Abstract:
A development apparatus for use in an image forming device includes a developer storage chamber for storing developer, a developer carrier having a film of the developer formed thereon, wherein a visible image is formed when the film interacts with an electrostatic latent image, and a developer feed member arranged adjacent to the opening of the developer storage chamber and configured to feed developer from the developer storage chamber to the developer carrier. A developer leakage prevention member is located between the developer feed member and the developer carrier and an adhesive adheres to the developer leakage prevention member in the longitudinal direction of the opening. Also, a layer including an agent is formed between the adhesive and the developer feed member.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims priority from Japanese Patent Application No. 2005-246026, filed on Aug. 26, 2005, the entire subject matter of which is incorporated herein by reference.  
       FIELD  
       [0002]     Aspects of the present invention relate to a development apparatus performing development using charged micro particles as a developer, a process cartridge, a development apparatus cartridge, and an image forming device using one of the above.  
       BACKGROUND  
       [0003]     In a development apparatus wherein the developing processing is carried out using toner, which is provided as charged micro particles as a developer and by depositing the toner as an electrostatic latent image, there is a problem with the leakage of toner from the development apparatus. If the leakage of toner occurs, the interior of the image forming device using the development apparatus is stained. As a result, printing failure may occur and an operator&#39;s hands and clothes may be soiled with the toner when the operator replaces the development apparatus.  
         [0004]     In the case of non-magnetic single component developing wherein a toner film is formed with a film thickness regulating blade on the developing roller having functions of conveyance while carrying the toner and faced against the electrostatic latent image to proceed with developing process, leakage of toner occurs easily around the developing rollers that are rotating.  
         [0005]     In order to prevent the leakage of toner from the direction of both ends of the developing roller, as in Japanese Laid Open Patent Application Publication 2001-134080, a side seal constituting a substrate of an end-to-end developer leakage prevention member slides on the circumferential face of the both ends of the developing roller, and a double-faced tape is used for installation in the case of the development apparatus.  
         [0006]     At both ends of the feed roller for feeding a toner to the developing roller, a side end toner leakage prevention member called a feed roller seal is arranged to face both ends and a side seal is installed in the development apparatus case to cover the feed roller seal and prevent the leakage of toner from both ends of the feed roller.  
         [0007]     In a development apparatus, when the toner (developer) becomes empty, it is replaced with a new development apparatus and the old development apparatus is recycled. When recycling the development apparatus, the old side seal (end-to-end developer leakage prevention member) is removed from the development apparatus case and a new side seal is installed. However, as mentioned above, since the side seal is installed using a double-faced tape in the case of the development apparatus, the side seal may be broken unless it is peeled properly. Peeling the side seal becomes more troublesome since residual side seal and double-faced tape (double-faced adhesive) must be further peeled off from the case of the development apparatus. In addition, installing a side seal at an appropriate position in the development apparatus case can become difficult due to the presence of double-faced tape on the back of the side seal. If the side seal adheres to the case of the development apparatus, it can be difficult to change the position of the side seal. In addition, when changing the position of the side seal, wrinkles and stretches frequently occur, which causes leakage of toner.  
       SUMMARY  
       [0008]     At least some aspects of the present invention provide a development apparatus, process cartridge, development apparatus cartridge, and image forming device wherein the leakage of toner due to inappropriate installation of the toner leakage prevention member can be prevented. According to at least some aspects, the task of removing the old side seal (end-to-end developer leakage prevention member) from the development apparatus case, and installing a new side seal may be simplified.  
         [0009]     According to at least one aspect of the invention, a development apparatus for use in an image forming device includes a developer storage chamber for storing developer, a developer carrier having a film of the developer formed thereon, wherein a visible image is formed when the film interacts with an electrostatic latent image, and a developer feed member arranged adjacent to the opening of the developer storage chamber and configured to feed developer from the developer storage chamber to the developer carrier. A developer leakage prevention member is located between the developer feed member and the developer carrier and an adhesive adheres to the developer leakage prevention member in the longitudinal direction of the opening. Also, a layer including an agent is formed between the adhesive and the developer feed member.  
