JP6213236B2 - Development device - Google Patents

Description

  The present invention relates to a developing device including a seal member disposed between both ends of a developing roller and a frame.

  A developing device used in an image forming apparatus such as a laser printer includes a developing roller, a frame for containing a developer, and a seal member disposed between both ends of the developing roller and the frame. In the developing device of Patent Document 1 (see FIG. 8), the outer end of the seal member extends beyond the end of the developing roller (roller portion) in the rotation axis direction of the developing roller.

JP 2001-154480 A

  By the way, in the configuration in which the end of the seal member extends to the outside of the end of the developing roller, the developing roller is pressed against the seal member, so that a relatively large pressing force is applied to the seal member from the end of the developing roller. The member is crushed. As a result, a force to move outward in the rotational axis direction acts on the seal member. Therefore, when the developing roller rotates in this state, the seal member moves outward in the rotational axis direction to create a gap between the seal member and the frame. The developer may leak from the gap.

  The present invention has been made in view of the above background, and provides a developing device capable of suppressing developer leakage in a configuration in which the end of the seal member extends to the outside of the end of the developing roller. With the goal.

In order to achieve the above-described object, the developing device of the present invention includes a developing roller having a roller body configured to carry a developer, a frame that rotatably supports the developing roller, and both ends of the roller body. And an elastically deformable seal member disposed between the portion and the frame.
In the rotation axis direction of the developing roller, the outer end of the seal member is positioned outside the end of the roller body in the rotation axis direction of the seal member.
The frame has an installation surface on which the seal member is installed.
The installation surface includes a first surface and a second surface disposed on the outer side in the rotation axis direction than the first surface.
The second surface is provided such that an end of the roller body in the rotation axis direction is positioned within a width of the second surface in the rotation axis direction, and the first surface is positioned in the radial direction of the developing roller. It is arranged outside the surface.
The seal member is bonded to the first surface and is not bonded to the second surface.

  According to such a configuration, the second surface on the outer side in the rotational axis direction is arranged on the outer side in the radial direction than the inner first surface, so that the outer end portion of the seal member is moved away from the end of the developing roller. Since it can escape to the surface side of 2, the pressing force applied to the seal member can be reduced, and the force acting on the seal member to move outward in the rotation axis direction can be weakened. Further, since the seal member is bonded to the first surface, it is possible to suppress the displacement of the seal member itself. Thereby, since the position shift of the seal member when the developing roller rotates can be suppressed, the adhesion between the seal member and the frame can be ensured, and the developer leakage can be suppressed.

  In the developing device described above, the frame may be configured to have an inner abutting surface that is located on the inner side of the installation surface in the rotation axis direction and abuts against an inner end of the seal member.

  According to this, the position of the seal member in the rotation axis direction can be determined by bringing the inner end of the seal member into contact with the inner contact surface.

  In the developing device described above, the installation surface may have a step between the first surface and the second surface.

  According to this, since the difference in the radial position between the first surface and the second surface can be increased, the outer end of the seal member can be surely escaped by the second surface side, It is possible to more reliably weaken the force acting on the seal member to move outward in the rotation axis direction. Thereby, since the position shift of the seal member can be suppressed, developer leakage can be suppressed.

  In the developing device described above, the frame may be configured to have an outer contact surface that is positioned outside the installation surface in the rotation axis direction and contacts an outer end of the seal member.

  According to this, the position of the seal member in the rotation axis direction can be determined by bringing the outer end of the seal member into contact with the outer contact surface. Further, in the configuration having the above-described inner contact surface, the seal member is sandwiched between the inner contact surface and the outer contact surface, so that the positional deviation of the seal member can be further suppressed, and development is performed. Agent leakage can be further suppressed.

  In the developing device described above, the seal member includes a first portion that faces the first surface and a second portion that faces the second surface, and the first member in the rotation axis direction is the first portion. The length of the part may be longer than the length of the second part.

  According to this, since the contact area between the first portion, the first surface, and the developing roller can be increased, developer leakage can be further suppressed.

  In the developing device described above, the seal member includes a first portion that faces the first surface and a second portion that faces the second surface, and in the rotation direction of the developing roller, The length of the second part may be shorter than the length of the first part.

  According to this, since the length of contact between the second portion and the end of the developing roller can be reduced, the force acting on the seal member to move outward in the rotation axis can be further reduced. Thereby, since the position shift of the seal member can be further suppressed, developer leakage can be further suppressed.

  The developing device includes a layer thickness regulating member configured to regulate the amount of developer carried on the roller body, and the seal member includes a first portion facing the first surface; A second portion facing the second surface, wherein the layer thickness regulating member is in contact with the first portion and not in contact with the second portion.

