JP2019124721A - Developing device and image forming device equipped therewith - Google Patents

Abstract

To provide a developing device with which it is possible to efficiently collect toners accumulated in the periphery of blade in a developing container and toners accumulated in a seal member provided in an opening of the developing device that faces an image carrier, and an image forming device equipped with the developing device.SOLUTION: The developing device comprises a developing roller, a toner supply roller, a restricting blade, a developing container, a toner receiving support member, a toner receiving member, a vibration generator, and a seal member. The toner receiving support member is arranged in the developing container, and faces the developing roller or the toner supply roller between the restricting blade and an image carrier. Th toner receiving member is arranged along the longitudinal direction of the toner receiving support member and receives toner dropping from the developing roller. The vibration generator causes the toner receiving member to vibrate. At an edge on the image carrier side of the toner receiving member is fixed the seal member for preventing the leakage of toner from a gap between the image carrier and the developing container.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a developing device for supplying a developer to an image carrier and an electrophotographic image forming apparatus provided with the same.

  The electrophotographic image forming apparatus irradiates light based on image information read from a document image or image information transmitted from an external device such as a computer onto the peripheral surface of the image carrier (photosensitive drum). Form an electrostatic latent image. After a toner is supplied to the electrostatic latent image from the developing device to form a toner image, the toner image is transferred to a sheet. The sheet after the transfer processing is subjected to the fixing processing of the toner image and then discharged to the outside.

  In recent years, along with the progress of color printing and high-speed processing, the configuration of the image forming apparatus becomes complicated, and high-speed rotation of the toner stirring member in the developing device is required to cope with high-speed processing. In particular, in a developing method using a two-component developer containing a magnetic carrier and a toner and using a magnetic roller (toner supply roller) carrying a developer and a developing roller carrying only a toner, the developing roller and the magnetic roller In the opposite part of the above, only the toner is carried on the developing roller by the magnetic brush formed on the magnetic roller, and the toner not used for the development is pulled off from the developing roller. Therefore, scattering of toner tends to occur in the vicinity of the facing portion of the developing roller and the magnetic roller, and toner floating in the developing device is deposited around the ear cutting blade (regulating blade). When the accumulated toner is aggregated and adheres to the developing roller, the toner may be dropped and an image failure may occur.

  Therefore, for example, in Patent Document 1, in a developing device using a two-component developer containing a magnetic carrier and a toner, a developing roller using a magnetic roller carrying the developer and a developing roller carrying only the toner, Developing with a toner receiving and supporting member facing the roller, a toner receiving member disposed along the longitudinal direction of the toner receiving and supporting member and receiving the toner falling from the developing roller, and a vibration generating means for vibrating the toner receiving member An apparatus is disclosed.

JP 2012-208469 A

  A film-like seal member for preventing toner scattering is provided in contact with the surface of the image carrier at the opening of the developing device where the developing roller facing the photosensitive drum is exposed. The toner adhering to the seal member can not be completely shaken off by the vibration generated by the vibration generating means and is accumulated. As a result, the toner accumulated on the seal member is directly moved to the photosensitive drum, causing a problem of toner drop. In particular, toner is likely to be attached to the portion where the electrostatic latent image of the half image where the surface potential of the photosensitive drum is lowered, and toner contamination may occur during formation of the half image.

  SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a toner capable of efficiently collecting the toner deposited on the periphery of the blade in the developer container and the toner deposited on the seal member provided at the opening of the developing device facing the image carrier. An object of the present invention is to provide an apparatus and an image forming apparatus provided with the apparatus.

  In order to achieve the above object, according to a first aspect of the present invention, a developing roller, a toner supply roller, a regulating blade, a developing container, a toner receiving and supporting member, a toner receiving member, a vibration generating device, and a seal A developing device for developing the electrostatic latent image formed on the image carrier. The developing roller is disposed to face the image carrier on which the electrostatic latent image is formed, and supplies the toner to the image carrier in a region facing the image carrier. The toner supply roller is disposed to face the developing roller, and supplies toner to the developing roller in an area facing the developing roller. The regulating blade is disposed opposite to the toner supply roller at a predetermined interval. The developer container accommodates a developing roller, a toner supply roller, and a regulating blade. The toner receiving and supporting member is disposed in the developer container and faces the developing roller or the toner supply roller between the regulating blade and the image carrier. The toner receiving member is disposed along the longitudinal direction of the toner receiving support member, and receives the toner falling from the developing roller. The vibration generator vibrates the toner receiving member. The seal member prevents the toner from leaking from the gap between the image carrier and the developing container. A seal member is fixed to an edge of the toner receiving member on the image carrier side so as to be in contact with the image carrier.

