M, and 1C are separated. Of the four photoconductors 1Y, 1M, 1C, and 1K, only the K photoconductor 1K is rotated counterclockwise in the drawing to form only the K toner image. At this time, for Y, M, and C, not only the photosensitive members 1Y, M, and C but also the developing devices 4Y, M, and C are stopped to prevent unnecessary consumption of the photosensitive member and the developer.

  The copying machine 100 includes a control unit (not shown) including a CPU that controls the following devices in the copying machine 100, and an operation display unit (not shown) including a liquid crystal display, various key buttons, and the like. . The operator sends a command to the control unit by a key input operation on the operation display unit, so that one of the three modes is selected from the three-sided print mode, which is a mode for forming an image only on one side of the transfer paper. You can choose one. The three single-sided printing modes include a direct discharge mode, a reverse discharge mode, and a reverse decal discharge mode.

Next, the process cartridges 18Y, M, C, and K will be described in detail.
FIG. 2 is an enlarged configuration diagram illustrating the developing device 4 and the photosensitive member 1 included in one of the four process cartridges 18Y, 18M, 18C, and 18K. The four process cartridges 18Y, 18M, 18C, and 18K have substantially the same configuration except that the colors of the toners to be handled are different from each other. Therefore, the subscripts Y, M, C, and K are omitted in FIG. Yes.

  As shown in FIG. 2, in the process cartridge 18, the photosensitive member 1, the charger 61, and the cleaning unit 63 are integrally stored in a case 64. The cleaning unit 63 includes a cleaning blade 63 a that contacts the photoreceptor 1 and a cleaning roller 63 b. In the process cartridge 18, the developing device 4 is installed so as to face the photoreceptor 1. The developing device 4 is configured to supply toner from a toner bottle 33 by operating a toner replenishing device 34 provided in the apparatus main body.

  As will be described later, the developing device 4 carries a developer on the developing roller 5 and transports it to a developing region which is a portion facing the photoreceptor 1 in a thinned state. In the development area, the toner T in the developer adheres to the electrostatic latent image formed on the surface of the photoreceptor 1. Specifically, the toner T is latently exposed by an electric field formed by a potential difference (developing potential) between the latent image potential (exposure potential) of the image portion irradiated with the laser light L and the developing bias applied to the developing roller 5. Adhere to the image. Thereafter, most of the toner T adhering to the photoreceptor 1 in the developing process is transferred onto the intermediate transfer belt 110. The untransferred toner T remaining on the photosensitive member 1 is collected inside the cleaning unit 63 by the cleaning blade 63a and the cleaning roller 63b.

Next, the developing device 4 employed in the process cartridge will be described.
FIG. 3 is a cross-sectional view showing an example of the developing device. The developing device 4 includes a developing roller 5 as a developer carrying member for supplying toner to the latent image on the surface of the photoreceptor 1 while moving the surface in the direction of arrow I in FIG. A developing doctor 3 is provided as a developer regulating member that regulates the developer supplied to the developing roller 5 to a thickness suitable for development. Further, as a developer accommodating portion for accommodating the developer, there are provided two developer conveying paths including a supply / recovery conveying path 13 and an agitation conveying path 10, and a developer conveying member that conveys the developer to each conveying path. ing.

  The supply / recovery conveyance path 13 has a supply / recovery screw 12 as a supply / recovery conveyance member that supplies the developer to the developing roller 5 and conveys the developer in the depth direction of FIG. 3 while collecting the developed developer. is doing. That is, the developing device 4 of FIG. 3 performs supply and recovery of the developer to the developing roller 5 through one developer transport path. The supply / recovery screw 12 is a developer conveying member that includes a rotating shaft and a wing provided on the rotating shaft, and rotates to convey the developer in the axial direction.

A stirring conveyance path 10 is provided in parallel with the supply / recovery conveyance path 13. The agitating and conveying path 10 includes an agitating screw 11 as an agitating and conveying member that conveys the developer to the near side in the figure, which is in the opposite direction to the supply and recovery screw 12 while stirring the developer. The stirring screw 11 is also a developer conveying member that includes a rotation shaft and a blade provided on the rotation shaft, and conveys the developer in the axial direction by rotating.
The supply / recovery conveyance path 13 and the agitation conveyance path 10 are partitioned by a partition wall 136 as a partition member. The partition wall 136 divides the supply / recovery conveyance path 13 and the agitation conveyance path 10 into openings at the front side and the rear side in the figure, and the supply / recovery conveyance path 13 and the agitation conveyance path 10 communicate with each other. is doing. A toner replenishing port 95 for replenishing toner from the toner bottle 33 is provided above the upstream end of the stirring and conveying path 10 in the conveying direction.

Next, the circulation of the developer in the developer accommodating portion of the developing device in FIG. 3 will be described.
FIG. 4 is a schematic diagram of the developing device 4 for explaining the flow of the developer in the developer accommodating portion. Each arrow in FIG. 4 indicates the moving direction of the developer.

In the supply / recovery conveyance path 13 that receives the supply of developer from the agitation conveyance path 10, the developer is conveyed downstream in the conveyance direction of the supply / recovery screw 12 while supplying the developer to the developing roller 5. The developer supplied onto the developing roller 5 from the supply / recovery transport path 13 is transported to a developing region that is a portion facing the photoconductor 1 in a state where the developer is thinned by the developing doctor 3 and performs development. In the supply / recovery conveyance path 13, the developer is conveyed downstream in the conveyance direction of the supply / recovery screw 12 while collecting the developer after development. The developer conveyed to the downstream end in the conveyance direction of the supply / recovery conveyance path 13 is supplied to the agitation conveyance path 10 from the circulation opening 96 of the partition wall 136 (arrow Q in FIG. 4).
The agitation conveyance path 10 conveys the supplied developer to the downstream side in the conveyance direction of the agitation screw 11 while agitating the supplied developer, and conveys the supply recovery screw 12 to the upstream side in the conveyance direction, thereby supplying the supply opening 91 of the partition wall 136. To the supply / recovery conveyance path 13 (arrow D in FIG. 4).

