JP5672790B2 - Toner suction device and image forming apparatus - Google Patents

Description

  The present invention relates to a toner suction device and an image forming apparatus.

  In an image forming apparatus that forms an image by attaching toner to a latent image due to a difference in electrostatic potential, a member that holds toner on an endless peripheral surface is disposed opposite to an image carrier on which the latent image is formed. Then, development is performed by transferring the toner onto the image carrier. As a member facing the image carrier, a developing member that holds a one-component developer or a two-component developer is widely used. Further, a toner layer conveying member in which toner is transferred from a developing member holding a two-component developer may be used as a member facing the image holding member.

  As described above, the toner may be scattered at the position where the toner is transferred from the developing member to the image holding member or the position where the toner is transferred from the developing member to the toner layer conveying member. For example, the toner is scattered as a so-called toner cloud. An apparatus for sucking and removing such scattered toner is described in, for example, Patent Document 1 or Patent Document 2.

JP-A-62-194271 Japanese Patent Laid-Open No. 03-127087

  SUMMARY OF THE INVENTION An object of the present invention is to reduce image stains and internal stains caused by staying and dropping of sucked toner.

In order to solve the above-mentioned problem, the invention according to claim 1 is opposed to a position where toner for forming a visible image attached to a latent image due to a difference in electrostatic potential is transferred between members facing each other. A suction pipe that sucks the toner scattered at a position where the toner is transferred, and an air flow generating means that generates an air flow so as to suck air into the suction pipe through the opening, The opening sucks the toner upward from the position where the toner is transferred , and a plurality of the thin plate members attached so as to close the suction pipe at the tip of the suction pipe are provided at intervals. each of the openings is intended to cover a position away from the position from the position close to a position where the toner is transferred, the shape of the opening, the width direction with respect to the direction toward the direction of approaching the position where the toner is transferred Dimensions A toner suction device is provided.

  According to a second aspect of the present invention, in the toner suction device according to the first aspect, the opening of the suction tube is a position where the toner is transferred from the developing member to the image holding member having an endless peripheral surface, or a toner layer. Is provided opposite to the position where the toner is transferred from the developing member to the toner layer conveying member that holds the toner image on the endless peripheral surface and conveys the toner image to the position facing the image holding member, Assume that the shape of the portion facing the toner layer carrying member increases the widthwise dimension of the peripheral surface of the image carrier or the toner layer carrying member in the direction approaching the position where the toner is transferred.

  According to a third aspect of the present invention, in the toner suction device according to the second aspect, the opening extends from a portion of the suction tube facing the image holding member or the toner layer conveying member to a portion facing the developing member. It is assumed that the edge of the portion of the opening facing the developing member, which is provided continuously, on the side away from the toner transfer position is located above the peripheral surface of the developing member.

According to a fourth aspect of the present invention, an opening is provided opposite to a position where toner for forming a visible image by attaching to a latent image due to a difference in electrostatic potential is transferred between members facing each other. A suction pipe that sucks the toner scattered at the transfer position; and an air flow generation means that generates an air flow so as to suck air into the suction pipe through the opening, and the opening of the suction pipe includes: The toner is sucked upward from the position where the toner is transferred, and the position where the toner is transferred from the developing member to the image carrier having the endless peripheral surface, or the toner layer is held on the endless peripheral surface. The toner pipe is placed opposite the position where the toner is transferred from the developing member to the toner layer carrying member that is conveyed to the position facing the image carrier, and the suction pipes are arranged facing each other with a gap therebetween, and both side edges are connected to each other. Two plate-shaped members A thin plate member attached to a tip portion of the plate-like member so as to close a gap between the two plate-like members, and the thin plate member includes the image carrier or the toner layer conveying member. The peripheral surface is folded at a folding line in the width direction, and both sides of the folding line are attached so as to face the developing member and the image carrier or the toner layer conveying member, respectively, and the opening of the thin plate member It is provided at a position adjacent to the fold line and extends from a position close to the position where the toner is transferred to a position away from the position, and is opposed to the image carrier or the toner layer conveying member of the opening. shape of the portion is, the toner suction device in which the width dimension of the circumferential surface having the image carrier or toner layer conveying member in the direction of approaching the position where the toner is transferred is expanded It is intended to provide.