  According to the first configuration of the present invention, by fixing the seal member to the edge of the toner receiving member on the image carrier side, when the toner receiving member is vibrated by the vibration generating device, the seal member as well as the toner receiving member vibrates. . As a result, it is possible to shake off the toner attached to the seal member, and it is possible to effectively suppress the toner drop due to the transfer of the toner attached to the seal member to the image carrier and the contamination of the half image.

Schematic structure of color printer 100 according to one embodiment of the present invention Side cross-sectional view of the developing device 3a according to the first embodiment of the present invention mounted on the color printer 100 The perspective view which looked at the toner receiving support member 35 used for development device 3a from the inside of development container 20 The perspective view which looked at the toner receiving member 37 supported by toner receiving support member 35 from the back side The perspective view which shows the internal structure of the vibration generator 40 with which the toner receiving member 37 is mounted | worn FIG. 10 is a side cross-sectional view of the vicinity of the toner receiving and supporting member 35 of the developing device 3 a according to the first embodiment, showing a cross section near the vibration motor 43. A partial enlarged view of the toner receiving and supporting member 35 in FIG. 6 Side surface sectional view showing a sectional structure in the vicinity of the vibration motor 43 of the toner receiving and supporting member 35 used in the developing device 3a according to the second embodiment of the present invention

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an image forming apparatus provided with developing devices 3a to 3d according to an embodiment of the present invention, and shows a tandem type color printer here. In the main body of the color printer 100, four image forming portions Pa, Pb, Pc and Pd are disposed in order from the upstream side in the transport direction (right side in FIG. 1). These image forming portions Pa to Pd are provided corresponding to images of four different colors (cyan, magenta, yellow and black), and cyan, magenta and yellow are formed by the respective steps of charging, exposure, development and transfer. And black images are sequentially formed.

  Photosensitive drums 1a, 1b, 1c, and 1d, which carry visible images (toner images) of the respective colors, are disposed in these image forming portions Pa to Pd, respectively. Further, in FIG. 1, an intermediate transfer belt 8 rotating clockwise is provided adjacent to each of the image forming portions Pa to Pd.

  When image data is input from a host device such as a personal computer, first, the surfaces of the photosensitive drums 1a to 1d are uniformly charged by the charging devices 2a to 2d. Next, light is irradiated according to the image data by the exposure device 5, and electrostatic latent images corresponding to the image data are formed on the respective photosensitive drums 1a to 1d. The developing devices 3a to 3d are each filled with a predetermined amount of a two-component developer including toners of respective colors of cyan, magenta, yellow and black by toner containers 4a to 4d. Toners in the developer are supplied onto the photosensitive drums 1a to 1d by the developing devices 3a to 3d and electrostatically adhere to the photosensitive drums 1a to 1d. Thus, a toner image corresponding to the electrostatic latent image formed by the exposure from the exposure device 5 is formed.

  Then, an electric field is applied between the primary transfer rollers 6a to 6d and the photosensitive drums 1a to 1d at a predetermined transfer voltage by the primary transfer rollers 6a to 6d, and cyan, magenta, yellow, and the like on the photosensitive drums 1a to 1d. The black toner image is primarily transferred onto the intermediate transfer belt 8. The toner and the like remaining on the surfaces of the photosensitive drums 1a to 1d after the primary transfer are removed by the cleaning devices 7a to 7d.

  A transfer sheet P to which a toner image is transferred is accommodated in a sheet cassette 16 disposed in the lower part of the image forming apparatus 100. The transfer sheet P is a nip portion between the secondary transfer roller 9 and the intermediate transfer belt 8 provided adjacent to the intermediate transfer belt 8 at a predetermined timing via the sheet feeding roller 12a and the registration roller pair 12b (secondary transfer nip To the department). The transfer sheet P on which the toner image is secondarily transferred is conveyed to the fixing unit 13.

