JP5582738B2 - Cartridge and image forming apparatus - Google Patents

Description

The present invention relates to a cartridge used for a copying machine, a printer, or the like that employs an electrophotographic system, and an image forming apparatus using the same.
Here, the cartridge means that at least the developing means and the image carrier are integrally formed as a cartridge, and the cartridge can be attached to and detached from the image forming apparatus main body.

In a conventional image forming apparatus of this type, an electrostatic latent image formed on an image carrier is developed with a developer (toner) filled in a cartridge to be visualized as a developer image (toner image). ing.
Further, in an image forming apparatus that employs a cartridge, the user can perform maintenance of the apparatus himself, so that the operability can be remarkably improved.

As a developing method, the toner in the cartridge is thinly coated on the developer carrying member by the layer regulating member, and the image carrying member is developed. The layer regulating member is positioned and fixed to the cartridge body by using a screw fixing member so as to stably contact the developer carrying member.
In addition, when a thin sheet metal having elasticity is used as the layer restricting member and the structure in which the layer restricting member is stably brought into contact with the developer carrying member is adopted, the layer restricting member can be firmly fixed. A method using metal for the mounting seating surface of the regulating member is used. In that case, a method of fixing the regulating member of the thin sheet metal to the fixed seat surface using a pressing member made of metal is employed so that the regulating member does not float (see Patent Document 1).
Further, as a method of reusing the cartridge, as described in Patent Document 2, there is a case where the cartridge is divided into a toner container and a developing container, re-sealed and coupled, and a fixing member is used.

JP 2000-131950 A Japanese Patent No. 3363890

  Recent image forming apparatuses are required to be further improved in convenience, and a method for fixing the layer regulating member more simply is required. In particular, in a color image forming apparatus including a plurality of process cartridges, it is necessary to reduce the size of the image forming apparatus and improve the user-friendliness.

  SUMMARY An advantage of some aspects of the invention is that it provides a cartridge capable of easily and reliably fixing a layer regulating member and an image forming apparatus using the cartridge. is there.

In order to achieve the above object, a cartridge according to the present invention includes a developer carrying member carrying a developer for developing an electrostatic image on an image carrying member, one end fixed to the cartridge frame, and the other end carrying a developer. In the cartridge provided with a layer regulating member that regulates the layer thickness of the developer carried on the developer carrying body in contact with the body,
Positioning means for positioning the layer restricting member so that the layer restricting member does not move in a direction along a mounting seat surface provided directly on the cartridge frame;
A pair of gripping portions, and the layer regulating member and the back surface portion of the mounting seat surface being sandwiched between the pair of gripping portions in a state where the layer regulating member is positioned on the mounting seat surface; A fixing member for fixing the regulating member,
The layer regulating member is positioned and fixed to the cartridge frame by sandwiching the layer regulating member to the mounting seat surface while being held between the fixing members.
The pair of gripping portions are connected, and by the force generated by bending the gripping portion, the fixing member presses the layer regulating member against the mounting seat surface ,
Of the pair of gripping portions, the gripping portion on the side that comes into contact with the layer regulation member is provided with a ridge line portion that partially contacts the layer regulation member, and the layer regulation member is attached to the mounting seat surface at the ridge line portion. It is characterized by pressing .

  According to the present invention, in a state where the layer regulating member is temporarily fixed to the mounting seat surface of the cartridge frame, the layer regulating member is sandwiched between the mounting seat surface and the seat back surface portion by the pair of gripping portions of the fixing member. The layer restricting member can be reliably and stably fixed to the cartridge frame by a simple configuration for fixing to the mounting seat surface.

1 is a cross-sectional view illustrating an example of an image forming apparatus to which the present invention is applied. (A) is sectional drawing of a cartridge, (B) is detail drawing of a developing blade and a fixing member. (A), (B) is a perspective view which shows the assembly method of the control member using the fixing member of FIG. 4A is a rear perspective view of FIG. 4A, and FIG. 5B is a perspective view of a fixing member inserted state.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.
[Entire configuration of image forming apparatus]
First, with reference to FIG. 1, an outline of the overall configuration of an image forming apparatus to which the present invention is applied will be described. FIG. 1 is a longitudinal sectional view showing the overall configuration of the image forming apparatus 100. In this embodiment, a full-color multicolor image forming apparatus is illustrated.
An image forming apparatus 100 shown in FIG. 1 includes an image forming unit, a paper feeding unit 16 that feeds a transfer material to the image forming unit, and a fixing unit 20 that fixes an image transferred by the image forming unit. Yes.
The image forming unit includes four photosensitive drums 1 (1a, 1b, 1c, 1d) as image carrier members arranged in parallel in the vertical direction. The photosensitive drum 1 (1a, 1b, 1c, 1d) is rotationally driven counterclockwise in the drawing by a driving means (not shown). Around each photosensitive drum 1 (1a, 1b, 1c, 1d), in the rotational direction, charging device 2 (2a, 2b, 2c, 2d), scanner unit 3 (3a, 3b, 3c, 3d), development A unit 4 (4a, 4b, 4c, 4d), a transfer device 5, a cleaning device 6 (6a, 6b, 6c, 6d) and the like are disposed.

