JP4502771B2 - Development unit - Google Patents

Description

  The present invention relates to a developing unit that stores a developer used in an image forming apparatus such as a copying machine, a facsimile machine, and a printer.

  Conventionally, as this type of developing unit, there are those described in Patent Documents 1 to 3. In Patent Document 1, a cap is provided on a wall surface of a developer container containing a developer, a filter is attached to the cap, and the pressure in the developer container is released through the filter so that the developer seals the developer container. A technique for preventing leakage from the location together with air is disclosed.

In Patent Documents 2 and 3, a mesh filter is provided between a developer container containing a new developer and a collection container containing the collected developer, and the collected developer is obtained by the mesh filter. A technique is disclosed in which only the recyclable developer is passed from the collection container to the developer container to improve the utilization efficiency of the developer.
JP 2000-75624 A Japanese Patent Laid-Open No. 11-7227 Japanese Patent Laid-Open No. 10-142909

  By the way, in the image forming apparatus, the developing unit containing the developer is a consumable part and requires maintenance such as transportation and replacement. For this reason, a shock may be applied to the developing unit due to dropping or rough handling, and at this time, the pressure in the developing unit space containing the developer suddenly rises and the developer leaks from the developing unit together with air Invited.

  However, in Patent Document 1, although the pressure in the developing container can be released through the filter, the developer also passes through the filter together with air, so that the developer cannot be prevented from leaking outside.

  Further, in Patent Documents 2 and 3, no contrivance for releasing the pressure in the developer container has been made. Even if the pressure in the developer container can be released to the collection container through the mesh filter, a large amount of developer also moves to the collection container through the mesh filter.

  Accordingly, the present invention has been made in view of the above-described conventional problems, and even if the pressure in the developing unit space containing the developer suddenly increases, the developing unit does not leak together with the air. The purpose is to provide.

In order to solve the above problems, the present invention provides a developing unit comprising a developer container containing a developer to be supplied to the image forming, and a collection container for containing the collected developer, the collection container Is detachably mounted on the side wall of the developer container, and a filter is provided between the developer container and the collection container to release the space pressure in the developer container raised by the impact to the collection container, and the filter includes the developer It is attached to a cap provided detachably in the hole of the container or the hole of the recovery container.

  Furthermore, in the present invention, the cap is detachably mounted from the collection container side.

  In the present invention, a plurality of small holes are provided in the cap, and a filter is provided so as to overlap each small hole of the cap.

  Furthermore, in the present invention, the filter is disposed apart from the bottom of the collection container.

  Moreover, in this invention, a filter is a nonwoven fabric.

  According to such a developing unit of the present invention, a filter is provided between the developer container and the collection container to release the pressure in the developer container to the collection container. For this reason, even if the developer unit is shocked by dropping or rough handling, and the pressure in the developer container suddenly increases, the pressure in the developer container escapes to the recovery container through the filter. In addition, an increase in pressure in the developer container can be suppressed. This prevents the developer from leaking out of the developer container. Further, even if the developer leaks together with air from the developer container to the collection container through the filter, the developer remains in the collection container, so that the developer is not scattered outside.

  Further, a removable cap is provided between the developer container and the collection container, and a filter is provided on the cap.

  The collection container is detachably provided with respect to the developer container, and the cap is disposed on the collection container side. Alternatively, the collection container is provided detachably with respect to the developer container, and the cap is disposed on the developer container side. In this case, only the recovery container can be removed from the developer container, and the recovered developer in the recovery container can be discarded or the recovery container can be replaced.

  Further, since the cap is detachably attached from the collection container side, the new developer can be supplied to the developer container by further removing the cap with the collection container removed.

  In addition, since the cap is provided with a plurality of small holes and the filter is provided so as to overlap each small hole of the cap, even a large filter can be reliably supported to prevent the filter from peeling off. Further, the pressure in the developer container can be quickly released through the filter and each small hole, and the strength of the cap is further improved.

  Further, since the filter is disposed away from the bottom of the collection container, even if the collected developer is collected in the collection container, the filter is not buried in the collected developer.