  As described above, the developer is transported in the opposite directions in the two developer transport paths, and the developer that has reached the downstream end in the transport direction of the supply and recovery transport path 13 is transported in the stirring transport path 10 through the circulation opening 96. The developer that has been transferred to the upstream end in the direction and reaches the downstream end in the transport direction of the agitation transport path 10 is transferred to the upstream end in the transport direction of the supply transport path 9 via the supply opening 91, thereby The developer circulates. Then, the developer in the supply / recovery conveyance path 13 is supplied to the surface of the developing roller 5, and is used for development in a developing region which is a facing portion between the developing roller 5 and the photoreceptor 1. Then, the developer on the developing roller 5 that has passed through the developing region is collected in the supply / collection conveyance path 13. A toner density sensor (not shown) serving as a toner density detection unit (not shown) is provided below the agitation transport path 10, and the toner replenishing device 34 is operated by the sensor output to supply toner from the toner replenishment port 95 to the agitation transport path 10. The

  FIG. 5 is a cross-sectional view showing another example of the developing device. The developing device 4 in FIG. 5 is a developing device having three developer transport paths including a recovery transport path 7, a supply transport path 9, and an agitation transport path 10 as a developer storage section that stores the developer. The developing device 4 supplies toner to the latent image on the surface of the photoreceptor 1 while moving the surface in the direction of arrow I in FIG. 5, and develops the developing roller 5 for developing and the developer supplied to the developing roller 5 for development. And a developing doctor 3 that regulates the thickness to an appropriate thickness.

  The supply conveyance path 9 has a supply screw 8 as a supply conveyance member that conveys the developer in the depth direction of FIG. 3 while supplying the developer to the developing roller 5. The supply screw 8 is a developer conveying member that includes a rotating shaft and a wing provided on the rotating shaft, and rotates to convey the developer in the axial direction.

  The developed developer that has passed through the developing section is collected downstream from the developing section, which is the facing portion of the developing roller 5 with respect to the photoconductor 1, and the collected developer is collected in the same direction as the supply screw 8. A recovery screw 6 is provided as a recovery transport member for transporting to the front. A supply conveyance path 9 including a supply screw 8 is provided in the lateral direction of the developing roller 5, and a recovery conveyance path 7 serving as a recovery conveyance path including the recovery screw 6 is provided below the development roller 5. The collection screw 6 also includes a rotation shaft and a blade provided on the rotation shaft, and is a developer transport member that transports the developer in the axial direction by rotating.

  The developing device 4 is provided with a stirring conveyance path 10 in parallel with the collection conveyance path 7 below the supply conveyance path 9. The agitating and conveying path 10 includes an agitating screw 11 serving as an agitating and conveying member that conveys the developer to the near side in the figure, which is the direction opposite to the supply screw 8 while stirring the developer. The stirring screw 11 is also a developer conveying member that includes a rotation shaft and a blade provided on the rotation shaft, and conveys the developer in the axial direction by rotating.

  The supply conveyance path 9 and the stirring conveyance path 10 are partitioned by a first partition wall 133 as a partition member. In the first partition wall 133, the supply conveyance path 9 and the agitation conveyance path 10 are partitioned at both ends on the front side and the back side in the drawing, and the supply conveyance path 9 and the agitation conveyance path 10 communicate with each other. is doing. The supply conveyance path 9 and the recovery conveyance path 7 are both partitioned by the first partition wall 133, but an opening is provided at a location where the supply conveyance path 9 and the recovery conveyance path 7 of the first partition wall 133 are partitioned. Absent. Further, the two conveyance paths of the stirring conveyance path 10 and the collection conveyance path 7 are partitioned by a second partition wall 134 as a partition member. The second partition wall 134 has an opening on the front side in the figure, and the agitation transport path 10 and the collection transport path 7 communicate with each other. As described above, in the developing device 4, the developer accommodating portion that accommodates the developer is configured by the supply conveyance path 9, the recovery conveyance path 7, and the stirring conveyance path 10.

Next, the circulation of the developer in the developer container of the developing device in FIG. 5 will be described.
FIG. 6 is a schematic diagram of the developing device 4 for explaining the flow of the developer in the developer accommodating portion. Each arrow in FIG. 6 indicates the moving direction of the developer.

In the supply conveyance path 9 that has been supplied with the developer from the agitation conveyance path 10, the developer is conveyed downstream in the conveyance direction of the supply screw 8 while supplying the developer to the developing roller 5. Then, the excess developer that is supplied to the developing roller 5 and is not used for development and is transported to the downstream end in the transport direction of the supply transport path 9 is supplied to the stirring transport path 10 from the surplus opening 92 of the first partition wall 133 ( Arrow E) in FIG.
On the other hand, the developer supplied onto the developing roller 5 from the supply conveyance path 9 is conveyed to a developing region which is a portion facing the photoreceptor 1 in a state where the developer is thinned by the developing doctor 3 and performs development. The developer on the developing roller 5 after development is collected in the collection conveyance path 7, and the collected developer conveyed to the downstream end in the conveyance direction of the collection conveyance path 7 by the collection screw 6 is collected in the collection opening of the second partition wall 134. The portion 93 is supplied to the stirring and conveying path 10 (arrow F in FIG. 6).
The agitating and conveying path 10 agitates the supplied surplus developer and the recovered developer, conveys the agitating screw 11 to the downstream side in the conveying direction, and conveys it to the upstream side in the conveying direction of the supplying screw 8. It is supplied to the supply conveyance path 9 from the supply opening 91 of 133 (arrow D in FIG. 6).
A toner concentration sensor (not shown) serving as a toner concentration detection unit is provided below the agitation transport path 10, and the toner replenishing device 34 is operated by the sensor output, so that toner is supplied to the agitation transport path 10 from a toner replenishment port described later. Supplied.

