JP3406806B2 - Developing device for electrophotographic equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for an electrophotographic apparatus.

[0002]

2. Description of the Related Art Some electrophotographic devices are capable of performing multicolor printing. An example of such electrophotographic device is shown in FIG.
4 is shown.

That is, in the electrophotographic apparatus shown in FIG. 14, light rays from a light source (not shown) are mirrored by the optical scanning system 1 composed of the polygon mirror 2, the lens system 3 and the like to the mirrors 4, 5, 6 and 7, 8. Through the photosensitive drums 9A, 9B
To the charger 16A of the photosensitive drums 9A and 9B,
At the downstream side of the 16B arrangement position, the photosensitive drum 9A,
The surface of 9B is irradiated so that an electrostatic latent image can be formed on the outer peripheral surfaces of the photosensitive drums 9A and 9B.

The outer peripheral surfaces of the photosensitive drums 9A and 9B are in contact with the outer peripheral surface of the intermediate transfer sheet 15 attached to the outer peripheral surface of the drum 14. Thus, the intermediate transfer sheet 15 is a resistor having a volume resistivity in the medium resistance region of 10 ¹⁰ to 10 ¹⁴ Ωcm, and is formed of a carbonate, polyimide, polyetheretherketone or the like having a thickness of about 150 μm.

The photosensitive drum 9A is additionally provided with a developing device 10A for developing black color and a developing device 10B for developing magenta color which are developing devices on the upstream side, and the photosensitive drum 9B is a developing device on the downstream side. A developing device 10C for cyan color developer and a developing device 10D for yellow color developer are additionally provided.

The developing devices 10A, 10B, 10C,
A cam 10D is rotatable via horizontal shafts 11A, 11B, 11C, and 11D, and is urged clockwise by means (not shown) and can be rotated forward and backward by a cam shaft drive mechanism (not shown). 12A, 12B, 12
The positions are regulated by C and 12D, respectively. Cam 12
Each of A, 12B, 12C and 12D has a circumferential surface and a flat surface continuous with the circumferential surface.

Thus, the cams 12A, 12B, 12C,
12D circumferential surface and developing devices 10A, 10B, 10C, 1
When the surface of the casing at 0D is in contact,
The developing rollers 13A, 13B, 13C, 13D and the photosensitive drums 9A, 9B are separated by the maximum distance, and the cams 12A, 12
B, 12C, 12D flat surface and developing device 10A, 10
When the surfaces of the casings B, 10C and 10D face each other, the developing rollers 13A, 13B, 13C,
13D and the photosensitive drums 9A and 9B are configured so as to come close to each other to a developable state.

Therefore, each time the photosensitive drums 9A, 9B rotate once, the developing rollers 13A, 13B, 13C, 13D of the developing devices 10A, 10B, 10C, 10D sequentially develop the photosensitive drums 9A, 9B one color at a time. , Coulomb force from the photosensitive drums 9A and 9B to the intermediate transfer sheet 15
Is transferred to.

When the transfer of one color is completed, the photosensitive drums 9A, 9B
After the residual developer is removed by the cleaning blades 17A and 17B, another color is developed on the photosensitive drums 9A and 9B.

Specifically, the black color is transferred from the photosensitive drum 9A to the intermediate transfer sheet 15, and then the intermediate transfer sheet 15 rotated to the position of the photosensitive drum 9B transfers the cyan color from the photosensitive drum 9B.

The photosensitive drum 9A on which the black color is transferred to the intermediate transfer sheet 15 is rotated to remove the residual developer by the cleaning blade 17A, and then the developing device 1 is used.
The magenta color is developed by 0B, and the magenta color is transferred to the intermediate transfer sheet 15.

Similarly, the photosensitive drum 9B on which the cyan color has been transferred to the intermediate transfer sheet 15 is rotated to remove the residual developer by the cleaning blade 17B, and then the developing device 10D develops yellow to intermediate transfer the yellow. Transfer to the sheet 15.

