JP3232499B2 - Electrostatic latent image developing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing apparatus used for developing an electrostatic latent image into a toner image in an image forming machine such as an electrostatic copying machine or a laser printer. A developing roller that holds the developer on the peripheral surface and conveys the developer to a development area, and a developer regulating unit that acts on the peripheral surface of the developing roller and regulates the amount of developer retained on the surface; The present invention relates to a latent image developing device.

[0002]

2. Description of the Related Art In order to develop an electrostatic latent image into a toner image in an image generator, as is well known, an electrostatic latent image developing device having a developing roller which is driven to rotate in a predetermined direction is widely used. Has been provided. The developing roller is sequentially driven in a developer holding area, a developer amount regulating area, and a developing area by being rotationally driven in a predetermined direction. In the developer holding area, toner as a developer supplied in an appropriate manner is held on the peripheral surface of the developing roller.
In the developer amount regulation region, the developer regulation means acts on the toner as the developer retained on the peripheral surface of the developing roller, and regulates the toner retained on the peripheral surface of the developing roller to a required amount. . In the development area, toner as a developer is applied to the peripheral surface of an electrostatic latent image carrier such as a rotating drum having an electrophotographic photosensitive layer on the peripheral surface, and is formed on the surface of the electrostatic latent image carrier. The developed electrostatic latent image is developed into a toner image. In order to perform good development, the amount of toner held on the peripheral surface of the developing roller is appropriately regulated by a developer regulating unit so that the toner layer held on the peripheral surface of the developing roller has a predetermined thickness. It is important that they be formed uniformly and axially sufficiently.

[0003] Japanese Patent Publication No. 63-16736 discloses an electrostatic latent image developing apparatus provided with a regulating means in which a blade is constituted by a rubber elastic body made of synthetic rubber such as urethane rubber or silicon rubber. The rubber elastic body constituting the developer regulating means has one surface or leading edge pressed against the peripheral surface of the developing roller, regulates the amount of toner held on the peripheral surface of the developing roller to a relatively small amount, and regulates the periphery of the developing roller. A thin layer of toner is formed on the surface. In addition, a blade of the developer regulating means made of a stainless steel thin plate for a spring having a thickness of 0.1 to 0.2 mm has been put to practical use. On the other hand, an electrostatic latent image developing apparatus provided with a developer regulating means in which a blade is formed of a rigid member such as glass is disclosed in
No. 6277 discloses this.

[0004]

The thickness of the toner layer formed on the peripheral surface of the developing roller and the stability of the toner layer are determined by the contact between the blade constituting the developer regulating means and the peripheral surface of the developing roller. It is greatly affected by the amount of protrusion from the center to the lower end. Therefore, it is important to accurately configure the protrusion amount of the blade. However, since the developing roller and the blade are mounted on the developing housing via a bearing and a support member, their respective tolerances are accumulated, so that in the assembled state, the amount of protrusion of the blade considerably varies. Occurs. In order to make this variation in a range that does not affect the thickness of the toner layer formed on the peripheral surface of the developing roller, the production accuracy of each part is improved, or the amount of protrusion of the blade is adjusted during or after assembly. In any case, the production cost is greatly increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and its main technical problem is to eliminate the influence of an assembly error to a developing housing by unitizing a developing roller and a developer regulating unit. An object of the present invention is to provide an electrostatic latent image developing device capable of easily managing the protruding amount of the blade.

[0006]

In order to solve the above main technical problems, according to the present invention, a developing housing,
A developing roller disposed in the developing housing, for holding the developer on a peripheral surface in a developer holding area, and for transporting the held developer to the developing area to apply it to an electrostatic latent image; And a developer regulating means for regulating the amount of developer held on the peripheral surface of the developing roller in a developer regulating area located between the developing area and the developing area,
The developer regulating means includes a blade having one surface pressed against the peripheral surface of the developing roller, a support plate mounted on the blade and provided with positioning means at both ends, and a support holder for holding the support plate. And a pair of bearing support members each having an inner surface provided with a bearing for rotatably supporting both ends of the developing roller and a positioning means for engaging with the positioning means, respectively. Attached to the pair of bearing support members,
The developing roller is fixed by fixing the support plate to the support holder after positioning the positioning means provided on both side ends of the support plate by engaging the positioning means provided on the pair of bearing support members. Wherein the developer regulating means and the pair of bearing support members are unitized, and the unit is mounted on the developing housing.

