JP5956898B2 - Image forming unit and image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic image forming unit and an image forming apparatus.

  A conventional image forming unit includes a seal member for preventing toner in a toner storage chamber from leaking to the outside by being in contact with and pressed against the outer peripheral surface of the end portion of the developing roller. Is formed as a two-layer structure in which a highly slidable material is disposed on the surface of the base that contacts the outer peripheral surface of the end of the developing roller, and seals the toner storage chamber (For example, refer to Patent Document 1).

JP 2011-95323 A

However, in the prior art, there is a problem that toner accumulates in the sealing member over time, a gap is formed between the sealing member and the developing roller, and the sealing performance of the toner storage chamber is deteriorated.
An object of the present invention is to solve such a problem, and an object of the present invention is to suppress a decrease in sealing performance of a toner storage chamber.

Therefore, the present invention provides a developer storage chamber for storing a developer, a developer carrier for supporting the developer, a developer storage chamber, and a contact with the developer carrier. In the image forming unit having the seal member, the seal member is formed on the surface layer in contact with the developer carrier, the base layer bonded to the wall of the developer storage chamber, the surface layer, and the base layer. The base layer and the intermediate layer are bonded, the intermediate layer and the surface layer are bonded, and the Young's modulus of the base layer is smaller than the Young's modulus of the intermediate layer, Young's modulus of the layer is rather larger than the Young's modulus of the intermediate layer, the intermediate layer is the base layer side, characterized in that cuts extend in a direction parallel to the rotational axis of the developer carrier is formed And

  According to the present invention as described above, it is possible to suppress the deterioration of the sealing property of the toner storage chamber.

The side view which shows the structure of the edge part sealing material in a 1st Example. 1 is a schematic side view illustrating a configuration of an image forming apparatus according to a first embodiment. Sectional drawing which shows the structure of the image forming unit in 1st Example The perspective view which shows the structure of the edge part sealing material in a 1st Example. Sectional drawing of the edge part sealing material in 1st Example Sectional view of end seal material in comparative example Explanatory drawing which shows the effect | action of the edge part sealing material in a 1st Example. Sectional drawing of the edge part sealing material in 2nd Example

  Embodiments of an image forming unit and an image forming apparatus according to the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic side view showing the configuration of the image forming apparatus in the first embodiment.
In FIG. 2, an image forming apparatus 100 is a printer having, for example, an electrophotographic image forming unit capable of color printing.
The image forming apparatus 100 includes image forming units 1K, 1Y, 1M, and 1C for four colors of black (K), yellow (Y), magenta (M), and cyan (C).
Each of the image forming units 1K, 1Y, 1M, and 1C includes photosensitive drums 2K, 2Y, 2M, and 2C as image carriers, and above the photosensitive drums 2K, 2Y, 2M, and 2C, the photosensitive drums 2K, Exposure heads 3K, 3Y, 3M, and 3C as exposure devices are respectively disposed facing 2Y, 2M, and 2C, and a toner image is formed on the photosensitive drums 2K, 2Y, 2M, and 2C with toner as a developer.

The medium tray 4 is loaded with a medium 5 as a print medium, and the medium 5 is fed one by one by a paper feed roller 6 and conveyed.
In the conveyance path through which the medium 5 is conveyed, a registration roller 7 for conveying the medium 5 and a transfer belt 8 for transferring the toner images formed by the image forming units 1K, 1Y, 1M, and 1C to the medium 5. A fixing device 9 for fixing the toner image transferred to the medium 5, discharge rollers 10 and 11 for discharging the medium 5 on which the toner image is fixed, and a stack for loading the discharged medium 5. A stacker cover 12 is provided.

FIG. 3 is a cross-sectional view showing the configuration of the image forming unit in the first embodiment. Since the image forming units 1K, 1Y, 1M, and 1C shown in FIG. 2 have the same configuration, description will be made using the black image forming unit 1K.
In FIG. 3, the image forming unit 1 </ b> K is surrounded by a housing 13, in which a photosensitive drum 2, a charging roller 17, a developing roller 14, a supply roller 15, a developing blade 16, and toner are contained. A storage chamber 19, stirring members 20 and 21, a toner conveying member 22, a cleaning blade 23, a toner cartridge 25 and the like are included.

