JP2012128245A - Developing unit and image-forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing unit capable of efficiently controlling temperature rising of a developer.SOLUTION: A developing unit at least comprises: a container for keeping a developer containing a non-magnetic coloring material and a magnetic particle; a first route and a second route that are provided in a parallel way so as for the developer in the container to be circulated in a longitudinal direction and that connect to each other through an aperture formed at one end; first conveyance means that is provided at the first route and delivers the conveyed developer from the first route side to the second route side through the aperture; and second conveyance means for conveying the developer delivered through the aperture to the opposite side of the aperture. A bottom included in the first route is configured so that at least a portion including an area facing the aperture has higher thermal conductivity than other portions forming the bottom.

Description

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

  In an image forming apparatus using an electrophotographic system such as a copying machine, a printer, and a facsimile machine, for example, a developer including toner (nonmagnetic colorant) and a carrier (magnetic particle) is used, and a photosensitive drum or the like is used. A process is generally performed in which an electrostatic latent image formed on an image holding member is visualized with a developer, and the visible image (toner image) is transferred onto a recording medium such as a printing paper and then fixed. .

  By the way, in the developing device using the developer, the developer is agitated and mixed to charge the toner in order to satisfactorily develop with a developing roller or the like that holds the developer.

  At this time, the temperature of the developer rises due to friction between the developers, friction between the developer and various members, and the toner may melt in the worst case.

  In particular, when the developer is circulated and transported in the container for storing the developer, if the developer stays at the end of the container, the temperature of the developer near the end is increased. It could rise further.

  Thus, various techniques for suppressing the temperature rise of the developer have been proposed (for example, Japanese Patent Application Laid-Open Nos. 2008-129562 and 2008-70402).

JP 2008-129562 A JP 2008-70402 A

  An object of the present invention is to provide a developing device and an image forming apparatus that can effectively suppress the temperature rise of a developer.

  In order to solve the above problems, the developing device according to the first aspect of the present invention includes a container in which a developer containing a colorant is accommodated, and a parallel state so that the developer in the container is circulated in the longitudinal direction. The first passage and the second passage communicated with each other through openings formed at both ends, and the first passage, and conveys the developer to one opening side while stirring. And a first conveying means for delivering the conveyed developer from the first passage side to the second passage side through the one opening, and the one of the second passages. At least a second transport unit that transports the developer passed through the other opening to the other opening, and the bottom of the first passage faces at least the one opening. The part that includes the region is the other part that forms the bottom. Characterized in that also is configured so that the heat conductivity is high.

  According to a second aspect of the present invention, there is provided a developing device according to the first aspect, wherein at least a portion of the bottom portion of the first passage corresponding to the region facing the one opening is dissipated. A heat dissipating member is provided to perform the above.

  According to a third aspect of the present invention, there is provided a developing device according to the first or second aspect of the invention, wherein the bottom portion of the first passage corresponds to at least a region facing the one opening. A cooling means for cooling the part is provided.

  According to a fourth aspect of the present invention, there is provided the developing device according to the third aspect, wherein the cooling means is provided along a longitudinal direction of the container, and a vent for introducing air into the container; It is characterized by comprising an introduction path that guides air introduced into the container through the vent to a region facing the at least one opening in the first passage.

  An image forming apparatus according to a fifth aspect of the present invention includes at least the developing device according to any one of the first to fourth aspects and an image forming unit that forms an image developed by the developing device on a recording medium. It is characterized by that.

  According to the present invention, the following effects can be obtained.

  That is, according to the first aspect of the present invention, compared to the case where the present structure is not provided, the portion including at least the region facing the opening is included in the bottom portion of the first passage more than the other portions. It is possible to provide a developing device that is configured to have high thermal conductivity and that effectively suppresses the temperature rise of the developer.

  According to the second aspect of the present invention, it is possible to provide a developing device that more effectively suppresses the temperature rise of the developer by means of the heat dissipating member as compared with the case where this configuration is not provided.

  According to the third aspect of the present invention, it is possible to provide a developing device that more effectively suppresses the temperature rise of the developer by the cooling means as compared with the case where this configuration is not provided.

  According to the fourth aspect of the present invention, it is possible to provide a developing device that more effectively suppresses the temperature rise of the developer as compared with the case where this configuration is not provided.

  According to the fifth aspect of the present invention, it is possible to provide an image forming apparatus that more effectively suppresses the temperature rise of the developer as compared with the case where this configuration is not provided.

