JP6287400B2 - Development device - Google Patents

Description

  The present invention relates to a developing device that includes a lower seal that extends along a rotation axis direction of a developing roller and is in sliding contact with the developing roller.

  An electrophotographic image forming apparatus such as a laser printer forms an electrostatic latent image on the surface of a photosensitive drum, and supplies the toner to the electrostatic latent image on the photosensitive drum from a developing device containing toner as a developer. By doing so, a toner image is formed on the surface of the photosensitive drum. Then, the image forming apparatus performs image formation on the paper by transferring the toner image onto the paper as a transfer material.

  The developing device includes a developing roller for carrying toner, a housing having a developing chamber in which the developing roller is disposed, a toner containing chamber containing toner therein, and an end of the developing roller. And a side seal for suppressing toner leakage to the outside of the housing. The side seal includes a base material made of a sponge and a flocking material planted on the base material.

  The developing device further includes a lower seal made of a flexible sheet disposed along the rotational axis direction of the developing roller and disposed so as to be in sliding contact with the developing roller. The lower seal is made of PET (polyethylene terephthalate), and is arranged so that the end in the rotation axis direction of the developing roller rides on the side seal in order to suppress toner leakage from the side seal (patent) Reference 1).

JP 11-119547 A

  However, according to such a configuration, when the developing roller is assembled to the housing, a step corresponding to the thickness of the lower seal is generated between the developing roller and the side seal. For this reason, the toner contained in the housing may enter the side seal through this step.

  When the toner has entered the step, if the toner further enters the step, the toner that has previously entered the step is pushed by the toner that has entered the step later. Then, the toner that has previously entered the step is pushed in along the rotation axis direction of the developing roller. In other words, the toner that has previously entered the step is pushed toward the outside of the housing. As a result, the toner that has previously entered the step may leak to the outside of the housing.

  In view of the above, an object of the present invention is to provide a developing device capable of suppressing the developer that has entered from a step generated between the side seal and the lower seal from leaking to the outside of the housing.

  (1) To achieve the above object, a developing device of the present invention includes a developing roller for carrying a developer, a developing chamber in which the developing roller is disposed, and a developing for containing the developer therein. A housing having an agent storage chamber, a side seal disposed between the end portion of the developing roller in the rotational axis direction and the housing, and extending along the rotational axis direction of the developing roller. And a lower seal disposed so that the end in the rotation axis direction overlaps the side seal.

  The lower seal is made of a flexible sheet and has an extending portion that extends from an end portion in the rotation axis direction of the developing roller toward the downstream side in the rotating direction of the developing roller.

  The extending portion is disposed between both ends of the side seal extending in the rotation direction of the developing roller.

  According to such a configuration, the developer entering the side seal is blocked by the extending portion. That is, even if a large amount of developer enters from the step between the side seal and the lower seal, the entered developer is blocked by the extending portion.

  That is, the developer accommodated in the housing can be prevented from leaking to the outside of the housing.

  (2) The side seal is good to have a base material and a flocking material arranged on the base material.

  According to such a configuration, the flocking material comes into contact with the peripheral surface of the developing roller in a close contact state.

  Therefore, it is difficult for the side seal to form a gap between the side seal and the developing roller. That is, developer leakage from between the developing roller and the side seal can be suppressed.

  (3) The flocking material may be tilted so as to approach the developing chamber as it goes downstream in the rotation direction of the developing roller.

  According to such a configuration, the developer that has entered the side seal moves along the direction in which the flocking material is tilted with the rotation of the developing roller. In other words, the developer that has entered the side seal returns to the developing chamber.

  Therefore, the developer that has entered the side seal is not held for a long time on the side seal. That is, the developer can be prevented from sticking on the side seal.

  (4) The extending portion may have a first end and a second end disposed on the opposite side of the developing chamber across the first end in the rotation axis direction of the developing roller.

  The first end may be arranged so as to approach the developing chamber as it goes downstream in the rotation direction of the developing roller.

  According to such a configuration, when the developer further enters the state where the developer is blocked by the first end, the developer that has been blocked by the first end first causes the development that has entered later. Pushed by the agent. Then, the developer previously dammed up at the first end moves along the first end. In other words, the developer previously blocked at the first end returns to the developing chamber.

