JP3217526B2 - Developing device and image forming device - 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 using a one-component or two-component developer used in an image forming apparatus such as a copying machine, a facsimile, a printer, and the like. The present invention relates to a developing device that carries the developer, regulates the developer to a predetermined amount by a developer regulating unit disposed at a predetermined gap on the surface of a developing roller, and then performs the development.

[0002]

2. Description of the Related Art Conventionally, in this type of developing device, the position of the developer regulating means is appropriately set with respect to the developing roller such that the gap between the developing roller and the developer regulating means has a predetermined size. I needed to. Therefore, conventionally, as shown in FIG. 4, for example, a doctor 3a as a developer regulating means having an elongated hole 4a is replaced with a developing sleeve 1a and a magnet roller 2a as a magnetic field forming means housed therein.
A method is known in which the surface of the developing roller 100a is adjusted by vertically moving the surface of the developing roller 100a within the range of the long hole 4a, and fixed at an appropriate position with a screw 5a. Furthermore,
Developing roller 100a of doctor 3a (developing sleeve 1a)
The developing roller 100a is provided at both ends of the edge facing the surface.
(Developing sleeve 1a) A protruding member is provided which protrudes by a predetermined gap (hereinafter referred to as a doctor gap) between the surface and the edge of the doctor 3a.
The adjustment work is simplified by bringing the doctor 3a into contact with the surface of a developing sleeve 0a (developing sleeve 1a) and fixing the doctor 3a at that position with a screw 5a (for example, see Japanese Unexamined Patent Publication No.
0-95558).

Further, as a method for appropriately setting the position of the developer regulating means with respect to the developing roller, for example, a method as shown in FIG. 5 is known. In FIG. 5, shafts 4b are provided at both ends of the magnet roller 2b. At both ends of the developing sleeve 1b, flanges 6b and 7b, in which bearings 5b are press-fitted into holes at the center, respectively, are attached. And, on one flange 7b, a shaft portion 71b having a hollow portion having the same diameter as the hole at the center portion and having a bearing 5b press-fitted into the inner surface of the hollow portion at the outer end is formed. . A driving member 9b such as a gear for transmitting a driving force to the developing sleeve 1b is attached to an outer end of the shaft 71b. Then, the magnet roller 2b provided with the shaft 4b is connected to the developing sleeve 1 provided with the flanges 6b and 7b.
The magnet roller 2b and the developing sleeve 1b constitute a developing roller 100b. One end of the developing roller 100b is attached to the side plate 82b via a shaft 71b bearing of the flange 7b of the developing sleeve 1b, and the shaft 4b of the magnet roller 2b is attached to the side plate 81b via a bearing. , And are supported by the side plates 81b and 82b of the developing device. Further, the doctor 3b is fixed in a state where an end thereof abuts on a protrusion 10b formed on the inner surface of the side plates 81b and 82b. In the developing device having such a configuration, the doctor 3
The position of the doctor 3b with respect to the developing sleeve can be set by abutting and fixing the b to the protrusion 10b of the side plates 81b and 82b.

[0004]

However, according to the structure shown in FIG. 4, since the position of the doctor 3a is adjusted and then fixed with the screw 5a, it is difficult to set the doctor gap with high accuracy. There was a problem. Also,
According to the configuration shown in FIG. 5, the developing sleeve 1b is connected to the side plate 8 of the developing device via the flanges 6b, 7b, the shaft 4b, and the like.
1b, 82b, the flanges 6b, 7
b, the shaft 4b, etc., the side plate 81
The position of the surface of the developing sleeve 1b with respect to the points b and 82b varies. For this reason, the side plates 81b, 82
b of the side plate 81b, 82
The doctor gap, which is the gap between the doctor 3b fixed to the developing sleeve 1b and the surface of the developing sleeve 1b, cannot be set with high accuracy due to the variation in the position of the surface of the developing sleeve 1b due to the accumulation of components, and an abnormal image is generated due to a wrong doctor gap setting. There was a problem that there is. Further, the developing sleeve 1b is provided with a bearing 5b, and a magnet roller 2b is mounted via flanges 6b, 7b mounted on both ends. The developing roller 100b is composed of the magnet roller 2b and the developing sleeve 1b. Is a shaft portion 71b of the flange 7b of the developing sleeve 1b at one end.
The shaft 4b of the magnet roller 2b is attached to the side plate 81b via a bearing, and the shaft 4b of the magnet roller 2b is attached to the side plate 81b via a bearing.
b, the cost is high, and when the shaft 4b of the magnet roller 2b is damaged, it is necessary to replace the entire developing roller 100b including the magnet roller 2b. . Further, as described above, the developing roller 100b includes the magnet roller 2b provided with the shaft 4b and the flange 6 into which the bearing 5b is press-fitted.
b, 7b (the driving member 9b is attached to the outer end of the shaft portion 71b of the flange 7b), and the developing sleeve 1b is attached. Therefore, the configuration is complicated and expensive. was there.

