JP4720957B2 - Developing device, process unit, and image forming apparatus - Google Patents

Description

The present invention relates to an image forming apparatus such as a laser printer, and a developing device and a process unit provided in the image forming apparatus.
About.

In an electrophotographic image forming apparatus such as a laser printer, a developing cartridge is detachably provided for developing an electrostatic latent image on a photosensitive drum.
The developing cartridge accommodates toner and has an opening formed therein. The developing cartridge is rotatably supported by the main body case so as to face the opening, and includes a developing roller for supplying toner to the photosensitive drum, and a developing roller. In order to carry a thin layer of toner, a layer thickness regulating blade pressed against the developing roller is provided (for example, see Patent Document 1).

  The developing cartridge is provided with a side seal for preventing the toner in the main body case from leaking to the outside. The side seals are arranged along the outer peripheral surface of the developing roller in the main body case facing both ends of the developing roller. The side seal is formed of an elastic member such as urethane sponge, and is in close contact with both end portions of the developing roller by pressing from the developing roller. This prevents the toner from leaking from both ends by the rotation of the developing roller.

As shown in FIG. 12, when the developing roller 101 is mounted on the main body case 102, the rotating shaft 105 of the developing roller 101 is inserted into the support hole 104 formed on the side wall 103 of the main body case 102 in a substantially straight line. Thus, the developing roller 101 is placed substantially perpendicular to the side seal 106.
JP 2001-134080 A

However, since the side seal 106 has a certain thickness, the direction in which the side seal 106 is crushed differs depending on the pressing direction of the developing roller 101. That is, when the developing roller 101 is mounted, it is difficult to control the exact position of the side seal 106 in consideration of the collapse.
For example, as shown in FIG. 12, when the developing roller 101 is mounted so as to crush the side seal 106 downward (in a direction away from the layer thickness regulating blade 107), a large gap is formed near the upper end of the side seal 106. S is formed. Then, a problem that toner leaks from the gap S occurs.

  An object of the present invention is to provide a developing device in which the crushing direction of the first seal member is controlled when the developer carrying member is attached to the housing, and the developer leakage can be suppressed. A process unit and an image forming apparatus are provided.

A developer carrying body that contains a developer and has a housing in which an opening is formed, a shaft member, and a roller member, and is rotatably supported in the opening of the housing and carries the developer. And a bearing member that is provided separately from the housing and rotatably supports an axial end portion of the shaft member, and the housing is disposed to face each other with an interval in the axial direction. a pair of side walls that are, prior Symbol sidewalls extending towards the interior of the housing along the axial direction, and the pedestal along the outer peripheral surface of the longitudinal ends of the roller member, the shaft member A shaft support groove that is rotatably supported, and is formed of an elastic material, and is disposed along an outer peripheral surface of the roller member between both longitudinal ends of the roller member and the pedestal. The agent leaks from both ends of the roller member to the outside of the casing. A first sealing member for preventing Rukoto, the shaft support groove, when viewed from the axial direction, an inlet groove extending in a direction crossing the base through the opening, and the opening of the inlet channel Has a guide groove that is formed along the pedestal as viewed from the axial direction from the opposite end, and that guides the shaft member to a fixed position, and the bearing member is formed along the guide groove. A guide portion that guides the shaft member at the end opposite to the opening of the inlet groove to the fixed position along the guide groove; and the guide portion is formed continuously. And a bearing portion for rotatably receiving the shaft member.

Invention according to claim 2, in the invention described in claim 1, wherein the guide portion, when the shaft member is disposed in the fixed position, the developer responsible bearing member of said first seal member The shaft member is guided such that the downstream end portion in the rotational direction is crushed toward the contact member provided adjacent to the downstream end portion in the rotational direction of the developer carrier of the first seal member. It is characterized by that.
According to a third aspect of the present invention, in the second aspect of the present invention, the first seal member is adjacent to the first seal member on the downstream side in the rotation direction of the developer carrier, and is elastic. A second seal member formed from a member is provided, and the contact member is an upstream end portion of the second seal member in the rotation direction of the developer carrier.

The invention according to claim 4 is the invention according to claim 3, further comprising a layer thickness regulating member that is pressed to form a thin layer of developer on the surface of the roller member. has a pressure contact rubber is pressed against the roller member, the second sealing member, across the press rubber between the developer carrying member to the opposite side, in contact with the layer thickness regulating member It is characterized by being arranged.
According to a fifth aspect of the present invention, in the second aspect of the present invention, the pedestal is disposed adjacent to a downstream end of the first seal member in the rotation direction of the developer carrier, and the developer. A rib protruding toward the carrier is provided, and the contact member is the rib.
The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the guide portion and the bearing portion are disposed adjacent to each other, and the side wall of the guide portion is directed toward the bearing portion. It is characterized in that an inclined surface that is inclined so as to be separated from the center is provided.

