JP2001281987A - Developing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developing device and an image forming device in which a layer thickness regulating member is fixed to a holding member without forming a screw hole so that the leakage of polymerized toner is prevented by improving a developing device for forming a developed image with toner on an electrostatic latent image carrier 20 by opposing a toner thin layer formed on a developer carrier by the layer thickness regulating member to the electrostatic latent image carrier 20. SOLUTION: The developing device 50 is equipped with the developer carrier 58 and the layer thickness regulating member 59, and the toner is the polymerized toner 55 produced by a polymerization method. The layer thickness regulating member is equipped with a leaf spring 79 generating pressing force to the developer carrier and a holder 81 holding the leaf spring and having rigidity, and the holder and the leaf spring are stuck with an adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a developing apparatus and an image forming apparatus using a polymerized toner as a developer.

[0002]

2. Description of the Related Art In recent years, polymerized toners have been increasingly used in electrophotographic image forming apparatuses. This is because the polymerized toner has a number of advantages due to its extremely excellent fluidity. In non-magnetic one-component development using such a polymerized toner as a developer, a layer thickness regulating member that simultaneously regulates the layer thickness of the toner layer and imparts charge to the toner plays a very important role. This layer thickness regulating member has conventionally been fixed to a holding member such as a metal plate serving as a base by screws.

[0003]

However, since the polymerized toner has too good a fluidity, it has a property of flowing out of a very small gap, and leaks out of a hole for fixing a screw. There was a problem that would.

Accordingly, an object of the present invention is to provide a developing device and an image forming apparatus in which a layer thickness regulating member is fixed to a holding member without providing a screw hole, thereby preventing leakage of polymerized toner.

[0005]

Hereinafter, the present invention will be described. In addition, in order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are added in parentheses, but the present invention is not limited to the illustrated embodiment.

According to the first aspect of the present invention, a thin layer of toner formed on a developer carrying member by a layer thickness regulating member is opposed to the electrostatic latent image carrying member (20) so that the toner on the electrostatic latent image carrying member can be removed. In the developing device for forming a developer image with the toner, the developing device includes a developer carrier (58) and a layer thickness regulating member (59), and the toner is a polymerized toner ( 55), wherein the layer thickness regulating member includes a leaf spring (79) for generating a pressing force on the developer carrying member and a rigid holder (81) for holding the leaf spring and having a rigidity. The above problem is solved by a developing device (50) which is adhered with an adhesive.

According to the present invention, even when a polymerizable toner having a high fluidity is used as the toner, since the holder and the leaf spring are bonded with the adhesive, there is no room for forming a gap between the two. Leakage of the polymerized toner can be completely prevented. Also, the pressing force of the layer thickness regulating member is generated by the leaf spring, and the leaf spring has no set, so that it can be stably pressed. Furthermore, fixing by adhesion may cause problems such as insufficient strength as compared with the case of screws, but the toner used is a polymerized toner obtained by a polymerization method, so that it has excellent fluidity and solidity. Since it also functions as a lubricant, the frictional force between the developing roller and the layer thickness regulating member can be reduced. Therefore, even if the strength is somewhat weak, the adhesive portion does not peel off. When the layer thickness of the polymerized toner is regulated, the layer thickness can be regulated by weakening the pressing force of the layer thickness regulating member. Therefore, the amount of deformation of the leaf spring can be reduced, and the stress applied to the adhesive can be reduced. This is advantageous for peeling off of the adhesive part.

According to a second aspect of the present invention, in the developing device according to the first aspect, the downstream side in the rotational direction of the developer carrier is adhered to the holder, and the upstream side in the rotational direction is a free end to hold the developer carrier. It is characterized by being pressed.

According to the present invention, the frictional force between the developer carrying member and the layer thickness regulating member acts in the direction of pressing the layer thickness regulating member against the developer carrying member. can do. On the other hand, in this configuration, since the frictional force acts in the direction of directly displacing the bonding portion between the leaf spring and the holder, peeling of the bonding portion at the time of durability becomes a problem. Since it acts as a solid lubricant between the agent carrier and the frictional force,
Peeling of the bonded portion can be prevented.

According to a third aspect of the present invention, in the developing device according to the second aspect, a sliding member (80) is provided at a free end of the leaf spring that presses the developer carrier, and the sliding member is It is characterized by being formed of a rubber elastic body.

According to the present invention, since the portion where the layer thickness regulating member slides while pressing the developer carrier is a member having rubber elasticity, it is deformed by pressing, so that an elastic body is used for the developer carrier. In this case, the deformation of the developer carrying member can be reduced. Therefore, it is possible to reduce the stress applied to the bonding portion of the layer pressure regulating member when the developer carrier rotates. Further, since the developer is not pressed with an excessive force, the deterioration of the developer is small, and good development can be performed for a long period of time.