         [0010]     In other illustrative aspects, the developer apparatus may include a case containing a developer storage chamber for storing developer, a developer carrier having a film of the developer formed thereon, wherein a visible image is formed when the film interacts with an electrostatic latent image, and a developer feed member arranged adjacent to an opening of the developer storage chamber and configured to feed developer from the developer storage chamber to the developer carrier. Also, the case may include a developer leakage prevention member located between the case and the developer carrier, an adhesive located between the case and the developer leakage prevention member and adhering to the developer leakage prevention member in the longitudinal direction of the opening, and a layer including an agent contacting the adhesive and the case. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a cross-sectional view showing the overall configuration of an image forming device according to at least one aspect of the present invention.  
         [0012]      FIG. 2A  is a partially dotted oblique view showing sealed units in the development apparatus case before installation of sealing members according to at least one aspect of the invention.  
         [0013]      FIG. 2B  is a view of the sealed units from the direction of the arrow B shown in  FIG. 2A .  
         [0014]      FIG. 3A  is a partially dotted oblique view showing sealed units in the development apparatus case when a side seal is installed according to at least one aspect of the invention.  FIG. 3B  is a view of the sealed units from the direction of the arrow B shown in  FIG. 3A .  
         [0015]      FIG. 4  is a partially dotted oblique view showing sealed units in the case after installing the lower film according to at least one aspect of the invention. 
     
    
     DETAILED DESCRIPTION  
       [0016]     Illustrative aspects of the present invention are explained below with reference to the attached drawings.  
         [0017]      FIG. 1  is a cross-sectional view showing an overall configuration of a laser beam printer  1  as an image forming device according to at least one aspect of the present invention. In  FIG. 1 , the laser beam printer  1  as an image forming device is equipped with a feeder unit for feeding a recording medium (e.g., paper) at the bottom of a body case  2 . The feeder unit includes a press plate  10  that is pressed with a spring (not shown), a feed roller  11 , and a friction separation member  14 . The recording medium is pressed by the press plate  10  against the feed roller  11  and with rotation of the feed roller  11 , a recording medium on the top of a stack (if more than one recording medium is present) is input between the feed roller  11  and the friction separation member  14  to feed the recording medium.  
         [0018]     At the downstream side in the direction of recording medium transfer due to the rotation of the feed roller  11  rotating in the direction of the arrow in  FIG. 1 , a pair of resist rollers  12  and  13  is installed in a rotating position to carry the recording medium to the transfer position at a specified timing constituted by a photosensitive drum  20  and a transfer roller  21  to be discussed later.  
         [0019]     The photosensitive drum  20  as a carrier of the electrostatic latent images is made of positively charged materials, for example, an organic photosensitive material primarily made of positively charged polycarbonate. Specifically, the photosensitive drum  20  includes a cylindrically-shaped aluminum cylindrical sleeve as a body, and a hollow drum forming a photoconductive layer with a specified thickness (e.g., approximately 20 μm) prepared by dispersing photoconductive resin in the polycarbonate. The cylindrical sleeve that is grounded is supported in a fully rotating manner through the body case  2 . Moreover, the photosensitive drum  20  is driven to be rotated in the direction of the arrow using a driving means (not shown).  
         [0020]     A charger  30  is constituted of, for example, a Scorotron type charger for positive charging that generates corona discharge from a wire for charging such as tungsten.  
         [0021]     A laser scanner unit  40  includes a laser generator (not shown) for generating laser beam L for forming electrostatic latent images on the photosensitive drum  20 , a polygon mirror (a pentahedron mirror)  41  to be rotated, a pair of lenses  42  and  45 , and reflective mirrors  43 ,  44  and  46 .  
