JP2012053111A - Developing device - Google Patents

Abstract

A developing device capable of suppressing developer leakage from between a pressing member and a seal member is provided.
A developing device (developing cartridge 100) includes a developing roller 120 that carries a developer, a casing 110 that supports the developing roller 120, a plate member 141, and a free end of the plate member 141. A pressing member 142 provided so as to protrude toward the roller 120, the layer thickness regulating blade 140 that slides against the developing roller 120 to regulate the thickness of the developer, and the developing roller 120. And a seal member 150 opposed to both ends. The seal member 150 is disposed between the developing roller 120 and the plate-like member 141 on the outer side in the longitudinal direction of the pressing member 142, and has a protruding portion 153 that protrudes toward the plate-like member 141. Has an opening (through hole 141 </ b> A) that engages with the protrusion 153.
[Selection] Figure 4

Description

  The present invention relates to a developing device used in an electrophotographic image forming apparatus.

  Generally, as a developing device such as a developing cartridge, for example, as described in Patent Document 1, a developing roller and a pressing member (pressing rubber member) provided at a lower end portion of a plate-like member (plate spring member) are provided. There is known one having a layer thickness regulating blade and a seal member (side seal) facing both end portions of the developing roller. The pressing member of the layer thickness regulating blade is not provided at both ends in the longitudinal direction of the plate member, and a seal member (felt seal member) is provided between the both ends, that is, between the developing roller and the plate member. Has been placed.

JP 2006-39428 A (FIGS. 4 and 9)

  By the way, in the developing device configured as described above, if the seal member is not accurately positioned with respect to the layer thickness regulating blade, a gap is generated between the pressing member and the seal member, and the developer leaks from this gap. There was a fear.

  SUMMARY An advantage of some aspects of the invention is that it provides a developing device capable of suppressing developer leakage from between a pressing member and a seal member.

  In order to achieve the above-described object, the developing device of the present invention includes a developing roller carrying a developer, a housing supporting the developing roller, a plate member, and the developing roller at a free end of the plate member. And a pressing member provided so as to protrude toward the surface, the pressing member slidingly contacts the developing roller and regulates the thickness of the developer, and both end portions of the developing roller. A developing device including an opposing seal member, wherein the seal member is disposed between the developing roller and the plate-like member on the outer side in the longitudinal direction of the pressing member, toward the plate-like member. It has the protrusion part which protrudes, The said plate-shaped member has an opening part engaged with the said protrusion part, It is characterized by the above-mentioned.

  According to the developing device configured as described above, the seal member disposed between the developing roller and the plate-like member has the protruding portion that protrudes toward the plate-like member, and the plate-like member protrudes from the seal member. Since it has the opening part engaged with a part, a sealing member can be accurately positioned with respect to a layer thickness control blade by engagement of a protrusion part and an opening part. Thereby, since the generation | occurrence | production of the clearance gap between a pressing member and a sealing member can be suppressed, the developer leakage from between a pressing member and a sealing member can be suppressed.

  According to the present invention, since the seal member can be accurately positioned with respect to the layer thickness regulating blade, the developer leakage from between the pressing member and the seal member can be suppressed.

1 is a diagram illustrating a schematic configuration of a color printer including a developing device (developing cartridge) according to a first embodiment. FIG. 3 is an enlarged view of the periphery of a developing cartridge. FIG. 3 is a perspective view of a developing cartridge. FIG. 4 is a perspective view (a) of a layer thickness regulating blade and a seal member, and an enlarged view (b) of a developing cartridge. It is sectional drawing of the edge part periphery of a developing roller. FIG. 4A is a cross-sectional view of the periphery of an end portion of a developing roller of a developing device (developing cartridge) according to a second embodiment, showing a state before assembling a layer thickness regulating blade and a diagram after assembling a layer thickness regulating blade ). FIG. 10 is an enlarged view of a developing device (developing cartridge) according to a modified example. It is a perspective view of the seal member concerning a modification.