  According to this, since no force is applied to the second portion from the layer thickness regulating member, it is possible to suppress an increase in the force acting on the seal member to move outward in the rotation axis direction, and the seal member is displaced. Can be suppressed. Thereby, developer leakage can be suppressed.

  In the developing device described above, the seal member may have a slit extending in a rotation direction of the developing roller on a surface that contacts the roller body.

  According to this, even when the portion outside the slit of the seal member tries to move outward when the developing roller rotates, the slit opens slightly, so that the portion inside the slit of the seal member moves outward. It becomes difficult to apply force to try. Thereby, since the position shift of the part inside the slit of the seal member can be suppressed, developer leakage can be further suppressed.

  In the developing device described above, the slit may be arranged at the same position as the boundary between the first surface and the second surface or outside the boundary in the rotation axis direction.

  According to this, since the position shift of the portion between the first surface and the roller body of the seal member can be suppressed, the adhesion between the portion and the frame or the roller body can be improved. Leakage can be further suppressed.

  The developing device includes a second seal member extending in the rotation axis direction between the developing roller and the frame, the seal member including a first portion facing the first surface, and the second portion. And the second seal member is in contact with the first portion and not in contact with the second portion.

  According to this, since no force is applied to the second portion from the second seal member, it is possible to suppress an increase in the force acting on the seal member to move outward in the rotational axis direction, and the seal member is displaced. Can be suppressed. Thereby, developer leakage can be suppressed.

  In the developing device described above, the installation surface has a third surface disposed on the outer side in the rotation axis direction than the second surface, and the third surface is more than the first surface. It can be set as the structure arrange | positioned at radial inside.

  According to this, since the seal member can be disposed at an inclination, it is possible to press the inner end of the seal member against the inner contact surface in a crushed state, and the adhesion between the seal member and the inner contact surface Can be increased. In addition, even if the seal member is slightly displaced, the crushed portion returns to the original shape, thereby ensuring the adhesion between the seal member and the inner contact surface. Thereby, developer leakage can be suppressed.

  In the developing device described above, the inner contact surface is a flat surface along the radial direction, and the inner end of the seal member is viewed from the radially outer side in a state before contacting the inner contact surface. It can be set as the structure which has a shape which approaches the said rotating shaft direction inner side as it goes inside.

  According to this, since it becomes possible to press the inner end of the seal member against the inner contact surface in a more compressed state, the adhesion between the seal member and the inner contact surface can be further improved. Developer leakage can be further suppressed.

  In the developing device, the seal member includes a first member that faces the first surface and a second member that faces the second surface, and the first member and the second member. Can be configured as a separate member.

  According to this, for example, by changing the materials of the first member and the second member, the functions of the first member and the second member can be made different, and it is possible to realize a configuration in which the developer is less likely to leak. It becomes.

  According to the present invention, developer leakage can be suppressed in the configuration in which the end of the seal member extends to the outside of the end of the developing roller.

FIG. 2 is a diagram illustrating a schematic configuration of a laser printer in which a developing cartridge as an example of a developing device is used. It is sectional drawing of a process cartridge. FIG. 3 is an exploded perspective view of a developing cartridge. It is an expansion perspective view of the installation surface and seal member concerning a 1st embodiment. It is a figure which shows the structure of the left end part vicinity of the developing roller which concerns on 1st Embodiment. It is a figure which shows the structure of the edge part vicinity of the developing roller which concerns on a comparative example. It is a figure which shows the structure of the left end part vicinity of the developing roller which concerns on 2nd Embodiment. FIG. 10 is an enlarged perspective view (a) of an installation surface and a seal member according to a third embodiment, and a view (b) showing the vicinity of the left end of the developing roller. FIG. 10A is a diagram showing a configuration near the left end of a developing roller according to a fourth embodiment, and FIG. The figure which shows the installation surface and seal member which concern on 5th Embodiment (a), the figure (b) which shows the state which assembled | attached the developing roller, and the figure (c) which shows the seal member which concerns on the modification of this embodiment is there. It is a figure which shows the structure of the left end part vicinity of the developing roller which concerns on 6th Embodiment. It is a figure which shows the structure of the left end part vicinity of the developing roller which concerns on a 1st modification. It is a figure which shows the structure of the left end part vicinity of the developing roller which concerns on a 2nd modification. It is a figure which shows the structure of the left end part vicinity of the developing roller which concerns on a 3rd modification.