In the first aspect of the present invention, when the developer carrier is rotatably supported in the opening of the housing, in the bearing member, first, the shaft member is guided to a predetermined position by the guide portion, and then the shaft member is It is rotatably received by the bearing portion. Therefore, the first seal member is pressed by the roller member in the direction in which the shaft member is guided to the predetermined position. Thereby, the collapsing direction of the first seal member can be controlled when the developer carrier is mounted on the casing. As a result, it is possible to prevent a gap that causes leakage of the developer from being formed around the first seal member, and to suppress leakage of the developer.

  Further, the shaft member is guided toward a predetermined position while the roller member presses the first seal member toward both ends of the casing. Therefore, the first seal member can be effectively crushed in the direction in which the shaft member moves toward the predetermined position. As a result, it is possible to effectively prevent formation of a gap that causes the developer to leak around the first seal member.

Further, when the shaft member is disposed at a predetermined position, the first seal member is crushed toward the downstream side in the rotation direction of the developer carrier. As a result, the rotation direction of the developer carrier coincides with the direction in which the first seal member is crushed. Therefore, it is possible to keep the first seal member from being crushed during development. As a result, the formation of a gap that causes the developer to leak around the first seal member can be prevented over a long period of time.

In the invention according to claim 2 , when the shaft member is disposed at a predetermined position, the first seal member is crushed toward the contact member provided in the vicinity of the first seal member. Therefore, the first seal member can be brought into close contact with the contact member. As a result, it is possible to reliably prevent the formation of a gap that causes the developer to leak between the contact member and the first seal member.

According to a third aspect of the present invention, the contact member is a second seal member disposed on the downstream side in the rotation direction of the developer carrier relative to the first seal member. Therefore, when the first seal member is crushed toward the second seal member, the second seal member is also elastically deformed in response thereto. As a result, the adhesion between the first seal member and the second seal member is improved, and it is possible to effectively prevent a gap that causes the developer from leaking between them. .

In the invention according to claim 4 , the second seal member is disposed between the housing and the layer thickness regulating member. The layer thickness regulating member regulates the developer layer thickness on the surface of the roller member. Therefore, the developer that has not been able to enter the surface of the roller member tends to stay between the developer entry side with respect to the layer thickness regulating member, that is, between the first seal member and the second seal member.
However, since the second seal member is disposed between the casing and the layer thickness regulating member, it is possible to prevent the developer from leaking from between them. Further, since the first seal member and the second seal member are in close contact with each other, leakage of the developer from between them can be prevented. As a result, it is possible to effectively reduce the leakage of the developer that tends to stay between the first seal member and the second seal member.

In the invention according to claim 6 , when the developer carrier is rotatably supported in the opening of the housing, in the bearing member, first, the shaft member is moved in the longitudinal direction of the shaft member by the inclined surface of the guide portion. The shaft member is guided from the inside to the outside, and then the shaft member is rotatably received by the bearing portion. Therefore, the shaft member can be reliably guided to a predetermined position with a simple configuration. Further, if the shaft member is guided by the inclined surface, the shaft member can be automatically guided to a predetermined position. Therefore, workability can be improved.

1. Laser Printer FIG. 1 is a side sectional view showing an embodiment of a laser printer as an example of an image forming apparatus of the present invention.
In FIG. 1, a laser printer 1 includes a main body casing 2 in which a paper feed unit 4 for feeding a paper 3 as an example of a recording medium and an image forming unit for forming an image on the fed paper. 5 and a paper discharge unit 6 for discharging the paper 3 on which an image is formed.
(1) Main Body Casing The main body casing 2 is formed in a box shape, and an opening is formed on one side wall, and a front cover 7 that opens and closes the opening is provided. By opening the front cover 7, the process unit 13 (described later) or the developing cartridge 24 (described later: when the process unit 13 is attached to the main casing 2) can be attached to and detached from the main casing 2.

In the following description, the side on which the front cover 7 is provided is the front side (front side), and the opposite side is the rear side (back side). Further, the front side in the paper thickness direction in FIG. 1 is the left side, and the back side in the paper thickness direction in FIG. 1 is the right side. Moreover, the left-right direction and the width direction are synonymous.
Further, the directions related to the process unit 13 and the developing cartridge 24 are also based on the state in which these are mounted on the main casing 2.
(2) Paper Feed Unit The paper feed unit 4 includes a paper feed tray 8, a paper feed roller 9 as an example of a transport mechanism, a separation pad 10, and a registration roller 11.

Sheets 3 are stacked in the sheet feed tray 8. The uppermost sheet 3 in the sheet feed tray 8 is fed one by one by the sheet feed roller 9 and the separation pad 10 and conveyed to the registration roller 11. Thereafter, the sheet 3 is conveyed by the registration roller 11 to a transfer position (described later) of the image forming unit 5.
(3) Image Forming Unit The image forming unit 5 includes a scanner unit 12, a process unit 13, and a fixing unit 14.
(A) Scanner unit The scanner unit 12 is provided in the upper part in the main body casing 2, and includes a laser light emitting unit (not shown), a polygon mirror 15, a plurality of lenses 16, and a plurality of reflecting mirrors 17.