[0005] The present invention has been made in view of the above problems, it is an object of the gap between the developing roller surface and the developer regulating means can be set well accuracy without adjustment, with a simple structure Another object of the present invention is to provide a developing device which is low in cost and excellent in maintainability. Also, for other purposes,
The gap between the developing roller surface and the developer regulating means can be adjusted without adjustment.
It can be set easily, has a simple configuration, is low-cost, and
An image forming apparatus equipped with a developing device with excellent maintainability
To provide.

[0006]

To achieve the above Symbol purpose SUMMARY OF THE INVENTION The invention of Claim 1 includes a hollow cylindrical developing sleeve,
Surface of the developing sleeve housed inside the developing sleeve
Magnetic field forming means for forming a predetermined magnetic field
A developing roller for carrying a developer on the surface of the image the sleeve is arranged to take a predetermined gap with respect to the surface of the developing sleeve, a developer regulating for regulating the developer on the surface of the developing sleeve to a predetermined amount And a developing device.
A developing sleeve support portion for supporting the developing sleeve in contact with the end surface of the sleeve, the developing scan of the developer regulating means
A longitudinal end portion of the opposing edges on the surface of the rib is the developer regulating means supporting portion that those Sessu, moiety and said to respond developer regulating means supporting portion pair among the developing sleeve support portion intervals in the radial direction of the developing sleeve between a developer regulating means supporting portion, developing a support member gap between the developer regulating means and the developing sleeve surface is formed to be the predetermined gap The developing sleeve is provided at each end of the sleeve.
Forming a magnetic field at one end of the leave to support the magnetic field forming means;
Means, and the other end of the developing sleeve is
The opening is formed so that the field forming means can be taken out.
The support portion supporting the other end of the developing sleeve has the magnetic field.
Forming a magnetic field forming means support portion for supporting one end of the field forming means
It is characterized by having done. According to a second aspect of the present invention, in the developing device according to the first aspect, the developing sleeve is provided.
A driving part for transmitting a driving force to the developing sleeve is formed at one end of the developing sleeve.
It is characterized by having achieved . According to a third aspect of the present invention, there is provided an image carrier and a method for forming a latent image on the image carrier.
Step and a developing device for developing the latent image formed on the image carrier
And an image forming apparatus having a developing device.
The developing device according to claim 1 or 2 is used .

[0007]