  5 includes a supply conveyance path 9 and a collection conveyance path 7 and supplies and collects the developer in different developer conveyance paths, so that the developed developer is mixed into the supply conveyance path 9. There is nothing to do. Accordingly, it is possible to prevent the toner density of the developer supplied to the developing roller 5 from decreasing toward the downstream side of the supply conveyance path 9 in the conveyance direction. Further, since the recovery conveyance path 7 and the agitation conveyance path 10 are provided and the developer recovery and agitation are performed in different developer conveyance paths, the developed developer does not fall during the agitation. Therefore, since the sufficiently agitated developer is supplied to the supply conveyance path 9, it is possible to prevent the developer supplied to the supply conveyance path 9 from being insufficiently agitated. In this way, the toner density of the developer in the supply conveyance path 9 can be prevented from decreasing, and the developer in the supply conveyance path 9 can be prevented from being insufficiently stirred. Can be constant.

  Further, in the developing device 4 of FIG. 5, a discharge conveyance path 2 for gradually discharging the developer from the developing device 4 can be provided, and a premix toner obtained by mixing the carrier and toner can be supplied from the toner bottle 33. As a result, the number of developer replacements due to carrier deterioration can be reduced, and maintenance can be facilitated. Specifically, the developer discharged as a discharge opening through which the developer that has passed downstream in the conveyance direction of the supply conveyance path 9 is discharged to the development apparatus 4 via the discharge conveyance path 2 is discharged from the development apparatus 4. An outlet 94 is provided. The developer that has passed through the developer discharge port 94 is transferred to the discharge conveyance path 2, and is conveyed to the outside of the developing device 4 by rotating the discharge screw 2 a that is a discharge conveyance member, and is discharged from the developing device 4. Made. The discharge conveyance path 2 is disposed on the downstream side in the conveyance direction of the supply conveyance path 9 so as to be adjacent to the supply conveyance path 9 with the discharge partition wall 135 interposed therebetween, and the developer discharge port 94 is connected to the supply conveyance path 9 and the discharge conveyance path 2. Are openings provided in the discharge partition wall 135 so as to communicate with each other.

  Further, the developing device 4 reaches the vicinity of the downstream end in the transport direction of the supply transport path 9, and retains the developer that has not entered the surplus opening 92 that is the circulation opening near the surplus opening 92. 80. Further, the developer discharge port 94 that is a discharge opening is located above the surplus opening 92 and the developer that has reached the position of the developer discharge port 94 among the retained developer retained by the developer retention means 80. It arrange | positions so that an agent may pass. In other words, the developer that has reached the vicinity of the downstream end in the transport direction of the supply transport path 9 cannot enter the surplus opening 92, and the surplus developer overflowing from the surplus opening 92 is blocked by the developer retaining means 80. Stopped and becomes a stagnant developer. Then, when the bulk of the staying developer increases, the developer that has reached the developer discharge port 94 provided above the surplus opening 92 passes through the developer discharge port 94 to the outside of the developing device 4. To be discharged.

  As described above, in the configuration in which the developer is gradually discharged from the developing device 4, the toner replenishing device 34 is operated to replenish the premixed toner in which the carrier and the toner are mixed from the toner bottle 33 through the toner replenishing port 95. . In this way, a new carrier is replenished to the developer container while gradually discharging the deteriorated carrier, and the carrier in the developer container is replaced. For this reason, it is possible to suppress a decrease in the developing capability of the developing device, but in the long term, such replacement of the carrier can reduce the number of times the developer is replaced due to carrier deterioration. The need remains.

  Next, the position where the developing device 4 replenishes toner to the developer conveyance path will be described. FIG. 7 is an external perspective view of the developing device 4. As shown in FIG. 7, a toner replenishing port 95 for replenishing toner is provided above the upstream end of the agitating and conveying path 10 including the agitating screw 11 in the conveying direction. Since the toner replenishing port 95 is provided outside the end portion in the width direction of the developing roller 5, it is outside the developing region width. In the developing device of FIG. 5, the toner replenishing port 95 is not limited to the position above the upstream end portion in the transport direction of the stirring transport path 10, and may be provided above the downstream end portion of the collection transport path 7. Further, a toner replenishing port 95 may be provided directly above the collection opening 93 where the developer is transferred from the collection conveyance path 7 to the stirring conveyance path 10. The above-described toner replenishing device 34 is operated in accordance with the output of a toner concentration sensor (not shown) provided below the agitation transport path 10, and the toner bottle 33 passes the toner supply port 95 to the developer transport path. Add toner.

Next, the filling of the developer into the developer transport path of the developing device 4 at the initial operation when the copying machine is transported to the user or when the developer is replaced due to carrier deterioration will be described.
First, when the developer is charged, the front door of the copying machine 100 is opened and the main power supply of the apparatus is turned off. The above-described toner replenishing device 34 is fixed to the side plate of the apparatus main body with screws. When the toner replenishing device 34 fixed with the screw is removed from the main body, the toner replenishing port 95 of each developing device 4 is exposed as shown in FIG. Next, the intermediate belt contact / separation mechanism 144 is set so that the intermediate transfer belt 110 is tilted to the lower left in the figure, and the upper stretched surface of the Y, M, C, K photoconductors 1Y, M, C, Separate from K. Then, as shown in FIG. 9, the developer bottle 180 is set so that the developer supply port of the developer bottle 180 containing the developer is aligned with the toner supply port 95.