  The invention according to claim 5 is the toner suction device according to claim 4, wherein the plate-like member is supported at a position along a peripheral surface of the developing member, and a portion of the thin plate member facing the developing member Is attached to the surface of the plate-like member facing the developing member, and the periphery of the opening of the plate-like member facing the developing member provided on the thin plate member is a position retreated from the edge of the opening. It is assumed that a notch is provided.

  The invention according to claim 6 is an image holding body that holds a latent image due to a difference in electrostatic potential on an endless peripheral surface, a latent image forming unit that forms a latent image on the image holding body, and an endless shape A developing device that includes a developing member that conveys toner held on the peripheral surface of the toner image to a position facing the image carrier, and that develops the latent image by transferring toner to the latent image formed on the image carrier. A transfer device that transfers the toner transferred onto the image holding member to a recording medium or to a recording medium via an intermediate transfer member, and transfers the toner from a developing member included in the developing device to the image holding member. An image forming apparatus having the toner suction device according to any one of claims 1 to 5, which sucks toner scattered from a position.

  The invention according to claim 7 comprises: an image holding body that holds a latent image due to a difference in electrostatic potential on an endless peripheral surface; a latent image forming unit that forms a latent image on the image holding body; A toner layer conveying member that holds the toner layer on the peripheral surface of the toner image and conveys the toner layer to a position facing the image carrier, and a developing member that transfers toner onto the peripheral surface of the toner layer conveying member. A developing device for developing a latent image on the body, a transfer device for transferring the toner transferred onto the image carrier to a recording medium or a recording medium via an intermediate transfer member, and a developing member provided in the developing device And a toner suction device according to any one of claims 1 to 5, which sucks toner scattered from a position at which toner is transferred from the toner to the toner layer conveying member. .

  In the toner suction device according to the first aspect of the present invention, as compared with the toner suction device that does not have the configuration of the present invention, it is possible to reduce the dirt on the image and the dirt in the machine due to the suctioned toner staying and dropping. .

  In the toner suction device according to the second aspect of the present invention, as compared with the toner suction device that does not have the configuration of the present invention, it is possible to reduce image stains and in-machine stains due to the staying and dropping of the sucked toner. .

  In the toner suction device according to the third aspect of the present invention, the influence of the toner falling from the edge of the opening on the image can be reduced as compared with the toner suction device that does not have the configuration of the present invention.

  In the toner suction device according to the fourth aspect of the present invention, the toner scattered near the position where the toner is transferred can be sucked as compared with the toner suction device that does not have the configuration of the present invention.

  In the toner suction device according to the fifth aspect of the present invention, the toner sucked into the suction tube from the opening is suppressed and is prevented from falling outside the suction tube, as compared with the toner suction device that does not have the configuration of the present invention. can do.

  In the image forming apparatus according to the sixth aspect of the present invention, as compared with the image forming apparatus that does not have the configuration of the present invention, it is possible to reduce the contamination of the image and the contamination in the apparatus caused by the attracted toner staying and dropping. .

  In the image forming apparatus according to the seventh aspect of the present invention, as compared with the image forming apparatus that does not have the configuration of the present invention, it is possible to reduce the contamination of the image and the contamination in the apparatus caused by the attracted toner staying and dropping. .

1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a developing device and a toner suction device used in the image forming apparatus shown in FIG. FIG. 3 is a schematic plan view showing a schematic configuration of a developing device shown in FIG. 2 and a position of a toner suction device. FIG. 2 is a schematic plan view of a toner suction device used in the image forming apparatus shown in FIG. 1. FIG. 3 is an enlarged cross-sectional view illustrating a distal end portion provided with an opening of a suction tube included in the toner suction device illustrated in FIG. 2. It is the schematic which shows the AA arrow in FIG. 5, and BB arrow. FIG. 3 is a schematic diagram illustrating a toner adhesion state around an opening for sucking toner in the toner suction device illustrated in FIG. 2. It is the schematic which shows the other example of the shape of the opening provided in the suction pipe. FIG. 5 is a schematic diagram showing a negative pressure distribution in the vicinity of an opening for sucking toner of the toner suction device shown in FIG. 4. FIG. 6 is a schematic diagram illustrating another example of an image forming apparatus in which the toner suction device according to the present invention can be used. FIG. 6 is a schematic diagram illustrating another example of an image forming apparatus in which the toner suction device according to the present invention can be used.