The laser beam based on the image data emitted from the laser light emitting unit is reflected by the polygon mirror 15 as shown by a chain line, and passes or reflects through the plurality of lenses 16 and the plurality of reflecting mirrors 17, and the photosensitive of the process unit 13. The surface of the drum 21 is scanned.
(B) Process Cartridge The process unit 13 is disposed below the scanner unit 12 in the main body casing 2 and is detachably attached to the main body casing 2.

The process unit 13 includes a photosensitive drum 21 as an example of a photosensitive member, a scorotron charger 22, a transfer roller 23, and a developing cartridge 24 as an example of a developing device in a process frame 20.
The photosensitive drum 21 is rotatably supported by the process frame 20. The scorotron charger 22 is supported by the process frame 20 above the photosensitive drum 21 and spaced from the photosensitive drum 21. The transfer roller 23 is opposed to the photosensitive drum 21 from the lower side of the photosensitive drum 21 and is rotatably supported by the process frame 20.

The developing cartridge 24 is detachably attached to the process frame 20.
The developing cartridge 24 includes a developing roller 26 as an example of a developer carrier, a layer thickness regulating blade 27 as an example of a layer thickness regulating member, and a supply roller 28 in a developing frame 25 as an example of a casing. ing. The developing frame 25 is formed in a box shape in which an opening 29 is formed on the rear side, and a toner storage chamber 30 is defined in front of the supply roller 28.

The developing roller 26 is disposed so as to be exposed rearward from the opening 29 so as to face the photosensitive drum 21. The developing roller 26 is an example of a roller member made of a metal-made developing roller shaft 31 that is rotatably supported by the developing frame 25 and a conductive rubber that covers the developing roller shaft 31. As a rubber roller 32.
The layer thickness regulating blade 27 includes a leaf spring member 33 formed in a thin plate shape and a pressure contact rubber 34 provided at a lower end portion of the leaf spring member 33. The upper end of the leaf spring member 33 is fixed to the developing frame 25, and the pressure contact rubber 34 is pressed against the surface of the rubber roller 32 by the elastic force of the leaf spring member 33.

The supply roller 28 is opposed to the front side of the developing roller 26, and is a metal-made supply roller shaft 41 that is rotatably supported by the developing frame 25, and a sponge roller made of a conductive sponge that covers the supply roller shaft 41. 42.
The toner storage chamber 30 stores a non-magnetic one-component positively charged polymerized toner. The polymerized toner has a substantially spherical shape and good fluidity. An agitator 35 is provided in the toner storage chamber 30.

  The toner in the toner storage chamber 30 is stirred by the rotation of the agitator 35 and supplied to the supply roller 28. Thereafter, the toner is supplied to the developing roller 26 by the rotation of the supply roller 28. At this time, the toner is frictionally charged positively between the supply roller 28 and the developing roller 26. Subsequently, the toner enters between the pressure contact rubber 34 and the rubber roller 32 as the developing roller 26 rotates, and is supported on the surface of the rubber roller 32 as a thin layer while the layer thickness is regulated between them. The

On the other hand, as the photosensitive drum 21 rotates, the surface of the photosensitive drum 21 is first uniformly charged positively by the scorotron charger 22, and then exposed by the laser beam from the scanner unit 12, and based on the image data. An electrostatic latent image is formed. Next, when the developing roller 26 rotates, the toner carried on the surface of the rubber roller 32 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 21 when it contacts the photosensitive drum 21. The As a result, the electrostatic latent image is developed (visualized), and a toner image is carried on the surface of the photosensitive drum 21. The toner image is transferred onto the sheet 3 conveyed between the photosensitive drum 21 and the transfer roller 23 (transfer position).
(C) Fixing Unit The fixing unit 14 is provided behind the process unit 13. The fixing unit 14 includes a heating roller 36 and a pressure roller 37 that is pressed against the heating roller 36 from below.