1 is a configuration diagram illustrating a schematic configuration of an image forming apparatus according to an embodiment. 1 is a configuration diagram showing a schematic configuration of a developing device according to an embodiment. 1 is an internal configuration diagram illustrating a schematic configuration of a developing device according to an embodiment. It is explanatory drawing which shows the principal part of the developing device which concerns on embodiment. It is explanatory drawing which shows the circulation condition of the developer in the developing device which concerns on embodiment. 1 is a perspective view showing a schematic configuration of a developing device according to an embodiment. It is explanatory drawing which shows the principal part of the developing device which concerns on embodiment. 1 is an internal configuration diagram illustrating a schematic configuration of a developing device according to an embodiment. It is a perspective view which shows schematic structure of the developing device which concerns on other embodiment. It is a block diagram which shows schematic structure of the developing device which concerns on other embodiment.

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Here, in the accompanying drawings, the same reference numerals are given to the same members, and duplicate descriptions are omitted. In addition, since description here is the best form by which this invention is implemented, this invention is not limited to the said form.

  With reference to FIGS. 1 to 10, an image forming apparatus PR1 according to an embodiment of the present invention will be described.

  FIG. 1 is an overall explanatory view of an image forming apparatus (tandem digital color copying machine) PR1 according to an embodiment of the present invention.

  As shown in FIG. 1, the image forming apparatus PR1 includes a user interface UI, an image input apparatus U1, a paper feeding apparatus U2, an image forming apparatus main body U3, and a paper processing apparatus U4.

  The user interface UI includes buttons for performing various scans and a display UI1.

  The image input device U1 includes, for example, an automatic document feeder and an image scanner.

  The image input device U1 reads a document, converts it into R (red), G (green), and B (blue) image data, and inputs the image data to the image forming apparatus body U3.

  The sheet feeding device U2 includes a plurality of sheet feeding units TR1 to TR4, a sheet feeding path SH1 that takes out the recording sheets S for image recording accommodated in the sheet feeding units TR1 to TR4, and conveys them to the image forming apparatus body U3. Have.

  The image forming apparatus main body U3 includes an image recording unit that records an image on the recording sheet S conveyed from the sheet feeding device U2, a toner supply unit U3a, a sheet conveying path SH2, a sheet discharging path SH3, a sheet reversing path SH4, and a sheet path SH6. Etc.

  The image forming apparatus main body U3 includes a laser drive circuit D and a power supply circuit E that are controlled by the control device C.

  The laser drive circuit D, the operation of which is controlled by the control device C, is laser driven in accordance with Y (yellow), M (magenta), C (cyan), and K (black) image data input from the image input device U1. The signal is output to the latent image forming devices Ry, Rm, Rc, and Rk of the toner image forming devices UY, UM, UC, and UK of the respective colors.

A charger CCk, a developing device 100k, a cleaner CLk, and the like are disposed around the photosensitive drum Pk of the K (black) toner image forming apparatus UK.
Further, around the photosensitive drums Py, Pm, and Pc of the other toner image forming apparatuses UY, UM, and UC, the same chargers CCy, CCm, and CCc as those around the photosensitive drum Pk, the developing devices 100y, 100m, 100c, cleaners CLy, CLm, CLc, etc. are arranged.

  The developing devices 100y, 100m, 100c, and 100k have the same configuration, and are hereinafter collectively referred to as the developing device 100.

  The configuration of the developing device 100 will be described later.

  The photosensitive drums Py, Pm, Pc, and Pk are uniformly charged by the chargers CCy, CCm, CCc, and CCk, respectively, and then the laser beams Ly, Lm output from the latent image forming devices Ry, Rm, Rc, and Rk. , Lc and Lk form an electrostatic latent image on the surface. The electrostatic latent images on the surfaces of the photosensitive drums Py, Pm, Pc, and Pk are converted into Y (yellow), M (magenta), C (cyan), and K (black) colors by the developing devices 100y, 100m, 100c, and 100k. The toner image is developed.

  The toner images on the surfaces of the photosensitive drums Py, Pm, Pc, and Rk are sequentially transferred onto the intermediate transfer belt B by the primary transfer rolls T1y, T1m, T1c, and T1k, and a color image is transferred onto the intermediate transfer belt B. The formed color toner image formed on the intermediate transfer belt B is conveyed to the secondary transfer region Q4.

  After the primary transfer, residual toner on the surface of the photosensitive drums Py, Pm, Pc, and Pk is cleaned by the cleaners CLy, CLm, CLc, and CLk for the photosensitive drums.