Hereinafter, embodiments of the invention according to the present application will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. 2 is an enlarged cross-sectional view of the developing device used in the image forming apparatus shown in FIG. 1, and FIG. 3 is a schematic plan view showing the schematic configuration of the developing device shown in FIG. 2 and the position of the toner suction device. is there.
The image forming apparatus includes a cylindrical photosensitive drum 1 on which a latent image is formed by irradiating image light after charging. Around the photosensitive drum 1, the surface of the photosensitive drum 1 is provided. A charging device 2 for charging the image forming region, an exposure device 3 for irradiating the photosensitive drum 1 with image light to form a latent image on the surface, and an electrostatic latent image on the photosensitive drum 1 as a selective toner. A transfer device 5 for transferring a toner image on the photosensitive drum to a recording medium by a transfer electric field applied by a transfer bias voltage between the developing device 4 and the photosensitive drum 1 that are visualized by the adhesion, and the toner image. And a cleaning device 6 for removing toner remaining on the photosensitive drum 1 after the toner is transferred.
Further, toner suction devices 7 and 8 for sucking scattered toner are provided on the upstream side and the downstream side of the position where the developing device 4 is provided in the moving direction of the peripheral surface of the photosensitive drum 1. .

  On the other hand, a recording medium supply unit 9 for supplying a recording medium P to which a toner image is transferred is provided, and the recording medium P for recording an image from the recording medium supply unit 9 faces the photosensitive drum 1 and the transfer device 5. One sheet at a time is supplied to the transfer section 5a. A fixing device 10 that heats and presses the toner image transferred to the recording medium is provided on the downstream side of the transfer unit 5a in the recording medium conveyance direction.

  The photosensitive drum 1 functions as an image carrier, and a photosensitive drum layer formed on the surface of a metal cylinder can be used. The photosensitive drum 1 is rotationally driven around a central axis, and processes such as charging, exposure, and development are sequentially performed on a moving peripheral surface.

  The charging device 2 is a corona discharger including an electrode wire stretched with a gap from the photosensitive drum 1, and a voltage is applied between the electrode wire and the photosensitive drum 1 to generate a corona discharge. Thus, the surface of the photosensitive drum 1 is charged.

  The exposure device 3 emits a flashing laser beam based on an image signal, and performs exposure scanning in the axial direction with respect to the circumferential surface of the photosensitive drum 1 that moves around. As a result, the potential of the exposed portion is attenuated on the peripheral surface of the photosensitive drum 1, and a latent image is formed due to the difference in electrostatic potential.

  The developing device 4 includes a toner layer transporting roll 11 (also referred to as a donor roll) that is a toner layer transporting member provided so as to face the photosensitive drum 1 with a space therebetween, and the toner layer transporting. A developing roll 12 which is a developing member supported at a position facing the roll 11 in the vicinity thereof is provided. The developing roll 12 magnetically attracts the two-component developer on the peripheral surface to form a developer layer. The developing roller 12 rotates to convey the developer layer on the peripheral surface to a position facing the toner layer conveying roller 11 and transfer the toner in the two-component developer to the toner layer conveying roller 11. The toner layer conveying roll 11 electrically adsorbs the toner transferred onto the peripheral surface and conveys the toner to a position facing the photosensitive drum 1 by rotating. Then, in the electric field formed between the toner layer conveying roll 11 and the photosensitive drum 1, the toner is transferred to the latent image to form a visible image.