[First Embodiment]
Next, a first embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, a schematic configuration of the image forming apparatus (color printer 1) including the developing cartridge 100 as an example of the developing device according to the embodiment of the present invention will be described, and then the developing cartridge 100 will be described in detail. The configuration will be described.

<Schematic configuration of color printer>
As shown in FIG. 1, the color printer 1 includes a paper supply unit 20 that supplies paper S, an image forming unit 30 that forms an image on the supplied paper S, and an image. And a paper discharge unit 90 for discharging the paper S.

  In the description of the schematic configuration, the direction will be described with reference to the user who uses the color printer 1. That is, the left side in FIG. 1 is “front”, the right side is “rear”, the front side is “right”, and the back side is “left”. Also, the vertical direction in FIG.

  On the upper side of the main body housing 10, an upper cover 12 is provided that can be opened and closed up and down with the rear side as a fulcrum. The upper cover 12 has an upper surface serving as a paper discharge tray 13 on which the paper S discharged from the inside of the main body housing 10 is placed, and four lower holding portions 14 that hold the LED units 40 are provided on the lower surface. ing.

  The paper feeding unit 20 is provided at a lower portion in the main body housing 10, and mainly includes a paper feeding tray 21 that stores the paper S and a paper supply mechanism 22 that supplies the paper S from the paper feeding tray 21 to the image forming unit 30. In preparation. The sheets S in the sheet feeding tray 21 are separated one by one by the sheet supply mechanism 22 and supplied to the image forming unit 30.

  The image forming unit 30 mainly includes four LED units 40, four process units 50, a transfer unit 70, and a fixing unit 80.

  The LED unit 40 is disposed so as to oppose the photosensitive drum 61 and is configured to expose the surface of the photosensitive drum 61. Since the LED unit 40 is held by the upper cover 12 via the holding portion 14, the LED unit 40 is configured to be retractable from above the photosensitive drum 61 by opening and closing the upper cover 12.

  The process unit 50 is arranged side by side between the upper cover 12 and the paper feeding unit 20 and is detachably attached to the main body housing 10 through an opening formed when the upper cover 12 is opened. It has become. The process unit 50 includes a photoconductor unit 60 and a developing cartridge 100 (developing device).

  As shown in FIG. 2, the photoreceptor unit 60 mainly includes a photoreceptor case 60 </ b> A, a photoreceptor drum 61, and a charger 62. By attaching the developing cartridge 100 to the photoconductor case 60A, an exposure hole 63 that faces the photoconductor drum 61 from the outside is formed. The LED unit 40 is inserted into the exposure hole 63 so as to face the photosensitive drum 61.

  The developing cartridge 100 is configured to be detachably attached to the photoreceptor unit 60, and mainly includes a housing 110, a developing roller 120, a supply roller 130, and a layer thickness regulating blade 140. Yes. The casing 110 supports the developing roller 120, the supply roller 130, and the like, and forms a toner storage portion 111 that stores toner as an example of a developer. The detailed configuration of the developing cartridge 100 will be described later.

  Returning to FIG. 1, the transfer unit 70 is provided between the paper feeding unit 20 and the process unit 50, and is endlessly stretched between the driving roller 71, the driven roller 72, and the driving roller 71 and the driven roller 72. And the transfer roller 74 are mainly provided. The outer surface of the conveyance belt 73 is in contact with each photosensitive drum 61, and the transfer rollers 74 are disposed inside the conveyance belt 73 so as to sandwich the conveyance belt 73 with the respective photosensitive drums 61.

  The fixing unit 80 is provided behind the process unit 50 and the transfer unit 70, and mainly includes a heating roller 81 and a pressure roller 82 that is disposed to face the heating roller 81 and presses the heating roller 81.

  In the image forming unit 30, the surface of the photosensitive drum 61 is uniformly charged by the charger 62 and then exposed by the LED unit 40, whereby the electrostatic latent image based on the image data is formed on the photosensitive drum 61. Is formed. The toner in the toner storage unit 111 is supplied to the developing roller 120 via the supply roller 130 and enters between the developing roller 120 and the layer thickness regulating blade 140 so as to form a thin layer having a certain thickness. Supported on.