[First Embodiment]
Next, the first embodiment will be described in detail with reference to the drawings as appropriate. In the following description, first, a schematic configuration of a laser printer in which the developing device according to the embodiment is used will be described, and then a detailed configuration of the developing device will be described. In the following description, the direction will be described with reference to the user who uses the laser printer 1. Specifically, the left side of FIG. 1 as viewed from the user is “front”, the right side of FIG. 1 as viewed from the user is “rear”, and the front side of FIG. 1 is “right”. ”, The left side of the page is“ left ”. Further, the vertical direction in FIG.

<Schematic configuration of laser printer>
As shown in FIG. 1, the laser printer 1 includes a feeder unit 4 for feeding a sheet 3 into a main body casing 2, an image forming unit 5 for forming an image on the sheet 3, and the like.

  The feeder unit 4 includes a paper feed tray 6 that is detachably attached to the bottom of the main body casing 2, a paper pressing plate 7 provided in the paper feed tray 6, and various types that carry the paper 3 and remove paper dust. The roller 11 is mainly provided. In the feeder unit 4, the sheet 3 in the sheet feeding tray 6 is moved upward by the sheet pressing plate 7 and conveyed to the image forming unit 5 by various rollers 11.

  The image forming unit 5 includes a scanner unit 16, a process cartridge 17, a fixing unit 18, and the like.

  The scanner unit 16 is provided at an upper portion in the main body casing 2 and includes a laser light emitting unit (not shown), a polygon mirror 19 that is rotationally driven, lenses 20 and 21, reflecting mirrors 22, 23, and 24. In the scanner unit 16, the laser beam is irradiated on the surface of the photosensitive drum 27 by high-speed scanning through a path indicated by a chain line in the drawing.

  The process cartridge 17 is configured to be detachably attached to the main casing 2 by appropriately opening a front cover 2A provided on the front side of the main casing 2. The process cartridge 17 mainly includes a developing cartridge 28 as an example of a developing device and a drum unit 39.

  The developing cartridge 28 is detachably attached to the main casing 2 while being attached to the drum unit 39. As shown in FIG. 2, the developing cartridge 28 includes a developing roller 31, a layer thickness regulating blade 32 as an example of a layer thickness regulating member, a supply roller 33, and a container 34 that contains toner as an example of a developer. And mainly.

  In the developing cartridge 28, the toner in the container 34 is stirred by the rotating agitator 34 </ b> A and then supplied to the developing roller 31 by the supply roller 33. The toner supplied to the developing roller 31 enters between the layer thickness regulating blade 32 and the developing roller 31 as the developing roller 31 rotates, and is carried on the developing roller 31 as a thin layer having a constant thickness. .

  The drum unit 39 mainly includes a photosensitive drum 27, a charger 29, and a transfer roller 30. In the drum unit 39, the surface of the photosensitive drum 27 is uniformly charged by the charger 29 and then exposed by high-speed scanning of the laser beam from the scanner unit 16, whereby image data is formed on the photosensitive drum 27. A based electrostatic latent image is formed.

  Thereafter, the toner carried on the developing roller 31 is supplied to the photosensitive drum 27, whereby a toner image is formed on the photosensitive drum 27. Then, the sheet 3 is conveyed between the photosensitive drum 27 and the transfer roller 30, whereby the toner image on the photosensitive drum 27 is transferred to the sheet 3.

  As shown in FIG. 1, the fixing unit 18 mainly includes a heating roller 41 and a pressure roller 42 that is disposed to face the heating roller 41 and pressurizes the heating roller 41. In the fixing unit 18, the toner transferred onto the paper 3 is thermally fixed while the paper 3 passes between the heating roller 41 and the pressure roller 42. The paper 3 thermally fixed by the fixing unit 18 is discharged onto a paper discharge tray 46 by a paper discharge roller 45.

<Detailed configuration of developing cartridge>
As shown in FIGS. 2 and 3, the developing cartridge 28 includes the developing roller 31, the layer thickness regulating blade 32, the supply roller 33, the lower film 35 as an example of the second seal member, the frame 100, and the like. And a seal member 200.

  In the following description, the rotation axis direction of the developing roller 31 corresponding to the left-right direction is referred to as “rotation axis direction”, the radial direction of the developing roller 31 is referred to as “radial direction”, and the rotation direction of the developing roller 31 ( 2) (refer to the arrow in FIG. 2) is referred to as “rotation direction”.

  The developing roller 31 mainly includes a shaft portion 31A and a roller main body 31B configured to carry toner on the surface thereof. The roller body 31B is formed by covering the surface of the shaft portion 31A with conductive rubber or the like.

  The layer thickness regulating blade 32 contacts the surface of the roller body 31B of the rotating developing roller 31 and scrapes off excess toner adhering to the surface of the roller body 31B, thereby reducing the amount of toner carried on the roller body 31B. A member configured to be regulated. The layer thickness regulating blade 32 mainly includes a plate-like member 32A formed of sheet metal and a contact member 32B formed of rubber and contacting the roller body 31B, and is fixed to the frame 100 by screws 38. ing.