  The transfer paper P conveyed to the fixing unit 13 is heated and pressed by the fixing roller pair 13a, the toner image is fixed on the surface of the transfer paper P, and a predetermined full-color image is formed. The transfer paper P on which the full color image is formed is discharged as it is (or after it is distributed to the reverse conveying path 18 by the branch portion 14 and the image is formed on both sides) by the discharge roller pair 15 to the discharge tray 17.

  FIG. 2 is a side sectional view of the developing device 3 a according to the first embodiment of the present invention mounted on the color printer 100. 2 shows a state as viewed from the back side of FIG. 1, and the arrangement of each member in the developing device 3a is reversed from that in FIG. Further, in the following description, the developing device 3a disposed in the image forming portion Pa of FIG. 1 is exemplified, but the configuration of the developing devices 3b to 3d disposed in the image forming portions Pb to Pd is basically the same. Therefore, the explanation is omitted.

  As shown in FIG. 2, the developing device 3 a includes a developing container (casing) 20 in which a two-component developer (hereinafter, also simply referred to as a developer) composed of toner and magnetic carrier is stored. The stirring and transfer chamber 21 and the supply and transfer chamber 22 are divided by the partition wall 20a. In the stirring and conveying chamber 21 and the feeding and conveying chamber 22, a stirring and conveying screw 25a for charging and charging the toner (positively charged toner) supplied from the toner container 4a (see FIG. 1) is mixed with the carrier and supplied and conveyed. The screws 25b are rotatably disposed.

  Then, while the developer is stirred by the stirring and conveying screw 25a and the feeding and conveying screw 25b, the developer is conveyed in the axial direction (the direction perpendicular to the sheet of FIG. 2) and passes through the developer (not shown) formed at both ends of the partition wall 20a. It circulates between stirring conveyance room 21 and supply conveyance room 22 via a path. That is, a circulation path of the developer is formed in the developing container 20 by the stirring and transfer chamber 21, the supply and transfer chamber 22, and the developer passage.

  The developing container 20 extends obliquely upward to the right in FIG. 2, and the toner supply roller 30 is disposed above the supply conveying screw 25 b in the developing container 20, and the developing roller is obliquely inclined to the right above the toner supply roller 30. 31 are arranged opposite to each other. The developing roller 31 faces the photosensitive drum 1a on the opening side (right side in FIG. 2) of the developing container 20, and the toner supply roller 30 and the developing roller 31 rotate counterclockwise in FIG. Rotate in the direction.

  In the stirring and conveying chamber 21, a toner concentration sensor 28 is disposed to face the stirring and conveying screw 25 a. The toner concentration sensor 28 detects the ratio (T / C) of the toner to the carrier in the developer, and for example, a permeability sensor that detects the permeability of the developer in the developing container 20 is used. In the present embodiment, the toner concentration sensor 28 detects the magnetic permeability of the developer, and outputs a voltage value corresponding to the detection result to the control unit 90 (see FIG. 3) described later. The toner density is determined from the output value of the toner density sensor 28 by 90. Control unit 90 transmits a control signal to a toner replenishing motor (not shown) according to the determined toner concentration, and a predetermined amount from toner container 4a to stirring and conveying chamber 21 via toner replenishing port (not shown) Toner is replenished.

  The toner supply roller 30 is composed of a nonmagnetic rotating sleeve that rotates in a counterclockwise direction in FIG. 2 and a fixed magnet body having a plurality of magnetic poles included in the rotating sleeve.

  The developing roller 31 is constituted by a cylindrical developing sleeve rotating in a counterclockwise direction in FIG. 2 and a developing roller side magnetic pole fixed in the developing sleeve, and the toner supply roller 30 and the developing roller 31 are the same. They face each other with a predetermined gap at the facing position (facing position). The developing roller side magnetic pole is different in polarity from the opposing magnetic pole (main pole) of the fixed magnet body.

