JP3682495B2 - Development device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a developing device that performs development using a developer that is charged fine particles of an image forming machine.
[0002]
[Prior art]
  In a developing device that uses toner, which is charged fine particles, as a developer and electrostatically attaches this toner to an electrostatic latent image, the toner leaks from the developing device. If the toner leaks from the developing device, the inside of the image forming machine equipped with the developing device becomes dirty, resulting in defective printing, and the operator's hands and clothes become dirty when the developing device is replaced. .
[0003]
  In particular, in the case of non-magnetic one-component development in which a thin layer of toner is formed by a layer thickness regulating blade on a developing roller having a function of carrying the toner while being carried, and development is performed by facing the electrostatic latent image. Therefore, toner leakage from the periphery of the rotating developing roller tends to occur.
[0004]
  Therefore, conventionally, as shown in FIGS. 6 and 7, the above-described toner leakage is prevented by providing a toner leakage preventing member inside the developing device. For example, in order to prevent toner leakage from both ends of the developing roller 16, the side seal 15 is brought into contact with the peripheral surfaces of the both ends of the developing roller 16 and the developing roller 16 formed below the developing roller 16. In order to prevent toner leakage from a gap with the opening of the housing 3, the lower film 4 is brought into contact with the developing roller 16 below the developing roller 16.
[0005]
  The side seal 15 has a structure in which a sliding member made of Teflon felt is attached to urethane sponge. Urethane sponges are required to be sufficiently soft and have little compression set. The Teflon felt is used for ensuring both pressing force and reducing rotational torque. The side seal 15 is bonded to the housing 3 with a double-sided adhesive tape 5.
[0006]
  The lower film 4 is made of a PET (polyethylene terephthalate) sheet or urethane rubber. Urethane rubber can be expected to be softly pressed, but since it has no waist, it must be pressed from the back with a sponge or the like. Since the PET sheet is harder than the urethane rubber film, there is no need to press it with a sponge or the like from the back, and there is an advantage that the assembly work is easier than the urethane rubber film. The lower film 4 is also bonded onto the housing 3 by a double-sided adhesive tape 6.
[0007]
  However, when the side seal 15 and the lower film 4 as described above are used, if the side seal 15 is rubbed against the peripheral surface of the developing roller 16, the toner is adhered at the joint portion between the lower film 4 and the side seal 15. There is a problem that it is easy to leak.
[0008]
  For example, if the length of the lower film 4 is set to such a length that the lower film 4 does not overlap the side seal 15, the toner leaks from the gap between the lower film 4 and the side seal 15.
[0009]
  Further, when both ends of the lower film 4 extend outward from both ends of the side seal 15 and the developing roller 16 is disposed in contact with both the lower film 4 and the side seal 15, the lower film 4 rides on the side seal 15. As a result, a minute gap corresponding to the thickness of the lower film 4 is formed, and the toner may leak from this gap. In particular, when a polymerized toner having excellent fluidity is used as the toner, toner leakage occurs even in such a small gap.
[0010]
  Therefore, it is considered that the length of the lower film 4 is such that both end portions of the lower film 4 are located near the center of the rubbing portion of the side seal 15.
[0011]
  With such a configuration, a gap corresponding to the thickness of the lower film 4 generated in the portion where the lower film 4 has run on the side seal 15 is interrupted in the middle of the side seal 15, and as a result, the polymerized toner is used. Even in such a case, toner leakage can be almost prevented.
[0012]
  However, the side seal 15 is configured so as to be pressed against the developing roller 16 by being crushed by the developing roller 16 when the developing roller 16 is attached. have. However, if this crushing amount is set too large, the pressing force of the side seal 15 against the developing roller 16 becomes too high and the rotational torque of the developing roller 16 is increased. Therefore, the attachment portion of the side seal 15 is previously set so that the height of the surface of the side seal 15 is equal to the height of the attachment portion of the lower film 4 when the side seal 15 is crushed by an appropriate amount by the developing roller 16. A step is provided so as to be lower than the attachment portion of the film 4.
