JP5035283B2 - Development device - Google Patents

Description

  The present invention relates to a developing device that includes a developing roller, a supply roller that supplies a developer to the developing roller, and a seal member that is disposed corresponding to both ends of the developing roller and the supply roller.

  2. Description of the Related Art Conventionally, a developing device is known that includes a side seal that is in sliding contact with the peripheral surfaces of both end portions of a developing roller, and a supply roller seal that penetrates a shaft portion of the supply roller and is in close contact with a first seal member. (See Patent Document 1). Specifically, in this technique, the side seal is composed of two layers of felt and sponge. The supply roller seal is formed of a sponge and is fitted into a recess formed in a frame that rotatably supports the supply roller.

  In this technique, side leakage is applied to the supply roller seal fitted in the recess and the frame portion adjacent to the supply roller seal, thereby suppressing toner leakage from the inside of the developing device. .

JP 2007-58056 A

  However, the above-described technique requires a process of fitting the supply roller seal into the recess and a process of attaching the side seal, which causes a problem that the assembling work is complicated.

  SUMMARY An advantage of some aspects of the invention is that it provides a developing device capable of facilitating assembly work of a seal member.

In order to solve the above problems, a developing device according to the present invention includes a developing roller that carries a developer, a developer roller that contacts the developing roller and supplies the developer, and is shorter in the axial direction than the developing roller; A case main body that rotatably supports the developing roller and the supply roller, and a recess that is formed in the case main body and that opens toward the peripheral surfaces of both end portions of the developing roller and in which the shaft portion of the supply roller is disposed A first seal member that is in sliding contact with the peripheral surfaces of both end portions of the developing roller, a second seal member that is penetrated by the shaft portion of the supply roller and that is in close contact with the recess and the first seal member, A side case mounted in the axial direction of the developing roller with respect to a side wall of the case main body, wherein the first seal member and the second seal member are arranged on the case main body. The case main body is integrally formed so as to be detachable integrally with the part, and the case main body opens to the upstream side in the rotational direction at a position upstream of the developing roller in the rotational direction. A cutout portion formed so as to communicate with the inside and outside of the case main body, the cutout portion protruding from one end edge in the axial direction toward the other end edge, and the tip from the other end edge An engagement protrusion that is disposed at a distant position and engages with a portion of the first seal member or the second seal member on the upstream side in the rotation direction of the developing roller, and is provided with the first seal member or the A portion of the second seal member on the upstream side in the rotation direction of the developing roller includes a first projecting portion projecting to the outside from between the bottom portion of the notch portion and the engaging projection, and the engagement from the first projecting portion. Projecting to the mating side And a second projecting portion, characterized in that it is configured to be sandwiched compressed between said side case the case body.

  According to the present invention, since the first seal member and the second seal member are integrally configured to be detachable integrally with the recess of the case body, the integrated seal member is attached to the recess. As a result, the assembly of the seal member to the case body can be completed.

  According to the present invention, since the first seal member and the second seal member are integrally configured so as to be detachable integrally with the concave portion of the case body, the assembly work of the seal member is facilitated. Can do.

1 is a side sectional view showing a laser printer provided with a developing cartridge according to an embodiment of the present invention. FIG. 6 is a side sectional view showing a developing cartridge. FIG. 6 is a perspective view showing a state where a side case and a developing roller are removed from the developing cartridge. They are the expansion perspective view (a) which shows the recessed part of the left side of a case main body, and the enlarged perspective view (b) which shows a recessed part of the right side. It is sectional drawing which shows the state which fitted the seal unit in the recessed part. It is a perspective view which shows a seal unit. FIG. 4 is an enlarged perspective view (a) in which the left and left side cases of the case body are disassembled and viewed from obliquely above, and an enlarged perspective view (b) in which the right and right side cases of the case body are disassembled and viewed from obliquely above. . FIG. 4 is an enlarged perspective view (a) in which the left and left side cases of the case body are disassembled and viewed from obliquely below, and an enlarged perspective view (b) in which the right and right side cases of the case body are disassembled and viewed from obliquely below. . They are the expansion perspective view (a) which shows the state which attached the left side case to the case main body, and the expansion perspective view (b) which shows the state which assembled the right side case to the case main body.

  Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of the laser printer will be briefly described, and then the details of the characteristic portions of the present invention will be described.

  Further, in the following description, the description will be made in the direction based on the user when the laser printer 1 is used. That is, in FIG. 1, the right side is “front side (front side)”, the left side is “rear side (back side)”, the back side of the paper vertical direction is “right side”, and the front side of the paper vertical direction is front side Is “left side”. In addition, the vertical direction toward the page is defined as the “vertical direction”.