The charging roller 17 is disposed so as to be in contact with the outer peripheral surface of the photosensitive drum 2 and uniformly charges the surface of the photosensitive drum 2.
The developing roller 14 as a developer carrying member for carrying the developer is disposed so as to contact the outer peripheral surface of the photosensitive drum 2, and the electrostatic latent image formed on the surface of the photosensitive drum 2 by exposure of the exposure head 3. Toner is transported to
The supply roller 15 as a developer supply member is disposed so as to contact the outer peripheral surface of the development roller 14, and supplies the toner 24 stored in the toner storage chamber 19 to the development roller 14.

The developing blade 16 is disposed so as to contact the outer peripheral surface of the developing roller 14, and thins the toner on the surface of the developing roller 14 supplied by the supply roller 15.
The toner storage chamber 19 as a developer storage chamber is a storage unit that stores toner supplied from the toner cartridge 25.
The agitating members 20 and 21 are rotatably disposed near the supply roller 15, and agitate the toner 24 stored in the toner storage chamber 19 by rotating.

The cleaning blade 23 is disposed so as to contact the outer peripheral surface of the photosensitive drum 2 and scrapes off the toner remaining on the surface of the photosensitive drum 2 after the toner image is transferred.
The toner conveying member 22 is disposed in the vicinity of the cleaning blade 23 and discharges the toner scraped off by the cleaning blade 23 to the outside of the image forming unit 1K.
The toner cartridge 25 is a storage unit that stores toner, and supplies the toner to the toner storage chamber 19. The agitating member 28 agitates the toner accommodated in the toner cartridge 25 by rotating.

FIG. 1 is a side view showing the configuration of the end seal material in the first embodiment. FIG. 1 is a side view of the image forming unit 1K shown in FIG.
In FIG. 1, seal sponges 41 are disposed at both ends in the axial direction of the rotating shaft 14a of the developing roller 14, and form the wall surface of the toner storage chamber 19 shown in FIG. In addition, 15a shows the rotating shaft of the supply roller 15, 20a shows the rotating shaft of the stirring member 20, and 21a shows the rotating shaft of the stirring member 21.

  The end seal member 40 as a seal member is adhered and disposed on the seal sponge 41 while maintaining a curvature so as to abut along the outer peripheral surfaces of both ends in the axial direction of the rotation shaft 14a of the developing roller 14. ing. As described above, the end seal material 40 and the developing roller 14 abut against the outer peripheral surfaces of both end portions in the axial direction of the rotating shaft 14a of the developing roller 14 to maintain the sealing performance, thereby storing the toner shown in FIG. The toner stored in the chamber 19 is prevented from leaking out of the toner storage chamber 19.

Here, the configuration of the end seal material 40 will be described using a perspective view showing the configuration of the end seal material in the first embodiment of FIG.
As shown in FIG. 4, the end seal material 40 has a three-layer structure having a surface layer 40a, an intermediate layer 40b, and a base layer 40c as a base layer, and is formed into a strip shape. Further, the end seal material 40 is laminated in the order of the surface layer 40a, the intermediate layer 40b, and the base layer 40c from the contact surface side with the developing roller 14 shown in FIG. That is, as shown in FIG. 1, the surface layer 40a is in contact with the developing roller 14, the base layer 40c is bonded to the seal sponge 41 that forms the wall of the toner storage chamber, and the intermediate layer 40b includes the surface layer 40a and the base layer 40c. It is sandwiched between.

The surface layer 40a and the intermediate layer 40b are joined by heat lamination adhesion. Since the adhesive layer has a thickness of 1/10 or less of the thickness of the surface layer 40a, the influence of adhesion can be ignored.
The intermediate layer 40b and the base layer 40c are bonded to each other with a baseless double-sided tape having a thickness of 0.1 mm and an adhesive strength of 22 N / 25 mm.
The end seal material 40 is curved in the longitudinal direction in the figure with the surface layer 40a on the inside, and the surface layer 40a is in contact with the outer peripheral surfaces of both ends in the axial direction of the rotation shaft 14a of the developing roller 14 To the seal sponge 41.