When the four color developers are transferred to the intermediate transfer sheet 15, the paper stored in the paper cassette (not shown) is conveyed between the intermediate transfer sheet 15 and the second transfer roller 18, and the intermediate transfer sheet 15 is transferred. A developer for forming each image is transferred from 15 to the paper, and the paper on which the developer is transferred is sent to a fixing unit to be fixed and then sent to the outside.

An example of the detailed structure of the developing device described above is shown in FIG.
2,13. The developing device 21 shown in FIGS. 12 and 13 includes a casing 22 and a magnet roller 2
3 and the developing rollers 13A, 13B, 13C, 1 of FIG.
A developing roller 24 corresponding to 3D, a blade 25, a mixer (not shown) for stirring the developer, and the like are provided.

The casing 22 is a plastic molded product,
The side plates 26 and 27 are provided at both ends in the longitudinal direction and the left and right side plates 26 and 27 are connected.
29 are provided.

The magnet roller 23 has a sleeve 30, and a magnet 32 integrated with a shaft 31 is supported in the sleeve 30 via a bearing (not shown). One end of the shaft 31 has a shaft 31. A bearing 33 is fitted on the outside.

The developing roller 24 has a roller body 35 integrally fixed to the shaft 34.

The blade 25 is made of brass, for example, having a thickness of about 3 to 5 mm, and is formed to have an L-shaped cross section and a length slightly longer than the length of the sleeve 30 of the magnet roller 23.

One end of the shaft 31 of the magnet roller 23 is
The bearing 33 provided at the other end of the shaft 31 is inserted into the hole 36 formed in the side plate 27.
It can be fixed to the screw hole 37 formed in the hole by the screw inserted into the hole 38 provided in the bearing 33.

By mounting the magnet roller 23 on the casing 22, the shaft 31 is fixed so as not to rotate, and by rotating the gears 39 concentrically provided at both ends of the sleeve 30, the sleeve 30 is fixed. It can rotate with respect to the shaft 31.

A hole 36 is formed at one end of the shaft 34 of the developing roller 24.
It is adapted to be inserted into a hole 38 formed in the side plate 27 so as to be positioned below the same, and the other end of the shaft 34 is inserted into a hole (not shown) provided in the side plate 26 to be rotatable. It is supposed to be supported.

Thus, the developing roller 24 is attached to the casing 22.
Mounted on the roller main body 35 of the developing roller 24 and the sleeve 30 of the magnet roller 23, 0.85 to
A clearance 40 of 0.90 mm is formed.

Positioning holes 41 are formed at both longitudinal ends of the blade 25, and a seating surface 42 provided downward in the vicinity of the outer side of the side plate 26 and a downward direction in the vicinity of the side plate 27 of the frame member 28. Positioning pins 44 project downward from the seating surfaces 43 provided as above.

The blade 25 can be positioned with respect to the casing 22 by fitting the positioning hole 41 of the blade 25 onto the positioning pins 44 provided on the seat surfaces 42 and 43 of the casing 22. The blade 25 can be fixed to the casing 22 by inserting a screw into the holes 45 formed at both ends in the longitudinal direction of the blade 25 and screwing the screw into the screw holes 46 formed in the seat surfaces 42 and 43. It is like this.

Under the frame members 28 and 29 of the casing 22, covers 47 and 48 having a shape narrowed toward the outer peripheral side of the developing roller 24 toward the lower end, the magnet roller 23, the developing roller 24 and the blade 25 are provided. It is attached to cover.

The casing 22 of the developing device 21 is mounted at a predetermined position on the frame of the electrophotographic device through a bracket and a pin (not shown), and is swung by the cam means as in the case of FIG. 14 to move toward and away from the photosensitive drum. Is ready to go.

In FIG. 12, numeral 49 indicates a hole in the bearing portion of the mixer for stirring the developer (a mixture of toner and carrier at a constant ratio).

At the time of development, the developing roller 24 approaches the photosensitive drum to a position where development is possible, and
The developing roller 24 and the magnet roller 23 as well as a mixer (not shown) are driven by a driving device to rotate.