         [0022]     In a development apparatus  50 , a toner storage chamber  52  containing a toner as a developer is constituted in a development apparatus case  51 , and an agitator  53  and a cleaning member  54  are installed in a fully rotating manner around the rotary shaft  55  in the toner storage chamber  52 . In this toner storage chamber  52 , positively charged non-magnetic one-component developer having an electrical insulation is stored as a toner. A light transmitting window  56  is installed at the side wall located at both edges of the rotary shaft  55  of the toner storage chamber  52 . Additionally, at the side of the photosensitive drum  20  of the toner storage chamber  52 , an opening A is made as an opening part of the development apparatus case and a developing chamber  57  connects to the toner storage chamber  52  via this opening A in order to perform a developing process. Also, a feed roller  58  as a developer feed roller and a developing roller  59  as a developer carrier are supported in a fully rotating manner. The feed roller  58  and the feed roller shaft  58   a  constitute a developer feed member in order to feed a toner in the toner storage chamber  52  to the developing roller  59 . The amount of toner on the developing roller  59  that is fed by the feed roller  58  is regulated to a specified layer thickness using a layer thickness regulating blade  64  having a thin plate elasticity.  
         [0023]     The developing roller  59  contains a cylindrical substrate made of a conductive silicone rubber containing conductive carbon micro particles on the core metal made of stainless steel. Furthermore, a resin containing fluorine or a rubber material coat layer is constituted on this substrate. However, it is not always necessary that the substrate of the developing roller  59  be made of conductive silicone rubber; conductive urethane rubber may also be used.  
         [0024]     Additionally, the toner stored in the toner storage chamber  52  is a positively charged non-magnetic one-component developer which contains toner base particles with a volumetric mean particle size of 10 μm with the particle size ranging from 5 μm to 15 μm. The particles are constituted in a spherical shape by suspension polymerization in which a known colorant such as carbon black and a charging control agent such as nigrosin, triphenylmethane, quaternary ammonium salts are added to a monomer mixture of styrene and acryl. The toner is then constituted by adding silica as an external additive on the surface of the toner base particles.  
         [0025]     The transfer roller  21  is supported in a fully rotating manner and is made of a foaming elastomer having conductivity such as silicone rubber and urethane rubber. The transfer roller  21  is constituted such that a toner image on the photosensitive drum  20  is definitely transferred onto a recording medium when a voltage is applied.  
         [0026]     The fixing unit  70  is installed at the downstream side in the transfer direction of the recording medium from the resist rollers  12  and  13  to the pressure contact units with the photosensitive drum  20  and the transfer roller  21 , and also includes a heated roller  71  and a pressing roller  72 . The toner image transferred on the recording medium is heated and pressed by the heated roller  71  and pressing roller  72  while being transferred to be fixed on the recording medium.  
         [0027]     A pair of carriage rollers  73  and an ejection roller  74  for transferring the recording medium is installed at the downstream side in the direction of carriage in the fixing unit  70 , and an ejection tray  75  is provided at the downstream side of the ejection roller  74 .  
         [0028]     The aforementioned photosensitive drum  20 , transfer roller  21 , charger  30  and development apparatus  50  are stored in a process cartridge  2   a , and the process cartridge  2   a  is installed in a fully detachable manner to the laser beam printer  1 . Moreover, the development apparatus  50  is installed as a development apparatus cartridge in a fully detachable manner to the process cartridge  2   a.    
         [0029]     In the laser beam printer  1  as in the aspects described above, when the surface of the photosensitive drum  20  is uniformly charged by the charger  30  and the laser beam L modulated according to the image information is irradiated from the laser scanner unit  40 , an electrostatic latent image is formed on the photosensitive drum  20 . This electrostatic latent image is visualized with a toner in the development apparatus  50 , and the visual image formed on the photosensitive drum  20  is then carried to a transfer position by the photosensitive drum  20 . To reach the transfer position, a recording medium is fed from the feed roller  11  via resist rollers  12  and  13 , and the visual image is imprinted on the recording medium by a transfer bias applied by the transfer roller  21 . In this case, the remaining toner on the photosensitive drum  20  after the transfer is recovered by the developing roller  59  in the developing chamber  57 .  
         [0030]     Next, the recording medium is carried to the fixing unit  70  and inserted through the heated roller  71  and the pressing roller  72  in the fixing unit  70  so that the visual image on the recording medium is fixed on the recording medium by application of pressure and heat. The recording medium discharged to an ejection tray  75  above the laser beam printer  1  via a pair of the carriage rollers  73  and the ejection roller  74 .  