[0013]
  In such a configuration, when the side seal 15 is crushed by the developing roller 16, the surface height of the side seal 15 is set to the height of the attachment portion of the lower film 4 while rubbing against the side wall surface forming the step. Will match. Further, since the side seal 15 slightly vibrates with the rotation of the developing roller 16, the friction between the side wall surface and the side seal side surface is small even during the developing operation. become.
[0014]
  Therefore, the side surface of the side seal 15 and the side wall surface cannot be bonded with a double-sided adhesive tape or the like. In addition, the rubbing portion between the side wall surface and the side seal side surface is an interface between the resin and the sponge, and as described above, the sponge rubs against the resin surface or vibrates slightly. In this case, the adhesion at this interface is extremely low. As a result, when a polymerized toner having extremely high fluidity is used as the developer, the toner easily leaks from the interface between the resin and the sponge.
[0015]
  Further, both ends of the lower film 4 positioned near the center of the rubbing portion of the side seal 15 are not crushed before the developing roller 16 is attached. The side seal 15 is deformed so as to bend upward by a difference in height from the surface of the rubbing portion.
[0016]
  When the developing roller 16 is attached in such a state, the side seal 15 is crushed, and accordingly, both end portions of the lower film 4 that have been deformed upward are crushed following the side seal 15. It is. As a result, there is a problem that the adhesion portion of the lower film 4 is displaced, or the lower film 4 is deformed to lower the toner sealability.
[0017]
  Therefore, in order to prevent toner leakage from the joint portion between the lower film 4 and the side seal 15 more reliably, the applicant of the present application disclosed in Japanese Patent Application No. 11-230309 as shown in FIGS. It has been proposed that a lower side seal 7 made of a foamed elastic body is provided between 4 and the side seal 15, and this is adhered to the housing 3 by a double-sided adhesive tape 8.
[0018]
[Problems to be solved by the invention]
  As described above, the developing device disclosed in Japanese Patent Application No. 11-230309 is intended to prevent the leakage of the developer by providing the lower side seal 7 made of sponge at the joint between the lower film 4 and the side seal 15. However, the sponge of the lower side seal 7 is sandwiched between the lower film 4 and the housing 3, and is pressed by the lower film 4 which is bent by the pressure from the developing roller 16. Is designed not to float.
[0019]
  However, in such a configuration, it is difficult to provide the sponge, which is the lower side seal 7, so as to be in contact with the adhesive portion between the lower film 4 and the housing 3 without a gap. There is a problem that the developer leaks from the gap 9.
[0020]
  If the gap 9 is completely eliminated, the elastic force generated by compressing the sponge that is the lower side seal 7 is concentrated on the boundary 6a between the bonded portion and the non-bonded portion of the lower film 4, Problems such as deformation of the lower film 4 at this portion and peeling of the double-sided adhesive tape 6 for bonding the lower film 4 to the housing 3 occur. If the lower film 4 is deformed or the double-sided adhesive tape 6 is peeled off, toner leakage may occur.
[0021]
  Therefore, an object of the present invention is to provide a developing device that can solve such problems and prevent toner leakage more reliably.
[0022]
[Means for Solving the Problems]
  In order to solve the above problems, the invention of claim 1A casing having an opening, a developer carrier that is rotatably supported by the opening, and a foamed elastic body that is provided near both ends in the longitudinal direction of the opening so as to press against the developer carrier And one end side is bonded to the casing with a double-sided adhesive tape on the upstream side in the rotation direction of the developer carrier relative to the foamed elastic body, and the other end side is covered with the foamed elastic body. On the peripheral surface of the developer carrier. A sheet-like member provided so as to be in uniform contact over the longitudinal direction,In the developing device for preventing leakage of the developer from the housing, the double-sided adhesive tape includes an elastic sheet having elasticity in the thickness direction, and an adhesive layer formed on both surfaces of the elastic sheet. The foamed elastic body is compressed and inserted between the sheet-like member and the housing, the foamed elastic body is in contact with the double-sided adhesive tape, and the double-sided adhesive tape is also bonded to the foamed elastic body. The developing device is adopted.
[0023]
  According to the first aspect of the present invention, the gap that has been easily generated when the sheet member is directly bonded to the casing is eliminated by the interposition of the elastic sheet in the bonded portion, and therefore, leakage of the developer is prevented. .