[0007]

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an electrostatic latent image developing device constituted according to the present invention will be described below in more detail with reference to the accompanying drawings.

FIG. 1 shows an image forming machine equipped with an electrostatic latent image developing device constructed according to the present invention. The illustrated image forming apparatus includes a rotating drum 2 having an electrostatic photosensitive member as an image carrier disposed on a peripheral surface. The rotating drum 2 is rotatably mounted on a body housing (not shown) by a rotating shaft 21. Around the rotating drum 2 rotated in the direction indicated by the arrow 22, a charging corona discharger 4 for charging the photosensitive layer of the rotating drum 2 to a specific polarity sequentially in the rotation direction, the charging corona discharger A laser optical device 6 as an exposure means for forming an electrostatic latent image on the photosensitive layer of the rotary drum 2 charged to a specific polarity by the laser device 2, and an electrostatic latent image formed by laser light emitted from the optical device 6. An electrostatic latent image developing device 8, which develops into a toner image, a transfer roller 10, a cleaning device 14, and a static elimination lamp 16 are provided.

The electrostatic latent image developing device 8 includes a developing housing 30 which can be formed of a synthetic resin.
A replenishing roller 50, a stirring means 60 and a developer regulating means 70 are provided. Further, a toner cartridge 100 as a developer container is mounted on the developing housing 30.

The developing housing 30 is formed of a synthetic resin, and has a bottom wall 31 and both side walls 32 and 33.
(See FIG. 2) and an upper wall 34.
5 and a stirring chamber 36. Further, the developing housing 3
0 is provided with an opening 37 formed between the bottom wall 31 and the upper wall 34 at the upper right end in the figure.
The toner cartridge 100 is mounted in seven parts. An opening 38 is also provided at the left end of the developing housing 30 in the drawing, that is, at the end facing the rotating drum 2.

The developing roller 40 is connected to the developing housing 3.
0 in the developing chamber 31 and the developing housing 3
0 includes a rotating shaft 41 rotatably mounted between both side walls (not shown), and a solid synthetic rubber roller 42 fixed to the outer peripheral surface of the rotating shaft 41. The rotating shaft 41 can be formed from an appropriate metal material such as stainless steel. The solid synthetic rubber roller 42 is made of a relatively flexible and conductive material, for example, a conductive solid synthetic rubber such as urethane rubber. In the illustrated embodiment, the surface roughness of the peripheral surface of the solid synthetic rubber roller 42, ie, J
Ten point average roughness Rz specified in IS B 0601
Is set to 5.0 to 12.0. The volume resistance of the solid synthetic rubber roller 42 is set to about 10 ⁶ to 10 ⁹ Ω · cm. The developing roller 40 including the rotating shaft 41 formed of the metal material and the solid synthetic rubber roller 42 fixed to the outer peripheral surface of the rotating shaft 41 has, for example, an outer diameter of the rotating shaft 41 of 8 to 10. The outer diameter of the solid synthetic rubber roller 42 is 10 mm and 16 mm. Therefore, when the rotating shaft 41 has an outer diameter of 8 mm, the radial thickness of the solid synthetic rubber roller 42 is 4 mm, and when the rotating shaft 41 has an outer diameter of 10 mm, the radial thickness of the solid synthetic rubber roller 42 is 3 mm. Becomes a solid synthetic rubber roller 4
If the rubbers having the same hardness are used,
The roller hardness of the developing roller assembly changes. That is, the roller hardness of the developing roller using the rotating shaft having the outer diameter of 8 mm is lower than the roller hardness of the developing roller using the rotating shaft having the outer diameter of 10 mm. In the illustrated embodiment, the roller hardness of the developing roller assembly including the rotating shaft 41 and the solid synthetic rubber roller 42 fixed to the outer peripheral surface of the rotating shaft 41 is set to 60 to 80 in Asker C hardness. ing. The developing roller 40 thus configured
The roller 42 is exposed through an opening formed in the developing housing 30 and is positioned to face the rotating drum 2. The peripheral surface of the roller 42 constituting the developing roller 40 is pressed against the peripheral surface of the rotary drum 2, and the peripheral surface of the roller 42 is slightly elastically compressed in the pressure contact region. The rotating shaft 41 of the developing roller 40 is continuously driven to rotate in a direction indicated by an arrow 401 in FIG. Rotary axis 4
Due to the above rotation of the roller 1, the roller 42 is also continuously driven to rotate in the direction indicated by the arrow 401, and the peripheral surface of the roller 42 has the developer holding area 402, the developer regulating area 403, and the developing area 4
04 is sequentially moved. In the illustrated embodiment, a constant voltage of 300 V is applied to the rotating shaft 41 of the developing roller 40. The developing roller 40 is rotatably supported at both ends of the rotating shaft 41 by bearing support members 80, 80, and is unitized with a developer regulating unit 70 described later so as to be mounted on the developing housing 30. Is configured. The developing roller 40 and the developer regulating unit 70
The unitization with the bearing support members 80, 80 will be described later in detail.