  The toner carried on the developing roller 120 is supplied to the photosensitive drum 61 supplied to the electrostatic latent image, whereby the electrostatic latent image is visualized, and the toner is transferred onto the photosensitive drum 61. An image is formed. Thereafter, the sheet S supplied from the sheet feeding unit 20 is conveyed between the photosensitive drum 61 and the conveying belt 73 (transfer roller 74), so that the toner image formed on each photosensitive drum 61 becomes a sheet. The images are sequentially superimposed and transferred onto S. The sheet S on which the toner image has been transferred is conveyed between the heating roller 81 and the pressure roller 82, whereby the toner image is thermally fixed.

  The paper discharge unit 90 mainly includes a paper discharge path 91 formed so as to extend upward from the exit of the fixing unit 80 and change its direction forward, and a plurality of conveyance rollers 92 that convey the paper S. Yes. The sheet S on which the toner image is thermally fixed is transported along a paper discharge path 91 by a transport roller 92, is discharged outside the main body housing 10, and is discharged onto the paper discharge tray 13.

<Detailed configuration of developing cartridge>
As shown in FIG. 3, the developing cartridge 100 (developing device) includes a casing 110, a developing roller 120, a supply roller 130, and a layer thickness regulating blade 140, and further includes two seal members 150. Hereafter, the structure relevant to this invention of each member is demonstrated in detail.

  The casing 110 mainly includes a lower frame 112 whose upper portion is opened, and an upper frame 113 that is attached (welded) so as to cover the opened portion of the lower frame 112.

  The developing roller 120 is a known roller that carries toner and supplies it to the photosensitive drum 61, and the supply roller 130 is a known roller that supplies toner to the developing roller 120.

The layer thickness regulating blade 140 mainly includes a plate-like member 141 and a pressing member 142.
The plate-like member 141 is a substantially rectangular thin metal plate, and, as shown in FIG. 4A, projecting portions of the seal member 150, which will be described later, at both ends in the longitudinal direction (the axial direction of the developing roller 120). A through-hole 141A is provided as an example of an opening that engages with 153 (FIGS. 4 and 5 show only one in the longitudinal direction).

  The pressing member 142 is formed of a rubber material or the like, and is provided by being attached to the free end (lower end in FIG. 2) of the plate-like member 141 so as to protrude toward the developing roller 120. . The layer thickness regulating blade 140 regulates the thickness of the toner carried on the surface of the developing roller 120 by the pressing member 142 being in direct contact with the rotating developing roller 120.

  As shown in FIGS. 2 and 3, the layer thickness regulating blade 140 is exposed to the outside on the surface opposite to the surface of the free end of the plate-like member 141 where the pressing member 142 is provided. It is assembled to do. Each through-hole 141A is formed at the exposed free end of the plate-like member 141. As shown in FIGS. 4A and 4B, the rotation direction of the developing roller 120 (the short direction of the plate-like member 141). ) In the shape of a substantially oval longer than the protruding portion 153 of the seal member 150.

  As shown in FIG. 3, the seal member 150 is disposed so as to face both end portions of the developing roller 120. Further, as shown in FIG. 5, the upper portion of the seal member 150 is disposed between the developing roller 120 and the plate-like member 141 of the layer thickness regulating blade 140 on the outer side in the longitudinal direction of the pressing member 142 of the layer thickness regulating blade 140. Has been. As shown in FIG. 4A, the seal member 150 mainly includes an elastic seal member 151 and a positioning member 152.

  The elastic seal member 151 is an elastically deformable seal material made of a sponge material, felt, or the like, and is formed in a substantially bow shape in a side view. The elastic seal member 151 is disposed so as to be in sliding contact with both end portions of the developing roller 120, and suppresses toner leakage from between the housing 110 and both end portions of the developing roller 120. In the present invention, the elastic seal member 151 may have a single layer structure or a multilayer structure.