<Overall 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 casing 2 and a paper pressing plate 7 provided in the paper feed tray 6. The feeder unit 4 includes various rollers 11 that carry the paper 3 and remove paper dust. 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, 21 and reflecting mirrors 22, 23, 24, and the like. . 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 two-dot 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 is mainly composed of 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 body casing 2 while being attached to the drum unit 39. The developing cartridge 28 may be configured to be detachable from the drum unit 39 fixed to the main casing 2. As shown in FIG. 2, the developing cartridge 28 mainly includes a developing roller 31, a layer thickness regulating blade 32, a supply roller 33, and a toner storage chamber 34.

  In the developing cartridge 28, toner as an example of the developer in the toner storage chamber 34 is stirred by the agitator 34A and then supplied to the developing roller 31 by the supply roller 33. At this time, the supply roller 33 and the developing roller 31 are supplied. And positively triboelectrically charged. The toner supplied onto 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 further developed as a thin layer having a constant thickness while being frictionally charged. It is carried on a roller 31. Details of the developing cartridge 28 will be described later.

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

  Next, by the rotation of the developing roller 31, the toner carried on the developing roller 31 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 27, so that the toner image is formed on the surface of the photosensitive drum 27. It is formed. Thereafter, the sheet 3 is conveyed between the photosensitive drum 27 and the transfer roller 30, whereby the toner image carried on the surface of the photosensitive drum 27 is transferred onto the sheet 3.

  As shown in FIG. 1, the fixing unit 18 includes a heating roller 41 and a pressure roller 42 that presses 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 sheet 3 thermally fixed by the fixing unit 18 is conveyed to a paper discharge roller 45 disposed on the downstream side of the fixing unit 18, and is sent out from the paper discharge roller 45 onto a paper discharge tray 46.

<Detailed structure of developing cartridge>
Next, the detailed structure of the developing cartridge 28 will be described.
As shown in FIG. 3, the developing cartridge 28 mainly includes a case main body 50 that rotatably supports the developing roller 31 and the supply roller 33 described above, and seal units 60 that are disposed on both ends of the supply roller 33. ing.

  Here, the supply roller 33 is shorter than the developing roller 31 in the axial direction. Therefore, when the developing roller 31 is attached to the case main body 50 so as to be in contact with the supply roller 33, the peripheral surfaces of both ends of the developing roller 31 are in contact with the seal unit 60. Further, the developing roller 31 and the supply roller 33 include large-diameter roller portions 31A and 33A that carry toner, and a shaft portion 31B that is formed in a smaller diameter than the roller portions 31A and 33A and is rotatably supported by the case body 50. , 33B.

  The case body 50 is formed in a box shape that opens to the rear, and supports the shaft portions 31B and 33B of the developing roller 31 and the supply roller 33 so as to be rotatable on the opening side. 4B. As shown in FIGS. 4A and 4B, the case body 50 is opened at both ends of the supply roller 33 toward the peripheral surfaces of both end portions of the roller portion 31A of the developing roller 31, and is supplied. A recess 51 in which the shaft 33B of the roller 33 is disposed is formed.

  The recess 51 is formed in a shape that gradually expands in a substantially vertical direction from the bottom surface 51A toward the opening (see FIG. 5). That is, a pair of upper wall 51B and lower wall 51C which are opposed to each other in the substantially vertical direction among the walls forming the recess 51 are inclined so as to gradually separate from the bottom surface 51A toward the opening. Thereby, the corner | angular part of the seal unit 60 becomes easy to contact | adhere to the corner of the recessed part 51 easily.

  A substantially U-shaped notch 52 communicating with the inside and outside of the case main body 50 is formed on the rear side of the recess 51 (upstream in the rotation direction of the developing roller 31 shown in FIGS. 2 and 3). Further, an engaging protrusion 53 as an example of an engaging portion is formed on the side portion 52A on the inner side in the left-right direction of the substantially U-shaped cutout portion 52 so as to protrude outward in the left-right direction.

  And between the engagement protrusion 53 and the bottom part 52B of the substantially U-shaped notch part 52 is a communication path through which a first protrusion 62B of a seal unit 60 described later passes.

  As shown in FIG. 6, the seal unit 60 is integrally configured by joining a first seal member 61 and a second seal member 62 with a double-sided tape, an adhesive, or the like. The case main body 50 can be integrally attached to and detached from the recess 51.

  The first seal member 61 is a member that is in sliding contact with the peripheral surfaces of both ends of the developing roller 31 (roller portion 31 </ b> A), and is formed in a sheet shape with felt or the like that has good slidability with respect to the developing roller 31.

