JP2011197219A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of a transfer type image forming device, which scrapes toner remaining on a development roller by a feed roller during development, that the toner cannot be fully removed and thus an afterimage of the development roller cycle is generated.SOLUTION: An image forming device includes: a development roller 8 to which a development voltage V1 is applied and which feeds toner in contact with a photoreceptor drum 51; a feed roller 9 to which a feed voltage V2 is applied and which feeds toner in contact with the development roller 8; a toner containing part for storing toner to be fed to the feed roller 9; a collecting roller 11 to which collection voltage is applied and which collects development residual toner from the development roller 8 in contact with the development roller 8; and a collection roller cleaning member 12 which cleans the collection roller 11.

Description

  The present invention relates to an image forming apparatus such as a printer or a copying machine using an electrophotographic system, and more particularly to a developing device thereof.

  Conventionally, in an image forming apparatus, the surface of a photosensitive drum uniformly charged by a charging device is exposed by an exposure device to form an electrostatic latent image, and the electrostatic latent image is developed by a developing device to be formed on the photosensitive drum. A method of forming a toner image and then transferring and fixing the toner image onto a sheet is performed. At this time, in the developing device, the toner supplied from the toner cartridge is supplied to the developing roller by the supply roller, and a uniform toner layer is formed on the developing roller by the regulating blade to form an electrostatic latent image on the photosensitive drum. Is developing. The toner remaining on the developing roller during development is scraped off by a supply roller (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2002-108090 (first page, FIG. 4)

  However, in the apparatus having the above configuration, the toner remaining on the developing roller at the time of development is scraped off by the supply roller. However, since the toner cannot be completely removed, there is a problem that an afterimage of the developing roller cycle occurs. An object of the present invention is to provide a developing device and an image forming apparatus that can solve these problems and suppress the occurrence of afterimages in the developing roller cycle.

  The developing device according to the present invention includes a developer carrying member that is supplied with a developing voltage and that contacts the image carrying member to supply the developer, and a supply voltage that is applied to the developer carrying member to bring the developer into contact with the developer carrying member. A supply member to be supplied, a developer storage section for storing a developer to be supplied to the supply member, and a recovery voltage is applied to recover the developer from the developer carrier in contact with the developer carrier. It has a member and the cleaning member which cleans the said collection | recovery member, It is characterized by the above-mentioned.

  According to the present invention, it is possible to eliminate the above-mentioned problems and to sufficiently remove the toner remaining on the developing roller at the time of development, thereby suppressing the occurrence of a residual image in the developing roller cycle.

1 is a main part configuration diagram schematically showing a main part configuration of Embodiment 1 of an image forming apparatus including a developing device according to the present invention; FIG. 2 is a main part configuration diagram schematically showing a main part configuration of a developing unit of a developing unit together with a photosensitive drum in the first embodiment. It is a perspective view which shows the positional relationship of a developing roller, a supply roller, and a collection | recovery roller. It is the schematic which shows the example which applied sponge to the developing roller. FIG. 4 is a main part configuration diagram schematically showing a main part configuration of a developing device according to a second embodiment of the present invention together with a photosensitive drum 51;

Embodiment 1 FIG.
FIG. 1 is a main part configuration diagram schematically showing the main part configuration of Embodiment 1 of an image forming apparatus equipped with a developing device according to the present invention.

  The image forming apparatus 1 shown in FIG. 1 has a configuration as a tandem color electrophotographic printer of a direct transfer type, and a paper feed tray 23 for storing recording paper 25 as a recording medium is mounted inside the apparatus, and recording is performed. A hopping roller 33 that picks up the paper 25 from the paper feed tray 23 and a registration roller 31 that corrects the skew of the recording paper 25 and conveys it to the image forming unit are arranged. Further, in the image forming apparatus 1, as an image forming unit, a developing unit 61 that forms an image of toner as a developer of each color of black (K), yellow (Y), magenta (M), and cyan (C). ˜64 are arranged in order from the upstream side along the conveyance path of the recording paper 25. These developing units have the same configuration except that toner of a predetermined color is used.