  The lower film 35 is a sheet-like member made of a resin such as polyethylene terephthalate (PET), and is arranged in a state of extending in the rotation axis direction between the developing roller 31 and the frame 100 and in contact with the lower portion of the roller body 31B. ing. By providing such a lower film 35, toner leakage from between the lower portion of the roller body 31B and the frame 100 is suppressed.

  As shown in FIG. 3, the frame 100 is a member that forms the accommodating portion 34 and supports the developing roller 31, the layer thickness regulating blade 32, the supply roller 33, and the like. The frame 100 rotatably supports the developing roller 31, the supply roller 33, and the like. The frame 100 includes an opening 110 that is long in the rotational axis direction for supplying the toner in the container 34 to the developing roller 31 via the supply roller 33, an installation surface 120 formed on each of the left and right sides of the opening 110, and an inner contact It mainly has a contact surface 130 and an outer contact surface 140.

  4 and 5 show a configuration in the vicinity of the left installation surface 120. FIG. In the present embodiment, since the configuration near the installation surface 120 is substantially the same, the configuration near the installation surface 120 on the right side is not shown.

  As shown in FIGS. 4 and 5, the installation surface 120 is a surface on which the seal member 200 is installed facing the seal member 200 in the radial direction (corresponding to the vertical direction in FIG. 5). In the present embodiment, the installation surface 120 includes a first surface 121 and a second surface 122 disposed adjacent to the outer side in the rotation axis direction than the first surface 121. The first surface 121 and the second surface 122 are formed as surfaces that are substantially parallel to the rotation axis direction and long in the rotation direction.

  The second surface 122 is provided so that the end 31E in the rotation axis direction of the roller body 31B of the developing roller 31 is located within the width W2 in the rotation axis direction. In addition, the second surface 122 is disposed on the outer side (a position far from the developing roller 31) than the first surface 121 in the radial direction. Specifically, the second surface 122 is formed as a surface that is one level lower than the first surface 121. That is, in the present embodiment, the installation surface 120 has a step 125 between the first surface 121 and the second surface 122.

  The inner contact surface 130 is a surface located inside the installation surface 120 in the rotation axis direction. Specifically, the inner contact surface 130 is a side surface of the film attachment portion 105 that is long in the rotation axis direction to which the lower film 35 is attached, and from the end on the inner side in the rotation axis direction of the installation surface 120 (first surface 121). It is formed as a plane (plane along the radial direction) that extends inward in the radial direction and is substantially parallel to the radial direction. The inner contact surface 130 is in contact with an inner end 201 that is an inner end in the rotation axis direction of a seal member 200 described later.

  The outer contact surface 140 is a surface that is positioned outside the installation surface 120 in the rotation axis direction and faces the inner contact surface 130. Specifically, the outer abutment surface 140 is a surface on the inner side in the rotational axis direction of the protruding portion 102 that projects inwardly from the inner surface in the rotational axis direction of the side wall 101 of the frame 100, and the installation surface 120 (second surface) 122) is formed as a plane substantially parallel to the inner contact surface 130 that extends radially inward from the outer end in the rotational axis direction. The outer abutment surface 140 abuts on the outer end 202 which is the outer end of the seal member 200 in the rotation axis direction.

  In this embodiment, the seal member 200 has the inner end 201 in contact with the inner contact surface 130 and the outer end 202 in contact with the outer contact surface 140. It is arranged in a state sandwiched between.

  The seal member 200 is a member for suppressing toner leakage from between both ends of the developing roller 31 and the frame 100, and is disposed between both ends of the developing roller 31 and the frame 100. Specifically, the seal member 200 has the outer end 202 extending outside the end 31E in the rotation axis direction of the roller body 31B in the rotation axis direction, and the inner end 201 side on the end of the roller body 31B and the frame 100. It is arrange | positioned between the installation surfaces 120 of.

  The seal member 200 mainly includes an elastic member 210 and a contact member 220 disposed between the elastic member 210 and the developing roller 31.

  The elastic member 210 is provided for the purpose of bringing the contact member 220 into close contact with the developing roller 31 by a restoring force when being crushed, and is made of an elastically deformable material such as urethane sponge.

  The contact member 220 is a member that contacts the roller body 31B. For the purpose of reducing the sliding resistance with the roller body 31B in order to smoothly rotate the developing roller 31, the contact member 220 is made of, for example, a woven fabric such as a pile fabric, a nonwoven fabric such as a felt, a resin film, It is formed from resin tape.