In the present invention , since the supporting member is provided with the developing sleeve supporting portion and the developer regulating means supporting portion, both the developing sleeve and the developer regulating device are directly supported by the supporting member. Is done. Further, a distance in a radial direction of the developing sleeve between a portion of the developing sleeve support portion where the developer regulating device support portion faces and the developer regulating device support portion is equal to the developer regulating device and the developing roller. Between the surface
Since the gap is formed so as to be the predetermined gap, the position of the developer regulating unit with respect to the surface of the developing sleeve is always accurately set by merely fixing the developer regulating unit in contact with the developer regulating unit support. it can. Also, one of the developing sleeves
At the end, a magnetic field forming means supporting portion for supporting the magnetic field forming means
And the other end of the developing sleeve is provided with the magnetic field forming means.
The developing three
The supporting portion for supporting the other end of the magnetic field
Since the magnetic field forming means support part that supports one end of
The magnetic field forming means includes a support member and a developing sleeve in the developing sleeve.
Is supported directly by chromatography blanking, the developing sleeve is open
By removing the supporting member on the side, the magnetic field forming means can be easily taken out of the developing sleeve .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a developing device used in an electrophotographic copying machine (hereinafter referred to as a copying machine) as an image forming apparatus will be described. FIG. 1 is a front view illustrating an example of the developing device according to the present embodiment. A developing device 2 is disposed on the right side of the photosensitive drum 1 as an image carrier. Around the photosensitive drum 1, a well-known charging device, an exposure optical system, a transfer separation device, a cleaning device, and a static elimination device (all not shown) are provided for performing an electrophotographic process. The developing device 2 of this example includes a developing device 3 facing a surface of a photosensitive drum 1 on which an electrostatic latent image is formed by the exposure optical system, and a cylindrical shape as a toner container attached to the developing device 3. And the toner cartridge 4. The developing device 3 includes a casing 31 having an opening A facing the surface of the photosensitive drum 1, a developing roller 32 partially exposed from the opening A, and a developing roller 3.
A stirring roller 33 that supplies a two-component developer composed of toner and carrier to the two surfaces and agitates the developer in the casing 31, and regulates the amount of the developer supplied to the surface of the developing roller 32 by the stirring roller 33. And a separator 35 that guides the developer that is regulated by the doctor 34 and returned to the lower part of the casing 31. The separator 35 includes a conveying screw 35a for stirring the developer in the axial direction of the photosensitive drum in the casing 31 and a stirring separator 35b.
Is provided. Further, a hopper 36 is formed at the upper right portion of the casing 31 for temporarily storing the toner to be replenished into the casing 31 as the toner is consumed. A toner supply roller 37 is disposed in an opening of the hopper 36 facing the inside of the casing 31, and a holder 38 for detachably supporting the toner cartridge 2 is formed in an upper opening of the hopper 36. This holder 3
8 has a cylindrical cavity slightly larger than the outer shape of the toner cartridge 2. The toner cartridge 2 has a toner discharge opening (not shown) formed therein, and an agitator 41 provided therein. The toner supply roller 36
The agitator 41 is rotationally driven by driving from the main body side.

The developing roller 32 is composed of, for example, a cylindrical developing sleeve 321 and a magnet roller 322 as a magnetic field forming means having a plurality of magnetic poles housed therein. Next, the support portion of the developing roller 32 will be described in detail. FIG. 2 is a cross-sectional view of the vicinity of the supporting portion of the developing roller 32. The shafts 20a and 20b are provided on both end surfaces of the magnet roller 322.
The developing sleeve 321 is made of, for example, a conductive resin, and has an opening at one end 321a and a side plate portion 21 that supports the shaft 20b of the magnet roller 322 at the other end 321b. Further, on the outer peripheral surface of the other end 321b, a driving unit 22 formed of, for example, gear teeth for transmitting an external driving force to the developing sleeve 321 is formed.
Then, the magnet roller 322 is connected to the developing sleeve 321.
The shaft 20b is fitted to the side plate 21 formed in the developing sleeve 321 and housed inside the developing sleeve 321. In the developing sleeve 321, the sleeve portion is made of, for example, metal (Al,
SUS or the like, and the side plate portion 21 and the driving portion 22 may be made of resin and press-fitted into a metal sleeve.

Further, supporting members 24a and 24b are attached to the side plates 23a and 23b of the developing device 2, respectively. Both support members 24a, 24b are connected to side plates 23a, 23b.
, And has an annular flange portion extending inward of the developing sleeve 321.
Sleeve support portion 24 with respect to the outer peripheral surfaces of 21a and 321b
2a and 242b, and the outer peripheral surface is the doctor 3
No. 4 are abutting support portions 243a, 243b at longitudinal ends of edges facing the surface of the developing sleeve 321. The support member 24a corresponding to the open end of the developing sleeve 321 is also formed with a side plate portion 241 having a receiving portion for the shaft 20a of the magnet roller 322.

Here, as shown in FIG. 3A, when the diameter of the developing sleeve 321 is d and the doctor gap is δ,
Butt support portion 243a of support member 24a (24b)
The diameter D (see FIG. 3B) of (243b) is set to the value of the diameter d of the developing sleeve 321 + the doctor gap δ. That is, the butting support portion 243a (243b)
A portion of the doctor 34 whose edge facing the surface of the developing sleeve 321 is in contact with the sleeve support portion 242a (24).
2b) of an end 321a (321) of the developing sleeve 321
b) The support member 24a (2
4b) is formed such that the thickness t is the same as the doctor gap δ.