Returning to the description of FIG. 1, in this embodiment, a double-sided tape containing a base material having a thickness of 0.16 mm and an adhesive strength of 12 N / 25 mm is used for bonding the end seal material 40 and the seal sponge 41. .
At this time, if the Young's modulus of the surface layer 40a shown in FIG. 4 is Y40a and the Young's modulus of the intermediate layer 40b is Y40b, the relationship between the Young's modulus Y40a and the Young's modulus Y40b is
Young's modulus Y40a>Young's modulus Y40b
It has become.

Thus, in the end seal member 40, the base layer 40c and the intermediate layer 40b are bonded, the intermediate layer 40b and the surface layer 40a are bonded, and the Young's modulus Y40a of the surface layer 40a is equal to the Young's modulus Y40b of the intermediate layer 40b. It is formed to be larger.
Further, since the surface layer 40a is a sliding surface in contact with the developing roller 14, it is desirable that the coefficient of friction is low and the wear resistance is excellent.
Further, since the base layer 40c is adapted to generate pressure on the surface of the developing roller 14 due to its elasticity when the end seal member 40 comes into contact with the developing roller, the base layer 40c is in close contact with the end seal member 40. It is said.

In this embodiment, the surface layer 40a is a sheet member made of ultra high molecular weight polyethylene, has a thickness of 0.05 mm, a dynamic friction coefficient of 0.11, a wear amount of 1.0 mm ³ by a wear test method using a JISK7204 wear ring, and a Young's modulus of 2000 MPa. It was.
The intermediate layer 40b is a urethane film as a sheet member made of urethane, and has a thickness of 0.1 mm and a Young's modulus of 45 MPa.
Furthermore, the base layer 40c was made of a soft urethane sponge, had a thickness of 2.35 mm, an apparent Young's modulus of 0.1 MPa, and an indentation pressure of 0.02 MPa.

In the present embodiment, the surface layer 40a is made of ultra-high molecular weight polyethylene, but PTFE (polytetrafluoroethylene: coefficient of dynamic friction 0.11, wear amount 1.6 mm ³ by a wear test method using JIS K7204 wear ring, Young's modulus It is also possible to use other materials having high slidability such as 410 MPa) and higher Young's modulus than the intermediate layer 40b.
Further, when the base layer 40c is a urethane sponge having a thickness of 2 mm or more and an indentation pressure of 0.01 MPa or more and 0.05 MPa or less, the end seal material 40 is in close contact with the surface of the developing roller 14 and maintains the sealing performance. Can do.

The operation of the above configuration will be described.
First, the operation of the image forming apparatus will be described with reference to FIG.
When a printing command is issued from a control unit (not shown), the image forming apparatus 100 conveys the medium 5 to the transfer belt 8 by the paper feed roller 6 and the registration roller 7. On the other hand, in the image forming units 1K, 1Y, 1M, and 1C, an electrostatic latent image is formed on the photosensitive drum 2 exposed by the exposure head 3, and the electrostatic latent image is developed as a toner image through a developing process described later. Is done.
The toner developed on the photosensitive drum 2 reaches a position facing the transfer belt 8 as the photosensitive drum 2 rotates, and is transferred by the transfer belt 8 to the medium 5 conveyed by the rotating transfer belt 8. The medium 5 on which the toner has been transferred is conveyed to the fixing device 9, and after the toner is fixed by the fixing device 9, the medium 5 is discharged onto the stacker cover 12 by the discharge rollers 10 and 11.

Next, the developing process performed by the image forming unit will be described with reference to FIG. Since the image forming units 1K, 1Y, 1M, and 1C have the same configuration, the operation of the image forming unit 1K will be described as a representative.
In the image forming unit 1K, a control signal is sent from a control unit (not shown), the photosensitive drum 2 is rotationally driven in a direction indicated by an arrow A in the figure by a driving source such as a motor, and the photosensitive drum 2 is driven by a driving transmission means such as a gear. The rotation drive is transmitted and the supply roller 15 rotates in the direction indicated by the arrow C in the figure, and the stirring members 20 and 21 disposed in the vicinity of the supply roller 15 are rotated in the direction indicated by the arrow D in the figure respectively. The toner 24 stored in the toner storage chamber 19 is agitated.