  Moreover, since the nonwoven fabric is used as the filter, the filter is less likely to be clogged or damaged.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a side view showing an image forming apparatus to which the first embodiment of the developing unit of the present invention is applied. The image forming apparatus 100 forms a multicolor or single color image on a recording sheet based on image data supplied from the outside. Inside the image forming apparatus 100, image forming stations 110a to 110d, a transfer conveyance belt unit 120, a fixing unit 130, a paper feed tray 140, and a control unit 150 are provided.

  The transfer / conveyance belt unit 120 is disposed at a substantially central portion inside the image forming apparatus 100, and an upper end portion of the endless transfer / conveyance belt 121 is made substantially horizontal by a driving roller 122, a driven roller 123, and tension rollers 124 and 125. It is stretched in a loop shape. The transfer conveyance belt 121 rotates in the direction of arrow A by the rotation of the driving roller 122 and conveys the recording paper electrostatically attracted to the outer surface in the upper portion of the loop. The transfer / conveying belt 121 is cleaned by a cleaner 126 at the lower portion of the loop. This is to remove the toner adhering to the photosensitive drums 111a to 111d, which will be described later, and prevent the back surface of the recording paper from being stained.

  The image forming stations 110a to 110d are arranged side by side along an upper portion of a loop formed by the transfer conveyance belt 121. Each of the image forming stations 110a to 110d has the same configuration, and performs electrophotographic image formation based on image data of each color of black (K), cyan (C), magenta (M), and yellow (Y). Do. As an example, in the image forming station 110a, a charger 112a, an exposure unit 113a, a developing unit 114a, a transfer unit 115a, and a cleaner 116a are arranged around the photosensitive drum 111a in this order along the rotation direction of the photosensitive drum 111a. Configured.

  The photoconductive drum 111a has a photoconductive layer that generates a photoconductive action on the surface, and is supported so as to be rotatable in the direction indicated by the arrow in the figure. The charger 112a uniformly charges the surface of the photosensitive drum 111a to a predetermined potential by a roller-type or brush-type contact method or a charger method that performs corona discharge. The exposure unit 113a uses a writing head in which light-emitting elements such as EL or LED are arranged in an array in the rotational axis direction (main scanning direction) of the photosensitive drum 111a, or laser light emitted from a semiconductor laser by a rotating polygon mirror. A laser scanning unit (LSU) that deflects in the main scanning direction, and exposes the surface of the photosensitive drum 111a with image light modulated based on K image data. An electrostatic latent image is formed on the surface of the photosensitive drum 111a by exposure of image light from the exposure unit 113a.

  The developing unit 114a supplies K toner to the surface of the photosensitive drum 111a on which the electrostatic latent image is formed, and visualizes the electrostatic latent image into a K toner image. The transfer device 115a faces the photosensitive drum 111a across the upper portion of the loop formed by the transfer conveyance belt 121, and a high voltage having a polarity opposite to the charging polarity of the toner is applied. As an example, the transfer device 115a is configured by covering a surface of a metal roller such as stainless steel having a diameter of 8 to 10 mm with a conductive elastic material made of EPDM, urethane foam, or the like. A high voltage is uniformly applied to the electrostatically adsorbing recording paper to transfer the toner image carried on the surface of the photosensitive drum 111a onto the surface of the recording paper. The transfer device 115a can also be configured in a brush shape. The cleaner unit 116a collects toner, paper dust, and the like remaining on the surface of the photosensitive drum 111a that has passed through the position facing the transfer unit 115a.

  As described above, the image forming stations 110b to 110d perform image formation based on the image data of C, M, and Y, respectively. Therefore, the exposure units 113b to 113d have images of C, M, and Y, respectively. Data is supplied, and C, M, and Y toners are stored in each of the developing units 114b to 114d.

  The paper feed tray 140 stores recording paper used for image formation, and is detachably mounted below the image forming apparatus 100. Inside the image forming apparatus 100, the upper portion of the loop formed by the transfer conveyance belt 121 from the paper feed tray 140, and between the pressure roller 131 and the pressure roller 132 in the fixing unit 130, A pickup roller 141, conveying rollers 161 to 163, registration rollers are provided between the paper discharge tray 170 a mounted on one side surface of the image forming apparatus 100 and the paper discharge tray 170 b formed on the top of the image forming apparatus 100. 164, flapper 165, and paper discharge roller 166 constitute a paper transport path 160.