  For example, as shown in a developing unit 61 that uses black (K) toner, each developing unit includes a photosensitive drum 51 as an image carrier, and a charging roller 52 that supplies and charges the surface of the photosensitive drum 51 to charge. The surface of the charged photosensitive drum 51 is selectively irradiated with light based on image data to form an electrostatic latent image, and the electrostatic latent image formed on the photosensitive drum 51 The developer 54 that forms a toner image by developing with toner, the transfer roller 26 that transfers the toner image formed on the photosensitive drum 51 onto the recording paper 25, and the non-transferred toner remains on the photosensitive drum 51. A cleaning device 56 for scraping and discarding the toner and waste toner moved from the developing unit 54 onto the photosensitive drum 51 is provided.

  Further, in the image forming apparatus 1, as a belt unit, the transfer belt 22 that is sandwiched between the respective photosensitive drums 51 and the transfer roller 26 and conveys the recording paper 25, and is rotated by a drive unit (not shown) to perform an endless transfer. A drive roller 20 that drives the belt 22 in the direction of the arrow, an idle roller 21 that forms a pair with the drive roller 20 and stretches the transfer belt 22, and a belt cleaning device 24 that scrapes and cleans toner adhering to the transfer belt 22. Is arranged. Then, the fixing device 30 for fixing the toner image formed on the recording paper 25 by applying heat and pressure, the recording paper 25 that has passed through the fixing device 30 is conveyed, and the recording paper 25 on which the image has been fixed is removed. A discharge roller 32 that discharges to the discharge section 34 that stores is disposed.

  Note that the X, Y, and Z axes in FIG. 1 take the X axis in the transport direction when the recording paper 25 passes through the developing units 61 to 64, and the Y axis in the rotational axis direction of each photosensitive drum 51. The Z-axis is taken in a direction perpendicular to these two axes. Moreover, when each axis | shaft of X, Y, and Z is shown in the other figure mentioned later, these axial directions shall show a common direction. That is, the XYZ axes in each figure indicate the arrangement direction when the depicted portion of each figure constitutes the image forming apparatus 1 shown in FIG. Here, it is assumed that the Z-axis is arranged in a substantially vertical direction.

  FIG. 2 is a main part configuration diagram schematically showing a main part configuration of the developing device 54 of the developing unit 61 together with the photosensitive drum 51.

  The developing device 54 is a device for developing the electrostatic latent image formed on the photosensitive drum 51 with toner. The developing roller 8 serving as a developer carrying member, and a supply arranged so as to be in contact with the developing roller 8 A supply roller 9 as a member, a regulating blade 10 arranged to press the tip portion against the developing roller 8, a collecting roller 11 as a collecting member arranged to contact the developing roller 8, and the surface of the collecting roller 11 A collecting roller cleaning member 12 as a cleaning member for scraping off the toner, and a stirring member 13 for mixing the toner scraped off by the collecting roller cleaning member 12 with the toner on the upper portion of the supply roller 9, and serving as a developer storage unit The container 16 is configured to be supplied with toner from above the supply roller 9 by a toner cartridge (not shown). It is placed in contact with the surface of the photosensitive drum 51.

  As shown in FIG. 2, the collecting roller 11 is downstream of the contact portion between the developing roller 8 and the photosensitive drum 51 and from the contact portion between the developing roller 8 and the supply roller 9 with respect to the rotation direction of the developing roller 8. It is located upstream and is further arranged below the supply roller 9 in the direction of gravity. In this way, by disposing the collection roller 11 below the supply roller 9, the toner falling from above to the contact portion between the development roller 8 and the supply roller 9 is received by the contact portion between the development roller 8 and the supply roller 9. In other words, by supplying sufficient toner to the developing roller 8, it becomes possible to avoid fading.