  Behind the developing roll 12, a first developer containing chamber 13 and a second developer containing chamber 14 for containing a two-component developer supplied to the surface of the developing roll 12 are provided. One stirring and conveying member 15 and a second stirring and conveying member 16 are provided. As shown in FIG. 3, the first agitation transport member 15 and the second agitation transport member 16 are composed of a first developer storage chamber 13 and a second developer storage chamber 14 partitioned by a partition wall 17. The two-component developer is conveyed in the opposite direction, and circulates between the first developer storage chamber 13 and the second developer storage chamber 14 in which the developer can move at both ends. The two-component developer is conveyed to

  The toner suction devices 7 and 8 will be described in detail later.

  The transfer device 5 is a corona discharger that applies a charge from the back side of the recording medium to be conveyed, and records toner having a charge by the action of an electric field formed between the transfer device 5 and the photosensitive drum 1. It is transferred on the medium.

  The recording medium supply unit 9 includes a storage unit 9a that stores the recording media P in a stacked manner, and a transport path 9b that transports the recording medium fed from the storage unit 9a to the transfer unit 5a. The accommodating portion 9a sequentially takes out the accommodated recording media P one by one from the uppermost one and sends it out to the transport path 9b. The conveyance path 9b conveys the recording medium P and sends it to the transfer unit 5a as the toner image formed on the photosensitive drum 1 is conveyed.

  The fixing device 10 includes a fixing roll 10a having a built-in heat source and a pressure roll 10b that is pressed against the fixing roll 10a, and is conveyed between the fixing roll 10a and the pressure roll 10b. The recording medium is heated and pressurized to press the toner image onto the recording medium.

  In the image forming apparatus as described above, the photosensitive drum 1 is charged negatively by the charging device 2. The exposure device 3 irradiates the charged surface of the photosensitive drum 1 with image light based on the image data, the charged potential of the exposed portion of the surface of the photosensitive drum 1 is attenuated, and the potential difference from the non-exposed portion. A latent image is formed. The developing device 4 transfers the negatively charged toner from the developing roll 12 to the toner layer conveying roll 11 and conveys the toner to a position facing the peripheral surface of the photosensitive drum 1. An electric field based on a developing bias voltage is formed between the photosensitive drum 1 and the toner layer transport roll 11, and toner having a negative charge is transferred to the exposed portion.

The toner image formed in this way is conveyed to the transfer unit 5 a provided with the transfer device 5 by the rotation of the photosensitive drum 1.
On the other hand, the recording medium supplied one by one from the recording medium supply unit 9 is sent to the transfer unit 5 a so as to be superimposed on the toner image on the photosensitive drum 1. The toner image is transferred to the recording medium by the transfer bias voltage.

  The recording medium onto which the toner image has been transferred is sent to the fixing device 10 while holding the toner image, and the toner image on the recording medium is heated and pressurized and fixed on the recording medium.

Next, the toner suction devices 7 and 8 will be described.
A toner suction device 7 provided on the upstream side of the developing device 4 in the rotation direction of the photoconductive drum 1 includes a developing roll 12, a toner layer conveying roll 11, and a rear side of the developing device 4 supported toward the photoconductive drum 1. A suction tube 21 is provided toward the position where the two face each other, and an opening 22 for sucking toner is formed at the tip of the suction tube 21. As shown in FIGS. 2 and 5, the suction tube 21 has a first plate-like member 23 having a leading edge in the axial direction of the toner layer transport roll 11, and a space from the first plate-like member 23. It has the 2nd plate-shaped member 24 arrange | positioned so that it may overlap, and these clearance gaps are used as the suction path of a flat shape. As shown in FIG. 4, the rear ends of the first plate-like member 23 and the second plate-like member 24 are connected to the cylindrical portion 25, and the side edges 26, 27 are first to the rear end. The first plate member 23 and the second plate member 24 are connected to each other. The cylindrical portion 25 has an axial line in a direction along the axial direction of the toner layer transporting roll 11, one end 25 a in the axial direction is closed, and the other end is connected to a blower 28 that is an air flow generating means. An air flow for sucking the air is formed.