  The positioning member 152 is a substantially plate-like member made of a rubber material or the like, and is disposed between the elastic seal member 151 and the plate-like member 141 of the layer thickness regulating blade 140 (see also FIG. 5). At the center of the upper surface of the positioning member 152, a substantially long columnar protruding portion 153 that protrudes upward (a plate-shaped member 141) is formed. The protrusion 153 is elastically deformable.

  The seal member 150 and the inner surfaces 151A and 152A of the elastic seal member 151 and the positioning member 152 (the surfaces facing the inner side in the axial direction of the developing roller 120) are flush with the upper surface of the elastic seal member 151 and the positioning member 152. It is formed by adhering to the lower surface, and is attached to the housing 110 as one component. Further, grease (not shown) is held between the seal member 150 (positioning member 152) and the plate-like member 141, and toner leakage from between the positioning member 152 and the plate-like member 141 is suppressed. .

Next, a procedure for assembling the developing cartridge 100 of this embodiment will be described.
First, after the upper frame 113 is welded to the lower frame 112 and the housing 110 is assembled, the supply roller 130 is assembled, and the pair of seal members 150 are further attached. Next, the developing roller 120 is assembled to the housing 110, and each seal member 150 (elastic seal member 151) and both ends of the peripheral surface of the developing roller 120 are brought into close contact with each other.

  Next, the layer thickness regulating blade 140 is assembled to the housing 110 while the position of the through hole 141 </ b> A is adjusted to the position of the protruding portion 153 of the seal member 150. As shown in FIG. 4B, when the layer thickness regulating blade 140 is assembled to the housing 110, the through hole 141 </ b> A is engaged with the protruding portion 153.

  Thereafter, the toner cartridge 111 is filled with toner from a filling port (not shown) provided on the side wall of the housing 110, and a developing cartridge 100 is assembled by attaching a cap (not shown) to the filling port.

  In the present embodiment, since the through hole 141A is formed at the free end exposed to the outside of the layer thickness regulating blade 140 (plate member 141), the engagement between the through hole 141A and the protrusion 153 is visually observed. Can do. Accordingly, the layer thickness regulating blade 140 can be assembled by reliably engaging the through-hole 141A and the protruding portion 153, so that the generation of a gap between the plate-like member 141 and the positioning member 152 can be suppressed. In addition, toner leakage from between the layer thickness regulating blade 140 and the seal member 150 can be suppressed.

  Further, since the through hole 141A has a shape longer than the protruding portion 153 in the rotation direction of the developing roller 120, the protruding portion is caused by a dimensional error or deformation of the seal member 150 when being brought into contact with the developing roller 120. Even if the position of 153 is slightly deviated in the rotation direction of the developing roller 120, the protrusion 153 can be reliably engaged. Further, after the engagement, the projecting portion 153 has some play in the rotation direction of the developing roller 120, so that the seal member 150 and the developing roller 120 and the layer thickness regulating blade 140 are not sealed. The formation of a gap due to the deformation of the member 150 can be suppressed. Thereby, toner leakage can be suppressed.

  Here, in this embodiment, when the protrusion 153 engages with the through hole 141A, the peripheral wall of the through hole 141A bites into the developing roller 120 slightly inward in the axial direction as shown in FIG. It is elastically deformed so as to be recessed, and is provided at such a position as to push the peripheral wall of the through hole 141A toward the outside in the axial direction of the developing roller 120 by its restoring force.

  Thus, when the through hole 141A and the protrusion 153 are engaged, the peripheral wall of the through hole 141A is pressed against the protrusion 153 in the axial direction of the developing roller 120 by the reaction force of the force pressed by the protrusion 153. It will press toward the member 142 side. In this way, the peripheral wall of the through hole 141A presses the protruding portion 153 toward the pressing member 142, so that a force as shown by an arrow in FIG. 5 acts, and the seal member 150 is moved in the longitudinal direction of the pressing member 142. It can abut (press) the end 142A.

  With such a configuration, it is possible to suppress the occurrence of a gap between the seal member 150 and the pressing member 142, and thus it is possible to suppress toner leakage from between the seal member 150 and the pressing member 142. .