According to a fourth aspect of the present invention, in the developing device according to any one of the first to third aspects, the holder is formed of a bent plate and is attached to a housing of the developing device.
The mounting surface of the holder to the housing is the same as the bonding surface of the leaf spring.

According to the present invention, the holder is formed of a bent plate, and the bent plate can easily maintain rigidity, so that a uniform pressing force can be applied to the surface of the developer carrying member. . Further, by making the mounting surface of the holder to the housing and the bonding surface of the leaf spring the same surface, it is possible to increase the assembling accuracy of the layer thickness regulating member and to simplify the assembling process.

According to a fifth aspect of the present invention, the above object is achieved by an image forming apparatus (1) including the developing device according to any one of the first to fourth aspects.

According to the present invention, by providing the image forming apparatus with the developing device according to claims 1 to 4, the invention of the developing device according to each claim can be applied to the image forming apparatus.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments shown in the drawings. FIG. 1 is a schematic sectional side view of a developing device to which the present invention is applied and a laser beam printer as an image forming apparatus provided with the developing device. The laser beam printer 1 includes a feeder unit 10 for feeding a sheet P on the bottom of the main body case 2. The feeder unit 10 includes a paper pressing plate 11 pressed by a compression spring (not shown) and a paper feed roller 13, and holds the paper P between the paper pressing plate 11 and the paper feed roller 13 at a predetermined timing. The top sheet P is supplied.

A pair of registration rollers 14 and 1 are located downstream of the paper feed roller 13 in the transport direction indicated by arrow A.
5 is rotatably supported, and conveys the sheet P to a transfer position formed by the photosensitive drum 20 and the transfer roller 60 at a predetermined timing.

Photosensitive drum 20 as electrostatic latent image carrier
Is driven to rotate in the direction of arrow B by a driving unit (not shown). The charger 30 includes a scorotron charger having a corona discharge electrode of a tungsten wire and a bleed electrode.

The laser scanner unit 40 includes a laser generator (not shown) that generates a laser beam L for forming an electrostatic latent image on the photosensitive drum 20, and a polygon mirror (pentahedral mirror) 41 that is driven to rotate. , A pair of lenses 42 and 4
3 and a pair of reflecting mirrors 44 and 45.

The developing device 50 has a toner accommodating chamber 53 in a housing 51. In the toner accommodating chamber 53, an agitator 54 and a positively chargeable non-magnetic 1
A polymer toner 55 as a component developer is stored. A developing chamber 56 for performing development is formed on the photosensitive drum 20 side of the toner storage chamber 53, and a supply roller 57 and a developing roller 58 as a developer carrier are rotatably supported. The toner 55 on the developing roller 58 is regulated to a predetermined layer thickness by a layer thickness regulating member 59 whose leading end is pressed by the developing roller 58, and is used for development.

The transfer roller 60 is rotatably supported,
It is made of a conductive foamed elastic body made of silicone rubber or urethane rubber. This transfer roller 60
Is configured to reliably transfer the toner image on the photosensitive drum 20 to the paper P by the applied voltage.

The fixing unit 70 is provided downstream of the photosensitive drum 20 in the transport direction of the sheet P indicated by an arrow A,
A heating roller 71 and a pressing roller 72 are provided. The toner image transferred to the sheet P is pressed while being heated and fixed on the sheet P.

A pair of paper transport rollers 73 and a paper discharge roller 74 are provided on the downstream side in the transport direction of the fixing unit 70, and a paper discharge tray 75 is provided on the downstream side of the paper discharge roller 74. ing.

In the laser beam printer 1 of the present embodiment as described above, the surface of the photosensitive drum 20 is
When the laser beam L modulated according to image information is emitted from the laser scanner unit 40, an electrostatic latent image is formed on the surface of the photosensitive drum 20.
The electrostatic latent image is visualized by the developing device 50 with the toner 55, and the visible image formed on the photosensitive drum 20 is transported by the photosensitive drum 20 to a transfer position. At the transfer position, the paper P is supplied via the feeder unit 10 and the registration rollers 14 and 15, and the visible image is transferred to the paper P by a transfer bias applied to the transfer roller 60.

Next, the sheet P is conveyed to the fixing unit 70, and is nipped and conveyed by the heating roller 71 and the pressing roller 72 of the fixing unit 70. The visible image on the sheet P is pressurized and heated. Is established. Then, the sheet P is discharged to the discharge tray 75 above the laser beam printer 1 by the pair of transport rollers 73 and the discharge rollers 74, and the image forming operation is completed.