The developer supplied into the casing 22 of the developing device 21 is supplied to the magnet roller 23 side by a mixer (not shown), and the magnet roller 23
The magnetic force of the non-rotating magnet 32 contained in the magnet is attracted to and held on the outer peripheral surface of the magnet roller 23.

The developer attracted and held by the magnet roller 23 rotates together with the magnet roller 23 in the direction of the arrow (clockwise) in FIG. 13, and when passing through the gap between the blade 25 and the magnet roller 23, the blade 25 By this, a part is removed to obtain a predetermined thickness.

When the developer attracted and held by the magnet roller 23 moves to the developing roller 24 side, the developer is separated from the developing roller 24 in accordance with the electrostatic latent image on the photosensitive drum and is developed on the photosensitive drum. A drug image is formed.

The developer image formed on the photosensitive drum is shown in FIG.
The image is transferred to the intermediate transfer sheet in the same manner as described above, and then transferred from the intermediate transfer sheet to the sheet.

[0033]

In the developing device of the electrophotographic apparatus described above, the clearance between the magnet roller 23 and the developing roller 24 is adjusted, and
Individually attached to the casing 22 and the magnet roller 2
The blade 25 is attached to the casing 22 after adjusting the clearance between the blade 25 and the casing 3.

On the other hand, since the casing 22 is a molded product of resin, there are variations in the dimensions, so that the rollers 23,
The assembly accuracy of the casing 24 of the 24 depends on the dimensional accuracy of the molded casing 22.

As a result, in order to obtain the accuracy of the clearance between the rollers 23 and 24, the positions of the rollers 23 and 24 must be individually adjusted each time the rollers 23 and 24 are assembled, and the development is performed. The clearance between the roller 24 and the blade 25 also needs to be dimensioned in the longitudinal direction using a gap gauge.

Therefore, in the conventional developing device, the roller 2
There is a problem that skill is required for assembling the 3, 24 casings 22 and it takes time to assemble.

Further, when the conventional electrophotographic apparatus is a color printer, a plurality of sets of developing apparatuses are required.
As is clear from the above, each developing device has a different shape and structure, and therefore requires a large number of types of parts, which complicates parts management and assembly work.

In view of the above situation, the present invention improves the assembling accuracy of the rollers and blades of the developing device, and easily and quickly installs the roller assembly configured by assembling the rollers and blades on the flange with respect to the casing. It is possible to assemble, and when using multiple developing devices such as a color printer, the shape and structure of each developing device are made common to reduce the number of types of parts, and it is easy to manage parts and assemble. The purpose is to get it.

[0039]

A developing device for an electrophotographic apparatus according to the present invention comprises a roller assembly and a box-shaped casing in which the roller assembly is mounted. The roller assembly develops the carried developer on a photosensitive drum. Developing roller, a magnet roller disposed with a predetermined clearance from the developing roller and supplying the adsorbed developer to the developing roller, and a magnet roller disposed with a predetermined clearance. A roller having a thin plate blade for adjusting the thickness of the developer supplied from the roller to the developing roller, and a pair of left and right flanges, and the developing roller and the magnet roller are bearing portions provided on the pair of left and right flanges. Rotatably supported by the blade, the blade is fixed to the flange, and the roller assembly of the casing. An opening is formed in the facing surface so that a portion of the magnet roller opposite to the developing roller side is located in the casing and the developer contained in the casing is supplied to the outer peripheral portion of the magnet roller. The surface of the flange facing the casing or the surface of the casing facing the flange may be fitted into a pin fitting hole provided in the casing or the flange when the roller assembly is assembled to the casing to position the roller assembly with respect to the casing. As such, a positioning pin is provided.

Further, the developing device of the electrophotographic apparatus of the present invention is
A backup member for backing up the blade is fixed to the flange, and a surface of the casing facing the roller assembly can be held in cooperation with the backup member when the roller assembly is mounted on the casing. An elastic body is provided.

Therefore, in the present invention, it is not necessary to adjust the clearance between the developing roller and another roller, the clearance between the magnet roller and the developing roller, or the clearance between the magnet roller and the blade.
Moreover, the precision of these clearances is good, and the developing device can be assembled with a small number of assembling steps.