In the fixing unit 14, the toner transferred to the paper 3 at the transfer position is thermally fixed while the paper 3 passes between the heating roller 36 and the pressure roller 37.
(4) Paper Discharge Unit The paper discharge unit 6 includes a conveyance roller 38, a paper discharge roller 39, and a paper discharge tray 40. Then, the heat-fixed paper 3 is transported to the paper discharge roller 39 by the transport roller 38 and is discharged onto the paper discharge tray 40 by the paper discharge roller 39.
2. 2 is a plan view of the developing cartridge, FIG. 3 is a right side view of the developing cartridge (with a bearing member attached), FIG. 4 is a cross-sectional view taken along line AA in FIG. 2, and FIG. FIG. 4 is a rear view of the developing cartridge, where (a) shows a developing frame (with the developing roller and a layer thickness regulating blade removed), (b) shows a layer thickness regulating blade, and (c) shows the developing roller. 6 is a right side view of the developing cartridge (with the bearing member removed), FIG. 7 is a right side view of the bearing member, FIG. 8 is a left side view of the bearing member, and FIG. 9 is B in FIG. FIG. 10 is a sectional view corresponding to FIG. 8 for explaining the mounting of the bearing member to the developing roller. FIG. 10A is a state in which the developing roller is guided by the inclined surface. , (B) shows a state in which the developing roller is inserted into the bearing portion. Show.

In the following description, the rotation direction of the developing roller 26 is a direction in which the portion of the developing roller 26 facing the supply roller 28 is sequentially opposed to the layer thickness regulating blade 27 and further to the photosensitive drum 21. . Further, the upstream side and the downstream side in the rotation direction of the developing roller 26 indicate a relative positional relationship between two positions in the circumferential direction of the developing roller 26, and the rotation direction described above is used as a reference.
(1) Development Frame As shown in FIGS. 2 and 5, the development frame 25 includes a right side wall 45 and a left side wall 46 that are opposed to each other at an interval in the width direction, and is formed in a box shape extending in the width direction. ing. The developing frame 25 has an opening 29 extending in the width direction (longitudinal direction) on the rear side.

As shown in FIG. 6, the right side wall 45 is formed with a shaft support groove 47 that is notched forward from the rear edge.
The shaft support groove 47 is formed of an inlet groove 48 extending in a substantially horizontal direction from the rear end edge of the right side wall 45 and a guide groove 49 that bends obliquely forward upward from the inlet groove 48. The deepest portion 50 of the guide groove 49 is a fixed position (predetermined position) of the developing roller shaft 31.

Although not described in detail, the left side wall 46 is also formed with a shaft support groove 47 (see FIG. 5A) similar to the right side wall 45.
A screw fixing hole 58 is formed in the right side wall 45 in front of the shaft support groove 47.
Further, as shown in FIGS. 4 and 5, the developing frame 25 is provided with a seal pedestal 51 that extends inward in the width direction from the inner surface of the right side wall 45.

The seal pedestal portion 51 is formed in a substantially bow shape that is recessed forward in a side view, and a lower pedestal 52 to which a side seal 61 (described later) is attached and an upper seal 62 (described later) are attached. The upper pedestal 53 is provided.
The lower pedestal 52 is formed in a curved shape along the outer periphery of the developing roller 26, and has an upper surface extending in a substantially vertical direction on the front side and a rear side with a shaft insertion portion 54 through which the supply roller shaft 41 is inserted. It is divided into a rear surface extending substantially in the front-rear direction.

The upper pedestal 53 is adjacent to the upper surface of the lower pedestal 52 and is formed in a substantially concave shape in side view that is recessed forward from the upper surface. That is, a step 55 is formed between the lower pedestal 52 and the upper pedestal 53.
Although not described in detail, a seal pedestal 51 (see FIG. 5A) similar to that of the right side wall 45 is also formed on the left side wall 46.

Further, the developing frame 25 is provided with a support wall 56 for supporting the layer thickness regulating blade 27 along the upper edge of the opening 29. The support wall 56 is provided along the width direction at the upper end edge of the opening 29. Both end portions in the width direction of the support wall 56 are adjacently disposed above the upper pedestal 53. Moreover, the upper end part of the width direction both ends of the support wall 56 bulges back, and the screw hole 57 is provided there.
(2) Side Seal To prevent the toner carried on the developing roller 26 from leaking from the both ends of the developing roller 26 to the outside of the developing frame 25 in the developing frame 25 as shown in FIGS. A side seal 61 as an example of the first seal member is provided.

The side seal 61 is formed in a sheet shape having a thickness in a back view band (for example, 3 to 4 mm). The side seal 61 is made of an elastic foam material such as urethane sponge. More specifically, the side seal 61 is made of high-density microcell urethane foam (trade name: Polon, manufactured by Roger Sinoac).
Further, in the side seal 61, a felt material made of Teflon (registered trademark) or the like is attached to the surface of the elastic foam material (the surface facing the developing roller 26) in order to improve slidability. .

The side seals 61 are attached to the lower pedestals 52 of the right side wall 45 and the left side wall 46, respectively. Specifically, the side seal 61 is adhered to the upper surface and the rear surface of the lower pedestal 52 via a double-sided tape so as to extend over them. As a result, the side seal 61 is disposed along the outer peripheral surface of the rubber roller 32 between the axial end portions of the rubber roller 32 and the lower pedestals 52 disposed at both end portions of the developing frame 25 facing them. Is done.
(3) Upper seal In order to prevent the toner carried on the developing roller 26 from leaking from the back surface side (front surface side) of the layer thickness regulating blade 27 to the developing frame 25 as shown in FIGS. The upper seal 62 as an example of the contact member and the second seal member is provided.