FIG. 3 is a perspective view showing the positional relationship between the developing roller 8, the supply roller 9, and the collection roller 11. As shown in the figure, each roller has its rotation shaft extending in parallel with the rotation shaft of the photosensitive drum 51, the width of the roller portion of the developing roller 8 in the longitudinal direction (axial direction) is L 1, and the supply roller 9. When the width in the longitudinal direction (axial direction) of the roller portion is L2, the width in the longitudinal direction of the roller portion of the collecting roller 11 is L3, and the width of the image forming region (printing region) is W1, here,
L1>L2> W1,
L1>L3> W1
The width centers are arranged so as to substantially overlap each other. Thereby, the toner in the developing device 54 can be easily prevented from leaking to the outside by a method such as applying a sponge to the developing roller 8.

  FIG. 4 is a schematic view showing an example in which the sponge 18 is applied. As shown in the figure, the plate-like sponge 18 is placed in contact with both ends of the roller portion of the developing roller 8 that are not in contact with the other roller portions so that the roller portion of the supply roller 9 is sandwiched between them. The toner around the roller 9 can be prevented from leaking outside.

  The photosensitive drum 51 is rotationally driven in the direction of an arrow by a drum driving gear (not shown), and the drum driving gear is rotationally driven by a drum motor (not shown). The charging roller 52 (FIG. 1) is rotationally driven in the direction of the arrow by friction transmission with the surface of the photosensitive drum 51. The developing roller 8 (FIG. 2) is rotationally driven in the direction of the arrow by the gear transmission from the photosensitive drum 51, and the supply roller 9 (FIG. 2) is rotated in the direction of the arrow by the gear transmission from the developing roller 8 through the idle gear. Driven, the collection roller 11 (FIG. 2) is rotationally driven in the direction of the arrow by gear transmission from the supply roller 9 via the idle gear. The stirring member 13 (FIG. 2) is rotationally driven in the direction of the arrow by gear transmission from the collection roller 11 via an idle gear, for example. Here, the rotation direction of the stirring member 13 is the same as that of the collection roller 11, but is not limited thereto.

  Here, the developing roller 8 rotates in the reverse direction with respect to the photosensitive drum 51 at a linear speed ratio of 1.6 times, and the supply roller 9 rotates in the same direction with respect to the developing roller 8 at a linear speed ratio of 1.2 times. The collection roller 11 rotates in the reverse direction with respect to the developing roller 8 at a linear speed ratio of 1.0. However, these linear speed ratios are not limited to this.

  Next, the material and configuration of each part will be further described.

  First, the toner used in this embodiment will be described. The toner used in the present embodiment is obtained by, for example, adding silica and titanium oxide fine powder to toner particles formed by mixing and aggregating a styrene acrylic copolymer resin, a colorant, and a wax produced by an emulsion polymerization method. What was mixed with the mixer and used the thing with an average particle diameter of 6 micrometers. In the emulsion polymerization method, primary particles of the polymer that is the binder resin of the toner are prepared in an aqueous solvent, and the colorant emulsified with an emulsifier (surfactant) is mixed in the same solvent as the primary particles. Depending on the conditions, wax, charge control agent, etc. are mixed and agglomerated to create toner particles in the solvent. The toner particles are removed from the solvent, and unnecessary solvent components and by-product components are removed by washing and drying. Thus, the toner particles are obtained. Here, a styrene acrylic copolymer resin was produced from styrene, acrylic acid, and methylmethacrylic acid. As the colorant, carbon black was used as black, pigment yellow 74 was used as yellow, pigment red 238 was used as magenta, and pigment blue 15: 3 was used as cyan. Further, as the wax, stearyl stearate was used as a higher fatty acid ester wax.