Further, when a plurality of developing devices are required, the corresponding parts of each developing device can be made common, which is also advantageous in management and maintenance of parts during manufacturing and assembly.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 11 show an example of an embodiment of a developing device of an electrophotographic apparatus of the present invention.

1 to 5, FIGS. 8, 9 and 10, the upper part of the figure shows the upper part of the device and the lower part of the figure shows the lower part of the device. However, in FIG. 6 and FIG. For the sake of simplicity, the top and bottom are reversed from those of FIGS. 1 to 5, 8, 9, and 10. The lower part of the drawing is the upper part of the device, and the upper part of the drawing is the lower part of the device. 1 to 5 and FIGS. 6 and 7, the arrangement in the longitudinal direction is also opposite to the arrangement on the front side and the back side.

In the figure, 51 is a magnet roller,
Like the conventional one, a sleeve 52 is provided, and inside the sleeve 52, a magnet 54 having both ends integrated with a shaft 53 protruding to the outside of the sleeve 52 is fitted (see FIGS. 8 and 9). The sleeve 52 is supported by the shaft 53 via a bearing (not shown) fitted to the shaft 53, and a gear 55 for rotating the sleeve 52 is fixed to one end of the sleeve 52.

A developing roller 56 is provided with a roller body 58 integrally fixed to the shaft 57.

Reference numeral 59 is the sleeve 5 of the magnet roller 51.
2 and a roller body 58 of the developing roller 56, which is slightly longer than the roller body 58, and is made of phosphor bronze, brass, copper, or SU.
S, spring steel, polyester film, or polycarbonate aluminum, with a width of about 10 mm and a plate thickness of 0.03 to 1 mm, preferably 0.1 to 0.3 mm. The blade 59 may be magnetic or non-magnetic depending on the developer used. The blade 59 is a thin plate
This is because the accuracy and flatness of both ends of the blade 59 in the longitudinal direction can be easily obtained.

Reference numeral 60 denotes a round bar-shaped backup member for backing up the blade 59 and having a length substantially the same as that of the blade 59. The material is iron, SUS, aluminum, bronze,
The diameter is 5-12 mm, preferably 6 mm. The backup member 60 may be a square bar instead of a round bar, but a commercially available inexpensive and accurate rod-shaped body is desirable in order to maintain a predetermined straightness. Thus, the backup member 60 provides the rigidity and straightness of the blade.

Reference numerals 61 and 62 denote resin-made small block flanges having a shape as shown in detail in FIGS.

The flange 61 will be described with reference to FIG. 1. A hollow hole 64 is provided at the center of the cylindrical member 63 of the flange 61 so as to penetrate in the axial direction. A bush-shaped bearing 65 for supporting the roller 51 is fitted.

In FIG. 1, a block-shaped member 66 provided directly below the cylindrical member 63 so as to be integrally formed with the cylindrical member 63 is provided with a hollow hole 67 as a bearing portion for supporting the developing roller 56. It is provided directly below the hollow hole 64 so as to be parallel to the hole 64 and penetrate the block-shaped member 66.

A pedestal 68 having a flat top surface is provided on the left and right sides (left side in FIG. 1) of the cylindrical member 63 so as to have a height substantially matching the axis of the hollow hole 64. Positioning pins 69 project upward on the upper surface of the so that the blade 59 can be locked and the roller assembly 91 can be positioned with respect to the casing 102 when the roller assembly 91 is mounted on the casing 102, which will be described later. .

At the bottom of the base 68, the backup member 6
A hollow hole 70 for supporting 0 is provided at a side portion of the hollow hole 64 so as to be parallel to the hollow hole 64 and penetrate the pedestal 68.

A hollow cylindrical member 72 having a diameter smaller than that of the cylindrical member 63 is integrally formed on the axially outer side of the cylindrical member 63 with a cutout 71 so as not to interfere with the gear 55.

On one of the left and right sides of the cylindrical member 72, the pedestal 7 is located axially outward of the pedestal 68 and has its upper surface located above the upper surface of the pedestal 68 in FIG.
3 is integrally formed with the pedestal 68,
The pedestal 73 is provided with a screw insertion hole 74 through which the screw 112 when the roller assembly 91 is set in the casing 102 described later is inserted.