The upper seal 62 is formed in a sheet shape that is thicker than the side seal 61 (for example, 5.0 to 6.0 mm) and is substantially U-shaped in a rear view. The upper seal 62 is formed of an elastic foam material such as urethane sponge, similar to the side seal 61.
The upper seal 62 is stuck through a double-sided tape across the support wall 56 and the upper pedestal 53 of the right side wall 45 and the left side wall 46. Specifically, the upper seal 62 is provided along the width direction on the surface of the support wall 56 (except for the bulging portion having the screw holes 57), and the right side wall 45 and the left side are provided at both ends in the width direction. It is continuously provided on the upper pedestal 53 of the wall 46. As a result, the upper seal 62 is disposed between the support wall 56 and the upper base 53 of the developing frame 25 and the layer thickness regulating blade 27.

Further, both end portions in the width direction of the upper seal 62 are disposed adjacent to both side seals 61 above, that is, downstream in the rotation direction of the developing roller 26. As a result, the rear part of the lower end edge of the both ends in the width direction of the upper seal 62 contacts the front part of the upper end edge of the side seal 61.
(4) Layer Thickness Restricting Blade As shown in FIG. 5B, the layer thickness restricting blade 27 includes a flexible leaf spring member 33 and a pressure contact rubber 34 provided at the lower end of the leaf spring member 33. It has.

The plate spring member 33 is formed in an elongated thin plate shape extending in the width direction to a position where it overlaps with the upper seals 62 disposed at both ends of the opening 29 in the width direction, when viewed from the back.
In addition, mounting holes 65 are formed on the upper side of both end portions in the width direction of the leaf spring member 33. Further, a rectangular cut-out portion 66 that is cut out upward from the lower end edge is formed slightly inside from both ends in the width direction of the leaf spring member 33.

Further, a front seal 67 is provided below the both ends in the width direction of the leaf spring member 33 between the both edges in the width direction and the notches 66.
The front seal 67 prevents the toner carried on the developing roller 26 from leaking from the surface side (rear surface side) of both end portions of the layer thickness regulating blade 27 to the outside of the developing frame 25. It is formed in a sheet shape that is thinner (for example, 1.5 to 2.0 mm) and is substantially rectangular when viewed from the back. The front seal 67 is made of an elastic foam material such as urethane sponge, similar to the side seal 61, and is adhered to the leaf spring member 33 via a double-sided tape.

The pressure contact rubber 34 is made of an elastic rubber such as an insulating silicone rubber, and is formed in a rectangular cross section that protrudes toward the developing roller 26. The pressure contact rubber 34 is provided at the lower end portion of the leaf spring member 33 so as to extend along the width direction to a position in contact with both front seals 67.
Then, as shown in FIG. 4, the layer thickness regulating blade 27 is arranged with the upper side of the leaf spring member 33 along the support wall 56, and the fixing screw 68 is inserted through the mounting hole 65 of the leaf spring member 33, Further, it is fixed to the developing frame 25 by being screwed into the screw hole 57 of the support wall 56.

In fixing the layer thickness regulating blade 27, the leaf spring member 33 is sandwiched by the reinforcing member 69 from the front side and the rear side, and is fixed to the support wall 56 by the fixing screw 68 together with the reinforcing member 69.
Accordingly, both end portions in the width direction of the leaf spring member 33 overlap with the upper seal 62 disposed on the upper base 53 in the rear view, and are disposed adjacent to the side seal 61 on the downstream side in the rotation direction of the developing roller 26. Further, the front seal 67 overlaps with the upper seal 62 disposed on the upper pedestal 53 via the plate spring member 33 in the rear view, and is disposed adjacent to the side seal 61 on the downstream side in the rotation direction of the developing roller 26. . As a result, the lower end edge of the front seal 67 contacts the rear portion of the upper end edge of the side seal 61. That is, the upper end edge of the side seal 61 is in contact with the upper seal 62 at the front side and is in contact with the front seal 67 at the rear side.
(5) Developing Roller The developing roller 26 includes a developing roller shaft 31 and a rubber roller 32 as shown in FIG. Both end portions in the axial direction of the developing roller shaft 31 are exposed from the rubber roller 32, and both end portions in the axial direction of the developing roller shaft 31 are received in both shaft support grooves 47 of the developing frame 25, as will be described in detail later. The right side wall 45 and the left side wall 46 are rotatably supported. When the developing roller shaft 31 is rotatably supported, the side seal 61 is pressed by the rubber roller 32. The side seal 61 has a thickness of 2/3 or less in the pressing direction with respect to the thickness when the rubber roller 32 is not pressed.
(6) Bearing Member The developing cartridge 24 is provided with a bearing member 71 that guides the developing roller shaft 31 to the deepest portion 50 of the guide groove 49 and rotatably receives the deepest portion 50. The bearing member 71 is disposed at the right end of the opening 29 and is provided on the right wall 45 as shown in FIG.