Therefore, in the above configuration, the doctor 34
To the support member 243a of the support member 24a (24b).
The doctor gap can be accurately set only by abutting and fixing to (243b).

As described above, according to this embodiment, the developing sleeve 3
Since 21 is directly supported by the support members 24a (24b), and the doctor 34 is also directly supported by the support members 24a (24b), the variation in the doctor gap due to the stacking of components is reduced, and the doctor gap is set. The accuracy when doing so is improved. The developing sleeve 3
Since the end 321a of the support member 21 is open,
By removing a, the magnet roller 322 can be easily replaced. Further, the developing sleeve 321 has the driving section 22 formed of, for example, gear teeth for transmitting a driving force to the developing sleeve 321 on the outer peripheral surface of the end portion 321b, so that the configuration is simple and the cost can be reduced.

[0014]

According to the present invention, the position of the developer regulating means with respect to the surface of the developing sleeve can always be set with high accuracy simply by bringing the developer regulating means into contact with the developer regulating means supporting portion and fixing it. There is an excellent effect that a stable developed image can be obtained without generating an abnormal image due to a poor position setting of the agent regulating means. Further , the magnetic field forming means includes a support member and a developing three in the developing sleeve.
Bed is supported directly by and can be taken out easily the magnetic field forming means by detaching the supporting member DOO
Provide special members for supporting the magnetic field forming means
There is no need, it is possible to a developing device configured simply, there is excellent effect that a low cost, yet it is possible to provide a superior developing device maintainability. What
Note that a drive unit that transmits drive force to the developing sleeve is formed.
If the driving unit applies an external driving force to the developing sleeve,
Since rotation is transmitted directly obtain the line without providing a special member the transmission of driving force.

[Brief description of the drawings]

FIG. 1 is a front view illustrating an example of a developing device according to an embodiment.

FIG. 2 is a sectional view of the vicinity of a support portion of a developing roller in FIG.

FIG. 3A is a diagram illustrating a developing sleeve diameter d and a doctor gap δ. (B) is an explanatory view of the diameter D of the butting support portion of the supporting member and the thickness t of the supporting member between the butting support portion and the sleeve supporting portion.

FIG. 4 is an explanatory view of a conventional doctor gap setting method.

FIG. 5 is an explanatory diagram of a configuration of a conventional developing roller and another method of setting a doctor gap.

[Explanation of symbols]

 21 Side plate part 22 Drive part 321 Developing sleeve 322 Magnet roller 34 Doctor 241 Side plate part 242a (242b) Sleeve support part 243a (243b) Butt support part 24a (24b) Support member

Claims (3)

(57) [Claims] A developing sleeve having a hollow cylindrical shape;
The developing sleeve is housed inside the
And a magnetic field forming means for forming a field.
Developing roller and, developing three carrying the developer on the surface
Is disposed at a predetermined gap from the surface of the
In the developing device having a developer regulating means for regulating a predetermined amount of the developer on the surface of the sleeve, the developing sleeve support portion for supporting the developing sleeve in contact with the end surface of the developing sleeve, the developer The longitudinal end of the edge of the regulating means facing the surface of the developing sleeve is the
And a developer regulating means supporting portion that Sessu, the between the part and the developer regulating means supporting portion for response developer regulating means supporting portion pair among the developing sleeve <br/> support portion The distance between the developing sleeve in the radial direction is determined by the developer regulating means and the developing sleeve.
Provided a support member gap between the blanking surface is formed to be the predetermined gap to each end portions of the developing sleeve, the end portion of the developing sleeve, to support the magnetic field forming means
The other end of the developing sleeve forms a magnetic field forming means support portion.
Is opened so that the magnetic field forming means can be taken out.
In addition, the supporting portion for supporting the other end of the developing sleeve has the
Form a magnetic field forming means support portion that supports one end of the magnetic field forming means.
Developing apparatus is characterized in that form. 2. The developing sleeve according to claim 1, wherein said developing sleeve is provided at one end of said developing sleeve.
The developing device according to claim 1, further comprising a driving unit that transmits a driving force to the developing unit. 3. An image forming apparatus comprising: an image carrier; means for forming a latent image on the image carrier; and a developing device for developing the latent image formed on the image carrier. An image forming apparatus using the developing device according to claim 1 or 2 as an apparatus.