  As the photosensitive drum 51, for example, a photosensitive drum 51 having a 0.5 μm-thick charge generation layer and a 18 μm-thick charge transport layer on an aluminum base tube having a thickness of 0.75 mm and an outer diameter of 30 mm was used. Charge generation materials used in the charge generation layer include selenium and its alloys, arsenic selenide compounds, cadmium sulfide, zinc oxide, other inorganic photoconductive materials, phthalocyanines, azo dyes, quinacridones, polycyclic quinones, pyrylium salts, thiapyrylium Various organic pigments and dyes such as salt, indigo, thioindigo, anthrone, pyranthrone, and cyanine are desirable. Examples of the charge transport material used in the charge transport layer include heterocyclic compounds such as carbazole, indole, imidazole, oxazole, pyrazole, oxadiazole, pyrazoline, thiadiazole, aniline derivatives, hydrazone compounds, aromatic amine derivatives, An electron donating substance such as a stilbene derivative or a polymer having a group composed of these compounds in the main chain or side chain is desirable.

  The charging roller 52 is a device for uniformly charging the surface of the photosensitive drum 51. For example, the charging roller 52 is coated with a conductive elastic body such as epichlorohydrin around a conductor such as stainless steel. It is arranged to touch.

  The LED head 53 is an exposure device for selectively exposing the surface of the uniformly charged photosensitive drum 51 to form an electrostatic latent image pattern, and includes an LED element, an LED driving element, and a lens array. The irradiation light from the LED element is arranged at a position where it forms an image on the surface of the photosensitive drum 51.

  The developing roller 8 (FIG. 2) has, for example, a configuration in which an elastic layer is arranged in a roll shape on a conductive shaft (core metal) made of a SUM material (free-cutting steel material) and has a surface layer covering the elastic layer, It arrange | positions so that the photoreceptor drum 51 may be contacted. For the elastic layer, urethane rubber or silicone rubber was used, and for the surface layer, one treated with a urethane solution or one coated with acrylic resin or acrylic-fluorine copolymer resin was used. In order to impart conductivity to the surface layer of the acrylic resin and the acrylic-fluorine copolymer resin, carbon black was blended, and the blending amount was 1 part by weight with respect to 100 parts by weight of the acrylic resin component. .

  The supply roller 9 (FIG. 2) is formed of, for example, a conductive shaft (core metal) made of a SUM material and an elastic layer, and is disposed so as to contact the developing roller 8. This elastic layer is a conductive silicone rubber foam layer or a conductive urethane rubber foam layer. When the elastic layer has semiconductivity, acetylene black or carbon black is added.

  The regulating blade 10 (FIG. 2) is made of, for example, SUS (stainless steel) having a thickness of 0.08 mm, and the contact portion with the developing roller 8 is bent, and the curvature radius R of the bent portion is 0.2 mm. The linear pressure on the developing roller 8 was 30 gf / cm. However, the radius of curvature R and the linear pressure of the regulating blade 10 are not limited to this, and can be adjusted according to the toner charge amount.

  The collection roller 11 (FIG. 2) uses, for example, a conductive material obtained by nickel plating a SUM material and is disposed so as to contact the developing roller 8. By using a metal for the collection roller 11, the load on the developing roller 8 can be reduced, and the smoothness of the surface of the collection roller 11 can be increased to reduce the friction coefficient, so that the toner adhering to the surface of the collection roller 11 is collected. When scraping off with the roller cleaning member 12, the toner can be easily scraped off. Here, the collection roller 11 is made of metal, but the material is not limited to this as long as it is conductive, has high smoothness, and is excellent in durability.

  The collection roller cleaning member 12 (FIG. 2) is constituted by, for example, a rubber blade and is disposed so that the tip of the rubber blade is brought into contact with the surface of the collection roller 11. The stirring member 13 (FIG. 2) is the same as the collection roller 11. The SUM material is a nickel-plated conductive material. The transfer roller 26 (FIG. 1) is made of, for example, a conductive shaft and a conductive foaming elastic body, and the cleaning device 56 is formed of, for example, a rubber blade so that the tip of the rubber blade is brought into contact with the surface of the photosensitive drum 51. Is arranged.

  In the above configuration, the operation of the printing process of the image forming apparatus 1 will be described with reference to FIGS.