The charging device 2 (2a, 2b, 2c, 2d) uniformly charges the surface of the photosensitive drum 1 (1a, 1b, 1c, 1d). The scanner unit 3 (3a, 3b, 3c, 3d) irradiates a laser beam based on the image information to form an electrostatic latent image on the photosensitive drum 1 (1a, 1b, 1c, 1d). The developing device 4 (4a, 4b, 4c, 4d) develops a toner image by attaching toner to the electrostatic latent image. The transfer device 5 transfers the toner images on the photosensitive drums 11a, 1b, 1c, and 1d onto the transfer material S, and the cleaning device 6 (6a, 6b, 6c, and 6d) transfers the photosensitive drums 11a, 1b, and after transfer. The transfer residual toner remaining on the surfaces 1c and 1d is removed.
Photosensitive drum 1 (1a, 1b, 1c, 1d), charging device 2 (2a, 2b, 2c, 2d), developing device 4 (4a, 4b, 4c, 4d), cleaning device 6 (6a, 6b, 6c, 6d) is integrated as a cartridge 7 (7a, 7b, 7c, 7d). Each cartridge 7 (7a, 7b, 7c, 7d) is detachable from the image forming apparatus main body A.

Regarding each configuration described above, four configurations are distinguished from each other by adding alphabets a, b, c, and d to the numbers. However, since they are basically the same configuration, they are commonly described. In such a case, the description will be made by attaching only numbers without attaching subscripts.
As an image forming operation, the cartridges 7a, 7b, 7c, and 7d are sequentially driven in accordance with the printing timing, and the photosensitive drums 1a, 1b, 1c, and 1d are driven to rotate counterclockwise in accordance with the drive. Is done.
The scanner units 3a, 3b, 3c, 3d corresponding to the process cartridges 7a, 7b, 7c, 7d are sequentially driven. By this driving, the charging rollers 2a, 2b, 2c, and 2d apply a uniform charge to the peripheral surfaces of the photosensitive drums 1a, 1b, 1c, and 1d. The scanner units 3a, 3b, 3c, and 3d perform exposure on the peripheral surfaces of the photosensitive drums 1a, 1b, 1c, and 1d in accordance with image signals, and statically expose the peripheral surfaces of the photosensitive drums 1a, 1b, 1c, and 1d. An electrostatic latent image is formed. That is, the image light corresponding to the image signal is reflected by the polygon mirror 9 (9a, 9b, 9c, 9d), and the surface of the charged photosensitive drum 1 through the imaging lens 10 (10a, 10b, 10c, 10d). Are selectively exposed.
Each of the developing rollers 40a, 40b, 40c, and 40d in the developing devices 4a, 4b, 4c, and 4d transfers toner to the low potential portion of the electrostatic latent image and is on the circumferential surface of the photosensitive drums 1a, 1b, 1c, and 1d. A toner image is formed (developed).

On the other hand, the transfer material S separated and fed by the paper feed roller 18 from the paper feed cassette 17 of the paper feed unit 16 is temporarily stopped by the registration roller 19.
At the timing when the leading edge of the toner image on the most upstream photosensitive drum 1a is rotated and conveyed to the point facing the electrostatic transfer belt 11, the registration roller is set so that the printing start position of the transfer material S coincides with the point facing the electrostatic transfer belt 11. 19 starts rotating, and the transfer material S is fed to the electrostatic transfer belt 11.
The transfer material S is pressed against the outer periphery of the electrostatic transfer belt 11 so as to be sandwiched between the electrostatic adsorption roller 22 and the electrostatic transfer belt 11, and a voltage is applied between the electrostatic transfer belt 11 and the electrostatic adsorption roller 22. Apply. As a result, charges are induced in the transfer material S, which is a dielectric, and the dielectric layer of the electrostatic transfer belt 11, and the transfer material S is electrostatically attracted to the outer periphery of the electrostatic transfer belt 11. As a result, the transfer material S is stably adsorbed to the electrostatic transfer belt 11 and conveyed to the most downstream transfer unit.