  The seal member 200 is installed on the installation surface 120 in a state where it is bonded to the first surface 121 and not bonded to the second surface 122. In addition, the adhesion method of the sealing member 200 and the 1st surface 121 is not specifically limited, For example, it can adhere | attach using an adhesive agent, a double-sided tape, etc.

Next, the effect of this embodiment comprised as mentioned above is demonstrated.
As shown in FIG. 6 as a comparative example, when the installation surface 920 is a flush surface, the outer end 202 of the seal member 200 extends outside the end 31E of the roller body 31B of the developing roller 31. When the developing roller 31 is attached to the frame 100 and pressed against the seal member 200, a relatively large pressing force is applied to the outer end portion of the seal member 200 from the end 31E of the roller body 31B. The edge is crushed.

  Then, when the sealing member 200 pushes the end 31E of the roller body 31B by the restoring force of the sealing member 200, a force is exerted on the sealing member 200 to move outward in the rotation axis direction indicated by an arrow. In this state, when the developing roller 31 rotates, the contact member 220 side of the seal member 200 moves outward in the rotation axis direction, and a gap is formed between the inner end 201 and the inner contact surface 130, and toner leaks from the gap. there is a possibility. Such a possibility becomes conspicuous when the diameter of the end portion of the roller body 31B is larger than the slightly inner portion.

  As shown in FIG. 5, in the present embodiment, the outer second surface 122 is one step lower than the inner first surface 121, so that the outer end of the seal member 200 becomes the end 31 </ b> E of the roller main body 31 </ b> B. Can be released to the second surface 122 side, the pressing force applied from the end 31E to the outer end can be reduced, and the force acting on the seal member 200 to move outward in the rotational axis direction can be weakened. . Moreover, in this embodiment, since the sealing member 200 is bonded to the first surface 121, it is possible to suppress the positional deviation of the sealing member 200 itself. Thereby, since the position shift of the seal member 200 when the developing roller 31 rotates can be suppressed, the adhesion between the seal member 200 and the frame 100, specifically, the inner end 201 and the inner contact surface 130 is ensured. Toner leakage can be suppressed.

  In the present embodiment, the installation surface 120 has a step 125 between the first surface 121 and the second surface 122, so that the first surface 121 is in the radial direction between the second surface 122 and the first surface 121. The difference in position, specifically, the height difference can be increased. As a result, the outer end of the seal member 200 can be surely released by the second surface 122 side, and the force to move outward in the rotation axis direction acting on the seal member 200 can be more reliably weakened. Therefore, the position shift of the seal member 200 can be more reliably suppressed. As a result, the adhesion between the first surface 121 and the inner contact surface 130 can be further improved, so that toner leakage can be further suppressed.

  In this embodiment, since the frame 100 has the inner contact surface 130 and the outer contact surface 140, the ends 201 and 202 of the seal member 200 are brought into contact with the inner contact surface 130 and the outer contact surface 140. Thus, the position of the seal member 200 in the rotation axis direction can be determined. Further, in the present embodiment, since the seal member 200 is sandwiched between the inner contact surface 130 and the outer contact surface 140, the position shift of the seal member 200 can be further suppressed, and toner leakage is further reduced. Can be suppressed.

[Second Embodiment]
Next, a second embodiment will be described. In the embodiments described below, including this embodiment, components different from those of the first embodiment will be mainly described in detail, and the same components as those described in the above will be denoted by the same reference numerals. The description will be omitted.

  As shown in FIG. 7, the installation surface 120 is formed such that the length of the first surface 121 is longer than the length of the second surface 122 in the rotation axis direction.

  The seal member 200 includes a first portion 203 that faces the first surface 121 and a second portion 204 that faces the second surface 122. The first portion 203 and the second portion 204 correspond to the first surface 121 and the second surface 122, and the length of the first portion 203 is longer than the length of the second portion 204 in the rotation axis direction. Is formed.

  In this embodiment, since the contact area between the first portion 203, the first surface 121, and the developing roller 31 can be increased, toner leakage can be further suppressed.

[Third Embodiment]
Next, a third embodiment will be described.
As shown in FIG. 8A, the seal member 200 is formed such that the first portion 203 is long along the rotation direction of the developing roller 31 indicated by an arrow. On the other hand, the second portion 204 is formed so as to extend from the vicinity of the center in the rotation direction toward the outer side in the rotation axis among the side surfaces on the outer side in the rotation axis direction of the first portion 203. That is, the seal member 200 is formed in a T shape so that the length of the second portion 204 is shorter than the length of the first portion 203 in the rotation direction. In the present embodiment, the surface on the inner side in the rotation axis direction of the side wall 101 of the frame 100 serves as the outer contact surface 140 with which the outer end 202 of the seal member 200 contacts.