  Further, since the foamed elastic body is interposed between the sheet-like member and the housing, the pressing force due to the deformation of the foamed elastic body acts on the sheet-like member, but this pressing force can be relaxed by the elastic sheet. .
  Further, the developer can be prevented from leaking from this portion by bringing the foamed elastic body into contact with the double-sided adhesive tape without any gap.
  Further, the leakage of the developer from between the double-sided pressure-sensitive adhesive tape and the foamed elastic body can be prevented.
Further, since the sheet-like member must be strongly pressed against the moving developer carrying member, a large elastic force is applied to the sheet-like member, and this elastic force can be absorbed by the elastic sheet.
[0024]
  A second aspect of the invention employs the developing device according to the first aspect, wherein the elastic sheet is formed of a foam.
[0025]
  According to the invention of claim 2, a sufficient amount of deformation can be obtained even if the elastic sheet is thin.
[0026]
  The invention according to claim 3 employs the developing device according to claim 1 or 2, wherein the thickness of the double-sided pressure-sensitive adhesive tape is 0.4 mm or more.
[0027]
  A fourth aspect of the invention employs the developing device according to any one of the first to third aspects, wherein the sheet-like member is a resin sheet.
[0028]
  According to the fourth aspect of the invention, since the sheet-like member is a resin sheet, the sheet-like member is easy to handle and easy to assemble.
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
[0035]
[0036]
  Claim5The invention according to claim 1, wherein the end surface of the foamed elastic body and the end surface of the elastic sheet are in contact with each other with the double-sided adhesive tape.4Is used. This claim5According to this invention, it is possible to reliably close a gap that has been easily generated.
  Claim6In the invention, the foamed elastic body is disposed in the vicinity of an edge in the longitudinal direction of the developer carrier, and an end surface of the foamed elastic body and an end surface of the elastic sheet are in contact with each other in the rotation direction of the developer carrier. It is adhere | attached with the said double-sided adhesive tape in the state.5The developing device described in any of the above is employed.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.
[0038]
  First, an overview of the entire image forming machine to which the developing device is attached will be described.
[0039]
  The image forming apparatus shown in FIG. 1 is a laser beam printer 1, and the laser beam printer 1 includes a feeder unit that feeds paper (not shown) at the bottom of a main body case 2. The feeder unit includes a paper pressing plate 10 that is pressed by a spring (not shown), a paper feeding roller 11, and a friction separating member 14. The paper pressing plate 10 presses the paper against the paper feeding roller 11, and the paper feeding roller 11. , The uppermost sheet is separated between the sheet feeding roller 11 and the friction separating member 14 and the sheet is supplied at a predetermined timing.
[0040]
  A pair of registration rollers 12 and 13 are rotatably supported on the downstream side in the sheet conveyance direction by the rotation of the paper feed roller 11 rotating in the direction of the arrow in FIG. The sheet is conveyed at a predetermined timing to the transfer position to be formed.
[0041]
  The photosensitive drum 20 is made of a positively chargeable material, for example, an organic photoreceptor whose main component is a positively chargeable polycarbonate. Specifically, the photosensitive drum 20 is a light having a predetermined thickness (for example, about 20 μm) in which a photoconductive resin is dispersed in polycarbonate on the outer periphery of a cylindrical cylindrical sleeve made of aluminum, for example. A hollow drum having a conductive layer is formed, and is pivotally supported by the main body case 2 in a state where the cylindrical sleeve is grounded. Further, the photosensitive drum 20 is rotationally driven in the direction of the arrow by a driving unit (not shown).
[0042]
  The charger 30 is composed of, for example, a positively-charged scorotron charger that generates corona discharge from a charging wire made of tungsten or the like.
[0043]
  The laser scanner unit 40 includes a laser generator (not shown) that generates a laser beam L for forming an electrostatic latent image on the photosensitive drum 20, a polygon mirror (pentahedral mirror) 41 that is driven to rotate, and a pair of Lenses 42 and 45 and reflecting mirrors 43, 44 and 46 are included.