  A portion of the first plate-like member 23 that faces the developing roll 12 is arranged along a circumferential surface of the developing roll 12 so that a tip thereof faces the circumferential surface of the toner layer conveying roll 11. The second plate-like member 24 is disposed along the first plate-like member 23, and the front end faces the toner layer transport roll 11. The tip of the second plate-like member 24 has a portion 24 a bent along the peripheral surface of the toner layer transport roll 11, and forms a tip facing surface 24 b that faces the toner layer transport roll 11.

  As shown in FIG. 5, a synthetic resin thin plate member 29, that is, a film-like member is provided at both ends in the width direction of the first plate-like member 23 and the second plate-like member 24. The thin plate member 29 is provided with the opening 22 so as to close the gap. The thin plate member 29 has a shape bent by a fold line in the axial direction of the toner layer conveying roll 11, and a surface 23 a of the first plate member 23 facing the developing roll 12, that is, one side of the fold line, that is, Affixed to the outside of the suction path. The opposite side of the folding line is affixed to the tip facing surface 24 b bent from the tip of the second plate-like member 24. Therefore, the fold line is closest to the position D where the toner transfer is performed with the toner layer conveying roll 11 and the developing roll 12 facing each other.

As shown in FIG. 6, a plurality of openings 22 provided in the thin plate member 29 are provided at intervals in the axial direction of the toner layer transport roll 11. These openings 22 are formed on both sides of the fold line as shown in FIGS. 5 and 6, and the portion facing the toner layer conveying roll 11 on the side supported by the second plate-like member 24 from the fold line is bent. It is a trapezoid whose bottom is on the line. Further, the portion facing the developing roll 12 on the side supported by the first plate-like member 23 from the fold line is a rectangle with one side on the fold line. The side 22 a farthest from the bend line is set at a position where the immediately lower side is the peripheral surface of the developing roll 12.
At a position where the opening 22 is not provided, the first plate member 23 and the thin plate member 29 attached from the second plate member 24 as shown in FIG. The gap between the plate member 23 and the second plate member 24 is closed.

  As the opening 22 is provided in the thin plate member 29 as described above, the first plate-like member 23 is provided with a notch 23b over the position where the opening 22 is provided and the periphery thereof as shown in FIG. 6B. It has been. Therefore, as shown in FIG. 5A, there is a portion where only the thin plate member 29 faces the developing roll 12 around the opening 22 provided at a position facing the developing roll 12, and in this portion, the first plate The suction path is enlarged from the portion where the plate-like member 23 faces the second plate-like member 24.

The shape of the portion of the opening 22 facing the toner layer transport roll 11 is a trapezoid whose bottom is on the fold line as described above, and the toner layer transport roll 11 becomes closer to the position D where the toner is transferred. The dimension in the axial direction is enlarged. That is, as shown in FIG. 7B, the angle θ formed by the side on the bend line of the opening 22 and the other side adjacent thereto is 90 degrees or less. As shown in FIG. 7A, when the shape of the opening is rectangular and the angle between the side on the folding line and the adjacent side is 90 degrees, the air flow sucked into the opening from the peripheral portion of the toner layer transport roll 11 However, toner stays outside the opening around the corner formed by the side on the folding line and the adjacent side. When the staying toner falls on the toner layer conveying roll 11, the image is smeared. On the other hand, as shown in FIG. 7B, the side of the opening 22 for sucking toner is close to the position where the toner is transferred, in this embodiment, the side on the fold line and the other side adjacent thereto. When the angle θ is 90 degrees or less, toner retention due to the sucked air flow is suppressed, and image contamination or internal contamination due to the fall of the toner attached to the thin plate member 29 is reduced.
It is to be noted that an effect is gradually produced when the angle θ between the side on the folding line of the opening, that is, the side close to the position D where the toner is transferred, and the other side adjacent thereto is 90 degrees or less. However, it is desirable that this angle θ is about 30 to 60 degrees.