  The paper discharge tray 170a stacks and stores recording sheets on which images have been formed in a face-up state with the image forming surface facing upward. The paper discharge tray 170b stacks and stores recording sheets on which images have been formed in a face-down state with the image forming surface facing downward. The flapper 165 selectively switches the recording paper discharge position to the paper discharge tray 170a or the paper discharge tray 170b.

  The conveyance rollers 161 to 163 are small rollers for promoting and assisting the conveyance of the sheet, and a plurality of pairs are provided along the sheet conveyance path 160. The pickup roller 141 is disposed on one end side of the paper feed tray 140 so as to face the uppermost surface of the recording paper stored in the paper feed tray 140, and guides the recording paper from the paper feed tray 140 to the paper transport path 160 one by one. . The registration roller 164 temporarily stops the recording sheet fed from the sheet feeding tray 140 on the upstream side of the transfer conveyance belt 121 in the sheet conveyance path 160, and then synchronizes with the rotation of each of the photosensitive drums 111a to 111d. It is guided to the transfer conveyance belt 121 at timing.

  That is, the registration roller 164 stops rotating at the timing when the recording paper is fed from the paper feed tray 140, and the front end of the recording paper is the position where the photosensitive drums 111a to 111d and the transfer devices 115a to 115d face each other. , The rotation starts at the timing coincident with the leading edge of the toner image carried on each of the photosensitive drums 111a to 111d. At the time of full-color image formation, the K, C, M, and Y toner images carried on the respective photoconductive drums 111a to 111d are superimposed on each other on a single recording sheet.

  The fixing unit 130 includes a heating roller 131 and a pressure roller 132. The heating roller 131 is controlled to a predetermined fixing temperature capable of melting the toner based on a signal from a temperature sensor (not shown), and the pressure roller 132 is in pressure contact with the heating roller 131 with a predetermined pressing force. The recording paper on which the toner image is transferred is heated and pressurized while passing through the fixing unit 130, and the toner image on the recording paper is melted and firmly fixed on the surface of the recording paper. The K, C, M, and Y toner images transferred onto one recording sheet at the time of full color image formation form a full color image by subtractive color mixing.

  At the time of full-color image formation, image formation is performed at all of the four image forming stations 110a to 110d. At the time of single-color image formation for forming a single-color image such as a monochrome image, among the four image forming stations 110a to 110d, formation is performed. Image formation is performed only in the image forming station corresponding to the image color to be processed.

  The paper discharge roller 166 discharges the recording paper conveyed toward the conveyance rollers 162 and 163 by the flapper 165 after passing through the fixing unit 130 to the paper discharge tray 170b in a face-down state. The paper discharge roller 166 is pivotally supported by the separator 1 constituting the sheet discharge means of the present invention at the upper end on one end side of the paper discharge tray 170b. The separator 1 is reciprocally movable over a predetermined range in a direction perpendicular to the sheet conveyance direction (the front-rear direction of the image forming apparatus 100), which is a direction perpendicular to the drawing. For example, recording during continuous image formation of a plurality of copies is performed. During the paper sorting process, the recording paper for each unit is sorted and discharged to a plurality of positions in the paper transport direction on the paper discharge tray 170b.

  By the way, in such an image forming apparatus 100, each of the developing units 114a to 114d causes the respective developing rollers to come into sliding contact with the respective photosensitive drums 111a to 111d so that the toner of each color of K, C, M, and Y is supplied. Since the photosensitive drums 111a to 111d are supplied, the developing roller and the like are consumed. Therefore, the developing units 114a to 114d are detachably mounted, and the developing units 114a to 114d are replaced at an appropriate time.

  Further, when the toner of each color of each developing unit 114a to 114d is low, it is necessary to replenish the toner.

  Further, when the toner is collected from the surfaces of the photosensitive drums 111a to 111d by the cleaner units 116a to 116d, the collected toner is returned to and stored in the developing units 114a to 114d. For this reason, it is necessary to remove the collected toner from the developing units 114a to 114d.