[0044]
  As shown in FIG. 2, in the developing device 50, a toner storage chamber 52 as a developer chamber is formed in a housing 51. In the toner storage chamber 52, an agitator 53 and a cleaning member 54 have a rotation shaft 55. It is provided so as to be rotatable around. The toner storage chamber 52 stores toner as a positively chargeable non-magnetic one-component developer having electrical insulation. Further, light transmission windows 56 are provided on the side walls of the toner storage chamber 52 located on both ends of the rotation shaft 55. Further, a developing chamber 57 is formed on the photosensitive drum 20 side of the toner storage chamber 52 through the opening A so as to communicate with the toner storage chamber 52 for development. The supply roller 58 and the developing roller 59 as a developer carrier rotate. It is pivoted as possible. The toner on the developing roller 59 is regulated to a predetermined layer thickness by a layer thickness regulating blade 64 having a thin plate-like elasticity and used for development.
[0045]
  Here, the developing roller 59 as the developer carrying member has a cylindrical base material formed of conductive silicone rubber containing conductive carbon fine particles on a metal core formed of stainless steel or the like. Furthermore, a coating layer of a fluorine-containing resin or rubber material is formed on the base material. The developing roller 59 does not necessarily have a base material made of conductive silicone rubber, and may be made of conductive urethane rubber.
[0046]
  The toner stored in the toner storage chamber 52 is a positively chargeable non-magnetic one-component developer, and a well-known color such as carbon black is added to a styrene-acrylic resin formed into a sphere by suspension polymerization. And toner base particles having a particle diameter of 6 μm to 10 μm and an average particle diameter of 8 μm obtained by adding a charge control agent such as nigrosine, triphenylmethane, and quaternary ammonium salt. The toner is constituted by adding silica as an external additive to the surface of the toner base particles.
[0047]
  The transfer roller 21 is rotatably supported, and is composed of a foamed elastic body having conductivity, such as silicone rubber or urethane rubber. The transfer roller 21 is configured to reliably transfer the toner image on the photosensitive drum 20 to a sheet by an applied voltage.
[0048]
  The fixing unit 70 is provided further downstream in the sheet conveyance direction from the registration rollers 12 and 13 to the pressure contact portion between the photosensitive drum 20 and the transfer roller 21, and includes a heating roller 71 and a pressing roller 72. The toner image transferred to the paper is pressed while being heated by the heating roller 71 and the pressure roller 72 and is fixed to the paper.
[0049]
  A pair of transport rollers 73 and a paper discharge roller 74 for paper transport are provided on the downstream side in the transport direction of the fixing unit 70, and a paper discharge tray 75 is provided on the downstream side of the paper discharge rollers 74. .
[0050]
  The photosensitive drum 20, the transfer roller 21, the charger 30, and the developing device 50 described above are accommodated in the process cartridge 2a, and the process cartridge 2a is detachably provided to the laser beam printer 1. Yes. Further, the developing device 50 is detachably provided as a developing device cartridge with respect to the process cartridge 2a.
[0051]
  In the laser beam printer 1 as described above, when the surface of the photosensitive drum 20 is uniformly charged by the charger 30 and irradiated with the laser light L modulated in accordance with the image information from the laser scanner unit 40, An electrostatic latent image is formed on the surface. The electrostatic latent image is visualized with toner by the developing device 50, and the visible image formed on the photosensitive drum 20 is conveyed to the transfer position by the photosensitive drum 20. At the transfer position, the paper is supplied via the paper feed roller 11 and the registration rollers 12 and 13, and the visible image is transferred to the paper by the transfer bias applied by the transfer roller 21. The toner remaining on the photosensitive drum 20 after the transfer is collected in the developing chamber 57 by the developing roller 59.
[0052]
  Next, the sheet is conveyed to the fixing unit 70 and is nipped and conveyed by the heating roller 71 and the pressing roller 72 of the fixing unit 70, and the visible image on the sheet is pressed and heated to be fixed on the sheet. Then, the paper is discharged to a paper discharge tray 75 above the laser beam printer 1 by a pair of transport rollers 73 and paper discharge rollers 74, and the image forming operation is completed.
[0053]
  The developing device has the following seal structure to prevent toner leakage from between the developing roller and the housing.