FIG. 2 is an enlarged view of the developing device 50 of the laser beam printer 1 shown in FIG. A layer thickness regulating member 59 is screwed to the housing 51 of the developing device 50 via attachment portions 81c provided at both ends in the longitudinal direction. The layer thickness regulating member 59 includes a holder 81 having a substantially “L” -shaped cross section, and a leaf spring 79 attached to the holder 81. The leaf spring 79 is attached to the holder 81 on the downstream side in the rotation direction of the developing roller 58. On the other hand, the upstream side in the rotation direction is a free end and is in contact with the developing roller 58, thereby forming a so-called “counter contact”. Leaf spring 7
9 is mounted on the holder 81 with its tip deflected slightly toward the roller center from the surface of the developing roller 58.
A sliding member 80 is attached to the tip of the leaf spring 79 and is in contact with the surface of the developing roller 58. Therefore, the sliding member 80 always presses the surface of the developing roller 58 by the elasticity of the leaf spring. Further, a sponge 82 for preventing toner leakage extending in the longitudinal direction is provided between the housing 51 and the layer thickness regulating member 59.

The leaf spring 79 is attached to the holder 81 by bonding. FIG. 3 is a diagram showing these bonding methods. In FIG. 3, an adhesive is applied to the holder back surface 81b, and the leaf spring surface 79a and the holder back surface 8 are applied.
1b. At both ends in the longitudinal direction of the holder 81, mounting portions 81c are provided, whereby the holder 81 is screwed and fixed to the housing 51 on the same surface as the bonding surface of the leaf spring 79. Further, a sponge 82 is fixed between the holder 81 and the housing 51 with a double-sided tape on both the housing 51 and the holder 81. Therefore, by applying an adhesive to the back surface 81b of the holder 81 and bonding the leaf spring 79, the process can be omitted, and the mounting accuracy can be reduced by screwing the holder 81 to the housing 51. Can be improved. With this configuration, the leaf spring 79 and the holder 81 are integrally bonded, and there is no space between them, so that leakage of the polymerization toner can be completely prevented.

FIG. 4 is a sectional view of a developing device 50m according to a second embodiment of the present invention. The leaf spring 79 is sandwiched between the holder 81 and the auxiliary member 83, and both surfaces thereof are adhered. That is, the surface 79 of the leaf spring 79
a is bonded to the back surface 81b of the holder 81, and the back surface 79b of the leaf spring 79 is bonded to the front surface 83a of the auxiliary member 83. In addition, since the space between them is completely sealed with an adhesive, there is no room for the polymerized toner to leak out of the gap in this embodiment. Further, in this embodiment,
Since the leaf spring 79 is bonded so as to be sandwiched between the holder 81 and the auxiliary member 83, higher bonding strength can be obtained.

For these embodiments, for example, FIG.
In the same developing device, the leaf spring 79 and the auxiliary member 83 are attached to the holder 81 by a screw 85 as shown in FIG.
As shown in FIG. 7, a plurality of screw holes 79 h, 79 h are formed in the leaf spring 79, the holder 81 and the auxiliary member 83.
, 81h, 81h, ..., 83h, 83
.. must be provided, and it is conceivable that the polymerized toner having high fluidity leaks from the gap between these and the screw 85.

The toner used in the embodiment of the present invention is a polymerized toner 55 produced by a polymerization method.
The polymerized toner 55 has excellent fluidity and also functions as a solid lubricant, and reduces the coefficient of friction. Therefore, the frictional force between the developing roller 58 and the sliding member 80 can be reduced. Further, the shearing force applied to the bonding portion between the plate spring 79 of the layer thickness regulating member 59 serving as the “counter pad” and the holder 81 can be reduced. Therefore, even if the strength is somewhat weak, the adhesive portion does not peel off. When the layer thickness of the polymerized toner is regulated, the layer thickness can be regulated by weakening the pressing force of the layer thickness regulating member. Therefore, the amount of deformation of the leaf spring 79 can be reduced, and the stress applied to the adhesive can be reduced.
This is also advantageous for peeling of the adhesive part. The developing roller 58 has a configuration in which a conductive elastic body is provided on a metal shaft. As the conductive elastic body, one obtained by dispersing conductive fine particles such as carbon in urethane rubber, silicon rubber, or the like is used. Can be More preferably, a coating layer is provided on the conductive elastic body to reduce the coefficient of friction.

In order to realize the elastic force of the leaf spring 79 as thin as possible, the material is selected from materials such as high nickel stainless steel such as 42 alloy or phosphor bronze which are used for IC lead frames. It is desirable to use. It is recommended that the plate thickness be about 0.1 mm.

As the sliding member 80, a member obtained by integrally molding silicone rubber can be used. The sliding member 80 made of silicone rubber has a cross-sectional shape of a plate having a thickness of about 2 mm, and a so-called “belly contact contact” which is brought into contact with the developing roller 58 using a portion other than the edge as shown in FIG. Contact ".