  The surface of the photosensitive drum 51 of each developing unit 61 to 64 is uniformly charged by a charging roller 52 to which a charging voltage is applied by a power supply device (not shown). The LED head 53 emits light according to the image data, and selectively exposes the uniformly charged surface of the photosensitive drum 51 to form an electrostatic latent image. On the other hand, the supply roller 9 supplies surrounding toner to the developing roller 8, and the regulating blade 10 thins the toner adhering to the surface of the developing roller 8 to form a uniform toner thin layer on the surface of the developing roller 8. To do.

  The developing roller 8 having the toner thin layer formed on the surface in this manner is applied with the developing voltage V1 to develop the electrostatic latent image formed on the surface of the photosensitive drum 51 to form a toner image. At this time, in order to uniformly form a toner thin layer on the developing roller 8 on the supply roller 9 and the regulation blade 10 and to set the charge amount of the toner in the toner thin layer to a predetermined value, the supply voltage V2 and the regulation blade voltage V3 is applied.

  On the other hand, the recording paper 25 stored in the paper feed tray 23 is taken out of the paper feed tray 23 by the hopping roller 33 and corrected for skew by the registration roller 31 and the transfer belt 22 driven in the direction of the arrow. It is conveyed to the vicinity of the transfer roller 26 of the developing unit 61. When the photosensitive drum 51 rotates and the toner image on the surface of the photosensitive drum 51 obtained by development reaches the vicinity of the transfer roller 26 and the transfer belt 22, a voltage is applied by a power supply device (not shown). The toner image on the surface of the photosensitive drum 51 is transferred onto the recording paper 25 by the transfer roller 26 and the transfer belt 22. Each time the transfer of the toner image onto the recording paper 25 passes through the developing units 61 to 64 that form toner images of the respective colors of black (K), yellow (Y), magenta (M), and cyan (C). And a color image is formed on the recording paper 25 using toner of each color.

  Subsequently, the recording paper 25 having the toner image of each color formed on the surface is conveyed to the fixing device 30 by the rotation of the transfer belt 22. The toner image on the recording paper 25 is melted by being heated while being pressed by the fixing device 30 and fixed on the recording paper 25. Further, the recording paper 25 is discharged to the discharge portion 34 by the transport roller 32, and the image forming operation is completed. During this time, the transfer belt 22 after separating the recording paper 25 is cleaned by a belt cleaning device 24 that removes toner and other foreign matters remaining on the transfer belt 22.

  In the printing process described above, the development residual toner remaining on the surface of the developing roller 8 without moving to the photosensitive drum 51 during the development described above is attracted to the collecting roller 11 set at a predetermined potential described later and collected. Further, the toner is scraped off from the recovery roller 11 to the toner receiver 14 by the recovery roller cleaning member 12. The development residual toner scraped off by the toner receiving portion 14 is mixed with the toner above the supply roller 9 by the toner stirring member 13 disposed above the toner receiving portion 14, and again to the developing roller 8 by the supply roller 9. Supplied with.

  When the image forming apparatus 1 is operated in a room temperature and humidity environment using negatively chargeable toner, for example, the charging voltage is set to −1100V, the developing voltage V1 is −200V, and the supply voltage V2 is − 300V and the regulation blade voltage V3 are set to −300V. The surface of the photosensitive drum 51 is charged when a charging voltage of a predetermined value or more is applied to the charging roller 52, and the surface potential changes in proportion to the applied charging voltage. Here, when the charging voltage is applied as −1100V, the surface potential of the photosensitive drum 51 becomes about −600V. Then, the latent image potential of the electrostatic latent image formed by the selective exposure by the light emission of the LED head 53 is about -50V, and development in which a DC voltage of -200V is applied to this electrostatic latent image portion. The roller 8 causes the toner to adhere and develop at the contact portion with the photosensitive drum 51 to form a toner image. In the case of positively chargeable toner, the sign of each voltage is reversed.

  Since the collection roller 11 collects the development residual toner from the developing roller 8 by electric force, it is necessary to apply a collection voltage having a polarity opposite to the charging polarity of the toner to the collection roller 11. Here, the recovery roller 11 is dealt with by grounding it through a resistor.