  In addition, a brush cutter blade 33 is attached to the developing container 20 along the longitudinal direction of the toner supply roller 30 (the direction perpendicular to the sheet of FIG. 2), and the brush cutter blade 33 rotates in the rotational direction of the toner supply roller 30. In (the counterclockwise direction in FIG. 2), it is positioned upstream of the opposing position of the developing roller 31 and the toner supply roller 30. A slight gap is formed between the tip of the blade 33 and the surface of the toner supply roller 30.

  A DC voltage (hereinafter referred to as Vslv (DC)) and an AC voltage (hereinafter referred to as Vslv (AC)) are applied to the developing roller 31. A DC voltage (hereinafter referred to as Vmag (DC)) and an AC voltage (hereinafter referred to as Vmag (AC)) are applied to the toner supply roller 30. The direct current voltage and the alternating current voltage are applied from the developing bias power supply to the developing roller 31 and the toner supply roller 30 via a bias control circuit (neither is shown).

  As described above, while the developer is being stirred by the stirring and conveying screw 25a and the feeding and conveying screw 25b, the toner is charged by circulating through the stirring and conveying chamber 21 and the feeding and conveying chamber 22 in the developing container 20. The developer is supplied to the toner supply roller 30. Then, a magnetic brush (not shown) is formed on the toner supply roller 30. The magnetic brush on the toner supply roller 30 is regulated in layer thickness by the blade cutting blade 33, and then conveyed to the opposing portion of the toner supply roller 30 and the developing roller 31. The magnetic brush is in contact with the developing roller 31, and a potential difference ΔV between Vmag (DC) applied to the toner supply roller 30 and Vslv (DC) applied to the developing roller 31, and a magnetic thin layer on the developing roller 31 Form

  The layer thickness of the toner on the developing roller 31 changes depending on the resistance of the developer, the rotational speed difference between the toner supply roller 30 and the developing roller 31, and the like, but can be controlled by ΔV. When ΔV is increased, the toner layer on the developing roller 31 becomes thicker, and when ΔV is decreased, the toner layer becomes thinner. Generally, a range of about 100 V to 350 V is appropriate for the range of ΔV at the time of development.

  The thin toner layer formed on the developing roller 31 by the contact with the magnetic brush on the toner supply roller 30 is conveyed to the facing portion (facing region) of the photosensitive drum 1 a and the developing roller 31 by the rotation of the developing roller 31 Ru. Since Vslv (DC) and Vslv (AC) are applied to the developing roller 31, the toner flies due to the potential difference with the photosensitive drum 1a, and the electrostatic latent image on the photosensitive drum 1a is developed. .

  The toner remaining without being used for development is again conveyed to the opposing portion between the developing roller 31 and the toner supply roller 30, and is collected by the magnetic brush on the toner supply roller 30. Then, the magnetic brush is peeled off from the toner supply roller 30 at the same polarity part of the fixed magnet body, and then falls into the supply and conveyance chamber 22.

  Thereafter, based on the detection result of the toner concentration sensor 28, a predetermined amount of toner is replenished from a toner replenishing port (not shown), and while circulating through the supply / conveyance chamber 22 and the agitating / conveyance chamber 21 again uniformly with appropriate toner concentration. It becomes a charged two-component developer. The developer is again supplied onto the toner supply roller 30 by the supply and conveyance screw 25 b to form a magnetic brush, and is conveyed to the brush cutting blade 33.

  In the vicinity of the developing roller 31 on the right side wall in FIG. 2 of the developing container 20, a toner receiving and supporting member 35 having a triangular cross-sectional shape and projecting inside the developing container 20 is provided. As shown in FIG. 2, the toner receiving and supporting member 35 is disposed along the longitudinal direction of the developing container 20 (the direction perpendicular to the sheet of FIG. 2), and the upper surface of the toner receiving and supporting member 35 A wall portion facing the developing roller 31 and inclined downward from the developing roller 31 toward the toner supply roller 30 is configured. A toner receiving member 37 is attached to the upper surface of the toner receiving and supporting member 35 along the longitudinal direction to receive the toner that is pulled off from the developing roller 31 and falls.

  3 is a perspective view of the toner receiving and supporting member 35 used in the developing devices 3a to 3d according to the first embodiment as viewed from the inside (left side in FIG. 2) of the developing container 20. FIG. FIG. 7 is a perspective view of the toner receiving member 37 as viewed from the back side (the inner side of the toner receiving and supporting member 35).