         [0031]     Next, a sealing structure for the prevention of leakage of toner in the development apparatus  50  according to some aspects of the invention will be explained with reference to  FIG. 2  or  FIG. 4  along with the installation procedures.  
         [0032]      FIG. 2A  and  FIG. 3A  are partially dotted oblique views showing a sealing structure of the case  51  in the development apparatus  50  according to at least one aspect of the inventions. Additionally,  FIG. 2B  and  FIG. 3B  are the partially dotted oblique views seen from the direction of the arrow B in  FIGS. 2A and 3A , respectively.  
         [0033]     In  FIG. 2A , the area indicated by the oblique lines is installed using a double-faced tape as a double-faced adhesive member as the sealing member explained below, which is divided into a side seal installation area  100  along the circumferential direction of the developing roller  59 , and a lower sealed area  101  along the longitudinal direction of the developing roller  59  in the lower position of the developing roller  59 .  
         [0034]     In the side seal installation area  100  of the case  51 , an opening  51   c  for installing the feed roller  58  is formed in order to install a feed roller seal  109 . The feed roller seal  109  constitutes a side edge face developer leakage prevention member. The feed roller seal  109  can be a cubic urethane sponge (or other appropriate material that would prevent leakage) forming an opening  109   a  the size of the feed roller shaft  58   a  (see  FIG. 1 ) in the longitudinal direction of the feed roller  58  as indicated by the two-dotted broken parallel lines in  FIG. 2A . This feed roller seal  109  is positioned such that it is installed to face the side end face of the feed roller  58 , and it is also installed so that one of the edges of the feed roller seal  109  faces a side face of the opening  51   c . The side end face of the feed roller  58  slides against a portion of the side end face of the side seal  104  (this element is shown in  FIG. 3A ) and the side face of the feed roller seal  109  so that it prevents leakage of the toner from the side end face of the feed roller  58 .  
         [0035]     Additionally, the developing roller  59  is arranged such that a side face unit comes close to, but does not contact the side face unit  51   a  of the developing roller storage unit in case  51  shown in  FIG. 2A . The center point Q shown in  FIG. 2B  indicates the position of the central rotational axis of the developing roller  59 .  
         [0036]     Next, as shown in  FIG. 3A  and  FIG. 3B , in order to prevent leakage of toner from both ends of the developing roller  59 , side seal  104  is installed with double-faced tape  102 . A Teflon® felt  113  constituting the upper-most layer of an end-to-end developer leakage prevention member is located on the upper face of the side seal  104  and extends to the side seal installation area  100  indicated by the two-dotted lines in  FIG. 3B . In  FIG. 4 , Teflon® felt  113  installed with a double-faced tape  102  is shown to cover the side seal  104 . The end-to-end developer leakage prevention member according to illustrative aspects of the present invention includes the side seal  104  and Teflon® felt  113 .  
         [0037]     The side seal  104  can be formed of a urethane sponge (e.g., Poron™ manufactured by the Rogers INOAC Foam Company) that has relatively high rigidity in comparison to other sponges and it can have a certain thickness to exhibit a specified pressure for compression when the developing roller  59  is installed. For instance, the thickness of the side seal  104  may be approximately 3 mm. When compressed against the developing roller  59 , the thickness of the side seal  104  may be approximately 1.5 mm. According to this aspect, the end-to-end developer leakage prevention member can be pressed with a specified pressure against the developing roller  59 .  