The replenishing roller 50 is disposed in the developing chamber 32 of the developing housing 30 in parallel with the developing roller 40, and both side walls 32 and 33 of the developing housing 30 are provided.
A rotating shaft 51 rotatably mounted between the rotating shaft 51 and the rotating shaft 5
1 and a roller 52 fixed to the outer peripheral surface. The rotating shaft 51 can be formed of an appropriate metal material such as stainless steel, similarly to the rotating shaft 41 of the developing roller 40. The roller 52 is made of foam such as foamed silicone or foamed urethane. The roller 52 is pressed against the roller 42 of the developing roller 40. The hardness of the foam forming the roller 52 is the same as that of the roller 4 of the developing roller 40.
Considerably smaller than the hardness of 2 (for example, 3 in Asker C hardness).
5), and the roller 52 is pressed against the roller 42 of the developing roller 40 so that the roller 52
Is desirably elastically compressed by about 0.1 to 0.6 mm. The roller 52 also has conductivity,
The volume resistance is set to about 10 ⁶ to 10 ⁹ Ω · cm. The roller 52 is continuously driven to rotate in a direction indicated by an arrow 501 in FIG. 1 by driving means (not shown). In the illustrated embodiment, a constant voltage of 450 V higher than the voltage applied to the developing roller 40 is applied to the rotating shaft 51 of the developing roller 50.

The agitating means 60 is disposed in the agitating chamber 32 of the developing housing 30 in parallel with the replenishing roller 52. Both side walls (not shown) of the developing housing 30 are provided.
A rotating shaft 61 rotatably mounted between the rotating shaft 61 and the rotating shaft 6
1 and a stirring sheet member 63 having elasticity attached to the stirring member 62.
The stirring member 62 is formed of a synthetic resin, and has a plurality of openings in the width direction. Agitation sheet member 63
Is formed of, for example, polyethylene terephthalate (PETP) resin, has an opening at one end corresponding to the opening provided in the stirring member 62, and is fixed to the stirring member 62 with an adhesive or the like. The other end of the stirring sheet member 63 is configured to protrude from the stirring member 62. The stirring means 60 configured as described above
Is continuously rotated in a direction indicated by an arrow 601 in FIG. 1 by a driving unit (not shown).

The developer regulating means 70 has a flexible blade 71 which is pressed against the peripheral surface of the roller 42 constituting the developing roller 40, and has a flexibility constituting a supporting means of the blade 71. A support plate 72;
An elastic urging means 73 for pressing one side of the blade 71 in a direction of pressing against the peripheral surface of the roller 42;
1, a support plate 76 and a support holder 76 for holding the elastic urging means 73.

The support holder 76 is formed by, for example, extruding an aluminum alloy. The support holder 76 has a length in the width direction corresponding to between the side walls 32 and 33 of the developing housing 30, and includes an upper wall 761 on which an upper end of the support plate 72 is mounted, and an upper wall 7.
61 and a rear wall 763 connecting the rear ends of the upper wall 761 and the lower wall 762 to each other.
It consists of A guide rail 764 projecting inward and extending in the entire width direction is provided at an intermediate portion of the upper wall 761, and the guide rail 764 of the upper wall 761 and the rear wall 763 are provided.
A plurality of (three in the illustrated embodiment) pin insertion holes 765 are provided between the two. A guide groove 766 extending from the rear wall 763 to the position corresponding to the guide rail 764 is formed in the lower wall 762 so as to extend in the entire width direction.
A plurality of (five in the illustrated embodiment) screw holes 767 (see FIG. 3) are provided on the front end surface of the upper wall 761. The support holder 76 thus configured is equipped with a blade 71, a support plate 72, and an elastic urging means 73, which will be described later, by attaching the
Is configured as a unit with the developing roller 40 and is mounted on the developing housing 30. The unitization of the developing roller 40 and the developer regulating unit 70 will be described later in detail.