  The toner receiving and supporting member 35 is attached to a resin supporting member main body 36, a sheet metal toner receiving member 37 swingably supported by the supporting member main body 36, and a substantially central portion of the toner receiving member 37 in the longitudinal direction. And a vibration generating device 40. The supporting member main body 36 is formed with a storage portion (not shown) in which the vibration generating device 40 is stored when the toner receiving member 37 is mounted.

  The toner receiving member 37 has a bending shape in which a bending portion 37a is formed along the longitudinal direction, and the toner receiving surface 37b facing the developing roller 31 (see FIG. 2) with the bending portion 37a interposed therebetween, and the toner supply roller 30 And a substantially vertical toner drop surface 37c facing the toner. At one end side of the toner receiving member 37 in the longitudinal direction, an engaging portion 38 is formed in which a contact spring 48 for grounding the toner receiving member 37 is engaged. The lower end portion of the contact spring 48 contacts the cutting blade 33 (see FIG. 2) via a conductive spring receiving member (not shown). A holding portion 39 having a pair of holding claws 39 a for holding the vibration generating device 40 is formed in a substantially central portion in the longitudinal direction of the toner receiving member 37. In the vibration generating device 40, a substrate 45 on which a circuit for controlling the drive of the vibration motor 43 (see FIG. 5) and an electronic component (not shown) are mounted is fixed by a screw 46.

  Further, the upper end of the toner receiving member 37 is bent upward to form a seal support portion 37d, and a film-like seal member 44 is provided on the seal support portion 37d. The seal member 44 extends in the longitudinal direction (left and right direction in FIG. 4) of the support member main body 36 so that the tip end portion contacts the surface of the photosensitive drum 1a, and the inside of the developer container 20 (see FIG. 2). It has a function of shielding toner from leaking out. The material of the seal member 44 may, for example, be a urethane sheet.

  Sheet members 41 a and 41 b are attached to the surface of the toner receiving member 37 (the surface facing the developing roller 31 or the toner supply roller 30). The sheet members 41 a and 41 b are formed of a material to which toner is less likely to adhere than the toner receiving member 37 in order to suppress toner adhesion to the toner receiving member 37. As a material of sheet member 41a, 41b, the sheet made of a fluorine resin etc. are mentioned, for example.

  FIG. 5 is a perspective view of the vibration generator 40. As shown in FIG. Note that FIG. 5 shows a state in which the substrate 45 (see FIG. 4) is removed from the motor mounting holder 42 so that the inside of the vibration generator 40 can be seen. The vibration generator 40 includes a motor mounting holder 42 and a vibration motor 43. The motor mounting holder 42 has a motor holding portion 42a for holding the vibration motor 43 and a screw hole 42b in which a screw 46 (see FIG. 4) is fastened. It is formed. A vibrating weight 50 is fixed to an output shaft 43 a of the vibration motor 43. When the vibration generator 40 is attached to the toner receiving member 37, the output shaft 43 a of the vibration motor 43 is fixed along the longitudinal direction of the toner receiving member 37. Further, lead wires (not shown) for supplying power to the vibration motor 43 are connected to the motor mounting holder 42.

  When viewed from the direction of the output shaft 43a of the vibration motor 43 (the left direction in FIG. 5), the excitation weight 50 has a cam shape in which a part of the disc is cut away and is asymmetrical with respect to the output shaft 43a. It has a shape. When the output shaft 43a rotates at a predetermined speed or more, the centrifugal force acting on the notch portion is smaller than that of the other portions, so that the vibration weight 50 receives an uneven centrifugal force. This centrifugal force is transmitted to the output shaft 43a, whereby the vibration motor 43 vibrates. In addition, the shape of the weight 50 for vibration is not limited to a cam shape, It can be set as arbitrary shapes that a gravity center shifts with respect to the output shaft 43a.

  FIG. 6 is a side sectional view showing a cross section (cross section XX 'in FIG. 3) of the toner receiving and supporting member 35 used in the developing device 3a according to the first embodiment in the vicinity of the vibration motor 43; FIG. 16 is a partial enlarged view of the toner receiving and supporting member 35 in FIG.