While being transported in this manner, the transfer material S is subjected to the photosensitive drums 1a, 1b, 1c, and 1d by the electric fields formed between the transfer rollers 12a, 12b, 12c, and 12d. The toner images 1b, 1c, and 1d are sequentially transferred.
The transfer material S on which the toner images of four colors are transferred is separated from the electrostatic transfer belt 11 by the curvature of the belt driving roller 13 and is carried into the fixing unit 20. When the transfer material S passes through the fixing unit 20, the transfer material S is conveyed by the pressure roller 21b and is given heat and pressure by the heating roller 21a. As a result, the toner images of a plurality of colors are fixed on the surface of the transfer material S. After the toner image is thermally fixed by the fixing unit 20, the transfer material S is discharged by the paper discharge roller 23 from the paper discharge unit 24 to the outside of the main body with the image surface facing down.

[Cartridge configuration]
Next, the cartridge embodying the present invention will be described in detail with reference to FIGS. 2 and 3 show a main cross section and a perspective view of the cartridge 7 containing the toner. The yellow, magenta, cyan, and black cartridges 7a, 7b, 7c, and 7d have the same configuration.
That is, the cartridge 7 includes a developing roller 40 as a developer carrying member that carries toner as a developer for developing an electrostatic image on the photosensitive drum 1 as an electrostatic latent image on the image carrier, and a developing roller. And 40 developing blades 44 as layer regulating members.
The photosensitive drum 1 is an image carrier that holds an electrostatic latent image, and a developing roller 40 is disposed opposite to the photosensitive drum 1. The developing blade 44 regulates the toner layer thickness of the developing roller 40. One end of the developing blade 44 is fixed to the cartridge frame and the other end contacts the developing roller 40 to regulate the toner layer thickness of the developing roller 40.

The cartridge 7 is divided into a cleaner unit 50 and a developing unit 4.
In the cleaner unit 50, the photosensitive drum 1 is rotatably attached to a cleaning frame 51 constituting a cartridge frame via a bearing member (not shown). On the periphery of the photosensitive drum 1, a primary charger 2 for uniformly charging the photosensitive layer provided on the outer peripheral surface of the photosensitive drum 1, and residual toner remaining on the photosensitive drum 1 after transfer are removed. For this purpose, a cleaning device 6 and a flexible sheet member 80 are provided.
Residual toner (waste toner) removed from the surface of the photosensitive drum 1 by the cleaning device 6, specifically, a cleaning blade, is stored in a waste toner chamber 55 provided behind the cleaning frame 51. Further, the transfer residual toner on the photosensitive drum 1 reaches the position of the cleaning blade 60 through the drum contact portion of the flexible sheet member 80. The contact condition of the flexible sheet member 80 is set so that the residual toner removed from the photosensitive drum 1 by the cleaning device 6 does not leak out of the cleaning frame 51.

The developing unit 4 includes a toner container 41 that is a developer container that stores toners of yellow, magenta, cyan, and black, respectively. The toner T in the toner container 41 is supplied to a toner supply roller 43 by a toner transport mechanism 42. It is sent to. The toner supply roller 43 rotates in the clockwise direction (Y direction) in the drawing, and supplies toner to the developing roller 40 and peels off the toner from the developing roller 40 after developing the photosensitive drum 1.
The toner supplied to the developing roller 40 is applied to the outer periphery of the developing roller 40 rotating in the clockwise direction (Z direction in the figure) by a developing blade 44 as a layer regulating member pressed against the outer periphery of the developing roller 40, and Charge is applied. Then, by applying a developing bias to the developing roller 40 facing the photosensitive drum 1 on which the latent image is formed, toner development is performed on the photosensitive drum 1 in accordance with the latent image.
The toner container 41 has a hollow structure in which a toner storage portion is formed, and is constituted by developing frame bodies 45a and 45b joined to each other. The developing frame bodies 45a and 45b are joined together by, for example, ultrasonic welding.

[Developing blade]
Next, a method for fixing the developing blade 44 will be described with reference to FIGS.
FIG. 4A shows an external perspective view of the developing device 45 before the fixing member 81 is mounted. FIG. 5 (A) is a developing container 45 before the fixing member is mounted, and is an external perspective view of the back side of FIG. 4 (B).
That is, positioning means for temporarily fixing the developing blade 44 so as to be immovable in the direction along the blade seat surface 70 of the developing frame 45a which is a cartridge frame, and fixing for fixing the developing blade 44 in a state where it is temporarily fixed to the mounting seat surface 70. And a member 81. The blade seat surface 70 corresponds to the mounting seat surface of the present invention.