         [0038]     As shown in  FIG. 3B , the feed roller seal  109  is laminated with side seal  104  using the double-faced tape  102  adhered on the back of the side seal  104 . On the contact surface between the double-faced tape  102  and the feed roller seal  109 , a releasing layer  200  containing grease as a releasing agent is formed. The releasing agent may be any material, which allows the double-faced tape  102  and the feed roller seal  109  to be readily separated from each other when necessary (e.g., during servicing). For example, materials used in removing a plastic from a metal mold during a plug molding process could be used. Illustrative releasing agents included, but are not limited to, silicone oil, lubricant oil and fluorine solvents wherein fluorine resin is dispersed (e.g., Hanarl manufactured by Kanto Kasei), fluorine resin powder (e.g., Leblanc manufactured by Daikin Kogyo), silicone resin micro particles (e.g. Tospearl manufactured by Toshiba Silicone), etc. may also be used. In Fig. B, the releasing layer  200  is highlighted as a black layer. The amount of grease or releasing agent for forming the releasing layer  200  should be sufficient to allow the double-faced tape  102  to adhere to the feed roller seal  109  in an operating state while allowing the double-faced tape  102  to be separated from the feed roller seal  200  without damaging (e.g., removing portions of) the feed roller seal  109  in a repair/recycle or disassembly state when the side seal  104  can be removed from the case  51 . Additionally, in some aspects a new side seal  104  can be installed where it can be aligned on the contact surface and can be installed in the side seal installation area  100  in the case  51  without generating wrinkles and stretching.  
         [0039]     Since the releasing layer  200 , such as grease, is constituted in the area partially between the double-faced tape  102  and the case  51 , the task of removing the side seal  104  from the case  51  becomes easier.  
         [0040]     Additionally, according to one aspect if the releasing layer  200  is constituted only on the contact surface between the double-faced tape  102  and the feed roller seal  109 , high adhesive strength of the double-faced tape  102  on the back side of the side seal  104  relative to the case  51  can be maintained so that the leakage between the rotating developing roller  59  and the side seal  104  can be prevented.  
         [0041]     The releasing layer  200  containing the releasing agent may also be constituted on the entire surface where the double-faced tape  102  on the back side of the side seal  104  is in contact with the case  51 . According to this aspect, the side seal  104  can be easily removed from the case  51  at the time of recycling the development apparatus  50 . Since the side seal  104  can be placed at an appropriate position while sliding it in the case  51  due to the lubrication of the releasing agent, stretches or wrinkles may be prevented in the side seal  104 . In addition, Teflon® felt  113  can be installed on the side seal  104  over the side seal installation area  100  in the case  51  so that the leakage of toner from the installation point of the side seal  104  may be further prevented while maintaining the adhesive strength between the double-faced tape  102  and the case  51 .  
         [0042]     As shown in  FIG. 4 , a lower side seal  105  and a lower film  114  can be installed in the lower side seal installation area  101  in the case  51 . Although a PET (polyethylene terephthalate) sheet or a urethane rubber film may be used as the lower film  114 . Using a double-faced tape, a lower film  114  is placed partially on the lower seal installation area  101 , a part of the front frame  51   d  of the case  51 , and a part of the lower side seal  105  so that the leakage of toner from the lower part in the longitudinal direction of the developing roller  59  in the opening of the development apparatus  50  can be prevented.  
         [0043]     Moreover, a layer thickness regulating blade  64  is pressed in the longitudinal direction of the developing roller  59 . Since a blade back seal (not shown) is installed between the layer thickness regulating blade  64  and the case  51 , the leakage of toner from the upper part in the longitudinal direction of the developing roller  59  can be prevented.  
         [0044]     As explained above, the leakage of toner from the upper portion of the developing roller  59  can be prevented by each sealing member in the upper end, end-to-end and the lower end of the development apparatus  50 .  
         [0045]     When the toner of the development apparatus  50  is being recycled, a releasing layer  200  containing releasing agent is constituted on the contact surface between the double-faced tape  102  on the back of the side seal  104  and the base  51 , making the tasks of removal of the side seal  104  from the case  51  and the installation of a side seal  104  into the case  51  relatively easy.  
         [0046]     If the releasing layer  200  is constituted on the contact surface between the double-faced tape  102  on the back of the side seal  104  and the feed roller seal  109 , the side seal  104  can be removed without damaging the feed roller  109  from the case  51  with a high level of reliability.  
         [0047]     Although aspects of the present invention have been described above, the present invention is not limited by to the aforementioned aspects. Various modifications and changes can be made that fall within the scope of the present invention.