  In the initial operation when the copying machine 100 is conveyed to the user, the four developer bottles 180 of Y, M, C, and K are set in the corresponding toner replenishing ports 95, respectively. In the replacement operation of the developer when the carrier is deteriorated, the developer bottle 180 is set in the toner supply port 95 of the developing device 4 from which the old developer has been collected. In this state, the heat seal (not shown) that seals the supply port of the developer bottle 180 is peeled off, the front door of the copying machine 100 is closed, and the main power supply of the apparatus is turned on. Next, a hidden menu is called from an operation display panel (not shown), a color corresponding to the color in which the developer bottle 180 is set is selected, and the developer filling mode is executed. In the initial operation when the copying machine 100 is conveyed to the user, all colors are selected and the developer filling mode is executed. When all colors are selected and the developer filling mode is performed, each may be performed sequentially or all colors may be performed simultaneously. It is also possible to select a specific color and perform agent filling only for the specific color.

  FIG. 10 is a schematic configuration diagram when the developer bottle 180 is set in the process cartridge 18 employing the developing device of FIG. During the developer filling mode, a developing motor (not shown) of the developing device 4 is driven to drive the developing roller 5, the stirring screw 11, and the supply / recovery screw 12. Further, in the process cartridge 18 adopting the developing device of FIG. 5, during the developer filling mode, the developing motor (not shown) of the developing device 4 is driven to develop the developing roller 5, the recovery screw 6, and the supply screw. 8 and the stirring screw 11 are driven. As a result, the developer in the developer bottle 180 supplied from the toner replenishing port 95 is transported, and the developer is spread in the developer transport path of the developing device 4. In this embodiment, during the developer filling mode, the developing device 4 is continuously driven to fill the developer while continuing to operate the developer conveying member in the developer accommodating portion. It is possible to fill the developer container so as to spread.

  Further, the photosensitive member 1 is intermittently driven during the developer filling mode. In the developer filling mode, the developing roller 5 is also driven, so that a new developer is also supplied onto the developing roller 5. Therefore, by intermittently driving the photosensitive member 1, the new developer attached to the developing roller 5 is prevented from coming into contact with only a specific portion of the photosensitive member 1 for a long time, and the photosensitive member 1 is damaged. Can be prevented. In addition, since the photosensitive member 1 is not continuously driven, it is possible to suppress the rubbing between the photosensitive member 1 and the cleaning blade 63a for a long time, thereby suppressing the occurrence of blade turning. As a result, it is possible to suppress wasteful toner consumption input to the cleaning blade 63a in order to prevent the occurrence of blade turning.

  Further, in order to further prevent the occurrence of turning of the blade, a belt-like toner image is formed on the photosensitive member 1 when the developer is filled to some extent, and the toner is input to the cleaning blade 63a. You can also The amount of toner input to the cleaning blade 63a can be adjusted according to the toner adhesion amount of the toner image and the size of the toner image. Also in this case, wasteful toner consumption input to the cleaning blade 63a can be suppressed in order to prevent the occurrence of blade turning compared to the case where the photosensitive member 1 is continuously driven.

  In this way, all the developer in the developer bottle 180 is filled into the developing device 4, and the developer filling mode is terminated. Then, the main power of the apparatus is turned off, the front door is opened, the developer bottle 180 is removed, and the toner replenishing apparatus 34 is attached to the apparatus main body as it was. Next, the intermediate belt contact / separation mechanism 144a causes the upper tension surface of the intermediate transfer belt 110 to be separated from the Y, M, C, and K photoconductors 1Y, M, C, and K, and then the Y, M, and The C photoconductors 1Y, 1M, and 1C are separated from each other so that the K photoconductor 1K is brought into contact therewith, and the front door is closed.

  In this description, the initial developer is charged from the replenishment toner supply port 95, but a dedicated inlet for the initial developer may be provided and charged from there. Here, the developer bottle 180 is fixed to the toner replenishing port 95 and the developer is automatically charged. However, the developer bottle 180 may be manually charged from a gusset bag or the like.

  In this way, the time during which the photosensitive member 1 and the cleaning blade 63a continue to rub in the developer filling mode is shortened so that the blade is hardly turned over. Further, in order to surely prevent the occurrence of turning of the blade, even when a belt-like toner image is formed on the photosensitive member 1 and input to the cleaning blade 63a, the input amount of toner to the cleaning blade 63a is the same as that of the photosensitive member. 1 is adjusted so as to be smaller than the case where 1 is continuously driven.

The relationship between the development parameter in the process cartridge 18 and the toner adhesion amount on the photosensitive member 1 will be described in order to adjust the amount of toner that forms a belt-like toner image on the photosensitive member 1 and is input to the cleaning blade 63a.
FIG. 11 is a graph showing the surface potential of the photosensitive member 1 on which an electrostatic latent image is formed. The potential changes only in the exposed image portion. In order to simplify the description, the image is a solid image, and the image portion surface potential at that time is VL, and the non-image portion potential is Vd. The photosensitive member 1 having such a surface potential and the developing roller 5 that rotates at a faster speed than the photosensitive member 1 while carrying the developer are opposed to each other in the developing region. A DC or AC voltage is applied to the developing roller 5 as a developing bias, and toner is supplied from the developer on the developing roller 5 to the image portion of the photosensitive member 1 to be attached to form a visible image.