  Therefore, the developer that has entered the side seal is not held for a long time on the side seal. That is, the developer can be prevented from sticking on the side seal.

  (5) The angle formed by the first end and the rotation axis direction of the developing roller may be larger than the angle formed by the direction in which the flocking material is tilted and the rotation axis direction of the developing roller.

  When the angle between the first end and the rotation axis direction of the developing roller is smaller than the angle between the direction in which the flocking material falls and the rotation axis direction of the developing roller, the developer dammed up at the first end is When returning from the side seal to the developing chamber, the first end may be blocked.

  However, according to such a configuration, the developer dammed to the first end is difficult to be dammed to the first end when returning from the side seal to the developing chamber. In other words, the developer dammed up at the first end tends to return from the side seal to the developing chamber.

  Therefore, the developer that has entered the side seal is not held for a long time on the side seal. That is, the developer can be prevented from sticking on the side seal.

  (6) The first end may be arranged so as to move away from the developing chamber as it goes downstream in the rotation direction of the developing roller.

  According to such a configuration, when the developer enters the side seal, a part of the developer moves along the first end.

  Therefore, it is possible to suppress the developer that has entered the side seal from collecting in the vicinity of the first end. As a result, the developer that has entered the side seal is not held for a long time on the side seal. That is, the developer can be prevented from sticking on the side seal.

  (7) The angle formed by the first end and the direction in which the flocking material is tilted is preferably 90 degrees.

  According to such a configuration, when a large amount of developer enters the side seal, the developer spreads along the first end while being blocked by the first end.

  Therefore, the developer that has entered the side seal is blocked by the first end. Thereafter, the damped developer is unlikely to collect in the vicinity of the first end. That is, it is possible to suppress the developer from being fixed on the side seal while suppressing the developer contained in the housing from leaking to the outside of the housing.

  (8) The second end may be arranged so as to approach the developing chamber as it goes downstream in the rotation direction of the developing roller.

  When a large amount of developer enters from the step between the side seal and the lower seal, and a part of the entered developer cannot be blocked by the first end, the developer that cannot be blocked by the first end is When returning from the seal to the developing chamber, the second end may be dammed up.

  However, according to such a configuration, the developer that cannot be blocked by the first end is difficult to be blocked by the second end when returning to the developing chamber from the side seal.

  Therefore, it is possible to further suppress the developer from being held on the side seal for a long time. That is, the developer can be prevented from sticking on the side seal.

  (9) The angle formed by the second end and the rotation axis direction of the developing roller may be smaller than the angle formed by the direction in which the flocking material is tilted and the rotation axis direction of the developing roller.

  According to such a configuration, the developer that cannot be blocked by the first end is further difficult to be blocked by the second end when returning from the side seal to the developing chamber.

  Therefore, it is possible to further suppress the developer from being held on the side seal for a long time. That is, the developer can be prevented from sticking on the side seal.

  According to the present invention, it is possible to suppress the developer accommodated in the housing from leaking to the outside of the housing.

The schematic diagram of the cross section of a laser printer. FIG. 3 is a schematic cross-sectional view of a developing unit. The perspective view which looked at the state which removed the developing roller and the lower seal from the developing unit of FIG. 2 from upper right. The schematic diagram of the cross section of a side seal. Explanatory drawing for demonstrating the structure of a flocking material. The front view of a side seal. The perspective view of a lower seal. Explanatory drawing for demonstrating the structure of an extension part. Explanatory drawing for demonstrating the structure of the extension part of Embodiment 2. FIG.

<Embodiment 1>
Embodiment 1 of the present invention will be described in detail with reference to the drawings as appropriate.

1. First, the overall configuration of the laser printer 1 will be described with reference to FIG. The laser printer 1 includes a main body frame 10, a paper feeding unit 20 for feeding paper, an image forming unit 30 for forming an image on the fed paper, and paper discharge for discharging paper. Part 40.

  The main body frame 10 accommodates the paper feed unit 20, the image forming unit 30, and the paper discharge unit 40 therein. The paper feed unit 20 includes a paper feed cassette 21 for storing paper therein, and a paper feed roller 22 for picking up paper from the paper feed cassette 21 and transporting the paper toward the image forming unit. . The paper feed cassette 21 is configured to be detachable from the main body frame 10 by sliding in the front-rear direction, and is disposed at the bottom of the main body frame 10. The image forming unit 30 is disposed on the upper side of the paper feeding unit 20. The paper discharge unit 40 is disposed on the rear side of the image forming unit 30 and is configured to discharge the paper on which the image is formed by the image forming unit 30 to the outside of the housing.