  A stirring voltage V4 is applied to the stirring member 13. The stirring voltage V4 is set so as to have the same polarity and a larger absolute value than the supply voltage V2. The development residual toner collected by the collection roller cleaning member 12 is liable to cause a charging failure such as reverse charging or a decrease in the charge amount. However, when the stirring voltage V4 is applied, the collected toner is moved upward by the stirring member 13. Since it is negatively charged when it is sent to the printer, printing defects do not occur. Here, the stirring voltage V4 was set to -350V.

  As described above, according to the developing device of the present embodiment, the recovery roller 11 sufficiently removes the development residual toner that has not been developed from the development roller 8 to the photosensitive drum 1 by the recovery roller 11. It is possible to obtain an effect of suppressing an afterimage that occurs in a cycle. Further, the development residual toner removed and collected by the developing roller 8 can be reused without causing defective printing.

Embodiment 2. FIG.
FIG. 5 is a main part configuration diagram schematically showing a main part configuration of the developing device 154 according to the second embodiment of the present invention together with the photosensitive drum 51. The developing unit 154 is mainly different from the developing unit 54 of the first embodiment shown in FIG. 2 in that instead of the stirring member 13 (FIG. 2), a recovered toner transfer spiral 71, a recovered toner transfer screw 72, The collected toner storage unit 73, the separation wall 74 including the shutter 74 b, and the partition plate 75 are provided. Therefore, in the image forming apparatus adopting the developing unit 154, the same reference numerals are given to the parts common to the image forming apparatus 1 (FIG. 1) of the first embodiment described above, or the description is omitted with the drawing omitted. And focus on the differences.

  As shown in FIG. 5, the inside of the developing device 154 is separated by a separation wall 74 having a shutter 74b into a recovered toner storage portion 73 positioned above and a toner accommodating portion 77 positioned below, and further, a supply roller 9 A partition plate 75 disposed between the collecting roller 11 and the collecting roller 11 divides the toner containing portion 77 into a toner retaining portion 76 located below the toner containing portion 77. Here, the collected toner storage unit 73 and the toner storage unit 77 positioned below correspond to the developer storage unit.

  The toner scraped off by the collecting roller cleaning member 12 stays in an area substantially corresponding to the width of the roller portion of the collecting roller 11 in the toner staying portion 76. The toner retaining portion 76 is separated from the toner accommodating portion 77 by a partition plate 75, and is configured so that the toner in the toner accommodating portion 77 does not enter the toner retaining portion 76. The collected toner conveying spiral 71 is provided in the toner retaining portion 76 and extends over a region substantially corresponding to the width of the roller portion of the collecting roller 11, and is scraped off by the collecting roller cleaning member 12 to be stored in the toner retaining portion 76. The toner staying in the toner is conveyed to one side surface thereof, for example, the side surface portion in the positive direction of the Y axis (upward on the paper surface).

  The collected toner conveying screw 72 is provided on the side surface portion in the same direction so as to extend from the toner retaining portion 76 to the uppermost portion of the collected toner storage portion 73 in the Z-axis direction (vertical direction). The development residual toner staying at 76 and collected on the side surface by the collected toner conveying spiral 71 is further conveyed vertically upward, and the inside of the collected toner storage unit 73 is discharged from an outlet 72 a formed at the upper part of the collected toner storage unit 73. To release.

  The shutter 74b opens and closes the opening 74a formed in the separation wall 74 by sliding movement. For example, the shutter 74b is configured to be openable and closable by the user from the outside of the developing device 154 by an operating unit (not shown). Then, the shutter 74b is opened when the developed toner remaining in the collected toner storage unit 73 is reused, and the shutter 17 is closed when the developed toner is to be discarded. Note that the collected toner storage unit 73 may be provided, for example, in the half of the developing device 154 in the width direction (X-axis direction) on the side where the collected toner transport spiral 71 is disposed. The toner can be supplied from above the supply roller 9 by a toner cartridge (not shown).