  As shown in FIG. 8B, the layer thickness regulating blade 32 and the lower film 35 are in contact with the first portion 203 of the seal member 200 and the second portion 204 at the ends in the rotational axis direction. Arranged without any. Specifically, the end in the rotational axis direction of the layer thickness regulating blade 32 is in a state in which only the upper end of the first portion 203 is in contact with the upper end of the first portion 203 between the frame 100 (not shown). Has been placed. Further, the end portion of the lower film 35 in the rotation axis direction is disposed in a state of being in contact with only the lower end portion of the first portion 203 by sandwiching the lower end portion of the first portion 203 with the frame 100.

  In this embodiment, since the second portion 204 is shorter than the first portion 203 in the rotation direction, the length of contact between the second portion 204 and the end 31E of the roller main body 31B can be reduced. It is possible to further weaken the force that acts on the outer side in the rotation axis line acting on 200. Thereby, since the position shift of the seal member 200 can be further suppressed, toner leakage can be further suppressed.

  In the present embodiment, the layer thickness regulating blade 32 and the lower film 35 are in contact with the first portion 203 and are not in contact with the second portion 204, so that the layer thickness regulating blade 32 and the lower film 35 are not in contact with the second portion 204. No force is applied from the film 35. In a configuration in which a force is applied to the second portion from the layer thickness regulating blade or the lower film, there is a possibility that a strong force to move outward in the rotational axis direction is applied by the seal member 200. However, in this embodiment, the seal member 200 It is possible to suppress an increase in the force acting on the outer side in the direction of the rotational axis to increase. Thereby, since the position shift of the seal member 200 can be suppressed, toner leakage can be suppressed.

[Fourth Embodiment]
Next, a fourth embodiment will be described.
As shown in FIGS. 9A and 9B, the seal member 200 has a slit 240 on the surface that contacts the roller body 31B. The slit 240 is formed by making a cut in the seal member 200. Specifically, the slit 240 is formed with a depth from the surface of the contact member 220 to the middle of the elastic member 210. The slit 240 is formed from the upstream end to the downstream end of the seal member 200 in the rotational direction so as to extend along the rotational direction indicated by the arrow. In addition, the slit 240 is disposed outside the step 125 that is the boundary between the first surface 121 and the second surface 122 (between the step 125 and the end 31E (see the alternate long and short dash line)) in the rotation axis direction. Yes.

  In this embodiment, even when a portion outside the slit 240 of the seal member 200 moves outward when the developing roller 31 rotates, the slit 240 is slightly opened, and thus the slit 240 of the seal member 200 is opened. However, the inner part is less likely to be subjected to a force to move outward. As a result, the adhesion between the inner end 201 and the inner contact surface 130 can be ensured, and toner leakage can be further suppressed.

  Further, in the present embodiment, the slit 240 is disposed on the outer side in the rotation axis direction than the step 125, so that the position shift of the portion of the seal member 200 between the first surface 121 and the roller main body 31B is prevented. Can be suppressed. Thereby, since the adhesiveness of the part facing the 1st surface 121 of the sealing member 200 and the flame | frame 100 or the roller main body 31B can be improved, a toner leak can be suppressed further.

  9A, the slit is located at the same position as the step 125 which is the boundary between the first surface 121 and the second surface 122 in the rotation axis direction (on the dashed line on the left side in the drawing). May be arranged.

[Fifth Embodiment]
Next, a fifth embodiment will be described.
As shown in FIG. 10A, the installation surface 120 includes a first surface 121, a second surface 122 disposed adjacent to the outer side in the rotation axis direction than the first surface 121, and a second surface And a third surface 123 arranged adjacent to the outer side in the rotational axis direction than the surface 122. In the rotation axis direction, an inner contact surface 130 is formed adjacent to the first surface 121 on the inner side of the installation surface 120, and an outer contact surface 140 is adjacent to the third surface 123 on the outer side of the installation surface 120. Is formed.

  Similar to the first surface 121 and the second surface 122, the third surface 123 is formed as a surface that is substantially parallel to the rotation axis direction and that is long in the rotation direction. Further, the third surface 123 is disposed on the radially inner side than the first surface 121. Specifically, the third surface 123 is formed as a surface that is higher than the first surface 121 (a surface that is close to the developing roller 31). Thus, the installation surface 120 has a step 126 between the second surface 122 and the third surface 123 that is higher than the step 125 between the first surface 121 and the second surface 122. ing.

  The seal member 200 includes an elastic member 210 and a contact member 220, and is formed in such a length as to be sandwiched between the inner contact surface 130 and the outer contact surface 140 in the rotation axis direction. ing.