  On the other hand, in the suction pipe 21 as described above, when the magnetic carrier is attracted by being mixed with the toner, the attracting force by the magnet of the developing roll 12 acts on the portion facing the developing roll 12, and the toner containing the magnetic carrier is attracted. It becomes easy to adhere to the wall surface of the tube 21. In the toner suction device 7, the toner or magnetic carrier adhering to the inside of the suction tube 21 at the portion facing the developing roll 12 is easily held on the thin plate member 29 around the opening 22 as shown in FIG. It has become. Even if the toner T or the magnetic carrier held on the thin plate member 29 falls from the opening 22, it falls on the peripheral surface of the developing roll 12 as shown in FIG. It has become. On the peripheral surface of the developing roll 12, magnetic brushes with magnetic carriers standing in the form of spikes are formed, and toner adheres to these magnetic carriers. Therefore, the dropped toner or magnetic carrier is taken into the developer layer on the developing roll 12 and the influence on the toner layer on the toner layer transporting roll 11 is reduced.

  The shape of the opening 22 facing the toner layer conveying roll 11 is trapezoidal, but it may be triangular as shown in FIG. 8A. Such a shape may also be at the toner transfer position D of the opening 31. The angle formed between the near side 31a and the other side 31b adjacent thereto is 90 degrees or less, and similarly, toner adhesion is reduced. Further, as shown in FIG. 8B, the opening 31 may be provided only in a portion facing the toner layer conveying roll 11 and may not extend to a portion facing the developing roll 12. However, in the portion where the opening 31 is provided, it is desirable to provide a cutout 32 a in the first plate-like member 32 to ensure a flow path for air sucked from the opening 31.

In addition, the intervals of the openings 22 are equal in the axial direction of the toner layer conveying roll 11 in the above embodiment, but the openings can be provided at different intervals.
At the rear end of the flat suction path formed by the first plate member 23 and the second plate member 24, a cylindrical portion 25 is provided in a direction along the axis of the toner layer transport roll 11, and this When sucked from one of the cylindrical portions 25, the negative pressure sucked in the axial direction of the toner layer transport roll 11 is not constant at the tip of the suction tube 21. That is, as shown in FIG. 9, the absolute value of the negative pressure when sucking is reduced at the end opposite to the sucking direction, and the suction pipe 21 is sucked in the direction of suction because the width is reduced at the rear. The absolute value of the negative pressure also becomes small at the end. On the other hand, it is possible to adjust the suction capability in the axial direction of the toner layer conveying roll 11 by adjusting the interval between the openings. For example, the gap between the openings can be reduced in a basin where the absolute value of the negative pressure at both ends is small, and the gap between the openings can be increased at a position where the absolute value of the negative pressure is large.

Further, the toner conveying roll 11 can be adjusted so as to increase the ability to suck toner in one end region in the axial direction.
As shown in FIG. 3, when the agitating and conveying members 15 and 16 disposed in the developing device 4 convey the developer so as to circulate while being agitated, toner is supplied to one end portion in the axial direction of the developing roll. When the opening 18 is provided, charging of the toner supplied to the developing roll 12 is not charged in one end region, in this embodiment, in the end region opposite to the end where the toner supply port 18 is provided. May be enough. In this way, toner scattering is likely to occur in a region where the toner is insufficiently charged, and the space between the openings 22 can be adjusted in this region to increase the suction capability of the toner suction device.

  The toner suction device 8 provided on the downstream side of the developing device 4 in the rotation direction of the photosensitive drum 1 may have the same configuration as the toner suction device 7 provided on the upstream side. Other configurations can be used when there are few. In the above embodiment, the suction tube has a flat shape formed by two plate-like members in the same way as the toner suction device 7 provided on the upstream side, but a thin plate member is provided at the tip of the suction tube. It is not attached and has a continuous opening in the axial direction of the toner layer conveying roll 11.