  According to the developing cartridge 100 of the present embodiment described above, the seal member 150 has the protruding portion 153 that protrudes toward the plate-shaped member 141, and the plate-shaped member 141 has the through hole 141 </ b> A that engages with the protruding portion 153. Therefore, the seal member 150 can be accurately positioned with respect to the layer thickness regulating blade 140 by the engagement between the projecting portion 153 and the through hole 141A. As a result, the occurrence of a gap between the pressing member 142 and the seal member 150 can be suppressed, so that toner leakage from between the pressing member 142 and the seal member 150 can be suppressed.

  Further, since the seal member 150 includes the elastic seal member 151 and the positioning member 152 on which the protruding portion 153 is formed, it is possible to appropriately select an elastic coefficient or the like for each member. Accordingly, the position accuracy of the seal member 150 with respect to the layer thickness regulating blade 140 is improved while more reliably suppressing toner leakage between the casing 110 and both ends of the developing roller 120, and the pressing member 142 and the seal member. The toner leakage from between 150 can be more reliably suppressed.

[Second Embodiment]
Next, a second embodiment of the present invention will be briefly described. In the present embodiment, the configuration of the layer thickness regulating blade 140 is different from that of the first embodiment. Therefore, this point will be mainly described, and the same components as those in the first embodiment will be denoted by the same reference numerals and the description thereof will be given. Will be omitted.

  As shown in FIG. 6A, the layer thickness regulating blade 140 mainly has a plate-like member 141 in which a through-hole 141A is formed and a pressing member 142. The through-hole 141A of the present embodiment is formed by cutting up part of both end portions of the plate-like member 141 made of a thin metal plate (only one of the longitudinal directions is shown in FIG. 6). Thereby, as shown in FIG. 6B, the peripheral wall of the through hole 141A is an inclined surface inclined toward the pressing member 142 so as to press the engaged protrusion 153 toward the pressing member 142. 141B.

  With such a configuration, also in this embodiment, when the through hole 141A and the protruding portion 153 are engaged, the peripheral wall (the inclined surface 141B) of the through hole 141A presses the protruding portion 153 toward the pressing member 142. Thus, the seal member 150 can be abutted against the end 142 </ b> A of the pressing member 142. Thereby, toner leakage from between the seal member 150 and the pressing member 142 can be suppressed.

  In the present embodiment, the inclined surface 141B of the peripheral wall of the through hole 141A is formed by cutting up, but the present invention is not limited to this. For example, a part of the peripheral wall of the through hole 141A of the first embodiment is scraped. An inclined surface may be formed. Further, in the present embodiment, the configuration in which the peripheral wall of the through hole 141A has the inclined surface 141B is illustrated, but the present invention is not limited to this, and the protruding portion may have an inclined surface.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention.

  For example, as shown in FIG. 7, a plurality of protrusions 153 and through holes 141 </ b> A may be provided side by side in the rotation direction of the developing roller 120. According to this, since the seal member 150 can be prevented from being tilted around the single protrusion 153, toner leakage can be more reliably suppressed. In addition, when the configuration in which the peripheral wall of the opening presses the protruding portion toward the pressing member side is provided, the sealing member 150 is stronger than the end 142A of the pressing member 142 by providing a plurality of protruding portions 153 and through holes 141A. Since it can be pressed, toner leakage from between the seal member 150 and the pressing member 142 can be more reliably suppressed.

  In the above-described embodiment, the configuration in which the peripheral wall of the through hole 141A presses the protruding portion 153 toward the pressing member 142 to press the seal member 150 against the end 142A of the pressing member 142 is illustrated. Is not to be done. For example, the end in the longitudinal direction of the plate-like member is bent to the same side as the side on which the pressing member is provided, and the bent portion presses the sealing member toward the pressing member so that the sealing member is It is good also as a structure which abuts against the edge part of a longitudinal direction.

  In the above embodiment, the seal member 150 is composed of two parts (the elastic seal member 151 and the positioning member 152), but the present invention is not limited to this. For example, the elastic seal member is formed by bonding together a first seal member made of a sponge material such as urethane foam and a second seal member made of felt, so that the seal member has three parts (two or more parts) as a whole. You may be comprised from.