On the other side of the cylindrical member 63 (on the right side in FIG. 1), there is provided a pedestal 75 whose upper surface is flat so as to have a height substantially matching the axis of the hollow hole 64. The roller assembly 91 to the casing 10
Screw insertion hole 7 for inserting the screw 112 when it is mounted on
6 is drilled (see FIG. 1).

Explaining the flange 62 with reference to FIGS. 2 and 3, a hollow hole 78 is provided in the central portion of the cylindrical member 77 of the flange 62 so as to penetrate in the axial direction, and the hollow hole 78 has a hollow hole 78 therein. A bush-shaped bearing 79 for supporting the is fitted.

2 and 3, the block-shaped member 80 provided directly below the cylindrical member 77 so as to be integrally formed with the cylindrical member 77 has a hollow hole 8 for supporting the developing roller 56.
1 is provided directly below the hollow hole 78 so as to be parallel to the hollow hole 78 and penetrate the block-shaped member 80.

On the left and right sides of the tubular member 77 (shown on the left side in FIG. 2 and on the right side in FIG. 3, but actually the same side), the upper surface serves as the axis of the hollow hole 78. A pedestal 82 formed flat so as to have a height that substantially matches is provided,
The blade 59 is positioned on the upper surface of the pedestal 82, and the roller assembly 91 is attached to the casing 102 described later.
When mounting the roller assembly 91 to the casing 1
A positioning pin 83 projects upward so that the positioning pin 83 can be positioned with respect to 02.

At the bottom of the base 82, the backup member 6
A hollow hole 84 for supporting 0 is provided at a side portion of the hollow hole 78 so as to be parallel to the hollow hole 78 and penetrate the pedestal 82.

A hollow cylindrical member 85 having a diameter smaller than that of the tubular member 77 is integrally formed on the axially outer side of the tubular member 77.

A pedestal 82 is provided on the left and right sides of the cylindrical member 85.
2 and 3, the pedestal 86 is formed so as to be integrally connected to the pedestal 82 while being located axially outwardly of the pedestal 82 and the upper surface thereof is located above the upper surface of the pedestal 82 in FIGS. Has a screw insertion hole 87 for inserting a screw 112 when the roller assembly 91 is set in a casing 102 described later.

On the other side of the cylindrical member 77 (on the left side in FIG. 2 and on the right side in FIG. 3 but actually the same side), the upper surface is substantially the same as the axis of the hollow hole 78. A pedestal 88 formed flat so as to have a matching height is provided, and the pedestal 88 is provided with a roller assembly 91.
A screw insertion hole 121 (see FIG. 3) for inserting the screw 112 when it is set to 2 is provided.

In FIGS. 2 and 3, reference numeral 89 projects upward at the end of the base 86 opposite to the base 82, and is provided in a hollow hole 90 provided in parallel with the hollow hole 84 and the like of another developing device. It is a plate-shaped member adapted to support a component.

The magnet roller 5 is attached to the flanges 61 and 62.
A roller assembly 91 formed by assembling the developing roller 56, the blade 59, the backup member 60, etc. is shown in FIGS.

That is, the shaft 53 of the magnet roller 51.
Both ends of the sleeve 52 are fitted into and supported by the bearings 65 and 79 of the flanges 61 and 62, respectively.
Located between 62, and thus the shaft 53 does not rotate, but the sleeve 52 is rotatable with respect to the shaft 53.

Both ends of the shaft 57 of the developing roller 56 are rotatably supported by the hollow holes 67 and 81 of the flanges 61 and 62, respectively, and the roller body 58 is located between the flanges 61 and 62.

The blade 59 has flanges 61, 6 through holes 92, 93 (see FIGS. 1 and 2) provided at both ends in the longitudinal direction.
It is set on the two positioning pins 69 and 83 and is fixed to the positioning pins 69 and 83 by a retaining ring (not shown).