FIG. 3A shows the state of the developing unit 4 and the developing blade 44 before the developing blade 44 is attached.
That is, positioning bosses 72 and 73 and positioning holes 44a and 44b are provided as positioning portions that constitute positioning means for positioning the developing blade 44. The positioning bosses 72 and 73 and the positioning holes 44 a and 44 b engage with each other in the thickness direction of the developing blade 44.
The blade seat surface 70 is provided on the developing frame body 45a constituting the cartridge frame, and is longer than the longitudinal developing opening width along the longitudinal edge of the developing opening 45c in which the developing roller 40 of the toner container 45 is disposed. It is large and is formed over the entire length in the longitudinal direction of the developing device frame 45a.
Positioning bosses 72 and 73 as positioning portions for positioning the developing blade 44 are disposed at both left and right ends of the blade seat surface 70. The positioning bosses 72 and 73 are convex portions protruding from the blade seat surface 70.
On the other hand, positioning holes 44 a and 44 b for engaging with the positioning bosses 72 and 73 are provided at both ends in the longitudinal direction at the fixed end that is one end in the direction orthogonal to the longitudinal direction of the developing blade 44. The developing blade 44 is temporarily positioned in contact with the blade seat surface 70 in the illustrated arrow direction, that is, in the thickness direction of the developing blade 44.

In this state, positioning is fixed in the direction along the seating surface of the blade seating surface 70, but it is disengaged in the direction away from the blade seating surface 70, that is, in the thickness direction of the developing blade 44. It is. In this state, the developing blade 44 is temporarily fixed to the blade seating surface 70, and is held and fixed by the fixing member 81 with the fixed end of the developing blade 44 and the seating surface rear surface portion 71 interposed therebetween.
The fixing member 81 is a U-shaped member made of thin sheet metal, and includes a pair of gripping portions 81a and 81b and a connecting portion 81c that connects the gripping portions 81a and 81b. The seat surface 70 and the seat surface back surface portion 71 are sandwiched. The mounting direction of the gripping portions 81 a and 81 b of the fixing member 81 is a direction orthogonal to the engaging direction of the positioning bosses 72 and 73 and the positioning holes 44 a and 44 b, that is, a direction parallel to the blade seat surface 70. It is configured to be worn from the hand direction. The tip portions of the gripping portions 81a and 81b are inclined pieces that are inclined so that the intervals gradually increase toward the tips in order to enable smooth insertion.
The developing blade 44 as a layer regulating member is closely attached to the blade seating surface 70 of the developing frame 45a, and is sandwiched by the fixing member 81, whereby the developing blade 44 is positioned and fixed to the developing frame 45a.

The fixing member 81 is mounted from the short side direction of the developing blade 44 that is different from the mounting direction of the developing blade 44 (the thickness direction of the developing blade 44). Therefore, the frame body portion 46 in which the blade seat surface 70 of the developing container 45 is formed has a shape having a certain thickness. A plurality of reinforcing ribs 74 of the developing container 45 are connected to the frame body portion 46 of the blade seat surface 70 on the back surface portion 71 on the back side of the blade seat surface 70 of the frame body portion 46. The rigidity is maintained.
The gripping portion 81a on the blade seat surface side of the fixing member 81 has a groove 84 that escapes the positioning portions of the developing blade 44, that is, the positioning bosses 72 and 73 protruding from the positioning holes 44a and 44b when the developing container 45 is mounted. Is provided.

FIG. 3B shows a detailed cross-sectional view after the fixing member 81 is assembled in the developing container 45.
The fixing member 81 is provided with a ridge line portion 82 that contacts the developing blade 44. When the gripping portions 81 a and 81 b of the fixing member 81 are assembled while being bent so as to sandwich the blade seat surface 70 and the seating surface rear surface portion 71 via the developing blade 44, a blade pressing force acts from the fixing member 81.
The fixing member 81 has a blade pressing force p which is an adhesion force for closely contacting the blade seat surface 70 of the developing frame 45a which is a cartridge frame and the developing blade 44 which is a layer regulating member, and the blade pressing force p from the blade seat surface edge is Let the length to the working pressing position 82 be l.
The action of the blade pressing force p means that the developing blade 44 is brought into contact with the blade seat surface 70 in the pressing direction. Further, when the working length from the blade seat surface 70 to the contact position with the developing roller 40 is L, and the total contact pressure of the developing blade 45 from the developing roller 40 is P, the fixing member 81 presses the developing blade 45. The following relational expression holds for the blade pressing force p required for the above.
p> PL / l (1)

As described above, if the fixing member 81 satisfying the condition (1) is arranged as the fixing condition of the developing blade 44, it is used for fixing the developing blade 44, conventional screw fixing, or thin-layer sheet metal blade fixing. There is no need for auxiliary members such as holding sheet metal and support sheet metal.
Further, the developing blade 44 is positioned by engagement between the positioning bosses 72 and 73 of the developing container 45 and the positioning holes 44a and 44b of the developing blade 44 and can be fixed in close contact with the blade seat surface 70. The contact state can also be maintained stably.
By disposing the fixing member 81 to be larger than the developing opening width in the longitudinal direction of the developing device frame 45a, it is possible to stably regulate the toner layer as a developer in the image forming region with respect to the developing roller 40. it can.