The flexible blade 71 has a length in the width direction corresponding to the length of the roller 42 constituting the developing roller 40, and has at least one surface thereof (that is, the roller 42 constituting the developing roller 40). Surface pressed against the peripheral surface)
Is a plate-like member that is a plane extending in the width direction (the direction perpendicular to the paper surface in FIG. 1) along the peripheral surface of the roller 42. The surface roughness of at least a region of the one surface of the blade 71 pressed against the peripheral surface of the roller 42 is sufficiently small, and the ten-point average roughness Rz specified in JIS B0601 is 5.0 to 12.0. Is preferred. If the surface roughness of the one surface of the blade 71 is excessive, the surface of the toner layer formed on the peripheral surface of the roller 42 constituting the developing roller 40 is not sufficiently flattened and tends to be uneven. There is. Therefore, blade 7
As a suitable material having a sufficiently small surface roughness and a high hardness and abrasion resistance despite being relatively inexpensive as 1, commercially available plate glass can be mentioned. . Sheet glass thickness is 0.5 ~
Those having a size of about 2.0 mm can be used. According to experiments by the present inventors, when the thickness of the glass sheet constituting the blade 71 is smaller than 0.5 mm, the glass sheet may be broken during operation, and the thickness of the glass sheet is greater than 2.0 mm. It was found that the use of a material did not provide the desired flexibility. When it is desired to apply a required voltage to the blade 71 for controlling the charging characteristics of the toner, a conductive coating can be applied to one surface of the plate glass.
The blade 71 may be formed of a metal plate having appropriate flexibility such as stainless steel instead of the plate glass. In order to sufficiently reduce the surface roughness of one side of the metal plate constituting the blade 71, an appropriate surface treatment can be performed on one side of the metal plate as needed.

In the illustrated embodiment, the support plate 72 is made of a leaf spring material such as a thin leaf steel plate or a thin stainless steel plate, and has substantially the same length in the width direction as the blade 71. Since the support plate 72 is required to have flexibility, it is preferable to use a steel plate having a thickness of about 0.1 mm. This support plate 7
As shown in FIG. 3, a plurality (five in the illustrated embodiment) of elliptical holes 721 are provided at an upper end portion at predetermined intervals in the width direction. This oval hole 72
Numerals 1 are formed corresponding to a plurality (five in the illustrated embodiment) of screw holes 767 provided on the front end surface of the upper wall 761 of the support holder 76. Notched grooves 722, 722 for positioning are formed at both ends at the upper end of the support plate 72 as positioning means. The support plate 72 thus configured has its lower end surface fixed to the other surface of the blade 71 by a fixing means such as an adhesive. If it is desired to apply a required voltage to the blade 71 for controlling the charging characteristics of the toner, the conductive adhesive is used as the fixing means, so that the blade 71
Required voltage can be applied. As described above, the support plate 72 fixed to the other surface of the blade 71 has the upper end portion thereof inserted into the front end surface of the upper wall 761 constituting the support holder 76 through the backing plate 77 and the hole 721 so that the screw hole 767 is formed. Are fixedly supported by screws 78 screwed into the screw.

The pressing member 74 has substantially the same length in the width direction as the blade 71, is formed in a hat shape in cross section with an open rear end, and has a front wall 741 facing the support plate 72. , Upper wall 742, lower wall 743, upper wall 7
42 and guide support portions 744 and 745 extending vertically from the rear ends of the lower wall 743, respectively. On the front surface of the upper wall 742, a ridge 746 forming a pressing portion over the entire width direction is provided at an intermediate portion in the vertical direction.
Between the upper wall 742 and the lower wall 743, a plurality (six in the illustrated embodiment) of spring fitting chambers 749 formed by the partition walls 747 and 748 at equal intervals in the width direction are provided. A compression coil spring 731, which will be described later and constitutes the elastic urging means 73, is fitted in each of them.
The pressing member 74 thus configured is integrally formed of, for example, a synthetic resin material. It is important that the pressing member 74 has flexibility.