  As shown in FIGS. 6 and 7, only the edge 37e of the toner receiving member 37 on the toner supply roller 30 side is in contact with the support member main body 36, and the edge 37f of the opposite side (photosensitive drum 1a side) is It is a free end. The substantially central portion in the width direction (left and right direction in FIG. 6) of the toner receiving surface 37 b is supported by the support member main body 36 via the vibration generator 40. Thus, the toner receiving member 37 is configured to be swingable with the end edge 37e as a fulcrum. The vibration motor 43 is disposed such that the output shaft 43 a is substantially parallel to the longitudinal direction of the toner receiving member 37.

  The toner receiving member 37 is inclined such that the toner receiving surface 37b facing the developing roller 31 has an upward slope from the toner supply roller 30 side to the photosensitive drum 1a side, and the toner falling surface 37c facing the toner supply roller 30 Are arranged so as to be substantially vertical.

  The sheet member 41a is attached so as to cover the surface of the toner receiving member 37 (toner drop surface 37c) including the boundary between the support member main body 36 on the side of the brush cutting blade 33 and the toner receiving member 37. The sheet member 41b covers the entire area of the toner receiving surface 37b including the boundary between the support member main body 36 on the side of the seal member 44 and the toner receiving member 37, the engaging portion 38, and the holding portion 39 (see FIG. 4). It is pasted. The sheet members 41a and 41b suppress adhesion of toner to the toner receiving surface 37b and the toner falling surface 37c, and the toner to the inside of the toner receiving and supporting member 35 from the boundary between the toner receiving and supporting member 35 and the toner receiving member 37. And the malfunction of the vibration motor 43 caused by the penetration of toner.

  By rotating the output shaft 43a of the vibration motor 43 at high speed (for example, about 10,000 rpm) during non-image formation, the weight 50 for vibration also rotates at high speed together with the output shaft 43a. At this time, since the non-uniform centrifugal force is applied to the weight 50 for vibration, the vibration generator 40 including the vibration motor 43 and the motor mounting holder 42 vibrates via the output shaft 43a. Then, the toner receiving member 37 to which the vibration generating device 40 is attached also vibrates. Specifically, the toner receiving surface 37b of the toner receiving member 37 vibrates with an edge 37e as a fulcrum so as to increase in amplitude toward the edge 37f.

  Due to the vibration of the toner receiving surface 37b, as shown in FIG. 7, the toner T deposited on the toner receiving surface 37b slides down along the inclination of the toner receiving surface 37b (in the direction of the white arrow in FIG. 7). It falls freely to a region R sandwiched by the toner drop surface 37 c and the toner supply roller 30. A part of the toner dropped into the region R passes the gap between the blade cutting blade 33 and the toner supply roller 30 and drops into the supply and transfer chamber 22 as it is.

  In this embodiment, in order to return the toner dropped to the area R to the supply conveyance chamber 22, the developing roller 31 and the toner supply roller 30 are in the reverse direction (clockwise direction in FIG. 7) of the image formation. Rotate (reverse rotation). By rotating the toner supply roller 30 in the reverse direction, the toner dropped to the area R and accumulated at the tip of the ear cutting blade 33 is scraped off by the magnetic brush of the toner supply roller 30. The scraped toner is rotated along with the magnetic brush to the surface of the toner supply roller 30, passes through the gap between the toner supply roller 30 and the cutting blade 33, and is pulled from the toner supply roller 30 at the same polarity part of the fixed magnet body. After being peeled off, it is forcibly returned to the supply and transfer chamber 22.

  When the toner receiving member 37 is vibrated, the toner supply roller 30 and the developing roller 31 can also be rotated in the forward direction. By rotating the toner supply roller 30 forward, part of the toner dropped from the toner receiving surface 37 b to the region R adheres to the magnetic brush on the toner supply roller 30. The remaining toner that did not adhere to the magnetic brush on the toner supply roller 30 passes through the gap between the toner supply roller 30 and the blade 33 and drops into the supply and conveyance chamber 22.