The back surface gripping portion 81b of the fixing member 81 that engages with the seating surface back surface portion 71 is configured to include a plurality of cuts 83 corresponding to the reinforcing ribs 74, so that development is performed while maintaining rigidity by the reinforcing ribs 74. The fixing force of the blade 44 can be maintained.
By configuring so that the relational expression (1) holds, the developing blade 44 can be stably fixed to the blade seat surface 70 of the developing frame 45a at the fixing position of the fixing member 81.

1 (1a, 1b, 1c, 1d) Photosensitive drum (image carrier)
4 (4a, 4b, 4c, 4d) Developing unit 40 (40a, 40b, 40c, 40d) Developing roller (developer carrier)
44 Development blade (layer regulating member),
44a, 44b Positioning hole (positioning part),
45 Toner container, 45a, 45b Development frame body, 45c Development opening 46 Frame body portion 7 (7a, 7b, 7c, 7d) Cartridge 70 Blade seat surface (mounting seat surface)
71 Seat surface back surface parts 72, 73 Positioning boss (positioning part)
74 Reinforcement rib 81 Fixing member 82 Pressing position 83 Notch P Blade contact pressure L Blade free length (action length from seat surface to contact part)
l Bearing surface end surface-Fixed member fixing position length p Fixed member fixing force

Claims (7)

A developer carrier that carries a developer for developing an electrostatic image on the image carrier, and a developer that is carried on the developer carrier with one end fixed to the cartridge frame and the other end in contact with the developer carrier. In a cartridge provided with a layer regulating member that regulates the layer thickness,
Positioning means for positioning the layer restricting member so that the layer restricting member does not move in a direction along a mounting seat surface provided directly on the cartridge frame;
A pair of gripping portions, and the layer regulating member and the back surface portion of the mounting seat surface being sandwiched between the pair of gripping portions in a state where the layer regulating member is positioned on the mounting seat surface; A fixing member for fixing the regulating member ,
The layer regulating member is positioned and fixed to the cartridge frame by sandwiching the layer regulating member to the mounting seat surface while being held between the fixing members .
The pair of gripping portions are connected, and by the force generated by bending the gripping portion, the fixing member presses the layer regulating member against the mounting seat surface,
Of the pair of gripping portions, the gripping portion on the side that comes into contact with the layer regulation member is provided with a ridge line portion that partially contacts the layer regulation member, and the layer regulation member is attached to the mounting seat surface at the ridge line portion. A cartridge characterized by pressing.   The layer regulating member and the mounting seat surface are provided with positioning portions that engage with each other in the thickness direction of the layer regulating member as the positioning means, and the mounting direction of the gripping portion is along the mounting seat surface. The cartridge according to claim 1, wherein the cartridge is configured to be mounted from a short direction of the layer regulating member. The fixing member cartridge according to claim 1 or 2, characterized in that greater than the width in the longitudinal direction of the developing opening that opens to the cartridge frame for fixing the layer regulating member. The cartridge according to any one of claims 1 to 3 , wherein the grip portion includes a plurality of cuts corresponding to reinforcing ribs provided on the cartridge frame. The cartridge has a boss that engages with the layer restricting member as the positioning means,
Wherein the gripping portion is in a position corresponding to the boss, cartridge according to any one of claims 1 to 4, characterized in that the grooves are formed. The contact pressure total pressure received by the layer regulating member from the developer carrying member is P, the working length of the layer regulating member from the mounting seat surface to the contact position with the developer carrying member is L, the layer regulating member The length from the mounting seat surface edge of the member to the pressing position where the fixing member contacts the mounting seat surface in the pressing direction via the ridge line portion is l, and the fixing member is connected to the mounting seat surface and the mounting seat surface. When the adhesion force for closely contacting the layer regulating member is p,
The following relational expression p> PL / l
The cartridge according to claim 1 , wherein the cartridge is arranged so that A cartridge according to any one of claims 1 to 6, the image forming apparatus to which the cartridge is provided with an image forming apparatus main body detachably.

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