  The image forming unit 30 includes an exposure device 50 for forming an electrostatic latent image on an outer peripheral surface of a photosensitive drum 82 described later, a process unit 60, and a fixing device for fixing a toner image formed on a sheet. 70.

  The exposure apparatus 50 is disposed on the upper part of the main body frame 10. The process unit 60 is configured to be detachable from the main body frame 10 and includes a drum unit 80 and a developing unit 90 as an example of a developing device.

  The drum unit 80 includes a drum frame 81, a photosensitive drum 82, a charger 83 for uniformly charging the outer peripheral surface of the photosensitive drum 82, and a developer carried on the outer peripheral surface of the photosensitive drum 82 on a sheet. A transfer roller 84 for transferring. The developing unit 90 is configured to be detachable from the drum unit 80 and includes a developing frame 91 as an example of a housing and a developing roller 92 for supplying toner to the photosensitive drum 82.

  The fixing device 70 includes a heating roller 71 in which a heater as a heating source is disposed, and a pressure roller 72 that forms a nip portion between the heating roller 71. The developer image formed on the paper is fixed on the paper by passing through the nip portion.

2. Configuration of Developing Unit 90 Next, the configuration of the developing unit 90 will be described with reference to FIGS.

  As shown in FIG. 2, the developing unit 90 includes a developing frame 91, a developing roller 92, a supply roller 93, and a layer thickness regulating blade 94.

  The developing frame 91 includes a developing chamber 91a that stores a developing roller 92 and a supply roller 93, and a toner storage chamber 91b that stores a developer made of positively charged nonmagnetic one-component toner. .

  The developing roller 92 is supported by the developing frame 91 and is made of a metal shaft and urethane rubber or silicone rubber provided around the metal shaft. The supply roller 93 is supported by the developing frame 91 and includes a metal shaft and a sponge provided around the metal shaft. The layer thickness regulating blade 94 is disposed such that the base end is fixed to the developing frame 91 and the tip is in contact with the developing roller 92.

  As shown in FIG. 3, the developing unit 90 further extends along a pair of side seals 95 disposed so as to be in contact with the end portion of the developing roller 92 in the rotation axis direction, and the rotation axis direction of the developing roller 92. And a lower seal 100 disposed so as to be in contact with substantially the entire region of the developing roller 92 in the rotation axis direction. Further, the developing frame 91 further includes a lower seal support surface 91 c for supporting the lower seal 100.

  The pair of side seals 95 and the lower seal 100 are arranged to prevent the toner from leaking to the outside of the developing frame 91. The lower seal 100 is made of a flexible sheet-like member. In the present embodiment, the lower seal 100 is made of PET (polyethylene terephthalate) configured in a sheet shape.

  Further, the length of the developing roller 92 in the rotational axis direction of the lower seal 100 is configured to be longer than the length of the developing roller 92 in the rotational axis direction of the lower seal support surface 91c. For this reason, when the lower seal 100 is affixed to the lower seal support surface 91c, both end portions of the lower seal 100 in the rotation axis direction of the developing roller are not supported by the lower seal support surface 91c. Specifically, both end portions of the lower seal 100 in the rotation axis direction of the developing roller are arranged so as to overlap with the sliding surface of the side seal 95 with the developing roller 92. In other words, both end portions of the lower seal 100 in the rotational axis direction of the developing roller are disposed between the developing roller 92 and the side seal 95 when the developing unit 90 is assembled.

  The pair of side seals 95 has a symmetrical structure. Therefore, the right side seal 95 will be described in detail below. As shown in FIG. 4, the side seal 95 includes a base material 96 and a flocking material 97 disposed on the base material 96.

  The substrate 96 is made of a sponge such as polyethylene foam, and is attached to the developing frame 91 via an adhesive such as a double-sided tape.