  In the embodiment described above, the developing device 4 includes the developing roll 12 and the toner layer conveying roll 11, and the toner suction device 7 is a position where the toner is transferred from the developing roll 12 to the toner layer conveying roll 11. However, it is also possible to provide toner that is scattered at a position where the toner is transferred from the toner layer conveying roll 11 to the photosensitive drum 1 that is an image holding member. Further, as shown in FIG. 10, in the image forming apparatus in which the developing device 41 transfers toner from the developing roll 42 to the image holding body 1, scattered toner generated at a position where the developing roll 42 and the image holding body 1 face each other. The toner suction device of the present invention can be provided so as to suck the toner. The toner suction devices 43 and 44 used in the image forming apparatus shown in FIG. 10 are provided with openings for sucking toner facing the image carrier 1 or facing the image carrier 1 and the developing roll 42. However, the configuration of each part of the toner suction devices 43 and 44 can be the same as that shown in FIG. 2, FIG. 3, or FIG. In addition, the photosensitive drum 1, the charging device 2, the exposure device 3, the transfer device 5, the cleaning device 6, the recording medium supply unit 9, the fixing device 10 and the like, which are image carriers of the image forming apparatus, are also used. it can.

The image forming apparatus shown in FIGS. 1 and 10 forms a single color image having one developing device. However, as shown in FIG. 11, a color image forming apparatus having a plurality of developing devices is used. It can also be applied to an apparatus for forming an image. In this image forming apparatus, the image carrier 51 has a belt shape, and the toner is transferred from the toner layer conveying roll 53 of the developing device 52. In addition, toner suction devices 55 and 56 are provided for each developing device so as to suck the toner scattered at the position where the toner is transferred from the developing roller 54 of each developing device 52 to the toner layer conveying roller 53. Each developing device can transfer the toner directly from the developing roll to the image carrier 51. Similarly, the toner suction device of the present invention can be used, and the image carrier uses a drum-like member. You can also.
In FIG. 11, reference numeral 61 denotes a charging device, reference numeral 62 denotes an exposure device, reference numeral 63 denotes a transfer device, reference numeral 64 denotes a cleaning device, reference numeral 65 denotes a fixing device, and reference numeral 66 denotes a recording medium supply unit.

  Furthermore, the present invention is not limited to the above-described embodiments, and can be implemented as other forms within the scope of the present invention.

1: Photosensitive drum, 2: Charging device, 3: Exposure device, 4: Developing device, 5: Transfer device, 6: Cleaning device, 7, 8: Toner suction device, 9: Recording medium supply unit, 9a: Recording medium 9b: conveying path,
11: Toner layer conveying roll, 12: Developing roll, 13: First developer accommodating chamber, 14: Second developer accommodating chamber, 15: First agitating / conveying member, 16: Second agitating / conveying member, 17: partition wall, 18: toner supply port,
21: Suction tube, 22: Opening, 22a: Side of the opening facing away from the folding line, 23: Side of the first plate member, 23a: Development roller of the first plate member Opposing surfaces, 24: second plate-like member, 24a: bent portion at the tip of the second plate-like member, 24b: tip-facing surface of the second plate-like member, 25: cylindrical portion, 26, 27: Side edge part of plate-like member, 28: Blower, 29: Thin plate member,
31: Opening, 31a: Side near the toner transfer position D of the opening, 31b: Other side adjacent to the side of the opening near the toner transfer position D, 32: First plate member, 32a: First plate shape Cutouts of parts,
41: developing device, 42: developing roll, 43, 44: toner suction device,
51: belt-shaped image carrier, 52: developing device, 53: toner layer conveying roll, 54: developing roll, 55: toner suction device, 56: toner suction device,
61: Charging device 62: Exposure device 63: Transfer device 64: Cleaning device 65: Fixing device 66: Recording medium supply unit

Claims (7)