Further, the rotation drive of the photosensitive drum 2 is transmitted and the toner 24 is supplied by the supply roller 15 that rotates to the developing roller 14 that rotates in the direction indicated by the arrow B in the drawing, and the toner 24 supplied to the developing roller 14 is supplied by the developing blade. 16 is transported to an electrostatic latent image on the photosensitive drum 2 formed by being exposed to light by the exposure head 3 and developed as a toner image.
The toner 24 on the photosensitive drum 2 is transferred to the medium 5 by the transfer belt 8, and the toner 24 remaining on the photosensitive drum 2 after the transfer is scraped off by the cleaning blade 23 and conveyed by the toner conveying member 22.

Here, operation | movement of the edge part sealing material in a present Example is demonstrated based on FIG.
As shown in FIG. 1, the end seal member 40 is in close contact with the seal sponge 41 with a curvature, is brought into contact with the outer peripheral surface of the developing roller 14, and pressure due to the pressing of the developing roller 14 is applied. As a result, the developing roller 14 and the end seal member 40 are brought into close contact with each other without gaps, and the toner in the toner storage chamber 19 shown in FIG. 3 is sealed.

At this time, as shown in the sectional view of the end seal material in the comparative example of FIG. 6, the base layer 140c, which is an elastic body having a small Young's modulus, and a film-like film having a small Young's modulus but a small mechanical strength. In the end seal material 140 having a two-layer structure composed of the surface layer 140a, the straight-shaped seal member 140 shown in FIG. 6 (a) is attached to the seal sponge with a curvature as shown in FIG. 6 (b). Therefore, the surface layer 140a side tends to shrink due to a dimensional deviation caused by the difference between the inner diameter and the outer diameter generated when the thick base layer 140c is bent, but the surface layer 140a has a high Young's modulus and does not shrink. Occurs, and a gap is generated between the end seal material 140 and the developing roller, and toner leakage occurs.
6A shows the end seal material 140 before being deformed, and FIG. 6B shows the end seal material 140 after being deformed so as to be in close contact with the developing roller.

In this embodiment, as shown in FIG. 5, the end seal material 40 has a three-layer structure, and the intermediate layer 40b and the surface layer 40a are bonded to prevent wrinkles from occurring in the base layer 40c. By setting the Young's modulus Y40b of the layer 40b and the Young's modulus Y40a of the surface layer 40a to be Young's modulus Y40a>Young's modulus Y40b, as shown in FIG. 5B, the intermediate layer 40b and the base layer 40c are joined. Since the dimensional deviation generated on the surface can be absorbed by the deformation and extension of the intermediate layer 40b, no gap is generated between the developing roller 14 and the toner 24 does not leak.
5A shows the end seal material 40 before being deformed, and FIG. 5B shows the end seal material 40 after being deformed so as to be in close contact with the developing roller.

Further, since the intermediate layer 40b is provided and the surface layer 40a is made of a material that is not easily worn even when sliding with the developing roller 14, the intermediate layer 40b is made flexible. Maintains the adhesion to the developing roller 14 and can improve the sealing performance of the toner storage chamber.
Further, since the intermediate layer 40b and the base layer 40c are bonded with the base material-less double-sided tape, the intermediate layer 40b can be deformed more flexibly than the double-sided tape with the base material, and the movement of the intermediate layer 40b is regulated by the adhesive surface. Flexibility can be maintained.

Therefore, as shown in FIG. 7, the pressure 40f generated from the base layer 40c can be applied uniformly in the circumferential direction of the developing roller 14, and the toner is transferred between the developing roller 14 and the end seal 40 over time. High sealing performance can be secured without intrusion.
As described above, in the first embodiment, the end seal material is bonded to the base layer which is an elastic body, the intermediate layer is bonded, and the surface layer is bonded to the intermediate layer to form a three-layer structure. By making the Young's modulus greater than the Young's modulus of the intermediate layer, when the end seal material is deformed and brought into close contact with the developing roller, the intermediate layer is deformed and stretched to prevent generation of wrinkles to absorb dimensional deviations. And the effect of suppressing the deterioration of the sealing performance of the toner storage chamber can be obtained.

The surface layer is made of a material that does not easily wear even when it slides on the developing roller, but the intermediate layer is made flexible so that the end sealant maintains adhesion to the developing roller. And the sealing property of the toner storage chamber can be improved.
Therefore, it is possible to easily improve the sealing performance of the toner storage chamber without requiring special processing of the end seal material.