The elastic biasing means 73 is composed of a plurality of (six in the illustrated embodiment) compression coil springs 731, one end of which is provided in a plurality of spring fitting chambers 749 formed in the pressing member 74. Each part is fitted, and the other end is brought into contact with the front surface of the rear wall 763 that constitutes the support holder 76. With this configuration, the pressing member 74
The pressing force of the plurality of compression coil springs 731 arranged at regular intervals in the width direction of the
Acting on the blade 71 via the second roller 2, one surface of the blade 71 is pressed against the surface of the roller 42 constituting the developing roller. At this time, since the pressing member 74, the support plate 72, and the blade 71 have flexibility, one side of the blade 71 is The surface is pressed uniformly over the entire width. Further, since the support plate 72 mounted on the blade 71 is pressed by the ridge 746 formed on the front surface of the front wall 741 constituting the pressing member 74, the contact area thereof is small, so that the support plate 72 is stable in the entire width direction. And a uniform pressing force is applied. The pressing force of the blade 72 against the peripheral surface of the roller 42 constituting the developing roller 40 can be appropriately set according to the thickness of the developer layer to be formed on the peripheral surface of the roller 42. As the pressing force increases, the thickness of the developer layer formed on the peripheral surface of the roller 42 decreases. On the other hand, if the pressing force is excessively large, the smooth rotation of the roller 42 tends to be hindered. In the developing mode in the illustrated embodiment, the thickness of the toner layer formed on the peripheral surface of the roller 42 is generally about 20 to 35 μm. In order to appropriately form the developer layer having such a thickness, The blade 71 may be pressed against the peripheral surface of the roller 42 at a linear pressure (pressure per unit length in the width direction) of 4.0 to 12.0 g / mm.

The developer regulating means 70 has a pressure releasing means 79 for releasing the pressing force of the elastic urging means 73 on the support plate 72 and the blade 71 (see FIG. 5). The pressure releasing means 79 includes three stopper pins 791 in the illustrated embodiment. At the time of assembling the developer regulating means 70, the three stopper pins 791 are provided with a guide rail 764 provided on an upper wall 761 constituting the support holder 76 and a rear wall 7 as shown in FIG.
The guide support portions 76 inserted into the three pin insertion holes 765 formed between the guide support portions 76 and 63 respectively.
The pressing force of the elastic urging means 73 acting on the front surface of the support plate 72 and acting on the rear surface of the support plate 72 is released. After assembling the developer regulating means 70 to a predetermined portion of the developing device 8, the three stopper pins 791 are connected to the pin insertion holes 7.
By extracting the support plate 72 from the support plate 72, the pressing force of the compression coil spring 751 acts on the back surface of the support plate 72 as shown in FIG.

Next, the procedure for assembling the developer regulating means 70 will be described. When assembling the developer regulating means 70, as shown in FIG. 5, first, one end of the compression coil spring 731 is fitted into the spring fitting chamber 749 of the pressing member 74, and the support holder is compressed while compressing the compression coil spring 731. Insert from one end of 76 toward the other end of holder 76. At this time,
The upper guide support portion 744 of the pressing member 74 is positioned between the rear wall 463 and the guide rail 764, and the lower guide support portion 745 is positioned in the guide groove 766 to constitute the elastic urging means 73. The support holder 76 can be inserted into a predetermined position. In this way, when the elastic urging means 73 is mounted on the support holder 76, the front wall 741 of the pressing member 74 is pushed toward the rear wall 763 against the force of the compression coil spring 731. The guide support portion 744 is located between the pin insertion hole 765 and the rear wall 763.
By inserting the stopper pin 79 into the pin insertion hole 765 as shown in FIG.
The stopper pin 79 acts on the front surface of the guide support portion 764 constituting the pressing member 74 to regulate the forward movement of the pressing member 74, and reduces the pressing force of the compression coil spring 731 acting on the rear surface of the support plate 72. To release. In this way, the developer regulating means 70 assembled in a state where the pressing force is released is unitized with the developing roller 40, and
It is mounted on the developing housing 30.