As shown in FIGS. 7 to 9, the bearing member 71 includes a base plate 75, a guide portion 72 for guiding the developing roller shaft 31 to the deepest portion 50, and the developing roller shaft 31 being rotatable at the deepest portion 50. A receiving bearing 73 and a cover 74 for preventing toner from leaking from the right end of the rubber roller 32 are integrally provided.
The base plate 75 has a flat plate shape, and a shaft hole portion 76 through which the supply roller shaft 41 is inserted is formed in a front portion thereof. The front portion is provided with a fixing portion 77 protruding upward, and a screw mounting hole 78 is formed in the fixing portion 77.

A bearing portion 73, a guide portion 72, and a cover portion 74 are provided on the rear portion of the base plate 75.
The bearing portion 73 is disposed at the center of the rear portion. The bearing portion 73 has a cylindrical shape, extends through the base plate 75 in the width direction, and is provided so as to protrude rightward. In a portion adjacent to the guide portion 72 of the bearing portion 73, the left side (inside) from the base plate 75 is notched.

  The guide part 72 is disposed adjacently below the bearing part 73. On the inner side surface in the width direction of the guide portion 72, an inclined surface 79 having a substantially rectangular shape in side view is provided that extends obliquely rearward and downward from the bearing portion 73. The inclined surface 79 is inclined from the inner side (left side) in the width direction toward the outer side (right side) in the width direction as it goes toward the bearing portion 73. Further, as will be described later, the inclined surface 79 is arranged so as to extend in the same direction as the direction in which the guide groove 49 extends (upwardly on the oblique front side) when the bearing member 71 is attached to the right side wall 45.

The cover part 74 is arrange | positioned at the lower end of the rear side part. The cover portion 74 is provided so as to bend inward in the width direction from the lower end of the rear portion of the cover portion 74 so as to cover the lower rear side of the bearing member 71. (7) Mounting of developing roller Next, a method of mounting the developing roller 26 on the developing frame 25 will be described. In order to attach the developing roller 26 to the developing frame 25, first, the layer thickness regulating blade 27 shown in FIG. 5B is attached to the developing frame 25 shown in FIG. The developing roller 26 shown in FIG. 5C is opposed to the opening 29 so that both end portions of the developing roller shaft 31 are inserted into the boundary portion between the inlet groove 48 and the guide groove 49 of both shaft support grooves 47. Deploy.

And the bearing member 71 shown in FIG. 7 is attached to the right side wall 45 shown in FIG. In order to attach the bearing member 71, first, the right side wall of the bearing member 71 is arranged such that the screw mounting hole 78 overlaps the screw fixing hole 58 in the width direction and the shaft insertion portion 54 and the shaft hole portion 76 overlap in the width direction. 45 is arranged opposite to the right.
Thereafter, the bearing member 71 is moved substantially horizontally to the left and brought into contact with the right side wall 45. Then, as shown in FIG. 10A, the right end portion of the developing roller shaft 31 contacts the lower side of the inclined surface 79, and the inclined surface 79 is moved as the bearing member 71 moves substantially horizontally to the left. Slid diagonally forward upward. Then, as indicated by a virtual line in FIG. 6, the end portion of the developing roller shaft 31 arranged at the boundary portion between the entrance groove 48 and the guide groove 49 is in contact with the inclined surface 79 of the right end portion of the developing roller shaft 31. Along with the sliding, the guide groove 49 is moved diagonally forward upward. As shown in FIG. 10B, the right end portion of the developing roller shaft 31 is inserted into the bearing portion 73 from the upper side of the inclined surface 79. Then, as shown by the solid line in FIG. 6, both end portions of the developing roller shaft 31 are disposed at the deepest portion 50 and positioned at the deepest portion 50.

  Further, when the developing roller shaft 31 moves in this way, the rubber roller 32 also presses the side seal 61 while moving diagonally forward. That is, the rubber roller 32 moves diagonally forward and upward while pressing the side seal 61 toward the lower pedestal 52. The side seal 61 is slid on the rubber roller 32 that moves diagonally forward and upward. When the both end portions of the developing roller shaft 31 are disposed at the deepest portion 50, the side seal 61 is, as shown in FIG. Then, it is crushed obliquely forward upward, that is, toward the downstream side in the rotation direction of the developing roller. Therefore, when both end portions of the developing roller shaft 31 are disposed at the deepest portion 50, the side seal 61 is crushed toward the upper seal 62 and the front seal 67.