  The timing for vibrating the toner receiving member 37 may be performed each time the printing operation is completed, or may be a predetermined time such as when the number of printed sheets reaches a predetermined number or when the temperature in the developing device 3a exceeds a predetermined value. It may be performed at the timing. Further, the timing for vibrating the toner receiving member 37 and the timing for rotating the developing roller 31 and the toner supply roller 30 in reverse (or forward) may be the same or different. Further, by vibrating the toner receiving member 37 every time the number of printed sheets reaches, the vibration of the toner receiving member 37 is automatically executed according to the number of printed sheets. Therefore, it is not necessary for the user to manually set the vibration of the toner receiving member 37, and it is possible to avoid the setting error, the setting forgetting or the unnecessary execution of the vibration.

  By the way, the toner which is pulled off and falls from the developing roller 31 also adheres to the tip of the seal member 44 provided on the upper end of the support member main body 36. Therefore, the toner is gradually deposited on the tip of the seal member 44, and when the deposited toner block moves to the photosensitive drum 1a, the toner is dropped and an image defect occurs.

  In the present embodiment, the upper end (edge 37f) of the toner receiving member 37 is bent upward to form a seal support 37d, and the seal 44 is fixed to the seal support 37d. As a result, when the vibration generator 40 vibrates, the seal member 44 as well as the toner receiving member 37 vibrates, so that the toner attached to the seal member 44 can be shaken off. Therefore, it is possible to effectively suppress the toner drop and the contamination of the half image due to the transfer of the toner attached to the seal member 44 to the photosensitive drum 1a.

  Further, since the seal support portion 37d is formed by bending the side of the end 37f which is the free end of the toner receiving member 37, the vibration of the seal member 44 can be increased. Further, since the toner receiving member 37 and the seal member 44 separate the inside of the toner receiving and supporting member 35 from the inside of the developing container 20, it is difficult for the floating toner in the developing container 20 to enter into the toner receiving and supporting member 35. . As a result, it is possible to suppress the occurrence of malfunction of the vibration motor 43 and the substrate 45 in the vibration generating device 40.

  The toner attached to the tip of the seal member 44 falls onto the toner receiving member 37 by vibration, but does not completely drop onto the toner receiving member 37 even if vibration is applied depending on the charge amount and fluidity of the attached toner. Sometimes.

  Therefore, in order to completely remove the toner adhering to the tip of the seal member 44, the toner receiving member 37 is vibrated and a predetermined electrostatic latent image pattern is formed on the surface of the photosensitive drum 1a. Then, the photosensitive drum 1 a is rotated so that the formed electrostatic latent image pattern passes through the seal member 44. Since the tip of the seal member 44 is in contact with the photosensitive drum 1a, the toner attached to the tip of the seal member 44 develops the electrostatic latent image by the edge effect (edge electric field) of the electrostatic latent image. Thus, the toner attached to the seal member 44 can be collected to the photosensitive drum 1 a side.

  The electrostatic latent image pattern formed on the surface of the photosensitive drum 1a is a pattern in which the edges of the exposed portion and the white portion (non-exposed portion) exist at a predetermined interval or less in order to enhance the edge effect of the electrostatic latent image. used. In particular, the appearance ratio of the edge portion (boundary) in the main scanning direction and the sub scanning direction, such as a pattern in which the exposure portions D are arranged in a zigzag (zigzag shape) or a line pattern having a predetermined angle in the width scanning direction. Is preferred.

  Further, in order to enhance the cleaning effect of the toner adhering to the seal member 44, the charging voltage applied to the charging device 2a at the time of forming the electrostatic latent image pattern is made higher than at the time of image formation. The surface potential (dark potential) Vo is made higher than at the time of image formation. Further, the light amount (exposure amount) of light irradiated from the exposure device 5 to the photosensitive drum 1a is made higher than that at the time of image formation, and the exposed portion potential (bright potential) VL of the photosensitive drum 1a is lower than at the time of image formation. Do. As a result, the potential difference ΔV (= Vo−VL) at the edge portion of the electrostatic latent image is increased, so that the edge effect is enhanced, and the cleaning effect of the seal member 44 can be further improved.

  FIG. 8 is a side cross-sectional view showing a cross-sectional structure in the vicinity of the vibration motor 43 of the toner receiving and supporting member 35 used in the developing device 3a according to the second embodiment of the present invention. In the present embodiment, the seal member 44 is formed by extending the sheet member 41 b attached to the toner receiving member 37 toward the seal support portion 37 d of the toner receiving member 37. The configuration of the other parts of the developing device 3a is the same as that of the first embodiment.