Toner that adheres to the latent image due to the difference in electrostatic potential is provided with an opening opposite to the position where the toner for forming a visible image is transferred between the members facing each other, and the toner scattered at the position where the toner is transferred A suction tube for suction;
Air flow generating means for generating an air flow so as to suck air into the suction pipe through the opening, and
The opening sucks the toner upward from the position where the toner is transferred , and a plurality of the thin plate members attached so as to close the suction pipe at the tip of the suction pipe are provided at intervals. , Each opening extends from a position close to the position where the toner is transferred to a position away from the position,
A toner suction device characterized in that the shape of the opening is such that the dimension in the width direction with respect to the direction increases toward the position where the toner is transferred. The opening of the suction tube is located at a position where toner is transferred from the developing member to an image holding body having an endless peripheral surface, or at a position facing the image holding body by holding a toner layer on the endless peripheral surface. It is provided opposite to the position where the toner is transferred from the developing member to the toner layer conveying member to be conveyed,
The shape of the portion of the opening facing the image carrier or the toner layer carrying member is in the width direction of the circumferential surface of the image carrier or toner layer carrying member toward the direction approaching the position where the toner is transferred. 2. The toner suction device according to claim 1, wherein the size of the toner suction device is increased. The opening is continuously provided from a portion of the suction tube facing the image carrier or the toner layer transport member to a portion facing the developing member,
The edge of the part of the opening facing the developing member on the side away from the toner transfer position is located above the peripheral surface of the developing member. Toner suction device. Toner that adheres to the latent image due to the difference in electrostatic potential is provided with an opening opposite to the position where the toner for forming a visible image is transferred between the members facing each other, and the toner scattered at the position where the toner is transferred A suction tube for suction;
Air flow generating means for generating an air flow so as to suck air into the suction pipe through the opening, and
The opening of the suction tube is
The toner is sucked upward from the position where the toner is transferred,
Developing to a toner layer transport member that transfers toner from the developing member to an image carrier having an endless peripheral surface, or transports the toner layer to a position facing the image carrier while holding the toner layer on the endless peripheral surface The suction pipe provided opposite to the position where the toner is transferred from the member ,
Two plate-like members that are arranged opposite to each other with their gaps connected to each other, and a thin plate that is attached to the tip of the plate-like member so as to close the gap between the two plate-like members A member, and
The thin plate member is bent at a folding line in the width direction of the circumferential surface of the image holding member or the toner layer conveying member, and both sides of the folding line are the developing member and the image holding member or the toner layer conveying member, respectively. It is attached to face
The opening is
Provided at a position adjacent to the folding line of the thin plate member,
It extends from a position close to the position where the toner is transferred to a position away from the position,
The shape of the portion of the opening facing the image carrier or the toner layer carrying member is in the width direction of the circumferential surface of the image carrier or toner layer carrying member toward the direction approaching the position where the toner is transferred. A toner suction device having an increased size . The plate-like member is supported at a position along the peripheral surface of the developing member,
The portion of the thin plate member facing the developing member is attached to the surface of the plate member facing the developing member,
The periphery of the opening of the plate member facing the developing member provided in the thin plate member is provided with a notch to a position retracted from the edge of the opening. The toner suction device according to claim. An image carrier for holding a latent image due to a difference in electrostatic potential on an endless peripheral surface;
Latent image forming means for forming a latent image on the image carrier;
A developing member that conveys the toner held on the endless peripheral surface to a position facing the image carrier, and transfers the toner to a latent image formed on the image carrier to develop the latent image; A developing device;
A transfer device for transferring the toner transferred onto the image carrier to a recording medium or to a recording medium via an intermediate transfer body;
6. A toner suction device according to claim 1, wherein the toner suction device sucks toner scattered from a position at which toner is transferred from a developing member provided in the developing device to the image holding member. An image forming apparatus. An image carrier for holding a latent image due to a difference in electrostatic potential on an endless peripheral surface;
Latent image forming means for forming a latent image on the image carrier;
A toner layer conveying member that holds a toner layer on an endless peripheral surface and conveys the toner layer to a position facing the image carrier, and a developing member that transfers toner onto the peripheral surface of the toner layer conveying member; A developing device for developing a latent image on the image carrier;
A transfer device for transferring the toner transferred onto the image carrier to a recording medium or to a recording medium via an intermediate transfer body;
The toner suction device according to claim 1, wherein the toner suction device sucks toner scattered from a position at which the toner is transferred from the developing member provided in the developing device to the toner layer transport member. An image forming apparatus.

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