  Therefore, the development unit requires maintenance such as transportation and replacement. For this reason, a shock may be applied to the developing unit due to dropping or rough handling, and at this time, the pressure in the developing unit space containing the developer suddenly increases, and the developer may leak out from the developing unit together with air There is sex. For example, even if the walls forming the developing unit space are sealed with an elastic member such as sponge or an adhesive, the developer leaks from the walls together with air.

  Therefore, the developing unit of this embodiment is configured so that the pressure in the developing unit space containing the developer is released, thereby preventing the developer from leaking out of the developing unit.

  Next, the configuration of the developing unit of this embodiment will be described in detail. FIG. 2 is a front view showing the developing units 114a to 114d. 3 is a cross-sectional view taken along the line AA ′ in FIG. 2, and FIG. 4 is a cross-sectional view taken along the line BB ′ in FIG.

  2 to 4, each developing unit 114a to 114d is denoted by reference numeral 114.

  The developing unit 114 includes a toner container 11 that stores toner supplied to the photosensitive drum, a developing unit 12 that supplies toner to the surface of the photosensitive drum, and a recovery container 13 that stores toner recovered by the cleaner unit. I have.

  The toner container 11 includes a stirring member 19 that rotates to stir the toner, a toner replenishing roller 14, and the like, and while stirring the toner, Toner is supplied to the developing unit 12. The developing unit 12 brings the developing roller 15 into sliding contact with the photosensitive drum through the opening 12a and supplies toner to the surface of the photosensitive drum.

  Further, the toner container 11 and the developing unit 12 are integrally provided, and the collection container 13 is detachably attached to the toner container 11.

  FIGS. 5A and 5B are side views conceptually showing the toner container 11 and the recovery container 13. The collection container 13 is a separate container from the toner container 11 and is mounted adjacent to the side wall of the toner container 11 as shown in FIG. 5A, and the toner container 11 as shown in FIG. 5B. Can be removed.

  Further, holes 11a and 13a that overlap each other are formed in the side wall of the toner container 11 and the side wall of the collection container 13, and the cap 16 is fitted into these holes 11a and 13a from the collection container 13 side. The position of the cap 16 is sufficiently separated from the bottom of the collection container 13.

  As shown in FIG. 6, the cap 16 is formed by forming a circular hole 16b in the disk portion 16a and attaching a circular filter 17 to the edge of the hole 16b. The filter 17 may be attached using an adhesive, heat welding, adhesive tape, or the like.

  As the filter 17, a filtering member such as a non-woven fabric, for example, one having an air permeability of about 4 sec according to the test method of JISP8117 can be applied. More specifically, “Himeron HN-E series” “HN616B (t0.7 mm)” (trade name) manufactured by Amvic, “Tyvek” made of DuPont's 100% durable high-density polyethylene ( Product name) and polyester mesh.

  Non-woven fabric means that webs of various fibers are processed mechanically, chemically, thermally, or a combination thereof without using a loom, and the constituent fibers are joined together by the adhesive or the fusing force of the fibers themselves. It is a made cloth. Since the fibers are directly formed into a sheet shape without passing through the form of yarn, the structure is completely different from that of woven or knitted fabrics. As the raw material fiber, cotton, rayon, acetate, nylon, polyester or the like is used singly or in a mixture. Production methods mainly include a dry method and a wet method.

  In the developing unit having such a configuration, it is assumed that during maintenance such as transportation or replacement, the developing unit is impacted by dropping or rough handling, and the pressure in the toner container 11 suddenly increases. However, the pressure in the toner container 11 is released to the collection container 13 through the filter 17, and the increase in the pressure in the toner container 11 is suppressed. This prevents the developer from leaking out of the toner container 11.

  Further, even if the developer leaks together with air from the toner container 11 through the filter 17 to the recovery container 13, the toner remains in the recovery container 13, so that the toner is not scattered outside.

  Furthermore, since the nonwoven fabric is applied as the filter 17, the filter 17 is not clogged with toner, and the filter 17 is hardly damaged.