Both ends of the backup member 60 are fitted in the hollow holes 70 and 84 of the flanges 61 and 62, and the screw holes provided at both ends of the backup member 60 are inserted into the backup member 60 from outside in the axial direction of the flanges 61 and 62. The backup member 60 is fixed to the flanges 61 and 62 by screwing the screws 94 and 95.

The magnet roller 51, the developing roller 56, and the backup member 60 are all parallel, and when assembled on the flanges 61 and 62, the sleeve 52 of the magnet roller 51 and the roller body 5 of the developing roller 56.
A clearance 96 of about 0.85 to 0.90 mm is formed between the magnet roller 5 and the magnet roller 5 of the blade 59.
A clearance 97 of 0.8 to 0.85 mm is formed between the one end and the sleeve 52 of the magnet roller 51 (see FIG. 10). Further, the central position of the blade 59 in the thickness direction is substantially at the same height as the axial center of the magnet roller 51.

8, 9 and 10 are arranged along the roller main body 58 of the developing roller 56 to prevent contamination inside the machine, and both ends are formed into block-shaped members 66 and 80 of the flanges 61 and 62. The electrodes are fitted in the grooves 99 and 100.

Thus, the electrode 98 has the center line 101 formed by connecting the center of the developing roller 56 and the center of the magnet roller 51 as a reference, and the roller body 5 of the developing roller 56.
It is arranged so as to surround the left and right portions of the reference numeral 8. Casing 10 to which the above-mentioned roller assembly 91 is assembled
Details of 2 are shown in FIGS.

Thus, the casing 102 has an elongated box shape along each roller of the roller assembly 91, and the surface on which the roller assembly 91 is mounted has a flange 61,
An opening 103 having a width slightly larger than the diameter of the sleeve 52 of the magnet roller 51 is formed between 62.

The surface of the casing 102 opposite to the surface on which the roller assembly 91 is mounted has the entire length.
An opening 105 is provided so that the lid 104 (see FIG. 11) can be attached.
Are formed.

The both ends of the opening 103 of the casing 102 in the longitudinal direction are formed on the flange 6 of the roller assembly 91.
The cylindrical member 63 and the cylindrical member 77 of Nos. 1 and 62 have the casing 102 at the outer peripheral portion on the side opposite to the developing roller 56 side.
Is formed in an arc shape so as to be in a state of being close to.

The flange 61 of the casing 102,
The surface 10 with which the bases 73, 75, 86, 88 of 62 contact
6, 107, 108 and 109 are formed substantially flat as shown in FIG. 6, and the surfaces 106 and 108 are provided with pin fitting holes so that the positioning pins 69 and 83 provided on the flanges 61 and 62 can be fitted therein. 110 and 111 are provided. The pin fitting hole 111 is a long hole that is long in the longitudinal direction of the casing 102.
This is to absorb the error in standing between the parts 83.

The surfaces 106, 107 of the casing 102,
108 and 109 have screw insertion holes 74 and 7 formed in the pedestals 73, 75, 86 and 88 of the flanges 61 and 62.
Screw holes 113 are formed so that the screws 112 inserted through the screws 6, 87, 121 can be screwed to fix the roller assembly 91 to the casing 102 via the flanges 61, 62.

Seals 114 and 115 (see FIG. 8) made of elastic members formed in a substantially arc shape are formed on the edges of the opening 103 of the casing 102 at both ends in the longitudinal direction so that the sleeve 52 of the magnet roller 51 is slidably contacted. The seal 1 is attached and is formed on one side in the width direction of the opening 103 of the casing 102 (on the side where the pin fitting holes 110 and 111 are provided), which is made of an elastic member and extends in the longitudinal direction of the opening 103.
16 is attached.

In FIGS. 6, 8 and 9, 117 is a positioning pin for mounting a cover (not shown) to the casing 102, and 122 in FIG. 6 is a screw for fixing the cover positioned by the positioning pin 117. It is a screw hole.

The roller assembly 91 is attached to the casing 10
The state set to 2 is shown in FIGS.