  The belt BM includes an intermediate transfer belt B, a belt support roll (Rd, Rt, Rw, Rf, T2a) including a belt drive roll Rd, a tension roll Rt, a walking roll Rw, a plurality of idler rolls Rf, and a backup roll T2a. Primary transfer rolls T1y, T1m, T1c, and T1k are included.

  The intermediate transfer belt B is supported by a belt support roll (Rd, Rt, Rw, Rf, T2a) so as to rotate and move in the direction of the arrow Ya.

  A secondary transfer unit Ut is disposed below the backup roll T2a. A sheet transport path SH2 is disposed below the belt BM.

  The recording sheet S fed from the sheet feeding path SH1 of the sheet feeding device U2 is conveyed to the registration roll Rr in the sheet conveying path SH2, and the color toner image is conveyed to the secondary transfer area Q4 in time. The paper is conveyed to the secondary transfer region Q4 through the registration-side paper guide SGr and the pre-transfer paper guide SG2.

  The color toner image on the intermediate transfer belt B is transferred to the recording paper S by the secondary transfer unit T2 when passing through the secondary transfer region Q4. In the case of a full-color image, the toner images primarily transferred onto the surface of the intermediate transfer belt B are secondarily transferred onto the recording paper S all at once.

  The recording sheet S on which the toner image is secondarily transferred passes through the post-transfer sheet guide SG3 and the sheet transport belt BH, and a region (fixing region) Q5 where the pair of fixing rolls Fh and the pressure roller Fp of the fixing device F are in pressure contact with each other. It is conveyed to.

  The toner image on the recording paper S is heated and fixed by the fixing device F when passing through the fixing region Q5.

  The paper processing device U4 includes a curl correction device for the recording paper S and the like, and discharges the recording paper S to the paper discharge portion TH1 after processing.

  Next, the developing device 100 according to the embodiment will be described with reference to FIGS.

  As shown in FIG. 2, the developing device 100 is provided with a partition plate 48 inside the developing container 21 (an example of a container).

  The partition plate 48 partitions the first passage R1 and the second passage R2 for the developer.

  The first passage R1 and the second passage R2 are provided in a parallel state so that the developer in the developer container 21 is circulated in the longitudinal direction, and through an opening 200 formed at one end of the partition plate 48. (See FIG. 3 etc.).

  Through this opening 200, the developer is transferred from the first passage R1 side to the second passage R2 side (that is, from below to above).

  The first passage R1 communicates with the developer stirring chamber 56, and the second passage R2 communicates with the developer supply chamber 57.

  The partition plate 48 is provided such that one end thereof is fixed to the side surface of the developing container 21 and the other end extends in the direction of the developing roll 22.

  An opening 201 is also provided at the end opposite to the opening 200, and the developer is transferred from the second passage R2 side to the first passage R1 side (that is, from above to below). It is like that.

  In the vicinity of the photosensitive member 140 in the developer stirring chamber 56, there are provided a seal roll 23 for collecting floating toner and a scraper 24 for scraping off the floating toner hitting the seal roll 23, below the seal roll 23. A developer agitating and conveying member 26 (an example of a first conveying means) and an auxiliary conveying member 41 are provided in the first passage R1 located at the position.

  In addition, a supply conveyance member 27 (an example of a second conveyance unit) is provided in the second passage R <b> 2 leading to the developer supply chamber 57 so as to face the development roll (magnet roll) 22.

  Here, the conveyance auxiliary member 41 is provided between the seal roll 23 and the agitation conveyance member 26 in the horizontal direction and at a position between the agitation conveyance member 26 and the supply conveyance member 27 in the vertical direction.

  The conveyance auxiliary member 41 is configured to return the floating toner collected by the seal roll 23 and scraped off by the scraper 24 to the agitation conveyance member 26.

  In the present embodiment, the agitating / conveying member 26, the supply / conveying member 27, and the conveying auxiliary member 41 are configured in a spiral shape in which, for example, a rotating blade is provided with a spiral blade, but the present invention is not limited thereto. As long as it conveys, you may change suitably.

  A developer supply port 51 for supplying the developer is provided at the end of the developer stirring chamber 56.

  Here, as the developer, a two-component developer containing a non-magnetic colorant (toner) and magnetic particles (carrier) or a one-component developer containing a magnetic substance as a component is used.