  As described above, according to the developing device of the present embodiment, the undeveloped toner collected by the collecting roller 11 is moved to the collected toner storage unit located above the toner containing unit 77, so that the shutter 74b is opened. When the undeveloped toner is reused, the undeveloped toner does not stay in the developing device and is uniformly mixed, so that it is possible to prevent fog and graininess from deteriorating.

  In the present embodiment, the direct transfer type tandem color electrophotographic printer has been described as an example. However, it may be employed in an indirect transfer type printer in which the image is once transferred to a transfer belt and then transferred to a recording medium. Various aspects are possible.

  In each of the above-described embodiments, the case where the image forming apparatus is an electrophotographic printer has been described. However, the present invention is not limited to this, and the present invention is also applicable to a facsimile machine, a copier, a multi-function machine having them in combination, and the like. Is possible.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus, 8 Developing roller, 9 Supply roller, 10 Control blade, 11 Collection roller, 12 Collection roller cleaning member, 13 Stirring member, 14 Toner receiving part, 16 Toner storage part, 18 Sponge, 20 Drive roller, 21 Idle Roller, 22 Transfer belt, 23 Feed tray, 24 Belt cleaning device, 25 Recording paper, 26 Transfer roller, 30 Fixing device, 31 Registration roller, 33 Hopping roller, 34 Ejecting section, 51 Photosensitive drum, 52 Charging roller, 53 LED head, 54 developing device, 56 cleaning device, 61 developing unit, 62 developing unit, 63 developing unit, 64 developing unit, 71 recovered toner transport spiral, 72 recovered toner transport screw, 72a discharge port, 73 recovered toner storage unit, 7 Separation wall, 74a opening, 74b shutter, 75 partition plate, 76 a toner retention part, 77 toner containing section, 154 developing device.

Claims (15)

A developer carrying body to which a developing voltage is applied and which supplies the developer in contact with the image carrying body;
A supply member to which a supply voltage is applied and which supplies the developer in contact with the developer carrier;
A developer storage section for storing a developer to be supplied to the supply member;
A recovery member to which a recovery voltage is applied and which contacts the developer carrier and recovers the developer from the developer carrier;
And a cleaning member that cleans the recovery member.   The developing device according to claim 1, wherein both the developer carrying member and the collecting member have a roller shape.   With respect to the rotation direction of the developer carrier, the developer carrier is downstream from the contact portion between the image carrier and the developer carrier and upstream from the contact portion between the developer carrier and the supply member. The developing device according to claim 2, wherein a body and the recovery member are arranged to contact each other.   The developing device according to claim 3, wherein the recovery member is disposed vertically below the supply member.   5. The developer carrier according to claim 2, wherein the developer carrying member and the recovery member are in contact with each other on a peripheral surface and rotate so that the moving directions in the contact portion are the same direction. 6. Development device.   The developing device according to claim 1, wherein the recovery member is a metal roller.   The developing device according to claim 2, wherein a width of the roller portion in the rotation axis direction of the collecting member is shorter than a width of the roller portion in the rotation axis direction of the developer carrying member.   The developing device according to claim 1, wherein the cleaning member is a rubber blade.   The developing device according to claim 1, further comprising a stirring member that mixes the developer recovered by the recovery member with the developer in the developer storage unit.   The developing device according to claim 9, wherein the stirring member has conductivity.   The developing device according to claim 10, wherein a voltage having an absolute value larger than the recovery voltage is applied to the stirring member.   The developing device according to claim 1, further comprising a developer transport unit configured to transport the developer recovered by the recovery member to an upper part in the developer storage unit and discharge the developer.     13. The developing device according to claim 12, wherein a partition plate is provided so that the developer recovered by the recovery member and the developer in the developer storage section are not directly mixed.   14. The developing device according to claim 12, further comprising a recovered developer accommodating portion that is disposed in an upper portion of the developer storage portion and accommodates the recovered developer discharged from the developer conveying portion. . An image forming apparatus comprising the developing device according to claim 1.

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