  In the embodiment, the seal member 150 is composed of the elastic seal member 151 and the positioning member 152 on which the protruding portion 153 is formed. However, the present invention is not limited to this. For example, as shown in FIG. 8, the seal member 250 is an elastically deformable member made of a molded product such as Polon (registered trademark), soft resin, silicone, urethane, and the like, and the protruding portion 153 is integrally formed. May be. According to such a configuration, the process of assembling the seal member is not necessary, and the seal member can be manufactured easily and inexpensively.

  In the above-described embodiment, the through hole 141A is exemplified as the opening. However, the present invention is not limited to this. For example, the opening may be a hole with a bottom (such as a recess or a groove), or the plate-like member is free. It may be a notch that opens toward the end.

  In the embodiment, the developing cartridge 100 is exemplified as the developing device. However, the developing cartridge 100 is not limited thereto. For example, the developing unit 100 may be the process unit 50, or the photosensitive unit 60 and the developing cartridge 100 may be integrated (not detachable). It may be a formed unit. In the embodiment described above, the layer thickness regulating blade 140 is assembled so that the free end of the plate-like member 141 is exposed to the outside. However, the present invention is not limited to this, and the layer thickness regulating blade is assembled after the developing device is assembled. The structure which is not exposed outside may be sufficient.

  In the above-described embodiment, the color printer 1 that exposes the photosensitive drum 61 with the LED unit 40 is exemplified as the image forming apparatus including the developing device of the present invention. However, the image forming apparatus is not limited to this. It may be a printer that performs exposure. The image forming apparatus is not limited to a printer, and may be, for example, a copying machine or a multifunction machine.

DESCRIPTION OF SYMBOLS 100 Developing cartridge 110 Housing | casing 120 Developing roller 140 Layer thickness control blade 141 Plate member 141A Through-hole 141B Inclined surface 142 Press member 142A End part 150 Seal member 151 Elastic seal member 152 Positioning member 153 Projection part 250 Seal member

Claims (9)

A developing roller carrying a developer;
A housing that supports the developing roller;
A plate-like member, and a pressing member provided at the free end of the plate-like member so as to protrude toward the developing roller, and the pressing member is in sliding contact with the developing roller and has a thickness of developer. Layer thickness regulating blade to regulate,
A developing device comprising a seal member facing both ends of the developing roller,
The seal member is disposed between the developing roller and the plate-like member on the outer side in the longitudinal direction of the pressing member, and has a protruding portion that protrudes toward the plate-like member,
The developing device according to claim 1, wherein the plate-like member has an opening that engages with the protrusion.   The peripheral wall of the opening is configured to press the protruding portion toward the pressing member, so that the sealing member abuts against an end portion in the longitudinal direction of the pressing member. 2. The developing device according to 1. The protrusion is elastically deformable, and is provided so as to be elastically deformed when engaged with the opening and to press the peripheral wall of the opening by its restoring force.
The developing device according to claim 2, wherein the peripheral wall of the opening presses the protrusion toward the pressing member by a reaction force of a force pressed by the protrusion.   The peripheral wall of the opening has an inclined surface inclined toward the pressing member so as to press the engaged protruding portion toward the pressing member. 3. The developing device according to 3. The layer thickness regulating blade is assembled to the casing so that a surface of the free end of the plate-like member opposite to the surface on which the pressing member is provided is exposed to the outside.
The developing device according to claim 1, wherein the opening is a through-hole formed at an exposed free end.   The developing device according to claim 1, wherein the seal member is elastically deformable and is integrally formed with the protruding portion. The sealing member is
An elastically deformable elastic seal member that is in sliding contact with both ends of the developing roller;
The developing device according to claim 1, further comprising a positioning member formed between the elastic seal member and the plate-like member. .   8. The developing device according to claim 1, wherein the opening has a shape longer than the protrusion in the rotation direction of the developing roller. 9.   The developing device according to claim 1, wherein a plurality of the projecting portions and the opening portions are provided side by side in the rotation direction of the developing roller.

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