  The configuration of the second embodiment is different from the configuration of the first embodiment in the configuration of the intermediate layer of the end seal material. The configuration of the second embodiment will be described based on the sectional view of the end seal material in the second embodiment of FIG. 8A shows the end seal material 40 before being deformed, and FIG. 8B shows the end seal material 40 after being deformed so as to be in close contact with the developing roller. Further, the same parts as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof is omitted.

In FIG. 8, a cut 45 is formed on the base layer 40 c side of the intermediate layer 40 b of the end seal material 40. This notch 45 is formed so as to extend in the short direction of the end seal material 40 shown in FIG. 4, that is, in a direction parallel to the rotation axis of the developing roller in contact with the end seal material 40. A plurality are formed in the longitudinal direction, that is, in a direction perpendicular to the rotation axis direction of the developing roller while maintaining a predetermined interval.
The intermediate layer 40b and the surface layer 40a were integrated by thermal lamination bonding, and the integrated intermediate layer 40b and the surface layer 40a were bonded to the base layer 40c with a substrate-less double-sided tape.

The operation of the above configuration will be described.
As shown in FIG. 8, by forming the cut 45 in the intermediate layer 40b of the end seal material 40, the intermediate layer 40b can be flexibly deformed as shown in FIG. The followability of the end seal material 40 to the developing roller 14 is improved, and the adhesion between the end seal material 40 and the developing roller 14 is increased.
For this reason, even when creep deformation occurs in the base layer 40c due to changes in the environment or over time, and the pressing pressure against the developing roller 14 decreases, the adhesion between the end seal material 40 and the developing roller 14 can be maintained. it can.

As described above, in the second embodiment, in addition to the effects of the first embodiment, the intermediate layer can be flexibly deformed by forming a cut in the intermediate layer of the end seal material. Thus, the followability of the end seal material to the developing roller is improved, and the effect of improving the adhesion between the end seal material and the developing roller can be obtained.
In addition, even when creep deformation occurs in the base layer due to changes in the environment or over time, and the pressing pressure against the developing roller decreases, the effect that the adhesion between the end seal material and the developing roller can be maintained. can get.

Further, since no toner enters between the end seal material and the developing roller, the durability of the end seal member can be improved and the life of the image forming unit can be extended. can get.
In the first and second embodiments, the present invention has been described with reference to an example in which the present invention is applied to an image forming unit of an image forming apparatus. However, the present invention is not limited thereto, and a developer for a copying machine, a facsimile machine, a multifunction machine, etc. The present invention can also be applied to an apparatus that uses

DESCRIPTION OF SYMBOLS 1 Image forming unit 2 Photosensitive drum 3 Exposure head 4 Medium tray 6 Paper feed roller 7 Registration roller 8 Transfer belt 9 Fixing device 10, 11 Ejection roller 12 Stacker cover 13 Housing | casing 14 Developing roller 15 Supply roller 16 Developing blade 17 Charging roller 19 Toner storage chamber 20, 21, 28 Agitating member 22 Toner conveying member 23 Cleaning blade 25 Toner cartridge 40 End seal material 40a Surface layer 40b Intermediate layer 40c Base layer 45 Notch

Claims (4)

A developer storage chamber for storing the developer; a developer carrier for carrying the developer; and a seal member disposed in the developer storage chamber and disposed in contact with the developer carrier. In the image forming unit,
The sealing member is
A surface layer in contact with the developer carrier;
A base layer adhered to the wall of the developer storage chamber;
An intermediate layer sandwiched between the surface layer and the base layer,
The base layer and the intermediate layer are bonded, the intermediate layer and the surface layer are bonded, the Young's modulus of the base layer is smaller than the Young's modulus of the intermediate layer, and the Young's modulus of the surface layer is Young's modulus of the intermediate layer size than the rate rather than,
The image forming unit , wherein the intermediate layer is formed with a cut extending in a direction parallel to a rotation axis of the developer carrier on the base layer side . The image forming unit according to claim 1,
The image forming unit, wherein the surface layer is a sheet member made of high molecular polyethylene or polytetrafluoroethylene. The image forming unit according to claim 1 or 2,
The image forming unit, wherein the intermediate layer is a sheet member made of urethane. An image forming apparatus comprising the image forming unit according to claim 1 .

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