  According to the present embodiment, since the sheet member 41 b and the seal member 44 are formed of a single sheet, the sheet member 41 b and the seal member 44 can be attached to the toner receiving member 37 at one time. Therefore, the number of parts and the number of assembling steps can be reduced.

  Others The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, the shapes and configurations of the toner receiving and supporting member 35 and the toner receiving member 37 shown in each of the above-described embodiments are merely examples, and are not particularly limited to the above-described embodiments. can do.

  According to the present invention, the casing has a wall facing the developer carrier between the regulating blade and the facing area in the casing, and prevents toner scattering in the opening of the casing where the developing roller facing the image carrier is exposed. Can be used in a developing device provided with a sealing member for By the use of the present invention, it is possible to provide a developing device capable of efficiently collecting both the toner deposited around the blades in the casing and the toner deposited on the seal member.

Pa to Pd Image forming unit 1a to 1d Photosensitive drum (image carrier)
2a to 2d charging device 3a to 3d developing device 5 exposure device 20 developing container 30 toner supply roller 31 developing roller 33 earing blade (regulating blade)
35 toner receiving support member 36 support member main body 37 toner receiving member 37 b toner receiving surface 37 d seal supporting portion 37 e end edge (fulcrum)
37f edge (free end)
40 vibration generating device 41a, 41b sheet member 44 sealing member 100 color printer (image forming apparatus)

Claims (8)

A developing roller disposed opposite to an image carrier on which an electrostatic latent image is formed, and supplying toner to the image carrier in a region facing the image carrier;
A toner supply roller disposed opposite to the developing roller and supplying the toner to the developing roller in a region facing the developing roller;
A regulating blade disposed opposite to the toner supply roller at a predetermined interval;
A developing container that accommodates the developing roller, the toner supply roller, and the regulating blade;
A toner receiving and supporting member disposed in the developing container and facing the developing roller or the toner supply roller between the regulating blade and the image carrier;
A toner receiving member disposed along the longitudinal direction of the toner receiving and supporting member and receiving the toner falling from the developing roller;
A vibration generating device for vibrating the toner receiving member;
A developing device for developing an electrostatic latent image formed on the image carrier,
A seal member for preventing the toner from leaking from the gap between the image carrier and the developing container is fixed so as to be in contact with the image carrier at the edge of the toner carrier on the image carrier side. A developing device characterized by   2. The developing device according to claim 1, wherein the seal member is fixed to a seal support portion formed by bending an edge of the toner receiving member on the image carrier side upward.   2. The toner receiving member according to claim 1, wherein the toner receiving member is pivotably supported by the toner receiving and supporting member with an end edge on the restriction blade side as a fulcrum and an end edge on the image carrier side as a free end. The developing device according to claim 2. One or more sheet members having lower toner adhesion than the toner receiving member are attached to the surface of the toner receiving member on the side facing the developing roller or the toner supply roller.
The developing device according to any one of claims 1 to 3, wherein the seal member is formed by extending at least one of the sheet members. The vibration generating device is disposed inside the toner receiving and supporting member,
The developing device according to any one of claims 1 to 4, wherein an inside of the toner receiving and supporting member and an inside of the developing container are divided by the toner receiving member and the seal member.   The developing device according to any one of claims 1 to 5, wherein the developing roller and the toner supply roller are rotated in the same direction or in a reverse direction during image formation while the vibration generating device is driven. A developing device according to any one of claims 1 to 6.
The image carrier having a photosensitive layer formed on the surface;
An image forming apparatus equipped with A charging device for charging the surface of the image carrier;
An exposure device that irradiates light to the surface of the image bearing member charged by the charging device to form an electrostatic latent image;
And further
When the vibration generating device is driven, the exposure device irradiates the surface of the image carrier charged by the charging device with light by the exposure device, so that the exposed portion and the non-exposed portion do not extend across the entire image forming area of the image carrier. An electrostatic latent image pattern is formed in which the boundaries of the exposure section exist at a predetermined interval or less, and the image carrier is rotationally driven such that the electrostatic latent image pattern passes through the seal member. The image forming apparatus according to 7.

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