Next, the unitization of the developing roller 40 and the developer regulating means 70 will be described with reference to FIG. In order to unitize the developing roller 40 and the developer regulating means 70, in the present invention, two bearing support members 8 are provided.
0 and 80 are provided. The bearing support members 80, 80
, Bearings 81, 81 such as ball bearings, which rotatably support the rotating shaft 41 of the developing roller 40, are respectively mounted. On the inner surfaces of the bearing support members 80, 80, seal mounting portions 82, 82 are respectively provided from a part around the bearings 81, 81, that is, from the downstream side of the developing area 404 to the upstream side of the developer regulating area 403. The rollers 42 constituting the developing roller 40 are attached to the seal mounting portions 82, 82.
Seals 90, 90 are respectively provided at both ends of the. The seals 90, 90 mounted on the seal mounting portions 82, 82 are respectively provided with a seal main body 91 and a developer regulating area 40 on the upper surface of the seal main body 91 from the developing area 404 side.
Seal lip 9 formed to be inclined inward toward the third side
2 and an outer side wall 93 formed upright at the outer end of the seal body 91. With the rotating shaft 41 of the developing roller 40 mounted on the bearings 81, 81, both ends of the roller 42 are positioned by slightly compressing the seal lips 92, 92 of the seals 90, 90. Therefore, the developing roller 4
When 0 rotates, the developer accumulated on the seal bodies 90, 90 inside the seal lips 92, 92, respectively, is transported to the developer regulating area 403 side while being guided inward by the seal lips 92, 92. The bearing support members 80, 80
Positioning projections 83, 83 as positioning means for engaging the positioning notches 722, 722 formed in the support plate 72 are provided on the upper inner side surface of the support plate 72, respectively. In addition, three screw insertion holes 84, 85, 86 are provided in the upper part of the bearing support members 80, 80, respectively, and one screw hole 87 is provided in the lower part.
On the other hand, the support holder 7 constituting the developer regulating means 70
6, three screw holes 768a, 768b, 7
68c are provided respectively. The bearing support member 8
0 and 80, the replenishing rollers 5 mounted on the developing housing 30 when the developing roller 30 is mounted on the developing housing 30.
0 to prevent interference with the rotary shaft 51
8 and 88 are provided, and the bearing 81
Support projections 89, 89 each having a hole through which the rotating shaft 41 is inserted are provided on the outer surface of the portion.

After the rotating shaft 41 of the developing roller 40 is inserted and mounted on the bearings 81, 81 on the two bearing support members 80, 80 constructed as described above, except for the support plate 72 and the blade 71, The support holder 76 of the developer regulating means 70 assembled as described above is mounted. For mounting the support holder 76, three screw holes 768a, 768b, 768c provided at both ends of the support holder 76 are respectively inserted into three screw insertion holes 84, 85, 86 formed in the bearing support members 80, 80. , And screws 841 are inserted into one screw insertion hole 84 from the outer surface side of the bearing support members 80, 80, and screw holes 7 provided in the support holder 76 are provided.
It is fixed by screwing to 68a. Then, FIG.
As shown in FIG. 7, positioning notches 72 formed at both ends of a support plate 72 fixed to the other surface of the blade 71.
2, 722 are engaged with positioning projections 83, 83 provided on the bearing support members 80, 80 and positioned, and the upper end thereof constitutes a support holder 76 as shown in FIG.
The fixing plate 77 and the hole 721 are inserted into the front end surface of the first fixing member 1 and fixed by screws 78 screwed into the screw holes 767. Thus, the developing roller 40 and the developer regulating unit 70
Is unitized by being attached to two bearing support members 80, 80. The support plate 72 fixed to the other surface of the blade 71 of the developer regulating unit 70 unitized with the developing roller 40 has notched grooves 722, 722 formed at both ends thereof for bearing support members 80, 80. Is positioned by engaging the positioning projections 83 provided on the bearing support member 8.
Bearings 81 and 81 and bearing support members 8 mounted on
By controlling the positional relationship between the positioning projections 83 formed at the positions 0 and 80, the amount of protrusion (S) from the center of contact of the blade 71 with the peripheral surface of the developing roller 40 to the lower end thereof
Can be assembled to a predetermined value. The protrusion amount (S) of the blade 71 is, for example, 0.5 to 2.0 mm.
Is set to If the protrusion amount (S) is shorter than 0.5 mm, the regulating action by the blade 71 tends to be excessive, and it becomes difficult to form a good developer layer. If the length is longer, the thickness of the formed developer layer tends to be excessive.