  At this time, the toner adhesion amount on the photosensitive member 1 can be changed by the magnitude of the development potential | VB−VL | which is the absolute value of the difference between the development bias VB and the latent image potential VL shown in FIG. FIG. 12 is a graph showing the developing ability that is the relationship between the developing potential | VB−VL | and the toner adhesion amount M / A. FIG. 12 shows a case where a DC voltage is used as the developing bias.

  As a method of changing the toner adhesion amount (M / A) on the photoreceptor, 1) increase the exposure energy during exposure by the exposure apparatus to lower the exposure portion potential VL (close to the 0 direction), and 2) the development bias. Increase VB (remove from VL), 3) Perform both 1) and 2).

  The implementation method 1) can be realized by, for example, increasing the lighting time of the exposure apparatus (LD and LED) or increasing the light emission intensity, and has an advantage that it is not necessary to change the development conditions. In addition, as an implementation method of 2), the toner adhesion amount can be increased without causing background staining by keeping the difference between the non-image portion potential and the developing bias potential appropriate. A toner image in which the toner adhesion amount is adjusted on the photosensitive member 1 by such a method is formed in the entire longitudinal direction of the photosensitive member, and the amount of toner input to the cleaning blade 63a is adjusted. Further, the toner input amount can be changed by adjusting the circumferential length of the photoreceptor 1 of the toner image to be formed.

  Further, by increasing the amount of toner attached to the background (non-image portion attached toner), it is possible to input the toner for preventing the blade turning to the cleaning blade 63a without forming a toner image for cleaning input. The amount of toner attached to the background portion can be changed by the magnitude of the background potential | VB−Vd |, which is the absolute value of the difference between the non-image portion bias Vd and the developing bias VB shown in FIG. As this value increases, the amount of toner attached to the background increases, and as the value decreases, it decreases. However, if it is too large, the carrier may develop and damage the photoconductor or blade, so it is preferable not to make it too large.

  In any method, toner is input to the cleaning blade 63a in order to surely prevent the occurrence of blade turning. However, the photosensitive member 1 is driven intermittently, so that the cleaning is performed as compared with the case of continuous driving. The amount of toner input to the blade 63a can be reduced. Therefore, useless toner consumption can be suppressed.

  Hereinafter, Examples 1 to 6 and Comparative Examples 1 and 2 will be described. Table 1 summarizes the presence or absence of turning-up of the cleaning blade, the torque of the photosensitive member driving motor, and the presence or absence of abnormal images in Examples 1 to 6 and Comparative Examples 1 and 2.

<Example 1>
The developer storage unit shown in FIG. 3 includes two developer conveyance paths, a supply / recovery conveyance path 12 and an agitation conveyance path 10, mounted on an Ricoh imagio MP C7500. In the developing device 4, the developing roller 5 has an outer diameter of 25 mm and rotates at a linear speed of 562 mm / sec. The gap between the developing roller 5 and the developing doctor 3 is set to 0.3 ± 0.04 mm, and the developer passing through the developing doctor 3 is a thin layer of 38 ± 5 mg / cm ² . The photosensitive member 1 has a diameter of 60 mm and rotates at a linear velocity of 352.8 mm / sec. The gap between the developing roller 5 and the photosensitive member 1 in the developing area is set to be 0.3 ± 0.05 mm.

  In the copying machine 100 under the above conditions, a developer filling mode was carried out in order to fill 480 g of developer. During execution of the developer filling mode, the developing device 4 was continuously driven, and the photosensitive member 1 was stopped for 2 seconds and repeatedly driven for 2 seconds 8 times, and the charging of the developer was completed over 32 seconds. FIG. 13 shows a drive timing chart of a development drive motor (not shown) and a photoreceptor drive motor (not shown).

FIG. 15 is a diagram showing the position of the photosensitive member facing the developing roller 5 and the developer contact range by intermittent driving of the photosensitive member 1 in the developer filling mode. In the intermittent driving of the photoconductor 1 of the first embodiment, the surface of the photoconductor faces the developing roller 5 at a position as shown in FIG. Contact with a width of 2 mm. Due to this intermittent drive, the total photosensitive member drive time is shortened. Furthermore, the position where the surface of the photoreceptor 1 is in contact with the developer can be shifted, and the time during which the specific surface of the photoreceptor 1 is in contact with the developer can be shortened.

  Further, when the photosensitive member is driven in the developer filling mode, a bias is applied to the photosensitive member 1 and the developing roller 5 so that the background potential becomes 100 V, but for inputting toner to the cleaning blade 63a. No image has been created. Even under such conditions, the cleaning blade 63a did not turn over during the developer filling mode.

  Further, during the developer filling mode, the torque of the photosensitive member drive motor (not shown) is measured. During normal image formation, the torque of the photosensitive member driving motor is about 0.7 Nm. It has been found that when the frictional force between the photosensitive member surface and the cleaning blade 63a increases, the torque tends to increase, and when it exceeds 1.3 Nm, the blade may turn over. Therefore, it is necessary that the torque of the photosensitive member driving motor be smaller than 1.3 Nm during the developer filling mode. In this embodiment, the torque of the photosensitive member driving motor during the developer filling mode is 1.1 Nm, which is smaller than the value 1.3 Nm at which blade turning may occur. Further, a solid image and a halftone image were formed after completion of the developer filling mode. If the photosensitive member 1 or the cleaning blade 63a is damaged, abnormal images such as uneven density and vertical stripes in the photosensitive member cycle may occur. However, in Example 1, no abnormal image was generated.