  As shown in FIG. 5, the hair transplant material 97 includes a plurality of fiber bundles 97 a in which a plurality of fibers are bundled on a base material 96. As shown in FIG. 6, the plurality of fiber bundles 97 a are arranged at substantially equal intervals, and are tilted toward the developing chamber 91 a toward the downstream side in the rotation direction of the developing roller 92. Then, the toner that has entered the flocking material 97 returns to the developing chamber 91a along the plurality of fiber bundles 97a.

3. Detailed Configuration of Lower Seal 100 Next, the configuration of the lower seal 100 will be described in detail with reference to FIG.

  As shown in FIG. 7, the lower seal 100 includes a pair of extending portions 110 that extend from both ends in the rotation axis direction of the developing roller 92 toward the downstream side in the rotation direction of the developing roller 92. Note that the pair of extending portions 110 have the same structure. Therefore, in the following, the right extension 110 that extends from the right end in the rotation axis direction of the developing roller will be described in detail.

  As shown in FIG. 8, the extending portion 110 is disposed between a first end 95 a and a second end 95 b that extend in the rotation direction of the developing roller 92 in the side seal 95. The first end 95a is an edge of the side seal 95 that is disposed on the developing chamber 91a side. On the other hand, the second end 95b is an edge disposed on the side opposite to the developing chamber 91a across the first end 95a of the side seal 95. In other words, the extending part 110 is disposed between both ends of the side seal 95 extending in the rotation direction of the developing roller 92. Therefore, the length of the extending portion 110 in the rotation axis direction of the developing roller 92 is configured to be shorter than the length of the side seal 95 in the rotation axis direction of the developing roller 92.

  The extending portion 110 includes a first end 111 and a second end 112 disposed on the opposite side of the developing chamber 91a across the first end 111 in the rotation axis direction of the developing roller 92. .

  The first end 111 is disposed so as to approach the developing chamber 91c toward the downstream side in the rotation direction of the developing roller 92. In other words, the distance between the upstream end 111a in the rotation direction of the developing roller 92 at the first end 111 and the first end 95a of the side seal 95 is equal to the downstream end 111b in the rotation direction of the developing roller 92 at the first end 111 and the side seal. It is comprised so that it may become longer than the distance between 95 1st ends 95a. Further, the angle α formed by the first end 111 and the rotation axis direction of the developing roller 92 is configured to be larger than the angle θ formed by the direction in which the flocking material 97 falls and the rotation axis direction of the developing roller 92. .

  The second end 112 is disposed so as to approach the developing chamber 91a toward the downstream side in the rotation direction of the developing roller 92. In other words, the distance between the upstream end 112a of the developing roller 92 in the rotational direction at the second end 112 and the second end 95b of the side seal 95 is equal to the downstream end 112b in the rotational direction of the developing roller 92 at the second end 112 and the side seal. It is comprised so that it may become longer than the distance between 95 2nd ends 95b.

  In the present embodiment, the upstream end 112a in the rotation direction of the developing roller 92 at the second end 112 is disposed at the same position as the upstream end 111a in the rotation direction of the developing roller 92 at the first end 111. In addition, the downstream end 112 b in the rotation direction of the developing roller 92 at the second end 112 is disposed so as to overlap the second end 95 b of the side seal 95.

  Further, the angle β formed by the second end 112 and the rotation axis direction of the developing roller 92 is configured to be smaller than the angle θ formed by the direction in which the flocking material 97 falls and the rotation axis direction of the developing roller 92. .

4). Effects of First Embodiment (1) The lower seal 100 includes an extending portion 110 that extends from the end portion of the developing roller 92 in the rotation axis direction to the downstream side in the rotating direction of the developing roller 92.

  The extending part 110 is disposed between both ends of the side seal 95 extending in the rotation direction of the developing roller 92.

  According to such a configuration, the toner that enters the side seal 95 is blocked by the extending portion 110. That is, even if a large amount of toner enters from the step between the side seal 95 and the lower seal 100, the entering toner is blocked by the extending portion 110.

  That is, it is possible to suppress the toner stored inside the developing frame 91 from leaking to the outside of the developing frame 91.

  (2) The side seal 95 includes a base material 96 and a flocking material 97 disposed on the base material 96.

  According to such a configuration, the flocking material 97 comes into contact with the peripheral surface of the developing roller 92 in a close contact state.

  Therefore, it is difficult for the side seal 95 to form a gap between the side seal 95 and the developing roller 92. That is, toner leakage from between the developing roller 92 and the side seal 95 can be suppressed.