Thus, as shown in FIG. 7, the flange 6
The flat surfaces of the pedestals 73, 75, 86, 88 of 1, 62 are in contact with the surfaces 106, 107, 108, 109 of the casing 102, and the positioning pins 69, 83 are the positioning pins 69, 83.
The roller assembly 91 is positioned with respect to the casing 102 by being fitted into the two pin fitting holes 110 and 111.

The screws 112 are screw insertion holes 74, provided in the pedestals 73, 75, 82, 88 of the flanges 61, 62, respectively.
Surface 10 of casing 102 through 76, 87, 121
6, 107, 108, and 109 are screwed into the screw holes 113, so that the roller assembly 91 is attached to the casing 102.

The roller assembly 91 is attached to the casing 10
When mounted on 2, the sleeve 52 of the magnet roller 51
Is a state in which the outer peripheral portion on the side opposite to the developing roller 56 is slightly inserted into the casing 102 through the opening 103, and the blade 59 is sandwiched between the seal 116 and the backup member 60, which are elastic bodies, and due to the elastic force of the seal 116. It is pressed against the backup member 60 (see FIG. 9), thus forming the developing device 118.

When such a developing device 118 is attached to the photosensitive drums 9A and 9B for color printing, it becomes as shown in FIG. In FIG. 11, 119 is a mixer for mixing the developer, 120 is each developing device 118 for the photosensitive drum 9A,
9B is a cam for moving toward and away from 9B.

The development by each developing device 118 is performed in the same manner as described with reference to FIG. When viewed from the pair of developing devices 118, the developer supplied into the casing 102 is supplied to the magnet roller 51, and the developer is supplied to the magnet roller 51.
Is attracted to and rotates in the X direction (counterclockwise direction) in FIG.
The thickness of the photosensitive drum 9A or 9B is adjusted by the blade 59 and supplied to the developing roller 56.
To be developed.

Each magnet roller 51, developing roller 5
6, the blade 59, and the backup member 60 are mounted on the casing 102 as the roller assembly 91 assembled to the pair of left and right flanges 61 and 62, so that the assembly accuracy of these parts depends on the dimensional accuracy of the casing 102. Therefore, the accuracy of the positioning of the blade 59 with respect to the magnet roller 51, the clearance 96 between the magnet roller 51 and the developing roller 56, and the clearance 97 between the blade 59 and the magnet roller 51 can be made accurate, and the roller assembly can be carried out easily and quickly. 91 can be mounted on the casing 102.

Further, even when the electrophotographic apparatus is for color and a plurality of sets of developing devices 118 are required, the shape and structure of each developing device 118 can be made common, so that the number of types of parts can be reduced, and therefore the developing device 118. It is also advantageous in management and maintenance of parts at the time of manufacturing and assembling, and since the kinds of parts can be reduced, the kinds of dies can be decreased and the die cost can be reduced.

Further, since a thin plate can be used for the blade 59, the straightness of the tip of the blade 59 on the magnet roller 51 side in the longitudinal direction of the magnet roller 51 can be made accurate and the cost can be reduced. Blade 59
Is backed up by the backup member 60, the flatness of the tip of the blade 59 on the magnet roller 51 side in the longitudinal direction of the magnet roller 51 (the blade 59
(Which means the degree of bending in the longitudinal direction) can be made accurate and the strength can be made sufficiently strong.

In the embodiment of the present invention, the case where the positioning pin for the casing of the roller assembly is provided on the flange side has been described. However, the positioning pin can be provided on the casing side, and the magnet roller functions as a developing roller. The present invention is applicable not only to the case of using a two-component developer composed of a toner and a carrier, but also to the case of using a one-component developer composed of only a toner not using a carrier. It goes without saying that various changes can be made without departing from the scope of the invention.