[0054]
  That is, as shown in FIGS. 2 to 5, this seal structure is an elastic side provided near both ends in the longitudinal direction of the opening of the casing 51 so as to contact the peripheral surfaces of both ends of the developing roller 59. The direction of rotation of the developing roller 59 relative to the position where the seal 80, the lower side seal 81 having elasticity provided on the casing 51 so as to contact the side seal 80, and the electrostatic latent image of the developing roller 59 are opposed to each other. A double-sided adhesive tape 82 is attached to the lower end of the opening of the casing 51 so as to uniformly contact the circumferential surface of the developing roller 59 on the downstream side in the longitudinal direction of the developing roller 59 and to cover the lower side seal 81. And a lower film 83.
[0055]
  The lower film 83 is a sheet-like member having elasticity, and is adhered to the casing 51 that supports the developing roller 59 by a double-sided adhesive tape 82, and is supported by the double-sided adhesive tape 82 and pressed by the developing roller 59. The developer is prevented from being bent and leaking from the casing 51. The lower film 83 is made of, for example, a resin sheet. The lower film 83 prevents the toner from leaking out of the casing 51 while sliding on the surface of the rotating developing roller 59. The double-sided pressure-sensitive adhesive tape 82 for bonding the lower film 83 to the housing 51 will be described later.
[0056]
  The side seal 80 has the same configuration as that of the prior art, and is specifically formed of a square columnar sponge. As shown in FIGS. 3 and 4, the side seal 80 is double-sided at locations corresponding to both ends of the developing roller 59 in the casing 51. It is adhered by an adhesive tape 84. As this double-sided pressure-sensitive adhesive tape 84, for example, a tape in which a pressure-sensitive adhesive is applied to the front and back of a base material made of a nonwoven fabric with a uniform thickness is used. The side seal 80 is compressed and elastically deformed on the peripheral surfaces of both end portions of the developing roller 59 that is rotatably supported by the casing 51, whereby the surface of the side seal 80 is rotated around the end portions of the rotating developing roller 59. The developer is prevented from leaking in the side direction while contacting the surface with an appropriate pressure.
[0057]
  The lower side seal 81 is formed of a sponge, which is a rectangular parallelepiped foamed elastic body, as in the prior art, and is adhered to the casing 51 with a double-sided adhesive tape 85 so as to contact the side seal 80 as shown in FIGS. ing. The double-sided pressure-sensitive adhesive tape 85 is the same as that for adhering the side seal 80. The lower side seal 81 is sandwiched between the lower film 83 and the casing 51, and is pressed against the lower film 83 that is bent by the pressure from the developing roller 59. As a result, the lower side seal 81, which is a foamed elastic body, is compressed and inserted between the lower film 83 and the casing 51, and the lower film 83 and the casing 51 are closed so as not to generate a gap. Toner leakage from the joint between the lower film 83 and the side seal 80 is prevented.
[0058]
  As already described with reference to FIGS. 6 and 7, it is difficult to provide the lower side seal 81 so as to be in contact with the adhesive portion between the lower film 83 and the casing 51 without any gap. A gap 9 is generated at the boundary 6a between the bonded portion and the non-bonded portion, and the developer may leak from the gap 9. If the gap 9 is completely eliminated, the elastic force generated by compressing the sponge, which is the lower side seal 15, is concentrated on the boundary 6a between the bonded portion and the non-bonded portion of the lower film 4, Problems such as deformation of the lower film 4 at this portion and peeling of the double-sided adhesive tape 6 for bonding the lower film 4 to the housing 3 occur.
[0059]
  In order to prevent toner leakage due to deformation of the lower film and peeling of the double-sided adhesive tape, the double-sided adhesive tape 82 for bonding the lower film 83 to the housing 51 has elasticity in the thickness direction in the present invention. An elastic sheet 82a is provided.
[0060]
  Specifically, this double-sided pressure-sensitive adhesive tape 82 uses a foam base material type (product number # 8404B black) manufactured by Dainippon Ink & Chemicals, Inc. The double-sided pressure-sensitive adhesive tape 82 uses a special polyolefin foam for the elastic sheet 82a as a base material, and uses an acrylic pressure-sensitive adhesive material for the adhesive material applied to both surfaces of the elastic sheet 82a. Shape followability and adhesiveness can be secured.