  In such an embodiment, as shown in FIG. 10A, the seal member 200 can be disposed at an angle. At this time, the inner end portion of the seal member 200 is crushed and pressed against the inner contact surface 130, and the developing roller 31 is assembled as shown in FIG. Thus, the adhesion between the seal member 200 and the inner contact surface 130 can be enhanced. Further, even if the seal member 200 is slightly displaced outward when the developing roller 31 rotates, the adhesiveness between the seal member 200 and the inner contact surface 130 is restored by returning the crushed portion to the original shape. Can be secured. Thereby, toner leakage can be suppressed.

  As shown in FIG. 10C, the seal member 200 approaches the inner side in the rotational axis direction from the radially outer side toward the inner side in a state before the inner end 201 contacts the inner contact surface 130. Such an inclined shape (an inclined shape extending to the left side from the lower side to the upper side in FIG. 10) may be provided. According to such a configuration, the inner end portion of the seal member 200 can be pressed against the inner contact surface 130 in a more compressed state, so that the adhesion between the seal member 200 and the inner contact surface 130 is improved. Can be further increased, and toner leakage can be further suppressed.

[Sixth Embodiment]
Next, a sixth embodiment will be described.
As shown in FIG. 11, the seal member 200 includes a first member 205 that faces the first surface 121, and a second member 206 that faces the second surface 122. The member 206 is configured as a separate member, that is, as an individual seal member.

  The first member 205 includes an elastic member 210 and a contact member 220, and is disposed on the first surface 121 in a state where the inner end in the rotation axis direction is in contact with the inner contact surface 130. Are bonded to the first surface 121.

  The second member 206 includes an elastic member 210 and a contact member 220, and is disposed on the second surface 122 while being sandwiched between the step 125 and the outer contact surface 140. In addition, the inner end of the second member 206 and the outer end of the first member 205 are arranged in contact with each other in the rotation axis direction. The elastic member 210 of the second member 206 is formed thicker than the elastic member 210 of the first member 205. Accordingly, when the first member 205 is disposed (adhered) on the first surface 121 and the second member 206 is disposed on the second surface 122, the surfaces of the contact members 220 are substantially flush. It is supposed to be. The second member 206 is not bonded to the second surface 122.

  In this embodiment, for example, the functions of the first member 205 and the second member 206 are made different by changing the materials of the elastic member 210 and the contact member 220 of the first member 205 and the second member 206. Therefore, it is possible to realize a configuration in which toner leakage is less likely to occur.

  Although the embodiment has been described above, the present invention is not limited to the embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of invention as follows.

  In the embodiment, as shown in FIG. 5, the installation surface 120 having the first surface 121 and the second surface 122 having different radial positions (heights) is formed on the frame 100 in advance. However, the present invention is not limited to this. For example, as shown in FIG. 12, the frame 100 has a flush facing surface 103 that faces the seal member 200, and a thick double-sided tape 150 or the like is attached to a portion on the inner side in the rotation axis direction of the facing surface 103. The installation surface 120 having the first surface 121 and the second surface 122 having different heights may be formed.

  In the embodiment, as shown in FIG. 5, the installation surface 120 is a surface having the step 125 between the first surface 121 and the second surface 122, but is not limited thereto. . For example, as shown in FIG. 13, the installation surface 120 is an inclined surface that approaches the radially outer side from the inner end of the first surface 121 toward the outer end of the second surface 122 in the rotation axis direction. Also good. The seal member 200 is bonded to the first surface 121. In other words, in the form of FIG. 13, the seal member 200 is bonded to the installation surface 120 on the inner side in the rotation axis direction than the end 31E of the roller body 31B, and the surface to which the seal member 200 is bonded becomes the first surface 121. The surface to which the seal member 200 is not bonded becomes the second surface 122.

As shown in FIG. 14, the installation surface 120 is such that the first surface 121 is a surface substantially parallel to the rotation axis direction (a surface along the rotation axis direction) as in the first embodiment, and the second surface The surface 122 may be an inclined surface that approaches the radially outer side from the inner end to the outer end in the rotation axis direction.
In the form shown in FIGS. 13 and 14 as well, the outer end of the seal member 200 can be released from the end 31E of the roller body 31B to the second surface 122 side. The pressing force applied to the seal member 200 can be reduced, and the force acting on the seal member 200 to move outward in the rotational axis direction can be weakened.

  In the above-described embodiment, the frame 100 has the inner contact surface 130. However, the present invention is not limited to this. For example, the frame may have a configuration without the inner contact surface. Moreover, in the said embodiment, although the flame | frame 100 had the outer side contact surface 140, it is not limited to this, For example, the structure which does not have an outer side contact surface may be sufficient.