  The second seal member 62 is formed of a highly cushioning member such as a sponge and has a structure having a trapezoidal portion 62A, a first protrusion 62B, a second protrusion 62C, and a third protrusion 62D. .

  As shown in FIG. 5, the trapezoidal portion 62 </ b> A is formed in substantially the same shape as the recess 51 so as to be in close contact with the recess 51. A hole A1 through which the shaft portion 33B of the supply roller 33 passes is formed in a substantially central portion of the trapezoidal portion 62A. Further, the surface of the trapezoidal portion 62A on the side of the developing roller 31 is formed in an arc shape when viewed from the side, and the first seal member 61 is closely bonded so as to follow this surface.

  The first protrusion 62B is formed so as to protrude downward (outside in the radial direction of the developing roller 31) from the upstream side in the rotation direction of the developing roller 31 in the trapezoidal part 62A, and the communication path (engaging protrusion 53) described above. And the bottom 52B of the notch 52). The first protrusion 62B engages with the engagement protrusion 53 in the substantially front-rear direction.

  The second projecting portion 62C is formed so as to project from the tip end portion of the first projecting portion 62B (the portion projecting out of the case main body 50) to the engagement projection 53 side. And this 2nd protrusion part 62C is engaging with the engagement protrusion 53 in the substantially up-down direction.

  The third protrusion 62D is formed so as to extend in the direction opposite to the second protrusion 62C from the tip of the first protrusion 62B. And this 3rd protrusion part 62D is engaged with the case main body 50 (specifically lower wall 51C which forms the recessed part 51) in a substantially up-down direction.

  7A and 7B, a left side case 70 and a right side case 80 are provided on the left and right sides of the case body 50, respectively.

  The left side case 70 can be attached to the left side wall 50L of the case main body 50 by bringing it close to the left and right direction (the axial direction of the developing roller 31). Here, on the left side wall 50L of the case main body 50, as shown in FIG. 8A, a plurality of gears G for transmitting rotational force to the developing roller 31 (not shown) and the supply roller 33 are arranged.

  The left side case 70 functions as a cover member that covers the plurality of gears G. The left side case 70 is a bearing member having a bearing portion 71 that receives the shaft portion 31B (see FIG. 9A) of the developing roller 31.

  Further, an extension portion 72 that protrudes inward in the left-right direction and extends around the lower side of the case body 50 is formed at the lower rear portion of the left side case 70. Accordingly, when the left side case 70 is attached to the case main body 50, as shown in FIG. 9A, a part of the seal unit 60 protruding from the case main body 50 (first protrusion 62B) is crushed and extended. It is sandwiched between the protruding portion 72 and the case body 50.

  As shown in FIG. 7B and FIG. 8B, the right side case 80 can be attached by being brought close to the right side wall 50R of the case body 50 in the left-right direction (the axial direction of the developing roller 31). It has become. The right side case 80 is a bearing member having a bearing portion 81 that receives the shaft portion 31B of the developing roller 31 as shown in FIG. 9B.

  In addition, an extension portion 82 that protrudes inward in the left-right direction and extends around the lower side of the case body 50 is also formed in the lower rear portion of the right side case 80. Thus, when the right side case 80 is attached to the case main body 50, as shown in FIG. 9B, a part of the seal unit 60 protruding from the case main body 50 (first protrusion 62B) is crushed and extended. It is configured to be sandwiched between the protruding portion 82 and the case main body 50.

According to the above, the following effects can be obtained in the present embodiment.
Since the first seal member 61 and the second seal member 62 are integrally configured so as to be detachable integrally with the recess 51 of the case body 50, the assembling work to the recess 51 of the seal unit 60 or Removal work can be facilitated. In addition, since the shaft portion 33B of the supply roller 33 is passed through the hole A1 of the seal unit 60, these can be attached to and detached from the case main body 50, so that assembly and removal operations are easier. Can be.

  Since the seal structure on both ends of the supply roller 33 is composed of two layers of the first seal member 61 and the second seal member 62, the number of parts can be reduced as compared with the conventional structure composed of three layers. Cost can be reduced.

  Since the first protrusion 62B of the seal unit 60 (the upstream portion in the rotation direction of the developing roller 31) is sandwiched between the case body 50 and the side cases 80 and 90, the seal unit is rotated by the rotation of the developing roller 31. 60 first protrusions 62B can be prevented from being drawn into the developing roller 31.