[0091]

According to the developing device of the electrophotographic apparatus of the present invention, the following various advantageous effects can be obtained in any claims. I. Magnet roller, developing roller, blade 1 left and right
Since the roller assembly is constructed by assembling the flanges of the pair, it is possible to easily obtain the accuracy of the spacing between each roller and the clearance between the blade and the developing roller without being affected by the accuracy of the casing. Therefore, it becomes unnecessary to finely adjust the distance between the rollers and the clearance, and the developing device can be easily assembled with a small number of assembly steps. II. When multiple developing devices are required like a color printer, the corresponding parts of each developing device can be shared,
It is also advantageous in the management and maintenance of parts during manufacturing and assembly. III. By sharing the parts, it is possible to reduce the number of types of molds used to manufacture each part and reduce the mold cost. IV. From the above, the cost of the electrophotographic apparatus can be reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of one end of a flange of a roller assembly component in a developing device of an electrophotographic apparatus of the present invention.

FIG. 2 is a perspective view of the other end side of the flange of the roller assembly component in the developing device of the electrophotographic apparatus of the present invention.

FIG. 3 is a perspective view of the flange shown in FIG.

FIG. 4 is a perspective view of one end side of the flange of the roller assembly in the developing device of the electrophotographic apparatus of the present invention.

FIG. 5 is a perspective view of the other end side of the flange of the roller assembly in the developing device of the electrophotographic apparatus of the present invention.

FIG. 6 is a perspective view showing the roller assembly and the casing before the roller assembly is attached to the casing in the developing device of the electrophotographic apparatus of the present invention.

FIG. 7 is a perspective view showing a state where the roller assembly is mounted on the casing in the developing device of the electrophotographic apparatus of the present invention.

FIG. 8 is a sectional view showing the roller assembly and the casing before the roller assembly is attached to the casing in the developing device of the electrophotographic apparatus of the present invention.

FIG. 9 is a vertical cross-sectional view showing a state in which the roller assembly is mounted on the casing in the developing device of the electrophotographic apparatus of the present invention.

FIG. 10 is a vertical cross-sectional view showing a positional relationship among a magnet roller, a developing roller, a blade, and a backup member of a roller assembly in the developing device of the electrophotographic apparatus of the present invention.

FIG. 11 is a cross-sectional view showing a state where the developing device of the electrophotographic apparatus of the present invention is incorporated in the electrophotographic apparatus.

FIG. 12 is a perspective view of a developing device of a conventional electrophotographic apparatus before assembling of respective parts.

FIG. 13 is a vertical sectional view of a developing device of a conventional electrophotographic apparatus.

FIG. 14 is a vertical sectional side view schematically showing an example of a developing device of a conventional electrophotographic apparatus.

[Explanation of symbols]

9A, 9B photosensitive drum 51 magnet roller 56 developing roller 59 blade 60 backup material 61,62 Flange 65,79 Bearing (bearing part) 67,81 Hollow hole (bearing part) 69,83 Positioning pin 91 Roller assembly 96,97 clearance 102 casing 103 opening 110 and 111 pin insertion holes 116 seal (elastic body) 118 developing device

Claims (2)

(57) [Claims] 1. A roller assembly and a box-shaped casing in which the roller assembly is mounted, the roller assembly includes a developing roller for developing the carried developer on a photosensitive drum, and a predetermined clearance with respect to the developing roller. Adjusting the thickness of the developer supplied from the magnet roller to the developing roller, which is arranged with a predetermined clearance between the magnet roller and the magnet roller which supplies the attracted developer to the developing roller. And a pair of left and right flanges, the developing roller and the magnet roller are rotatably supported by bearings provided on the left and right pair of flanges, and the blade is fixed to the flange. The developing roller of the magnet roller is provided on the surface of the casing facing the roller assembly. As the developer stored in the casing portion of the opposite side is positioned in the casing is supplied to the magnet roller outer peripheral portion and,
An opening is formed, and the surface of the flange facing the casing or the surface of the casing facing the flange is fitted into a pin fitting hole provided in the casing or the flange when the roller assembly is assembled to the casing, and the casing of the roller assembly is fitted. A developing device for an electrophotographic apparatus, characterized in that a positioning pin is provided for positioning with respect to. 2. A backup member for backing up the blade is fixed to the flange, and a blade of the casing, which faces the roller assembly, cooperates with the backup member when the roller assembly is mounted on the casing. To be able to hold
The developing device of the electrophotographic apparatus according to claim 1, wherein an elastic body is provided.