  In the embodiment, the seal member 200 has a two-layer structure including the elastic member 210 and the contact member 220. However, the present invention is not limited to this. For example, the seal member may have a single-layer structure or a three-layer structure. The multilayer structure described above may be used. Moreover, in the said embodiment, although the sheet-like lower film 35 which consists of resin was illustrated as a 2nd sealing member, it is not limited to this, For example, a 2nd sealing member is material which can be elastically deformed, such as urethane sponge The member which consists of may be sufficient.

  In the embodiment, the developing cartridge 28 is exemplified as the developing device. However, the developing device 28 is not limited to this. For example, the developing device may further include a photosensitive drum, a charger, and the like. Specifically, the developing device may have the same configuration as the process cartridge 17 of the above embodiment. At this time, the developing cartridge and the drum unit may be configured to be detachable or may be configured integrally. In addition, the developing cartridge as the developing device may be configured such that a portion where the developing roller and the layer thickness regulating blade are disposed and a storage portion (toner box) for storing the toner are detachable.

  In the above embodiment, the laser printer 1 capable of forming only a monochrome image is exemplified as an image forming apparatus in which the developing device of the present invention is used. However, the present invention is not limited to this, and for example, a printer capable of forming a color image. There may be. The image forming apparatus is not limited to a printer, and may be, for example, a copier or a multi-function machine including a document reading apparatus such as a flat bed scanner.

28 Developing cartridge 31 Developing roller 31B Roller body 31E End 32 Layer thickness regulating blade 35 Lower film 100 Frame 120 Installation surface 121 First surface 122 Second surface 125 Step 130 Inner contact surface 140 Outer contact surface 200 Seal member 201 Inner end 202 Outer end

Claims (13)

A developing roller having a roller body configured to carry a developer;
A frame that rotatably supports the developing roller;
An elastically deformable seal member disposed between both ends of the roller body and the frame;
The seal member has an outer end of the seal member positioned outside an end of the roller body in the rotation axis direction in the rotation axis direction of the developing roller,
The frame has an installation surface on which the seal member is installed,
The installation surface includes a first surface and a second surface disposed on the outer side in the rotational axis direction than the first surface,
The second surface is provided such that an end of the roller body in the rotation axis direction is positioned within a width of the second surface in the rotation axis direction, and the first surface is positioned in the radial direction of the developing roller. Placed outside the surface,
The developing device according to claim 1, wherein the seal member is bonded to the first surface and is not bonded to the second surface.   The developing device according to claim 1, wherein the frame has an inner contact surface that is positioned inside the installation surface in the rotation axis direction and contacts an inner end of the seal member.   The developing device according to claim 1, wherein the installation surface has a step between the first surface and the second surface.   The said frame is located in the outer side of the said installation surface in the said rotating shaft direction, and has the outer side contact surface which contact | abuts the outer end of the said sealing member, The any one of Claims 1-3 characterized by the above-mentioned. The developing device according to item. The seal member has a first portion facing the first surface, and a second portion facing the second surface,
5. The developing device according to claim 1, wherein a length of the first portion is longer than a length of the second portion in the rotation axis direction. 6. The seal member has a first portion facing the first surface, and a second portion facing the second surface,
6. The developing device according to claim 1, wherein a length of the second portion is shorter than a length of the first portion in a rotation direction of the developing roller. 7. A layer thickness regulating member configured to regulate the amount of developer carried on the roller body;
The seal member has a first portion facing the first surface, and a second portion facing the second surface,
The developing device according to claim 1, wherein the layer thickness regulating member is in contact with the first portion and is not in contact with the second portion.   The developing device according to claim 1, wherein the seal member has a slit extending in a rotation direction of the developing roller on a surface that contacts the roller main body.   The developing device according to claim 8, wherein the slit is disposed at the same position as the boundary between the first surface and the second surface or outside the boundary in the rotation axis direction. . A second seal member extending in the rotational axis direction between the developing roller and the frame;
The seal member has a first portion facing the first surface, and a second portion facing the second surface,
The developing device according to claim 1, wherein the second seal member is in contact with the first portion and is not in contact with the second portion. The installation surface has a third surface disposed on the outer side in the rotational axis direction than the second surface,
The developing device according to claim 2, wherein the third surface is disposed on the radially inner side with respect to the first surface. The inner contact surface is a plane along the radial direction,
The inner end of the seal member has a shape that approaches the inner side in the rotational axis direction from the outer side in the radial direction toward the inner side in a state before coming into contact with the inner abutting surface. Item 12. The developing device according to Item 11 or Item 11. The seal member includes a first member facing the first surface, and a second member facing the second surface,
The developing device according to claim 1, wherein the first member and the second member are configured as separate members.

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