  In addition, since the cap 16 is disposed away from the bottom of the collection container 13, even if the collected developer is collected in the collection container 13, the filter 17 of the cap 16 is buried in the collected developer. There is nothing.

  Further, a large amount of the collected toner is collected in the collection container 13, and even if the collection container 13 is removed from the toner container 11 for replacement, the filter 17 of the cap 16 prevents the toner from spilling out of the collection container 13. , The surroundings are not soiled and work efficiency is improved.

  Further, when the collection container 13 is removed, new toner can be replenished through the hole 11a on the side wall of the toner container 11.

  In addition, this invention is not limited to the said Example, It can deform | transform variously. For example, instead of the cap 16, a cap 16A as shown in FIG. The cap 16A has a plurality of small holes 16c formed in the disk portion 16a, and a filter 17 is attached to each small hole 16c. Accordingly, the filter 17 can be reliably supported and the filter 17 can be prevented from peeling off, and the pressure in the toner container 11 can be quickly released through the filter 17 and each small hole 16c, and the cap 16A. The strength of the is also improved.

  Moreover, it is good also considering the disc part 16a as a net-like thing instead of forming each small hole 16c. Further, ribs forming a net shape may be provided in a lattice shape or a radial shape.

  Further, as shown in FIG. 8, the recovery container 13 may be attached to the toner container 11 after the cap 16 is fitted into the hole 11 a on the side wall of the toner container 11. In this case, even if the collection container 13 is replaced, it is not necessary to replace the cap 16, and the cost can be reduced. In addition, when the collection container 13 is replaced, the toner does not leak from the toner container 11.

  Further, as shown in FIG. 9, the toner container 11 and the collection container 13 may be integrated, a hole 18a may be formed in the partition wall 18 between the toner container 11 and the collection container 13, and the filter 17 may be attached to the hole 18a. Also in this case, the pressure in the toner container 11 is released to the collection container 13 through the filter 17, and the increase in the pressure in the toner container 11 is suppressed.

  Alternatively, the cap 16 with the filter 17 may be fitted in one hole of the side wall of the toner container 11 and the side wall of the recovery container 13, and only the filter 17 may be attached to the other hole, and the two filters 17 may be arranged in an overlapping manner. I do not care. In this case, the pressure in the toner container 11 is released to the collection container 13 through the two filters 17.

  Further, a filter or a small hole is also provided on the side wall or top plate of the collection container 13 that does not overlap the side wall of the toner container 11, and the pressure released from the toner container 11 to the collection container 13 is further reduced from the filter or the small hole. You can pull it out.

1 is a side view illustrating an image forming apparatus to which a first embodiment of a developing unit of the present invention is applied. FIG. 2 is a front view showing a developing unit in the image forming apparatus of FIG. 1. It is sectional drawing which follows AA 'of FIG. It is sectional drawing which follows BB 'of FIG. (A) And (b) is a side view which shows notionally the developing unit of FIG. It is a disassembled perspective view which shows the cap of FIG. It is a disassembled perspective view which shows the modification of the cap of FIG. FIG. 10 is a side view showing a modification of the developing unit in FIG. 2. FIG. 10 is a side view showing another modification of the developing unit in FIG. 2.

Explanation of symbols

11 Toner container 12 Developing unit 13 Collection container 14 Toner replenishing roller 15 Developing roller 16 Cap 17 Filter 19 Stirring member 114 Developing unit

Claims (5)

In a developing unit comprising a developer container containing a developer supplied for image formation and a recovery container containing a recovered developer,
The recovery container is detachably mounted on the side wall of the developer container, and a filter is provided between the developer container and the recovery container to release the space pressure in the developer container that has been raised by the impact to the recovery container,
The developing unit, wherein the filter is attached to a cap detachably provided in a hole of the developer container or a hole of the recovery container . Developing unit according to claim 1, characterized in that removably mounting the cap from the collection container side. Developing unit according to claim 1 or 2, characterized in that said cap is provided with a plurality of small holes, provided overlapping the filter to each small hole of the cap. Developing unit according to any one of claims 1 to 3, characterized in that arranged by spacing the filter from the bottom of the collection container. The developing unit according to claim 1 , wherein the filter is a nonwoven fabric.

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