It is desirable to use an epoxy resin adhesive from the viewpoint of keeping the adhesive strength high.

[0034]

As described above, even if polymerized toner having a high fluidity is used as the toner, since the holder and the leaf spring are adhered with the adhesive, there is room for a gap between the two. And leakage of the polymerized toner can be completely prevented. Also, the pressing force of the layer thickness regulating member is generated by the leaf spring, and the leaf spring has no set, so that it can be stably pressed. Furthermore, fixing by adhesion may cause problems such as insufficient strength as compared with the case of screws, but the toner used is a polymerized toner obtained by a polymerization method, so that it has excellent fluidity and solidity. Since it also functions as a lubricant, the frictional force between the developing roller and the layer thickness regulating member can be reduced. Therefore, even if the strength is somewhat weak, the adhesive portion does not peel off. When the layer thickness of the polymerized toner is regulated, the layer thickness can be regulated by weakening the pressing force of the layer thickness regulating member. Therefore, the amount of deformation of the leaf spring can be reduced, and the stress applied to the adhesive can be reduced. This is advantageous for peeling of the adhesive part.

Further, the frictional force between the developer carrying member and the layer thickness regulating member is exerted in the direction of pressing the layer thickness regulating member against the developer carrying member by "counter contact", which is advantageous for regulating the layer thickness. It can be configured. Further, since the polymerized toner having excellent fluidity acts as a solid lubricant between the layer thickness regulating member and the developer carrying member to reduce the frictional force, it is possible to prevent the adhesive portion from peeling off.

Further, since the portion where the layer thickness regulating member slides while pressing the developer carrying member is a member having rubber elasticity,
Since the deformation is caused by the pressing, when the elastic body is used as the developer carrier, the deformation of the developer carrier can be reduced. Therefore, it is possible to reduce the stress applied to the bonding portion of the layer pressure regulating member when the developer carrier rotates. Further, since the developer is not pressed with an excessive force, the deterioration of the developer is small, and good development can be performed for a long period of time.

The holder is formed of a bent plate, and the bent plate can easily maintain rigidity, so that a uniform pressing force can be applied to the surface of the developer carrier. In addition, by making the mounting surface of the holder to the housing and the bonding surface of the leaf spring the same surface, it is possible to increase the assembly accuracy of the layer thickness regulating member and to simplify the assembly process.

Further, by providing the above-described developing device in the image forming apparatus, the invention of the above developing device can be applied to the image forming apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic sectional side view of a laser beam printer.

FIG. 2 is a sectional view of a developing device.

FIG. 3 is a view showing adhesion of a sponge for preventing leakage, a holder, and a leaf spring.

FIG. 4 is a sectional view of a developing device according to a second embodiment.

FIG. 5 is a diagram showing adhesion between a sponge for preventing leakage, an auxiliary member, a holder, and a leaf spring of the developing device according to the second embodiment.

FIG. 6 is a sectional view of a developing device in which a leaf spring is attached to a holder with a screw.

FIG. 7 is a diagram showing attachment of a leaf spring to a holder with screws.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus (laser beam printer) 20 Photosensitive drum (electrostatic latent image carrier) 50 Developing device 55 Polymerized toner 58 Developing roller (developer carrier) 59 Layer thickness regulating member 79 Leaf spring 80 Sliding member 81 Holder

Claims (5)

[Claims] An image forming apparatus according to claim 1, wherein a thin layer of the toner formed on the developer carrier by the layer thickness regulating member is opposed to the electrostatic latent image carrier, so that the developer by the toner is formed on the electrostatic latent image carrier. In a developing device for forming an image, the developing device includes the developer carrier and the layer thickness regulating member, wherein the toner is a polymerization toner generated by a polymerization method, and the layer thickness regulation is performed. The member includes a leaf spring that generates a pressing force on the developer carrier, and a holder that holds the leaf spring and has rigidity, and that the holder and the leaf spring are bonded with an adhesive. The developing device according to any one of the preceding claims. 2. The layer thickness regulating member according to claim 1, wherein a downstream side in the rotation direction of the developer carrier is bonded to the holder, and an upstream side in the rotation direction is a free end to press the developer carrier. The developing device according to claim 1, wherein: 3. A sliding member is provided at a free end of the leaf spring that presses the developer carrier, and the sliding member is formed of a rubber elastic body. 3. The developing device according to 2. 4. The holder is formed of a bent plate and attached to a housing of the developing device, and a mounting surface of the holder to the housing is flush with an adhesive surface of the leaf spring. 4. The method according to claim 1, wherein
The developing device according to any one of the above. 5. An image forming apparatus comprising the developing device according to claim 1.