[0061]
  This double-sided adhesive tape 82 has a tape layer thickness of 0.4 mm. As a result of experiments, if the tape layer thickness is 0.4 mm or more, toner leakage can be prevented well. It was confirmed that there was. Furthermore, this double-sided pressure-sensitive adhesive tape 82 has an adhesive force of 2000 g / 20 mm (necessary to apply a force equivalent to 2000 g when peeling a strip-shaped tape having a width of 20 mm from the end). It was confirmed that an adhesive strength of 2000 g / 20 mm or more can withstand the expansion and contraction of the elastic sheet 82a, and thus can prevent toner leakage well.
[0062]
  As described above, the lower film 83 having elasticity is bonded to the casing 51 supporting the developing roller 59 by the double-sided adhesive tape 82 including the elastic sheet 82 a having elasticity in the thickness direction, and is supported by the double-sided adhesive tape 82. On the other hand, since it is bent by the pressure from the developing roller 59, even if the elastic force by the side seal 80 acts on the lower film 83, the sponge layer as the elastic sheet 82a is deformed and absorbs this elastic force. The stress is not concentrated on the boundary between the bonded portion and the non-bonded portion of the lower film 83, and the lower film 83 is prevented from peeling off from the casing 51. Further, a gap 9 (see FIGS. 6 and 7) generated at a position sandwiched between the lower film 4 and the housing 3 at the upstream end in the rotation direction of the developing roller of the conventional lower side seal 7. Is closed by the contact between the end face 86 of the elastic sheet 82a made of sponge or the like of the double-sided adhesive tape 82 and the end face 87 of the lower side seal 81, and therefore leakage of the developer from this point is prevented.
[0063]
  The end face 86 of the elastic sheet 82a of the double-sided adhesive tape 82 may be adhered to the end face 87 of the lower side seal 81 by the adhesive layer 82b of the double-sided adhesive tape 82. As a result, it is possible to reliably close a gap that has been easily generated.
[0064]
  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. For example, in the embodiment, the lower film has been described as an example, but the same effect can be obtained if the sheet member prevents the developer from leaking. Further, in the embodiment, an example is given in which the elastic force due to compression of the developer leakage prevention member of the sponge concentrates on the stress, but even if there is no sponge, the lower film is bent and pressed against the developing roller. In some cases, the present invention is effective to prevent the bending stress from concentrating on the boundary between the bonded portion and the non-bonded portion. Furthermore, the double-sided pressure-sensitive adhesive tape 82 may have a configuration in which a double-sided pressure-sensitive adhesive tape based on a conventional nonwoven fabric or the like is attached to the front and back of a tape-like foam. In the present embodiment, the example in which the lower film 83 directly rubs against the developing roller 59 has been described. However, the present invention is not limited to this, and a rubbing member is provided between the developing roller 59 and the lower film 83. May be provided separately.
[0065]
【The invention's effect】
  According to the first aspect of the present invention, the lower film 83 that is a sheet-like member having elasticity is adhered to the casing 51 that supports the developing roller 59 that is a developer carrying member by the double-sided adhesive tape 82, and the double-sided adhesive tape 82. In the developing device that is bent by the pressure from the developer carrier and prevents leakage of the developer from the housing, the double-sided pressure-sensitive adhesive tape includes the elastic sheet 82a having elasticity in the thickness direction. The gap 9 which has been easily generated by directly adhering the sheet member directly to the housing is eliminated by the interposition of the elastic sheet 82a in the adhesion portion, and thus leakage of the developer is prevented.
  Further, since the lower side seal 81, which is a foamed elastic body, is compressed and inserted between the lower film 83, which is a sheet-like member, and the casing 51, the foamed elastic body is interposed between the sheet-like member and the casing. The pressing force due to the deformation of the foamed elastic body acts on the sheet-like member, but this pressing force can be relaxed by the elastic sheet 82a.