  As shown in FIG. 3, the agitation transport member 26 is transported in the direction of arrow D <b> 1 toward the opening 200 in the first passage R <b> 1.

  The developer transferred from the first passage R1 to the second passage R2 through the opening 200 is transported in the direction of the arrow D2 toward the opening 201 by the supply transport member 27.

  Further, the developer transported to the opening 201 by the supply transport member 27 falls through the opening 201 to the first passage R1 side.

  As a result, the developer is circulated in the order of D1, D2, D1, and so on.

  In the developing device 100 having such a configuration, the developer replenished from the developer supply port 51 is first supplied into the developer stirring chamber 56 via the developer supply chamber 57 and the opening 201.

  The developer in the developer agitating chamber 56 is agitated and mixed by the agitating and conveying member 26 and conveyed to one end side (in the direction of the arrow D1) of the developer agitating chamber 56.

  A part of the developer conveyed to one end is conveyed in the direction of arrow D2 by the conveyance auxiliary member 41 in order to prevent the developer from being deposited near the opening 200, and the remaining developer is stirred by the developer. The developer is supplied from the chamber 56 through the opening 200 to the developer supply chamber 57 in the upper part thereof.

  The developer supplied to the developer supply chamber 57 is supplied from the supply conveyance member 27 to the developing roll 22, and the developer is supplied to the photoconductor 140.

  At this time, the floating toner floating between the developing roll 22 and the photoreceptor 140 is collected by the seal roll 23, and the collected floating toner is scraped off by the scraper 24 and then passed through the conveyance auxiliary member 41. Then, the developer is returned to the stirring and conveying member 26 in the developer stirring chamber 56.

  By the way, the developer delivered from the first path R1 to the second path R2 is held on the developing roll 22 by magnetic force (see arrow D10 in FIG. 4). A phenomenon that a part of the body 140 (see FIG. 2) that has not been used for development returns to the first passage R1 again through the opening 200 (that is, the arrow D11 in FIGS. 4 and 5 → It has been found that a phenomenon in which another developer circulation such as D12 → D13 → D0 occurs).

  Then, while being transported through the second path R2 by the supply transport member 27, the developer is radiated to some extent and then returns to the first path R1 through the opening 201, and is then transported by the stirring transport member 26. It is circulated to the opening 201. Thereby, an excessive temperature rise of the developer is suppressed.

  However, for the developer circulating in the vicinity of the opening 200 due to the phenomenon as described above, heat is not radiated through the above-described path, so that the developer continues to be stressed in the region 300 shown in FIG. 5, for example. There is a problem that the temperature of the developer increases.

  Therefore, in the embodiment according to the present invention, the thermal conductivity of the bottom portion R1a of the first passage R1 corresponding to the region A1 shown in FIGS. 3, 6, and 7 is higher than that of the other portion R1b. To improve heat dissipation.

  More specifically, when the bottom portion of the first passage R1 corresponding to the other portion R1b is made of, for example, ABS resin (thermal conductivity: 0.17 to 0.21 W / mK), it corresponds to the region A1. The bottom R1a of the first passage R1 is made of, for example, polyacetal (polyoxymethylene: abbreviation POM) (thermal conductivity: 0.25 W / mK).

  Further, the bottom portion R1a of the first passage R1 corresponding to the region A1 may be made of a nonmagnetic metal such as aluminum.

  In addition, the attachment method of bottom R1a of 1st channel | path R1 is not specifically limited, For example, screwing, adhesion | attachment, welding, etc. can be considered.

  Thereby, heat is radiated through the bottom portion R1a of the first passage R1 corresponding to the region A1, and the temperature rise of the developer is suppressed.

  Also, the area A1 shown in FIGS. 3, 6 and 7 is an area facing the opening 200, and this area may be the minimum area and the area A1 may be wider.

  That is, for example, as shown in FIG. 8, for example, the entire width of the first passage R1 or a portion facing the partition plate 48 and the opening 200 is defined as a region A2 (maximum region), and the first passage corresponding to this region A2 is used. The bottom portion R1a of R1 may have higher thermal conductivity than other portions.

  Further, as described above, the bottom portion R1a of the first passage R1 corresponding to the regions A1 and A2 is made to have higher thermal conductivity than other portions, or instead, the regions A1 and A2 A heat radiating member such as a heat radiating fin may be provided on the outer surface of the bottom R1a of the corresponding first passage R1.

  Further, a groove may be formed on the outer surface of the bottom R1a of the first passage R1 to increase the surface area.