  (3) The flocking material 97 is tilted so as to approach the developing chamber 91a toward the downstream side in the rotation direction of the developing roller 92.

  According to such a configuration, the toner that has entered the side seal 95 moves along the direction in which the flocking material 97 is tilted as the developing roller 92 rotates. In other words, the toner that has entered the side seal 95 returns to the developing chamber 91a.

  Therefore, the toner that has entered the side seal 95 is not held on the side seal 95 for a long time. That is, the toner can be prevented from sticking on the side seal 95.

  (4) The extending portion 110 has a first end 111 and a second end 112 disposed on the opposite side of the developing chamber 91a across the first end 111 in the rotation axis direction of the developing roller 92. ing.

  The first end 111 is disposed so as to approach the developing chamber 91a as it goes downstream in the rotation direction of the developing roller 92.

  According to such a configuration, when the toner is further blocked by the first end 111 and further enters the toner, the toner previously blocked by the first end 111 is caused by the toner that has entered later. Pushed in. Then, the toner previously blocked by the first end 111 moves along the first end 111. In other words, the toner previously blocked by the first end 111 returns to the developing chamber 91a.

  Therefore, the toner that has entered the side seal 95 is not held on the side seal 95 for a long time. That is, the toner can be prevented from sticking on the side seal 95.

  (5) The angle α formed by the first end 111 and the rotation axis direction of the developing roller 92 is larger than the angle θ formed by the direction in which the flocking material 97 is tilted and the rotation axis direction of the developing roller 92.

  When the angle α formed by the first end 111 and the rotation axis direction of the developing roller 92 is smaller than the angle θ formed by the direction in which the flocking material 97 falls and the rotation axis direction of the developing roller 92, the first end 111 is dammed. When the toner is returned from the side seal 95 to the developing chamber 91a, the toner may be blocked by the first end 111.

  However, according to such a configuration, the toner dammed to the first end 111 is hardly dammed to the first end 111 when returning from the side seal 95 to the developing chamber 91a. In other words, the toner blocked by the first end 111 is likely to return from the side seal 95 to the developing chamber 91a.

  Therefore, the toner that has entered the side seal 95 is not held on the side seal 95 for a long time. That is, the toner can be prevented from sticking on the side seal 95.

  (6) The second end 112 is disposed so as to approach the developing chamber 91a toward the downstream side in the rotation direction of the developing roller 92.

  When a large amount of toner enters from the step between the side seal 95 and the lower seal 100, and a part of the entered toner cannot be blocked by the first end 111, the toner that cannot be blocked by the first end 111 is When returning from the side seal 95 to the developing chamber 91a, the second end 112 may be dammed up.

  However, according to such a configuration, the toner that cannot be blocked by the first end 111 is difficult to be blocked by the second end 112.

  Therefore, the toner that has entered the side seal 95 is not held on the side seal 95 for a long time. That is, the toner can be prevented from sticking on the side seal 95.

  (7) The angle β formed between the second end 112 and the rotation axis direction of the developing roller 92 is an angle θ formed between the direction in which the toner that has entered the side seal 95 returns to the developing chamber 91a and the rotation axis direction of the developing roller 92. Smaller than.

  According to such a configuration, the toner that cannot be blocked by the first end 111 is not easily blocked by the second end 112 when returning from the side seal 95 to the developing chamber 91a.

  Therefore, the toner that has entered the side seal 95 is not held on the side seal 95 for a long time. That is, the toner can be prevented from sticking on the side seal 95.

<Embodiment 2>
With reference to FIG. 9, the structure of the extension part of Embodiment 2 is demonstrated. In addition, about the part of the same structure as Embodiment 1, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  The extending portion 200 according to the second exemplary embodiment includes a first end 210 and a second end 110 disposed on the opposite side of the developing chamber 91a of the developing frame 91 with the first end 210 in the rotation axis direction of the developing roller 92. And have.