  Since the engagement protrusion 53 that engages with the first protrusion 62B of the seal unit 60 (the upstream portion in the rotation direction of the developing roller 31) is provided on the case body 50, the first protrusion 62B of the seal unit 60 is engaged. If the seal unit 60 is fitted into the recess 51 while being engaged with the protrusion 53, the first protrusion 62B of the seal unit 60 can be prevented from floating to the developing roller 31 side. Accordingly, it is possible to prevent the first protrusion 62B floating on the developing roller 31 side from interfering with the mounting of the developing roller 31.

  Since the second projecting portion 62C projecting from the first projecting portion 62B toward the engaging projection 53 is provided, the first projecting portion of the seal unit 60 is mounted when the developing roller 31 is attached to the case body 50 while being pressed against the seal unit 60. It is possible to prevent the portion 62B from floating on the developing roller 31 side.

  Since the third protrusion 62D extending from the first protrusion 62B in the opposite direction to the second protrusion 62C is provided, the mounting of the seal unit 60 on the case body 50 while pressing the developing roller 31 against the seal unit 60 is performed. It is possible to further prevent the first protrusion 62B from floating on the developing roller 31 side.

  By forming the recess 51 in a shape that expands from the bottom surface 51A toward the opening, the corner of the seal unit 60 can be easily brought into close contact with the corner of the recess 51, so that the sealing performance can be further improved.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the embodiment, the first projecting portion 62B, the second projecting portion 62C, and the third projecting portion 62D are formed on the second seal member 62. However, the present invention is not limited to this, and the first projecting member projects to the first seal member. The second protrusion and the third protrusion may be formed. In this case, a portion of the first seal member on the upstream side in the rotational direction is sandwiched between the side case and the case main body and engaged with the engaging portion.

  In the embodiment, the engaging portion is the engaging protrusion 53, but the present invention is not limited to this. For example, when the communicating path through which the first protrusion 62B of the seal unit 60 passes is formed as a hole, a part of the edge of the hole may be used as the engaging portion.

  In the above embodiment, the developing cartridge 28 integrally including the toner storage chamber 34 is employed as the developing device. However, the present invention is not limited to this, and for example, a cartridge to / from which the toner cartridge having the toner storage chamber is attached / detached is used as the developing device. It may be adopted.

28 Developing Cartridge 31 Developing Roller 31A Roller Part 31B Shaft Part 33 Supply Roller 33B Shaft Part 50 Case Main Body 50L Left Side Wall 50R Right Side Wall 51 Recess 51A Bottom 51B Top Wall 51C Bottom Wall 52 Notch 52A Side 52B Bottom 53 Engaging Projection 60 Seal unit 61 First seal member 62 Second seal member 62A Trapezoidal part 62B First protrusion 62C Second protrusion 62D Third protrusion 70 Left side case 71 Bearing part 72 Extension part 80 Right side case 81 Bearing part 82 Extension Outing

Claims (5)

A developing roller carrying a developer;
A developer roller that is in contact with the developing roller and that is shorter in the axial direction than the developing roller;
A case body that rotatably supports the developing roller and the supply roller;
A recess formed in the case main body, opening toward the peripheral surfaces of both ends of the developing roller, and a shaft portion of the supply roller being disposed;
A first seal member that is in sliding contact with the peripheral surfaces of both ends of the developing roller;
A second seal member that penetrates the shaft portion of the supply roller and is in close contact with the recess and the first seal member;
A side case mounted in the axial direction of the developing roller with respect to the side wall of the case body,
The first seal member and the second seal member are integrally configured to be detachable integrally with the concave portion of the case body,
In the case body,
A notch formed to open to the upstream side in the rotational direction at a position upstream in the rotational direction of the developing roller with respect to the recess, and to communicate with the inside and outside of the case body;
The cutout portion protrudes from one end edge in the axial direction toward the other end edge, and a tip is disposed at a position away from the other end edge, and the first seal member or the second seal An engagement protrusion that engages with a portion of the seal member on the upstream side in the rotation direction of the developing roller,
Of the first seal member or the second seal member, the upstream portion of the developing roller in the rotational direction is:
A first protrusion protruding outward from between the bottom of the notch and the engagement protrusion;
A second protrusion protruding from the first protrusion toward the engagement protrusion,
A developing device configured to be compressed and sandwiched between the side case and the case body. The case body is provided with a gear for transmitting a rotational force to the developing roller and the supply roller,
The developing device according to claim 1 , wherein the side case is a cover member that covers the gear. The developing device according to claim 1 , wherein the side case is a bearing member that receives a shaft portion of the developing roller. 4. The developing device according to claim 1 , wherein the first protrusion is formed with a third protrusion extending in a direction opposite to the second protrusion. 5. . The developing device according to claim 1 , wherein the concave portion is formed in a shape that widens from the bottom surface toward the opening.

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