<Example 2>
In the same image forming apparatus as in Example 1, a developer filling mode was carried out in order to fill 480 g of developer. During the developer filling mode, the developing device 4 is continuously driven, and the photosensitive member 1 is stopped for 2.95 sec and driven for 0.05 sec 10 times, and the developer filling is completed over 30 sec. . In the intermittent driving of the photosensitive member 1 of Example 2, as shown in FIG. 15B, the surface of the photosensitive member is opposed to the developing roller 5 while being slightly shifted during the developer filling mode. Go around. The photosensitive member driving distance by the intermittent driving is shortened, and the cleaning blade 63a is not turned up during the developer filling mode. Further, the total time for stopping the photoconductor is longer, and the time for which the specific surface of the photoconductor is in contact with the developer is longer than that in the first embodiment, but the torque of the photoconductor drive motor is 0.9 Nm, No abnormal image occurred in the solid image and the halftone image after the mode ended.

<Example 3>
In the same image forming apparatus as in Example 1, a developer filling mode was carried out in order to fill 480 g of developer. During the developer filling mode, the developing device 4 was continuously driven, and the photosensitive member 1 was stopped for 2.5 sec and repeatedly driven for 0.534 sec 10 times to complete the developer filling. In the intermittent drive of the photoconductor 1 of the third embodiment, the photoconductor 1 makes almost one turn by one drive during the execution of the developer filling mode, and almost the same photosensitivity every time it is stopped as shown in FIG. The body surface faces the developing roller, and only this portion comes into contact with the developer more than the other portions. However, the total stop time is smaller than that when the motor is stopped all the time, and the surface of the photoconductor is not scratched or filming does not occur. Further, the cleaning blade 63a does not turn over during the developer filling mode, and the torque of the photosensitive member driving motor is 0.9 Nm, and an abnormal image is generated in the solid image and the halftone image after the developer filling mode ends. There was no.

<Comparative Example 1>
In the same image forming apparatus as in Example 1, a developer filling mode was carried out in order to fill 480 g of developer. During the developer filling mode, the developing device 4 was continuously driven and the photosensitive member 1 was also continuously driven, and the developer filling was completed in about 30 seconds. FIG. 14 shows a drive timing chart of a development drive motor (not shown) and a photoreceptor drive motor (not shown). Further, when the photosensitive member is driven in the developer filling mode, a bias is applied to the photosensitive member 1 and the developing roller 5 so that the background potential becomes 100 V, but for inputting toner to the cleaning blade 63a. No image has been created. The cleaning blade 63a did not turn up during the developer filling mode. However, the torque of the photosensitive member driving motor is as high as 1.4 Nm, and no turning has occurred, but there is no room for turning. In addition, no abnormal image occurred in the solid image and the halftone image after completion of the developer filling mode.

<Example 4>
The developer storage unit shown in FIG. 5 includes a developing device including three developer transport paths, ie, a recovery transport path 7, a supply transport path 9, and a stirring transport path 10, attached to an Ricoh immagio MP C7500. In the developing device 4, the developing roller 5 has an outer diameter of 25 mm and rotates at a linear speed of 562 mm / sec. The gap between the developing roller 5 and the developing doctor 3 is set to 0.27 ± 0.03 mm, and the developer passing through the developing doctor 3 is a thin layer of 27 ± 3 mg / cm ² . The photosensitive member 1 has a diameter of 60 mm and rotates at a linear velocity of 352.8 mm / sec. The gap between the developing roller 5 and the photoreceptor 1 in the developing area is set to be 0.225 ± 0.025 mm.

  In the copying machine 100 under the above conditions, a developer filling mode was carried out in order to fill 650 g of developer. During the developer filling mode, the developing device 4 was continuously driven, and the photosensitive member 1 was stopped for 2 seconds and repeated for 2 seconds 10 times, and the developer filling was completed over 40 seconds.

  In the intermittent driving of the photosensitive member 1 of the fourth embodiment, the surface of the photosensitive member is opposed to the developing roller 5 at a position as shown in FIG. Contact with a width of 3 mm. Due to this intermittent drive, the total photosensitive member drive time is shortened. Furthermore, the position where the surface of the photoreceptor 1 is in contact with the developer can be shifted, and the time during which the specific surface of the photoreceptor 1 is in contact with the developer can be shortened. In addition, although the position where the developer contacts on the photoreceptor 1 may be close, the same surface does not contact the developer more than once during the developer filling mode.

Further, when the photosensitive member is driven in the developer filling mode, a bias is applied to the photosensitive member 1 and the developing roller 5 so that the background potential is 100V. Further, from the third driving of the photoconductor, a toner image was formed on the photoconductor 1 every time the photoconductor was driven. The toner image to be formed was a belt-like toner image having a length of 22 mm in the circumferential direction in the entire longitudinal direction, and was formed with a developing potential at which the toner adhesion amount on the photosensitive member was about 0.5 g / cm ² . Such a toner image is input to the cleaning blade 63a. Since the developer conveying path of the developing device 4 of the fourth embodiment is longer than the developing device 4 used in the first, second, and third embodiments, the developer container is filled with the developer, and the balance is stabilized. The time will be longer. However, the cleaning blade 63a did not turn over during the developer filling mode of Example 4. Further, the torque of the photosensitive member driving motor was 0.8 Nm, and no abnormal image was generated in the solid image and the halftone image after completion of the developer filling mode.