  The first end 210 is disposed so as to move away from the developing chamber 91a toward the downstream side in the rotation direction of the developing roller 92. In other words, the distance between the upstream end 210a in the rotation direction of the developing roller 92 at the first end 210 and the first end 95a of the side seal 95 is equal to the downstream end 210b in the rotation direction of the developing roller 92 at the first end 210 and the side seal. It is comprised so that it may become longer than the distance between 95 1st ends 95a. In the present embodiment, the upstream end 210 a in the rotation direction of the developing roller 92 at the first end 210 is disposed at the same position as the upstream end 112 a in the rotation direction of the developing roller 92 at the second end 112.

  According to such a configuration, when toner enters the side seal 95, a part of the toner moves along the first end 111.

  Therefore, it is possible to suppress the toner that has entered the side seal 95 from collecting in the vicinity of the first end 111. As a result, the toner that has entered the side seal 95 is not held on the side seal for a long time. That is, the toner can be prevented from sticking on the side seal.

  In addition, an angle γ formed by the first end 210 and the direction in which the flocking material 97 falls is 90 degrees.

  According to such a configuration, when a large amount of toner enters the side seal 95, the toner spreads along the first end 210 while being blocked by the first end 210.

  Therefore, the toner that has entered the side seal 95 is blocked by the first end 210. Thereafter, the dammed toner is unlikely to collect in the vicinity of the first end 210. That is, it is possible to prevent the toner contained in the developing chamber 91a from leaking to the outside and to prevent the toner from adhering to the side seal 95.

<Modification>
Moreover, in this embodiment, the side seal was provided with the base material and the flocking material arrange | positioned on the base material. However, the present invention is not limited to this. For example, the side seal may include a base material and a woven member disposed on the base material.

  In the first embodiment, the first end of the extending portion is disposed so as to approach the developing chamber as it goes downstream in the rotation direction of the developing roller. However, the present invention is not limited to this. For example, the first end of the extending portion may be configured to extend linearly toward the downstream side in the rotation direction of the developing roller.

  In the first embodiment, the second end of the extending portion is disposed so as to approach the developing chamber as it goes downstream in the rotation direction of the developing roller. However, the present invention is not limited to this. For example, the second end of the extending portion may be configured to extend linearly toward the downstream side in the rotation direction of the developing roller.

DESCRIPTION OF SYMBOLS 1 Laser printer 70 Process unit 90 Developing unit 91 Developing frame 91a Developing chamber 92 Developing roller 95 Side seal 95a First end 95b Second end 96 Base material 97 Flocking material 100 Lower seal 110 Extension part 111 First end 112 Second end 200 Extension part 210 1st end

Claims (9)

A developing roller for carrying the developer;
A housing having a developing chamber in which the developing roller is disposed, and a developer accommodating chamber for accommodating the developer therein;
A side seal disposed between an end of the developing roller in the rotation axis direction and the housing;
A lower seal that extends along the rotational axis direction and is arranged so that an end in the rotational axis direction overlaps the side seal;
The lower seal is made of a flexible sheet, and has an extending portion extending from the end in the rotation axis direction toward the downstream side in the rotation direction of the developing roller,
The developing device, wherein the extending portion is disposed between both ends of the side seal extending in the rotation direction of the developing roller.   The developing device according to claim 1, wherein the side seal includes a base material and a flocking material disposed on the base material.   The developing device according to claim 2, wherein the flocking material is inclined so as to approach the developing chamber as it goes downstream in the rotation direction of the developing roller. The extending portion has a first end and a second end disposed on the opposite side of the developing chamber across the first end in the rotation axis direction,
The developing device according to claim 3 , wherein the first end is disposed so as to approach the developing chamber as it goes downstream in the rotation direction of the developing roller. The developing device according to claim 4, wherein an angle formed between the first end and the rotation axis direction is larger than an angle formed between the direction in which the flocking material is tilted and the rotation axis direction. The extending portion has a first end and a second end disposed on the opposite side of the developing chamber across the first end in the rotation axis direction,
The developing device according to claim 3 , wherein the first end is disposed so as to move away from the developing chamber as it goes downstream in the rotation direction of the developing roller. The developing device according to claim 6, wherein an angle formed by the first end and the direction in which the flocking material is tilted is 90 degrees.   The developing device according to claim 4, wherein the second end is disposed so as to approach the developing chamber as it goes downstream in the rotation direction of the developing roller. .   The developing device according to claim 8, wherein an angle formed between the second end and the rotation axis direction is smaller than an angle formed between a direction in which the flocking material is tilted and the rotation axis direction.