Then, after the bearing member 71 is brought into contact with the right side wall 45, as shown in FIG. 3, the screw 80 is inserted into the screw mounting hole 78 and then screwed into the screw fixing hole 58. Fix to the right side wall 45. Further, the supply roller shaft 41 is inserted through the shaft insertion portion 54 and the shaft hole portion 76.
3. Advantages of Embodiment (1) As described above, in the developing cartridge 24, when the developing roller 26 is rotatably supported in the opening 29 of the developing frame 25, first, the developing roller shaft 31 is moved by the bearing member 71. Guided by the inclined surface 79 of the guide portion 72 to the deepest portion 50 of the shaft support groove 47, the developing roller shaft 31 is then inserted into the bearing portion 73 and received rotatably.

Therefore, the side seal 61 is pressed by the rubber roller 32 in the direction in which the developing roller shaft 31 is guided to the deepest portion 50. Thereby, the crushing direction of the side seal 61 can be controlled when the developing roller 26 is attached to the developing frame 25.
(2) Specifically, the developing roller shaft 31 is guided toward the deepest portion 50 while the rubber roller 32 presses the side seal 61 toward the lower pedestal 52. Therefore, the side seal 61 can be effectively crushed in the direction in which the developing roller shaft 31 is directed toward the deepest portion 50, that is, in the downstream direction in the rotation direction of the developing roller 26.
(3) When the developing roller shaft 31 is disposed at the deepest portion 50, the side seal 61 is crushed toward the upper seal 62 and the front seal 67. Therefore, at the upper end edge of the side seal 61, the front portion is in close contact with the upper seal 62 and the rear portion is in close contact with the front seal 67. As a result, a gap S (see FIG. 12) that causes toner to leak is formed between the side seal 61, the upper seal 62, and the front seal 67, in particular, between the side seal 61 and the upper seal 62. Therefore, the toner leakage can be reliably and effectively prevented and toner leakage can be suppressed.
(4) When the developing roller shaft 31 is disposed at the deepest portion 50, the side seal 61 is crushed toward the downstream side in the rotation direction of the developing roller. As a result, the rotation direction of the developing roller 26 coincides with the direction in which the side seal 61 is crushed. Therefore, the crushing of the side seal 61 can be maintained during development. As a result, it is possible to prevent the formation of a gap that causes toner leakage between the side seal 61 and the upper seal 62 and the front seal 67 for a long period of time.
(5) When the side seal 61 is crushed toward the upper seal 62 and the front seal 67, the upper seal 62 and the front seal 67 are also elastically deformed in response thereto. As a result, the adhesion between the side seal 61 and the upper seal 62 and the front seal 67 is improved, and it is possible to effectively prevent a gap that causes toner from leaking between them. Can do.
(6) Further, both end portions in the width direction of the upper seal 62 are disposed between the support wall 56 and the upper pedestal 53 and the layer thickness regulating blade 27. The layer thickness regulating blade 27 regulates the toner layer thickness on the surface of the rubber roller 32. Therefore, the toner that could not enter the surface of the rubber roller 32 tends to stay between the toner entry side with respect to the layer thickness regulating blade 27, that is, between the side seal 61, the upper seal 62, and the front seal 67.

However, since the upper seal 62 is disposed between the support wall 56 and the upper pedestal 53 and the layer thickness regulating blade 27, it is possible to prevent toner from leaking between them. Further, since the side seal 61, the upper seal 62, and the front seal 67 are in close contact with each other, leakage of toner from between them can be prevented. As a result, leakage of toner that tends to stay between the side seal 61 and the upper seal 62 and the front seal 67 can be effectively reduced.
(7) When the developing roller 26 is rotatably supported in the opening 29 of the developing frame 25, the developing roller shaft 31 is guided to the deepest portion 50 of the shaft support groove 47 by the inclined surface 79, and the developing roller shaft 31 is It is inserted into the bearing portion 73 and is rotatably received. Therefore, the developing roller shaft 31 can be reliably guided to the deepest portion 50 with a simple configuration. If the developing roller shaft 31 is guided by the inclined surface 79, the developing roller shaft 31 can be automatically guided to the deepest portion 50 only by moving the bearing member 71 substantially horizontally to the left. Therefore, workability can be improved.
4). Other Embodiments (1) FIG. 11 is a cross-sectional view showing another embodiment corresponding to the cross-sectional view taken along the line AA of FIG. In FIG. 11, the same members as those described above are denoted by the same reference numerals, and the description thereof is omitted.

In the above description, the side seal 61 is brought into close contact with the upper seal 62 and the front seal 67. For example, as shown in FIG.
The five ribs 59 can be brought into close contact with each other.
That is, in FIG. 11, in the developing cartridge 24, the seal pedestal 51 is provided with a rib 59 as an example of a contact member that protrudes rearward. Specifically, the rib 59 is provided so as to protrude obliquely downward and rearward from a step 55 between the lower pedestal 52 and the upper pedestal 53.