<Comparative example 2>
In the same image forming apparatus as in Example 4, a developer filling mode was carried out in order to fill 650 g of the developer. During the developer filling mode, the developing device 4 was continuously driven and the photosensitive member 1 was continuously driven, and the developer filling was completed in about 40 seconds. Further, when the photosensitive member is driven in the developer filling mode, a bias is applied to the photosensitive member 1 and the developing roller 5 so that the background potential is 100V. Further, after 20 seconds from the start of the developer filling mode, a toner image was formed on the photoreceptor 1 every time it was driven. The toner image to be formed was a belt-like toner image having a length of 353 mm in the circumferential direction in the entire longitudinal direction, and was formed with a developing potential at which the toner adhesion amount on the photosensitive member was about 0.5 g / cm ² . Such a toner image is input to the cleaning blade 63a. For this reason, the cleaning blade 63a was not turned over during the developer filling mode, but the toner consumption was larger than that in Example 4. In Comparative Example 2, the photosensitive member 1 is also continuously driven while the developing roller 5 is being driven, and the developer does not contact only a specific surface of the photosensitive member 1, so that the photosensitive member 1 is not damaged. No abnormal image occurred in the solid image and the halftone image after completion of the developer filling mode.

<Example 5>
In the same image forming apparatus as in Example 4, a developer filling mode was carried out in order to fill 650 g of the developer. During execution of the developer filling mode, the developing device 4 was continuously driven, and the photosensitive member 1 was stopped for 3.35 seconds and driven for 0.65 seconds 10 times to complete the developer filling. In the intermittent drive of the photoconductor 1 of Example 5, the surface of the photoconductor faces the developing roller 5 at a position as shown in FIG. 15E and contacts the developer on the developing roller 5 with a width of about 3 mm. The position where the surface of the photoreceptor 1 is in contact with the developer can be shifted, and the time during which the specific surface of the photoreceptor 1 is in contact with the developer can be shortened. Further, the same surface does not come into contact with the developer more than once during the developer filling mode.

Further, when the photosensitive member is driven in the developer filling mode, a bias is applied to the photosensitive member 1 and the developing roller 5 so that the background potential is 100V. Further, from the third driving of the photoconductor, a toner image was formed on the photoconductor 1 every time the photoconductor was driven. The toner image to be formed was a belt-like toner image having a length of 5 mm in the circumferential direction in the entire longitudinal direction, and was formed with a developing potential at which the toner adhesion amount on the photosensitive member was about 0.5 g / cm ² . Such a toner image is input to the cleaning blade 63a. The cleaning blade 63a was not turned up during the developer filling mode of Example 5. In the fifth embodiment, the amount of toner input to the cleaning blade 63a is smaller than that in the fourth embodiment, but the torque of the photoreceptor driving motor is the same as 0.8 Nm. This is because the photosensitive member drive time is short, and even if the amount of toner input to the cleaning blade 63a is small, the frictional force between the photosensitive member and the cleaning blade 63a does not increase, and there is room for turning the blade. . On the other hand, although the photosensitive member stop time is longer than that in Example 4, it is not so long that the surface of the photosensitive member is damaged or filming occurs, so that the solid image and the halftone image after the end of the developer filling mode are abnormal. There was no generation of images.

<Example 6>
In the same image forming apparatus as in Example 4, a developer filling mode was carried out in order to fill 650 g of the developer. During the developer filling mode, the developing device 4 is continuously driven in the same manner as in the fifth embodiment, and the photosensitive member 1 is driven by 0.65 sec and stopped for 3.35 sec 10 times to fill the developer. Ended. For this reason, in the intermittent driving of the photosensitive member 1 of Example 6, the surface of the photosensitive member faces the developing roller 5 at a position as shown in FIG. 15E and contacts the developer on the developing roller 5 with a width of about 3 mm. To do. The position where the surface of the photoreceptor 1 is in contact with the developer can be shifted, and the time during which the specific surface of the photoreceptor 1 is in contact with the developer can be shortened. Further, the same surface does not come into contact with the developer more than once during the developer filling mode.

Further, when the photosensitive member is driven in the developer filling mode, a bias is applied to the photosensitive member 1 and the developing roller 5 so that the background potential is 150 V, but for inputting toner to the cleaning blade 63a. No image has been created. Even under the conditions of Example 6, the cleaning blade 63a was not turned up during the developer filling mode. Further, the torque of the photosensitive member driving motor was 0.8 Nm, which is the same as that in Example 5, and had a sufficient margin for turning over. As in the sixth embodiment, the photosensitive member is driven intermittently, and when the total driving time is short, the photosensitive member can be used even if the amount of toner adhering to the background portion is not increased without forming the toner image. This is sufficient as an amount of toner for preventing the frictional force between No. 1 and the cleaning blade 63a from increasing. In addition, no abnormal image occurred in the solid image and the halftone image after completion of the developer filling mode.

  As described above, according to the present embodiment, the image forming apparatus has a developer filling mode in which the developer is filled in the developer container from the developer bottle 180 in a state where the photoreceptor 1 and the developing device 4 are mounted in the device. In FIG. 5, during the developer filling mode, the developing device 4 is continuously driven and the photosensitive member 1 is intermittently driven. Since the developing device 4 is continuously driven to fill the developer while continuously operating the developer conveying member in the developer containing portion, the developer can be filled in a short time in the developer containing portion. . For this reason, the developer filling mode itself can be shortened. Further, the photosensitive member 1 is driven in the developer filling mode to prevent the developer attached to the developing roller 5 from coming into contact with a specific portion of the photosensitive member 1 for a long time and damaging the photosensitive member 1. At this time, by intermittently driving the photosensitive member, the photosensitive member 1 and the cleaning blade 63a can be kept from rubbing for a long time so that the blade is hardly turned over. For this reason, blade turning can be suppressed without relying on toner input to the cleaning blade 63a which has been conventionally performed to suppress blade turning, and wasteful toner consumption can be suppressed.