The unit of the developing roller 40 and the developer regulating means 70 assembled as described above is mounted on the developing housing 30 from the opening 38 side of the developing housing 30. At this time, the support projections 89, 89 provided on the outer surfaces of the bearing support members 80, 80 are provided with the notch recesses 3 formed on both side walls 32, 33 constituting the developing housing 30.
21 and 331. On the other hand, the notch recesses 88, 88 provided in the bearing support members 80, 80 are loosely fitted to the rotating shaft 51 of the supply roller 50 mounted on the developing housing 30. In this manner, the developing roller 40, the developer regulating means 70 and the bearing support member 80,
When the unit 80 and the unit 80 are positioned at predetermined positions in the developing housing 30, screws 851 and 851 are inserted into screw insertion holes 85 and 86 formed in the bearing support member 80 from outside the side walls 32 and 33 forming the developing housing 30. 8
61 and screw holes 768b and 76 formed at both ends of the support holder 76 constituting the developer regulating means 70.
8c, the support holder 76 and the bearing support members 80 and 80 are fastened and fixed to both side walls 32 and 33 constituting the developing housing 30. Further, screws 871 and 871 are screwed into screws 87 and 87 formed on the bearing support members 80 and 80 from outside the side walls 32 and 33 that constitute the developing housing 30, so that the bearing support members 80 and 80 are attached. The developing housing 30 is fixed to both side walls 32 and 33. When the unit of the developing roller 40 and the developer regulating unit 70 is mounted at a predetermined position of the developing housing 30 as described above, the stopper pin 79 is inserted into the pin insertion hole 765.
The pressing member 74 is allowed to move forward, that is, to the support plate 72 side, and the compression coil spring 73 is removed.
1, a ridge 746 provided on the front surface of the pressing member 74.
Is pressed against the back surface of the support plate 72. As described above, the developer regulating unit 70 according to the illustrated embodiment
Are assembled in a state where the pressing force acting on the back surface of the support plate 72 on which the blade 71 is mounted is released, so that the blade 71 does not damage the peripheral surface of the developing roller 40 when assembling to the developing housing 30. .

The electrostatic latent image developing device according to the illustrated embodiment is configured as described above, and its operation will be described below. When the operation of the electrostatic latent image developing device is started, the roller 42 of the developing roller 40, the roller 52 of the replenishing roller 50, and the stirring means 60 are each driven to rotate in the direction shown by the arrow by a driving means (not shown). The stirring means 60 is the arrow 6
By rotating in the direction indicated by 01, the developer contained in the stirring chamber 32 is supplied into the developing chamber 31 while being stirred. On the other hand, the used developer held on the peripheral surface of the roller 42 constituting the developing roller 40 and passing through the developing area 404 is transferred to the surface of the replenishing roller 50 at a contact portion between the developing roller 40 and the replenishing roller 50. Then, it is mixed with the developer fed by the stirring means 60 in the developing chamber 31. The developer mixed in the developing chamber 31 in this manner is supplied to the roller 5 made of a foam forming the supply roller 50.
2 and is conveyed toward the developing roller 40 while being held on the peripheral surface.

The developer held on the peripheral surface of the replenishing roller 50 and conveyed toward the developing roller 40 is supplied to the developer holding area 4.
At 02, the developer is supplied to and held on the peripheral surface of the roller 42 constituting the developing roller 40, and is conveyed toward the image agent regulating area 403. In the image material regulating area 403, the developer regulating means 7
The zero blade 71 acts on the developer held on the peripheral surface of the roller 42 of the developing roller 40 to regulate the developer held on the peripheral surface of the roller 42 to a required amount to form a thin layer. At this time, the blade 71, the support plate 72
Also, since the pressing member 74 has flexibility, even if the developing roller 40 has a slight axial deflection, one surface of the blade 71 is uniformly pressed against the surface of the roller 42 constituting the developing roller 40 over the entire width direction. I'm sullen.

Next, in the developing area 404, a developer is applied to the electrostatic latent image on the electrostatic photosensitive member disposed on the peripheral surface of the rotating drum 2 to convert the electrostatic latent image into a toner image. Developed. For example, an electrostatic latent image has a non-image area charged to about +600 V and an image area charged to about +120 V, and toner as a developer is attached to the image area (so-called reversal development). The rotating drum 2 is shown in FIG.
Is continuously driven to rotate in the direction indicated by the arrow 22,
Therefore, in the developing area 404, the peripheral surface of the rotating drum 2 and the peripheral surface of the roller 42 constituting the developing roller 40 are moved in the same direction. The moving speed V2 of the peripheral surface of the roller 42 is set to be somewhat higher than the moving speed V1 of the peripheral surface of the rotary drum 2, and 1.2V1 ≦ V2 ≦ 2.2V1
It is preferred that In this case, the developing roller 40
A sufficient amount of developer is conveyed to the developing area 404 by the roller 42, and the developer that has once adhered to the non-image portion of the electrostatic latent image due to the rubbing action of the peripheral surface of the roller 42 against the peripheral surface of the rotating drum 2 It is possible to obtain a good toner image which is appropriately peeled off and thus has an appropriate development density and is free from fog. As the developer, the volume average particle diameter (V
ol. 50%: the volume of the toner having a volume average particle diameter or less is equal to the volume of the toner having a volume average particle diameter or more) of 8.0 to 12.
A developer consisting of only a toner having a volume resistance of about 0 μm and a volume resistance of 10 ⁸ Ω · cm or more is preferably used.