  Further, since the lower side seal 81, which is a foamed elastic body, is in contact with the double-sided adhesive tape 82, leakage of the developer from this portion is prevented by bringing the foamed elastic body into contact with the double-sided adhesive tape without a gap. be able to.
  Further, since the double-sided pressure-sensitive adhesive tape 82 is also bonded to the lower side seal 81 that is a foamed elastic body, leakage of the developer from between the double-sided pressure-sensitive adhesive tape 82 and the foamed elastic body can be prevented.
Further, since the lower film 83 which is a sheet-like member rubs against the surface of the developing roller 59 which is a developer carrying member, the sheet-like member must be strongly pressed against the moving developer carrying member. However, this elastic force can be absorbed by the elastic sheet 82a.
[0066]
  According to the invention of claim 2, since the elastic sheet 82a is formed of a foam in the developing device of claim 1, a sufficient amount of deformation can be obtained even if the elastic sheet 82a is thin. .
[0067]
  According to the invention of claim 3, since the double-sided pressure-sensitive adhesive tape 82 in the developing device according to claim 1 or 2 is 0.4 mm or more, leakage of the developer is caused by the expansion and contraction effect of the double-sided pressure-sensitive adhesive tape 82. It becomes possible to prevent well.
[0068]
  According to the invention of claim 4, since the lower film 83 which is a sheet-like member in the developing device according to any one of claims 1 to 3 is a resin sheet, the sheet-like member can be easily handled and assembled. Is good.
[0069]
[0070]
[0071]
[0072]
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image forming machine to which a developing device according to the present invention is mounted.
FIG. 2 is an enlarged sectional view of the developing device shown in FIG.
FIG. 3 is a partially cutaway perspective view showing one side of the developing device shown in FIG. 1;
4A is an exploded cross-sectional view of a portion from the developing roller at the location shown in FIG. 3 to the housing, and FIG. 4B is a cross-sectional view taken along line BB in FIG.
FIG. 5 is a cross-sectional view taken along line VV in FIG. 4 (B).
FIG. 6 is a diagram showing a conventional example in comparison with FIG.
7 is a diagram showing a conventional example in comparison with FIG. 5, and is a cross-sectional view taken along the line VII-VII in FIG. 6 (B).
[Explanation of symbols]
  51 ... Case
  59 ... Developing roller
  81 ... Lower side seal
  82 ... Double-sided adhesive tape
  82a ... Elastic sheet
  83. Lower film

Claims (6)

A casing having an opening, a developer carrier that is rotatably supported by the opening, and a foamed elastic body that is provided near both ends in the longitudinal direction of the opening so as to press against the developer carrier And one end side is bonded to the casing with a double-sided adhesive tape on the upstream side in the rotation direction of the developer carrying body with respect to the foamed elastic body, and the other end side is covered with the foamed elastic body. A sheet-like member provided so as to be in uniform contact with the peripheral surface of the developer carrying member over the longitudinal direction thereof, in a developing device for preventing leakage of the developer from the housing,
The double-sided pressure-sensitive adhesive tape includes an elastic sheet having elasticity in the thickness direction, and an adhesive layer formed on both surfaces of the elastic sheet,
A foamed elastic body is compressed and inserted between the sheet-like member and the housing,
The foamed elastic body is in contact with the double-sided adhesive tape;
The developing device, wherein the double-sided pressure-sensitive adhesive tape is bonded to the foamed elastic body.   The developing device according to claim 1, wherein the elastic sheet is formed of a foam.   The developing device according to claim 1, wherein the double-sided pressure-sensitive adhesive tape has a thickness of 0.4 mm or more.   The developing device according to claim 1, wherein the sheet-like member is a resin sheet. An apparatus according to any one of claims 1 to 4, characterized in that it is adhered by the double-sided adhesive tape in a state where the end surface of the foamed elastic member and the end surface of the elastic sheet is in contact. The foamed elastic body is disposed in the vicinity of an end edge in the longitudinal direction of the developer carrier, and the both surfaces of the foamed elastic body and the elastic sheet are in contact with each other in the rotation direction of the developer carrier. an apparatus according to any one of claims 1 to 5, characterized in that it is bonded by an adhesive tape.

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