  According to the present embodiment, the photosensitive member 1 is driven so that the same portion of the photosensitive member 1 does not face the developing roller 5 when the photosensitive member 1 is intermittently stopped during the developer filling mode. This prevents the surface of the photoreceptor facing the developing roller from concentrating on a specific portion when the photoreceptor is stopped. By changing the portion facing the developing roller 5 without deviation when the photosensitive member is stopped, the area in contact with the developer on the surface of the photosensitive member 1 increases, but the contact time with the developer is dispersed and reduced. For this reason, it is possible to effectively suppress scratches caused by the developer coming into contact with the photoreceptor 1.

  Further, according to the present embodiment, the intermittent stop time of the photoreceptor 1 during the developer filling mode is made longer than the intermittent drive time. As described above, when the photosensitive member 1 is intermittently driven and the surface of the photosensitive member facing the developing roller 5 is not biased to a specific portion, the surface of the photosensitive member is hardly damaged when the photosensitive member is stopped. For this reason, even if the stop time is longer than the drive time, it is difficult to be damaged. As a result, the driving time of the photosensitive member 1 is relatively shortened, and the blade can be hardly turned over.

  Further, according to the present embodiment, a toner image to be supplied to the cleaning blade 63a is formed on the photosensitive member 1 when the photosensitive member 1 is intermittently driven. As a result, blade turning is less likely to occur. Also in this case, the amount of toner input to the cleaning blade 63a can be smaller than that in the case where the photosensitive member 1 is continuously driven, so that wasteful toner consumption can be suppressed.

  Further, according to the present embodiment, the photosensitive member is driven one or more times during one intermittent driving of the photosensitive member 1. If the driving time of the photosensitive member is too short, it is difficult to control, and the surface of the photosensitive member may not actually move even if driven. For this reason, the same surface of the photoconductor may be in contact with the developer for a long time. Therefore, the photosensitive member 1 can be easily adjusted so that the same surface does not face the developing roller 5 by rotating it one or more times.

  Further, according to this embodiment, when the photosensitive member 1 is intermittently driven, the background portion potential of the photosensitive member 1 is made larger than the background portion potential at the time of image formation. When the background potential is increased to increase the background potential, the amount of toner adhering to the background increases, so that a certain amount of toner can be input to the cleaning blade without forming a toner image. In this embodiment, since the driving time during execution of the developer filling mode is short, blade turning can be prevented with this amount of toner supply.

  Further, according to the present embodiment, the developer accommodating portion of the developing device 4 includes three developer conveyance paths including a collection conveyance path 7, a supply conveyance path 9, and an agitation conveyance path 10. A developer conveying member is provided. Since the developing device 4 having such a configuration has a long developer conveyance path and is unidirectionally circulated, it takes time to achieve a balanced state of the developer. In this way, it is particularly effective in a developing device that tends to take a long time to complete the developer filling, and it is possible to suppress damage to the latent image carrier and the cleaning blade while suppressing unnecessary toner consumption.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Discharge conveyance path 2a Discharge screw 3 Developing doctor 4 Developing apparatus 5 Developing roller 6 Collection screw 7 Collection conveyance path 8 Supply screw 9 Supply conveyance path 10 Stirring conveyance path 11 Stirring screw 12 Supply collection screw 13 Supply collection conveyance path 17 Intermediate transfer unit 18 Process cartridge 21 Optical writing unit 22 Secondary transfer device 25 Fixing device 33 Toner bottle 34 Toner supply device 49 Registration roller pair 61 Charger 62 Primary transfer bias roller 63 Cleaning means 63a Cleaning blade 63b Cleaning roller 80 Developer Storage means 91 Supply opening 92 Surplus opening 94 Discharge opening (developer discharge port)
95 Toner supply port 96 Circulation opening 100 Copying machine 110 Intermediate transfer belt 133 First partition wall 134 Second partition wall 135 Discharge partition wall 136 Partition wall 144 Intermediate belt contact / separation mechanism 150 Printer unit 180 Developer bottle 200 Paper feeding device

JP 2009-122619 A

Claims (7)

A developer accommodating portion for accommodating a developer composed of a carrier and a toner, a developer conveying member for conveying the developer in the developer accommodating portion, and carrying the developer to a portion facing the latent image carrier. And a developing device having a developer carrier that develops the latent image on the latent image carrier, and a cleaning blade that contacts the surface of the latent image carrier and removes deposits. A developer filling mode in which the developing device and the latent image carrier are driven in a state where the body and the developing device are mounted in the device to fill the developer container with the developer from the developer filling container. In the image forming apparatus,
An image forming apparatus, wherein the developing device is continuously driven during the developer filling mode, and the latent image carrier is intermittently driven.   2. The image forming apparatus according to claim 1, wherein when the latent image carrier is stopped intermittently during execution of the developer filling mode, the latent image carrier is arranged so that the same portion of the latent image carrier does not face the developer carrier. An image forming apparatus for driving a body.   3. The image forming apparatus according to claim 2, wherein an intermittent stop time of the latent image carrier is longer than an intermittent drive time.   4. The image forming apparatus according to claim 1, wherein a toner image to be supplied to the cleaning blade is formed on the latent image carrier when the latent image carrier is intermittently driven. Image forming apparatus.   5. The image forming apparatus according to claim 1, wherein the latent image carrier is driven one or more times during one intermittent drive of the latent image carrier. .   6. The image forming apparatus according to claim 1, wherein, when the latent image carrier is intermittently driven, the background potential of the latent image carrier is made larger than the background potential at the time of image formation. An image forming apparatus.   7. The image forming apparatus according to claim 1, wherein the developer accommodating portion includes a developer stirring conveyance path, a developer supply conveyance path, and a developer collection conveyance path. An image forming apparatus comprising a developer conveying member in the conveying path.

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