  Next, a developing device 100 ′ according to another embodiment will be described with reference to FIGS. 9 and 10.

  The overall configuration of the developing device 100 ′ is the same as that of the developing device 100.

  The developing device 100 ′ is provided along the longitudinal direction of the developing container 21, and has a vent 500 for introducing air into the developing container 21, and is introduced into the developing container 21 through the vent 500 (an arrow in FIG. 9). D20 (see D20) is provided with a cooling means including an introduction path 501 that guides air to be provided to at least a region facing the opening 200 in the first passage R1.

  As a result, the air introduced from the vent 500 is guided to the region facing the opening 200 from the direction of the arrow D21 via the introduction path 501, and the relatively high temperature developer circulating in the vicinity of the opening 200 is cooled by air. Is done.

  The cooling means may be provided for cooling the developer, or a structure for sucking the floating developer may be used.

  Thus, according to the image forming apparatus PR1 and the developing devices 100 and 100 'according to the present embodiment, the temperature rise of the developer is effectively suppressed.

  Although the invention made by the present inventor has been specifically described based on the embodiments, the embodiments disclosed herein are illustrative in all respects and are not limited to the disclosed technology. Should not be considered. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above embodiment, but should be construed according to the description of the scope of claims. All modifications that fall within the scope of the claims and the equivalent technology are included.

  For example, as a cooling means, a Peltier element or the like may be provided on the outer surface of the bottom portion R1a of the first passage R1.

  It is also conceivable to provide a flow path at the bottom R1a of the first passage R1 to circulate the refrigerant.

  Moreover, although the case where the first passage R1 and the second passage R2 are provided in parallel in the vertical direction has been described in the above embodiment, the present invention is not limited thereto, and the first passage R1 and the second passage R2 are provided. This is also applied to the case where are provided in parallel in the horizontal direction.

  The developing device and the image forming apparatus according to the present invention can be applied to a printer, a multifunction machine, or the like using a developer.

PR1 Image forming apparatus 100 Developing device R1 First passage R1a Bottom portion R1b Other portion R2 Second passage 21 Developing container 22 Developing roll 23 Seal roll 24 Scraper 26 Stirring conveyance member 27 Supply conveyance member 41 Conveyance auxiliary member 48 Partition plate 51 Developer supply port 56 Developer stirring chamber 57 Developer supply chamber 140 Photoconductor 200 Opening 201 Opening 500 Vent 501 Inlet path B Intermediate transfer belt BH Paper transport belt BM Belt C Controllers CCy, CCm, CCc, CCk Charging CLy, CLm, CLc, CLk Cleaner D Laser drive circuit E Power supply circuit F Fixing device Fh Fixing roll Fp Pressure rolls Ly, Lm, Lc, Lk Laser beam Py, Pm, Pc, Pk Photosensitive drum Q4 Secondary transfer region Q5 Fixing region Rd Belt drive roll Rf Idler roll Ry Rm, Rc, Rk latent image forming device Rr register roll Rt tension roll Rw walking roll S recording paper T1y, T1m, T1c, T1k 1 transfer roll T2 2 transfer device T2a backup roll TH1 sheet discharge portion

Claims (5)

A container for storing a developer containing a colorant;
A first passage and a second passage which are provided in parallel so that the developer in the container is circulated in the longitudinal direction and communicate with each other through openings formed at both ends;
The developer is provided in the first passage and transports the developer to one opening side while stirring, and the developer that has been transported is conveyed from the first passage side to the second passage through the one opening portion. First conveying means to be transferred to the side;
A second transport unit that is provided in the second passage and transports the developer passed through the one opening to the other opening;
Comprising at least
The bottom part of the first passage is configured such that a part including at least a region facing the one opening part has a higher thermal conductivity than the other part forming the bottom part. Developing device.   2. The developing device according to claim 1, wherein a heat radiating member for radiating heat from the portion of the bottom portion of the first passage is provided in a portion corresponding to at least a region facing the one opening.   3. The development according to claim 1, further comprising: a cooling unit configured to cool at least a portion corresponding to a region facing the one opening portion of the bottom portion of the first passage. apparatus. The cooling means is
A vent provided along the longitudinal direction of the container, for introducing air into the container;
An introduction path for guiding air introduced into the container through the vent hole to a region of the first passage facing the at least one opening;
The developing device according to claim 3, comprising: A developing device according to any one of claims 1 to 4,
Image forming means for forming an image developed by the developing device on a recording medium;
An image forming apparatus comprising:

Images