In this case, when both end portions of the developing roller shaft 31 are disposed at the deepest portion 50, the side seal 61 is crushed toward the lower surface of the rib 59. In the developing cartridge 24, it is possible to reliably and effectively prevent a gap S (indicated by an imaginary line) that causes toner leakage between the side seal 61 and the rib 59. Can do. As a result, toner leakage can be suppressed.
(2) In the above description, a monochrome laser printer has been exemplified as the image forming apparatus. However, the image forming apparatus to which the developing device (developing cartridge) of the present invention is attached is not limited to the above, for example, An intermediate transfer type color printer that is transferred from a tandem color laser printer provided with a photosensitive drum corresponding to a plurality of colors or a developing roller corresponding to a plurality of colors to an intermediate transfer member and then transferred to a sheet at once. Laser printers are included.

1 is a side sectional view showing an embodiment of a laser printer as an example of an image forming apparatus of the present invention. FIG. 3 is a plan view of a developing cartridge. FIG. 3 is a right side view of the developing cartridge (with a bearing member attached). It is the sectional view on the AA line of FIG. 2A and 2B are rear views of the developing cartridge, in which FIG. 1A shows a developing frame (with a developing roller and a layer thickness regulating blade removed), FIG. 2B shows a layer thickness regulating blade, and FIG. FIG. 3 is a right side view of the developing cartridge (with a bearing member removed). It is a right view of a bearing member. It is a left view of a bearing member. It is the BB sectional drawing of FIG. FIG. 9 is a cross-sectional view corresponding to FIG. 8 for explaining the mounting of the bearing member to the developing roller, where (a) is a state where the developing roller is guided by an inclined surface, and (b) is a state where the developing roller is a bearing. The state inserted in the part is shown. It is sectional drawing which shows other embodiment equivalent to the sectional view on the AA line of FIG. It is sectional drawing which shows the prior art example corresponded in the AA sectional view taken on the line of FIG.

DESCRIPTION OF SYMBOLS 1 Laser printer 3 Paper 9 Feed roller 13 Process unit 21 Photosensitive drum 24 Developing cartridge 25 Developing frame 26 Developing roller 27 Layer thickness control blade 29 Opening 31 Developing roller shaft 32 Rubber roller 50 Deepest part 61 Side seal 62 Upper seal 71 Bearing member 72 Guide part 73 Bearing part 79 Inclined surface

Claims (6)

A housing that houses the developer and in which an opening is formed;
A developer member that has a shaft member and a roller member, is rotatably supported in the opening of the housing, and carries the developer;
A bearing member provided separately from the housing, and rotatably supporting an axial end portion of the shaft member;
The housing includes a pair of side walls disposed to face each other with a space therebetween in the axial direction ,
Before SL sidewall extends towards the interior of the housing along the axial direction, and the pedestal along the outer peripheral surface of the longitudinal ends of the roller member, and the shaft supporting groove for rotatably supporting the shaft member Have
An elastic material is disposed along the outer peripheral surface of the roller member between both longitudinal ends of the roller member and the pedestal, and the developer passes from both ends of the roller member to the outside of the housing. A first seal member for preventing leakage into the
The shaft support groove, when viewed from the axial direction, an inlet groove extending in a direction crossing the base through the opening, from the end opposite to the opening of the inlet channel, seen from the axial direction A guide groove formed along the pedestal for guiding the shaft member to a fixed position,
The bearing member is formed along the guide groove, and guides the shaft member at the end opposite to the opening of the inlet groove to the fixed position along the guide groove. And a bearing portion formed continuously with the guide portion and rotatably receiving the shaft member. The guide portion, when the shaft member is disposed in the fixed position, the rotation direction downstream side end portion of the developer responsible bearing member of the first sealing member, the developer carrying the first seal member The developing device according to claim 1, wherein the shaft member is guided so as to be crushed toward an abutting member provided adjacent to an end portion on the downstream side in the rotation direction of the body. A second seal member formed of an elastic member is provided adjacent to the first seal member on the downstream side in the rotation direction of the developer carrier relative to the first seal member.
The developing device according to claim 2, wherein the contact member is an upstream end portion of the second seal member in the rotation direction of the developer carrier. A layer thickness regulating member that is pressed to form a thin layer of developer on the surface of the roller member,
The layer thickness regulating member has a pressure-contact rubber pressed against the roller member,
Said second sealing member, the opposite side to the developer carrying member to sandwich the pressing rubber, characterized in that it is placed in contact with the layer thickness regulating member, a developing device according to claim 3 . The pedestal is disposed adjacent to a downstream end of the first seal member in the rotation direction of the developer carrier, and has a rib protruding toward the developer carrier;
The developing device according to claim 2, wherein the contact member is the rib. The guide portion and the bearing portion are disposed adjacent to each other,
The developing device according to claim 1, wherein the guide portion is provided with an inclined surface that is inclined so as to be separated from the side wall toward the bearing portion.

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