[0029]

According to the present invention, there is provided an electrostatic latent image developing apparatus including a support holder for holding a blade in which developer regulating means is pressed against a peripheral surface of a developing roller, and having both ends of the support holder at both ends of the developing roller. The unit is mounted on a bearing support member mounted with a bearing that rotatably supports the unit, and a unit including the developing roller, the developer regulating unit and the bearing support member is configured to be mounted on the developing housing. By managing the positional relationship between the bearing and the support holder mounted on the blade, the amount of protrusion of the blade from the center of contact with the peripheral surface of the developing roller to the lower end can be assembled to a predetermined value.

According to the present invention, the blade is provided with a support plate, the support plate is provided with positioning means, and the bearing support member is provided with a positioning means for engaging with the positioning means. Since the means is provided, the positioning means provided on the support plate may be engaged with the positioning means provided on the bearing support member,
It is easy to manage the positional relationship between the developing roller and the plate.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of an image generator equipped with an electrostatic latent image developing device according to an embodiment configured according to the present invention.

FIG. 2 is a side view of a main part of the electrostatic latent image developing device shown in FIG.

FIG. 3 is an exploded perspective view of a developing roller, a developer regulating unit, and a bearing supporting member provided in the electrostatic latent image developing device shown in FIG.

FIG. 4 is an enlarged explanatory view showing a positional relationship between a developing roller provided in the electrostatic latent image developing device shown in FIG. 1 and a blade of developer regulating means.

5 is a fragmentary perspective view showing a part of a developer regulation unit provided in the electrostatic latent image developing device shown in FIG.

FIG. 6 is a cross-sectional view showing an assembled state of a developer regulating device provided in the electrostatic latent image developing device shown in FIG. 1;

[Explanation of symbols]

 2: rotating drum 4: charging corona discharger 6: laser optical device 8: electrostatic latent image developing device 10: transfer roller 14: cleaning device 16: static elimination lamp 30: developing housing 31: developing chamber 32: stirring chamber 40: Developing roller 50: Supply roller 60: Stirring means 70: Developer regulating means 71: Blade 72: Support plate 73: Elastic urging means 74: Pressing member 76: Support holder 80: Bearing support member 81: Bearing 82: Seal mounting part 83: Positioning projection (positioning means) 84: Screw insertion hole 85: Screw insertion hole 86: Screw insertion hole 87: Screw hole 88: Notch recess 89: Support projection 90: Seal 100: Toner cartridge 722: Notch groove for positioning (Positioning means)

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Aoki 1-2-28 Tamazo, Chuo-ku, Osaka City Inside Mita Kogyo Co., Ltd. (58) Investigated field (Int. Cl. ⁷ , DB name) G03G 15/08 G03G 15/00

Claims (1)

(57) [Claims] 1. A developing housing and an inside of the developing housing.
The developer is held on the peripheral surface in the developer holding area
Then, the held developer is transported to a development area and applied to an electrostatic latent image.
Between the developing roller and the developer holding area and the developing area.
Peripheral surface of the developing roller in the developer regulating region located at
Developer regulating means for regulating the amount of developer retained in the
In the electrostatic latent image developing device provided,One side of the developer regulating means is pressed against the peripheral surface of the developing roller.
Blades to be mounted and attached to the blades
And a support plate provided with a positioning means.
A support holder for holding the rate, A shaft for rotatably supporting both ends of the developing roller.
Receiving means and positioning means for engaging with the positioned means.
Each having a pair of bearing support members provided on the inner surface, Attach both ends of the support holder to the pair of bearing support members
And provided at both ends of the support plate.
Positioning means provided on the pair of bearing support members.
After engaging with the positioning means and positioning the support play,
Fixing the developing roller to the support holder,
The developer regulating means and the pair of bearing support members are united.
And attach the unit to the developing housing.
Configured in  An electrostatic latent image developing device, characterized in that: