JPH01246576A - Developing device - Google Patents

Abstract

PURPOSE:To uniformly supply developer to a 1st supplying means and to perform developing of high image quality by supplying the developer to the 1st supplying means through a developer reservoir by means of a 2nd supplying means. CONSTITUTION:The title device is provided with the 1st supplying means 30 supplying the developer 28 to a developer carrier 29, the 2nd supplying means 36 supplying the developer 28 to the 1st supplying means 30 and the developer reservoir 44 reserving the specified amount of the developer, which is provided on the 1st supplying means 30 between the developer carrier 29 and the 2nd supplying means 36. The developer 28 from the 2nd supplying means 36 is supplied to the 1st supplying means 30 through the developer reservoir 44. Therefore, the developer can uniformly be supplied to the 1st supplying means 30 so that the developer uniformly electrified is supplied to the developer carrier 29 by means of the 1st supplying means 30. Thus, developing of high image quality can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to image forming apparatuses such as copying machines and printers that apply electrophotography.

BACKGROUND OF THE INVENTION Conventionally, developing methods using a dry developer are broadly divided into two types: methods using a two-component developer and methods using a one-component developer.

The method using a two-component developer uses a mixed developer of toner and carrier, so it requires a toner concentration control device to maintain a constant mixing ratio of toner and carrier, and has disadvantages such as periodic replacement due to carrier deterioration. have. Therefore, recently, in order to eliminate the above-mentioned drawbacks, a developing method using only an l-component developer without using a carrier has been proposed.

This developing method is disclosed, for example, in Japanese Patent Publication No. 60-51856 and US Pat. No. 4,083,326, and its construction is shown in FIGS. 9 and 10.

In Figure 9 (Special Publication No. 60-51856), 1
2 is a developing roller, 2 is a toner, 3 is a hopper, 4 is a blade, and 5 is a photoreceptor. The developing roller 1 is made of a metal material with an uneven surface, and is supplied with toner 2 from a hopper 3 . Next, when the developing roller 1 rotates in the direction of the arrow, the toner 2 is charged to a predetermined polarity by the blade 4 that is in sliding contact with the surface of the developing roller 1, and is coated on the surface of the developing roller 1. Next, when the charged toner 2 faces the electrostatic latent image on the photoreceptor 5, it flies off and develops.

Figure io (U.S. Pat. No. 4,083,326, 5A)
13 is a developing roller, 14 is a toner, 15 is a hopper, 16 is a blade, 17 is a sheet-like photoreceptor, 1
8. 19 is a conductive fur brush that comes into sliding contact with the developing roller 13; 20 is a first power source that applies voltage to the hopper 15 and the conductive fur brush 18; and 21 is a power source that applies voltage to the conductive fur brush 18 and the developing roller. This is the second power source to be applied. Further, the voltage applied by the second power source 21 is the same as that of the first power source 2.
The applied voltage is set to be higher than the applied voltage of 0, and lower than the voltage of the electrostatic latent image on the photoreceptor 17. The toner 14 triboelectrically charged by the fur brush 18 is supplied to first and second power sources,
21, it is supplied from the hopper 15 to the developing roller 13 via the conductive fur brush 18, and after being smoothed by the blade 16, it adheres to the electrostatic latent image on the photoreceptor 17 and is developed. . Next, the developing roller 1 after development
The toner 14 on the developing roller 3 is scraped off with a conductive fur brush 19 to remove the development history on the developing roller.

Problems to be Solved by the Invention However, this method has a problem in uniform charging of the developer (toner), making it difficult to reproduce high-quality images.

In other words, in the case shown in FIG. 9, the amount of toner supplied to the developing roller varies depending on the amount of toner in the hopper, and the amount of charge of the toner on the developing roller fluctuates, making it difficult to reproduce high-quality images. .

In the case shown in FIG. 10, the amount of toner supplied to the fur brush varies depending on the amount of toner in the hopper, and the amount of charge on the toner on the developing roller fluctuates, making it difficult to reproduce high-quality images.

The present invention solves the conventional problems and provides a high-quality image forming apparatus.

Means for Solving the Problems and Technical Means of the present invention for solving the above-mentioned problems include a first supply means for supplying the developer to the developer carrier, and a first supply means for supplying the developer to the first supply means. and a developer reservoir for storing a predetermined amount of developer provided on the first supply means between the developer carrier and the second supply means; The developer from the supply means is supplied to the first supply means via a developer reservoir.

action The effect of this technical means is as follows.

That is, since the second supply means supplies the developer to the first supply means via the developer reservoir, it is possible to uniformly supply the developer to the first supply means, and therefore the first supply means can charge the developer uniformly. The developer is supplied to the developer carrier. As a result, high-quality development becomes possible.

Examples Examples of the present invention will be described below. 1 to 7 show a first embodiment of the present invention, which is an example used in an electrophotographic copying machine. In FIG. 1, reference numeral 22 denotes a charge carrier, such as electrostatic recording paper or a photosensitive drum. In this embodiment, the charge carrier 22 is a photosensitive drum having a photoconductor 24 such as zinc oxide, selenium, or an organic photoconductive material supported on the surface of an aluminum base 23 (therefore, hereinafter referred to as the charge carrier). 22 is referred to as a photosensitive drum 22). Reference numeral 25 denotes a charger which applies corona to the photoconductor 24 on the photosensitive drum 22 by a first DC high voltage power supply 26, for example, a negative corona in the case of zinc oxide and a positive corona in the case of selenium.
The entire surface is charged. Reference numeral 27 denotes an optical section that projects a patterned optical image onto the photosensitive drum 22 to form an electrostatic latent image. A developer 28 is a normal one-component insulating toner. Note that the developer 28 may be a magnetic toner or a non-magnetic toner. Reference numeral 29 denotes a developing roller which is a developer carrier. For example, a metal roller made of stainless steel or aluminum, a roller whose surface is coated with resin, etc. are used. Preferably, as shown in FIG. Both ends outer peripheral surfaces 29a, 29b are smooth and central surface 2
A rough surface with fine irregularities is formed on the surface of the photosensitive drum 9c, and the photosensitive drum 22 is placed at a constant distance from the photosensitive drum 22 and rotated counterclockwise, for example, as shown in FIG. 304. is a cylindrical elastic body which is a first supply means for supplying the developer 28 to the developing roller 29, and the cylindrical elastic body 30 is a fur brush,
A layer of elastic material 32 is formed on the outer peripheral surface of the mandrel 31 using a roller made of sponge or the like.

In this embodiment, the cylindrical elastic body 30 is a fur brush,
The elastic material 32 is made of conductive fur using rayon fiber containing carbon.

Further, the fur brush 30 is surrounded by a housing 33, is in sliding contact with the surface of the developing roller 29, and is rotated, for example, in a clockwise direction and at a circumferential speed higher than the circumferential speed of the developing roller 29. By setting the circumferential speed of the fur brush 30 in this manner, it is possible to increase the amount of developer 28 supplied to the developing roller 29, improve the followability of coating, and reduce spillage of the developer 28. Furthermore, the developer 28 adhering to the surface of the developing roller 29 can be scraped off after the developing process, and the history on the developing roller 29 can be erased.

Further, the m-fibers of the fur brush 30 are formed in a spiral shape in a direction in which the developer 28 moves from the outer peripheral portions of both ends of the fur brush 30 to the center portion during rotation, as shown in FIG.

Reference numeral 34 denotes a developer storage means, which includes a storage section 35 that stores the developer 28 and a second supply means 3 that supplies the developer to the first supply means 30.
It consists of 6 parts. Further, the storage section 35 has a developer 2 at one end.
It has eight replenishment openings 37 and is formed from a part of the housing 33. Further, the second supply means 36 fixes one end of a sheet-like elastic member 39 made of polyethylene terephthalate or the like with a thickness of about 30 to 80 μm to the outer peripheral surface of the mandrel 38, and rotates or swings the mandrel 38. The developer 28 is supplied to the first supply means 30. In this embodiment, the mandrel 38 rotates clockwise. Reference numeral 40 denotes a partition plate serving as a circulation means, which connects the first supply means 30 and the second supply means 3.
6, and has an opening 41 through which the developer 28 flows in and out at the interface between the first supply means 30 and the second supply means 36. Further, the opening 41 is provided at a position where the developer 28 from the sheet-like elastic member 39 is supplied to the outer circumference of the fur brush 30 in a tangential direction. By supplying the developer 28 in the tangential direction, the developer 28 does not become clogged in the fur brush 30. 42 is a scraping plate formed by a part of the housing 33, and is in sliding contact with the fur brush 30.
While making the amount of developer 28 in the fur brush 3 uniform,
This is to scrape off the overcharged developer 28 within 0. 4
3 is a lid of the replenishment opening 37. 44 is a developer reservoir, which is a link between the developer roller 29 and the second supply means 36, and is provided on the fur brush 30. The developer reservoir 44 has a capacity that can supply a predetermined amount of developer 28 to the fur brush 30.

Roughly, the developer reservoir 44 is located at the end 44 of the developing roller 29.
A and the outer peripheral surface of the fur brush 30 are provided with a gap δ, and the gap δ is smaller than the opening λ of the opening 41. With this condition, the developer 28 from the sheet-like elastic member 39 is divided into two parts, the storage part 35 and the developer reservoir 44, and is no longer directly supplied to the developing roller 29 via the gap δ. In addition, good supply performance was obtained when the gap δ was 0.5 to 3++w++ and the opening width λ was 4 to 8IIIll.

As shown in FIG. 2, 45 is a bearing for the developing roller 29;
is a bearing of the fur brush 30. Reference numeral 47 denotes a layer thickness regulating means for regulating the layer thickness of the developer 28. In this embodiment, a plate-shaped elastic blade made of urethane rubber is used, but other rubber materials, polyethylene terephthalate, etc. may be used as the elastic blade material. It may be made of an elastic synthetic resin, an elastic metal such as phosphor bronze, or spring steel, or an elastic metal or synthetic resin coated with a fluororesin. Further, the precision of the end face of the elastic blade 47, the position and method of attachment have a great influence on the formation of a uniform thin layer of the developer 28.

The straightness of the edge 47A of the elastic blade 47 is 0+15m
It is precisely finished to be less than m, and is mounted in pressure contact with the developer carrier at a surface including at least the downstream edge 47A of the blade 27 with respect to the moving direction of the developer roller 29.

As shown in FIG. 4, the attachment method is to press the end of the blade on the edge 47A side onto the developing roller 29, and at least the flat surface 47 of the shaded part of the other end.
B is adhered to the mounting member 63 provided on the housing 33 using, for example, hot melt, which enables uniform adhesion in a short time.

In addition, the adhesive surface end 47C of the developing roller 29 is connected to the developing roller 2.
It is provided substantially parallel to the rotational axis X of No.9.

64A and 64B are adjustment screws which are pressure adjustment mechanisms.
This is to adjust the pressure of the elastic blade 47 against the developing roller 29 to a predetermined value. The pressure adjustment is done by the mounting member 6.
3 and the housing 33.

After adjusting the predetermined blade pressure with 64B, tighten the fixing screw 65A.
.

65B fixes the mounting member 63 to the housing 33. Further, the width of the elastic blade 47 is set to such a length that it comes into contact with the outer circumferential surfaces 29a and 29b at both ends of the developing roller 29, as shown in FIGS. 2 and 4.

48 and 49 are outer peripheral surfaces 29a and 29 at both ends of the developing roller 29.
A first sealing material surrounds b and blocks the developer 28 moving to both ends thereof, and is made of an elastic material such as woven fabric, nonwoven fabric (felt), sponge, or rubber.

50 and 51 are the developing roller 29 and the first sealing material 48.4
9 and the elastic blade 47.
The sealing material is made of an elastic material such as sponge or rubber. 52 and 53 are elastic sheets to further block the developer 28 moving to both ends, for example, 70 to 150
It is made of an elastic material such as μm polyethylene terephthalate or metal. Further, the elastic sheets 52 and 53 have one end attached to the first sealing material 48 and 49, and the other end protruding downstream from the blade edge 47A with respect to the rotational direction of the developing roller 29. 2 sealing material 50.
51.

Elastic blades 47 and 54 and 55 are connected to the developing roller 29.
The elastic blade 47 is a presser plate spring that improves the adhesion of the elastic blade 47.
through the second sealing material 50. 51 and elastic sheet 5
It is provided by pressing 2.53.

56 is a means for preventing the developer 28 from spilling;
The developing roller 29 and the fur brush 3
0 and below the developing roller 29. The spill prevention means 56 includes a U-shaped leak prevention member 57 and a leak prevention sheet 58 whose one end is fixed to the leak prevention member 57 and the other end is in light contact with the surface of the developing roller 29.
It consists of Note that one end of the leak prevention sheet 58 of the spill prevention means 56 may be provided on the casing 33. In addition, the width of the leak prevention sheet 58 is equal to the width of the outer circumferential surface 2 at both ends of the developing roller 29.
9a and 29b, and both ends thereof are pressed against the developing roller 29 by sealing materials 48 and 49 provided at both ends of the developing roller 29, as shown in FIG. Roughly speaking, the end of the leak prevention sheet 58 on the side that lightly contacts the surface of the developing roller 29 is placed on the upstream side of the line connecting the centers of the developing roller 29 and the fur brush 30 with respect to the rotating direction of the fur brush 30. 29 and a fur brush 30. Further, the leak prevention sheet 58 is made of an elastic material such as polyethylene terephthalate or urethane rubber, and in this embodiment, urethane rubber with good adhesion to the developing roller 29 (the thickness at this time is preferably about 50 to 200 μm) is used. ing. The leak prevention member 57 is made of metal such as stainless steel or aluminum, and even if the developer 28 leaks from the gap between the developing roller 29 and the leak prevention sheet 58, the receiver prevents it from falling downward. In this case, since the leakage of the developer 28 is almost completely stopped by the leakage prevention sheet 58, the capacity of the leakage prevention member 57 may be small.

As shown in FIG. 1, reference numeral 60 denotes a second DC high voltage power source which is an application means for applying a voltage, and applies a voltage between the developing roller 29 and the fur brush 30 to apply a voltage onto the surface of the developing opening roller 29. This is to adjust the layer thickness of the developer 28 charged to . Further, although the applying means 60 uses a DC bias voltage in this embodiment, a voltage obtained by superimposing an AC voltage on a DC voltage may also be used. 61 is the second DC high voltage voltage R60
This is a detection means that detects the current value of and detects the presence or absence of the developer 28.

By using a conductive material, the fur brush 30 has the function of preventing overcharging of the frictionally charged developer 28 on the developing roller 29 and making the potential uniform. Therefore, the fur brush 30 has a specific resistance of about r□IIIQ0 or less, preferably 103ΩC11 to 10'ΩC.
It is better to use a conductive material of l11.

The fur brush 30 may be made of not only conductive rayon IIm as in this embodiment, but also other conductive fibers, or a fur brush made by electrostatic flocking to make the coating uniform. It is also effective to use

Furthermore, it goes without saying that the above-described effects of frictional charging, coating, etc. can be effectively performed even if a conductive sponge, conductive cloth, or soft wire brush is used as the elastic material 32 of the cylindrical elastic body 30. Incidentally, when the developer 28 is a one-component magnetic toner, it is also effective to use a magnetic roller as the mandrel 31 and form a magnetic brush on the outer periphery thereof to form the cylindrical elastic body 30.

The operation of the developing device of the first embodiment configured as described above will be explained. Here, in order to make the operation easier to understand, the photoconductor 24 on the photosensitive drum 22 is zinc oxide, and the cylindrical elastic body 30 is made of an aluminum core 31 and contains carbon as the elastic material 32. Fur brush with 3,600 rayon fibers flocked with a gloss level of 2, the surface roughness of the developing roller 29 is 5 μrn Rll
The linear pressure of the elastic blade 47 in pressure contact with the 1aXt developing roller 29 is 25 g/cm, the gap between the photosensitive drum 22 and the developing roller 29 is O.15+nm, and the developer 28 is a normal positively charged non-magnetic l component toner. I experimented using it.

In FIG. 1, the charger 25 is connected to a first high-voltage DC power source 26.
A high voltage of about -6 kV is applied, and the entire surface of the photosensitive drum 22 is negatively charged to about -600 cm by a negative corona. Next, if a reflected image (pattern light image) of the document irradiated by a halogen lamp or the like is projected by the optical section 27 onto the negatively charged photosensitive drum 22, the portion corresponding to the non-image area of the document on the photosensitive drum 22 will be exposed to the reflected light. The static electricity is removed to a residual potential close to Ov, forming a positive electrostatic latent image.

During this time, the developer 28 in the storage section 35 is uniformly supplied to the developer reservoir 44 through the opening 41 by the sheet-like elastic member 39. Next, the uniformly supplied developer 29 is supplied into the fur brush 30. During this supply, since the gap δ is smaller than the width λ of the opening 41, the developing roller 2
The uncharged developer 28 does not adhere to the surface of the developer 9.

Next, the excess developer 28 in the fur brush 30 is scraped off by a scraping plate 42 and an appropriate amount is supplied, and the developing agent 28 is positively charged by friction with the scraping plate 42 and the casing 33. Next, the charged developer 28 in the fur brush 30 causes the developing roller 2 to
An electric field is generated between the developing roller 9 and the fur brush 30 to coat the surface of the developing roller 29 with the charged developer 28. At this time, θ~250 from the second DC high voltage voltage ff60
The layer thickness is adjusted by applying a voltage of about V. Furthermore, when the developer 28 is transferred from the fur brush 30 to the developer a-ra 29 by applying this voltage, even if there is, for example, uncharged developer 28 or developer 28 charged with the opposite sign in the developer 28, The uncharged developer 28 and the developer 28 charged with the opposite sign are difficult to be transported, and only the normally charged developer 28 is selected and contributes to the development.

Therefore, the developing roller 29 is coated with the uniformly charged developer 28, and a high-quality image can be obtained. Here, the layer thickness of the developer 28 on the coated surface of the developing roller 29 is greater than a predetermined thickness, and there is some variation. Next, developing roller 2
When the charged developer 28 on the surface of the developing roller 29 passes through the elastic blade 47, a part of it is scraped off by the elastic blade 47 to a predetermined layer thickness, that is, about 40 μm (the layer thickness at this time is IO). ~70 μm is desirable). The end face of the elastic blade 47 is finished with a straightness of 0.15 mm or less, and the mounting position is as shown in FIG. Since the surface 47B is placed in pressure contact with the developer roller 29, the layer thickness and charge amount of the developer 28 on the developer roller 29 become uniform. Further, as shown in FIG. 4, the linear pressure of the elastic blade 47 in the axial direction of the developing roller 29 is applied to the flat surface 47B on the opposite side of the pressure contact portion of the elastic blade 47 to the mounting member 6.
By adhering to 3, it can be kept constant. moreover,
Since the linear pressure of the elastic blade 47 can be finely adjusted using the adjustment screws 64A and 64B, the layer thickness and charge amount of the developer 28 can be made more uniform. As a result, a high-quality image without density unevenness can be obtained.

Next, the position of the elastic blade will be roughly explained in detail based on FIG. 6. The position of the surface 47B including at least the downstream edge 47A of the elastic blade 27 with respect to the moving direction of the developing roller 29 is the nip when the edge 47A of the elastic blade 47 does not come into contact with the surface of the developing roller 29, as shown in FIG. This is the position where a surface 47B occurs and an edge 47A is provided within the range of the nip surface 47B.

Next, the developer 28 that has come into contact with the elastic blade 47 falls onto the fur brush 30 while moving from the center of the developing roller 29 toward both ends. By rotating the spiral fur brush 30, the fur brush 30 moves from both ends to the center. Therefore, the developer 28 near both ends of the developing roller 29 and the far roller 9300 does not increase, and the height of the developer 28 in the storage section 35 is kept constant.

Furthermore, the first sealing material 48, 49 and the second sealing material 5
0.51 and elastic sheet 52. 53 surrounds the outer circumferential surfaces 29a and 29b at both ends of the developing roller, so that the developer 28 moving to both ends of the developing roller 29
No scattering or leakage. In other words, the present developing device can charge the developer 28 on the developing roller 29 uniformly, and can also make the layer thickness uniform, and furthermore, there is no scattering or leakage of the developer 28, and there is no fogging or density unevenness. High quality images can be obtained.

Next, when the negatively charged electrostatic latent image on the photosensitive drum 22 faces the positively charged developer 28 of the developing roller 29-H, the developer 28 is blown away by the electrostatic force of the electrostatic latent image on the photosensitive drum 22. Then, the latent image can be developed.

The surplus developer 28 that has not been used for development is carried further downstream while adhering to the developing roller 29 and passes through the leak prevention sheet 58 . At this time, since the leak prevention sheet 58 is in light contact with the developing roller 29, the developer 28 is carried directly into the housing 33 by electrostatic adhesion, and after passing through the leak prevention sheet 58, it is returned to the outside. It won't leak.

The developer 28 adhering to the surface of the developing roller 29 is scraped off by the fur brush 30 to erase the history of the developing roller 29. Therefore, a high-quality image without ghosts can be obtained.

The developer 28 scraped off by the fur brush 30 is transported by the fur brush 30, and then scraped off by the scraping plate 42 and returned to the storage section 35 through the opening 41.
The developer 28 on the developer roller 29 is not overcharged. Therefore, high-quality development is possible.

In this developing state, an appropriate amount of developer 2 is in the fur brush 30.
8, so the fur brush 30 and the developing roller 29
The current value of the detection means 61 is small because the contact resistance between the two is high. Next, the developing process is repeated, and when the developer 28 in the storage section 35 and the developer 28 in the fur brush 30 are used up,
The contact resistance described above becomes lower and the current value of the detection means 61 becomes larger. Therefore, the presence or absence of the developer 28 in the storage section 35 can be detected based on the current value of the detection means 61. Furthermore, even if the amount of developer 29 decreases, the sheet-like elastic member 39 is rotated clockwise and is displaced as shown in FIG.
1 into the fur brush 30. Therefore, even if the bottom surface of the storage section 35 is made horizontal, the developer 28 in the storage section 35 can be transferred to the fur brush 3 without any problem.
Can be supplied to 0. Further, since the developer 28 is stirred by a sheet-like elastic member 39 within the storage section 35, the developer 28 is
This has the effect of keeping the height of the developer 28 in the developer 5 constant.

Note that since the circumferential speeds of the developing roller 29 and the photosensitive drum 22 are the same, it is possible to eliminate edge effects when developing a latent image.

This developing device can uniformly supply the developer to the fur brush using the developer reservoir, and since the developer is not directly supplied to the developing roller, it is possible to supply uniformly charged developer to the developing roller. Further, since the charged developer on the developing roller is returned to the developer storage means by the circulation means, there is no overcharged developer on the developing roller. Therefore, high-quality development becomes possible. Further, since one fur brush can supply the developer to the developing roller and scrape off the developer on the developing roller after development, the configuration can be simplified and the device can be made smaller.

In addition, since the structure is such that there is no developer leakage or scattering, restrictions on the arrangement of the developing device can be expanded.

Next, a second embodiment of the present invention will be described.

FIG. 8 shows a second embodiment of the invention, in which members having the same functions as in the first embodiment of the invention are given the same numbers. In the first supply means 36, a sheet-like elastic member 39 on the outer peripheral surface of a mandrel 38 rotates counterclockwise within the storage section 35. The developer reservoir 44 has a capacity capable of supplying a predetermined amount of developer 28 to the fur brush 30, and is provided with a gap δ between the end 44A of the developing roller 29 and the outer peripheral surface of the fur brush 30. The gap δ is smaller than the opening λ of the opening 41. Further, the developer reservoir 44 has a supply port 44B. Therefore, the sheet-like elastic member 39
The developer 28 is supplied to the developer reservoir 4 through the supply port 44B.
4. In addition, the supply opening width ε is 4 to 8 mn+, the gap δ is 0.5 to 3III11, and the closing width λ is 4 to 8 mn+.
Good supply performance was achieved in 8 cases. fur brush 3
The peripheral speed of 0 is slower than the peripheral speed of the developing roller 29. Therefore, the developer 28 adhering to the surface of the developing row 129 can be scraped off after the developing process. Application means 6
0 is AC between the developing roller 29 and the fur brush 30.
A voltage obtained by superimposing a positive DC voltage on the voltage is applied to the fur brush 30 side to adjust the layer thickness of the developer 28 charged on the surface of the developing roller 29.

L2 The operation of the second embodiment will be explained. In FIG. 8, the developer 28 in the storage section 35 is transferred to the sheet-like elastic member 3.
9 uniformly supplies the developer to the fur brush 30 via the supply port 44B and the developer reservoir 44. At this time of supply, the gap δ
is made smaller than the closed width λ of the opening 41, so that the uncharged developer 28 does not adhere to the developing roller 29.

Therefore, the developer 28 charged between the fur brush 30 and the housing 33 is supplied onto the developing roller 29 . Therefore, a high quality image can be obtained. Also AC
By providing the application means 60 that superimposes a DC voltage on the voltage, it is possible to coat the developer 28 on the developing roller 29 to a predetermined layer thickness or more, and furthermore, the developer 28 attached to the surface of the developing roller 29 after development can be coated. 28 is reciprocated between the fur brush 30 and the developing roller 29 using the AC voltage, erasing the history of the developing roller 29, and preventing aggregation of the developer 28 and high adhesion of the developer 28 to the developing roller 29. can be done. Therefore, a high-quality image without ghosts can be obtained.

In this embodiment, an example was explained in which regular development (positive-positive development) in an electrophotographic copying machine was tested, but it goes without saying that the present invention is also applicable to reversal development (negative-positive development) in a laser printer or the like. Furthermore, the present invention is not limited to the two embodiments described above, but also includes supplying the developer to the developer reservoir, charging the developer,
Needless to say, many more configurations are possible by combining various elements such as coating on the developing roller and regulation of layer thickness. Furthermore, the present invention is well suited to non-magnetic component developers, and by configuring the charge carrier and the developer carrier in a non-contact manner, multiple color developers can be stacked on the charge carrier for development. It also becomes possible to form color images.

As described in detail, in the present invention, since the second supply means supplies the developer to the first supply means via the developer reservoir, it is possible to uniformly supply the developer to the first supply means. ,
Therefore, the uniformly charged developer is supplied to the developer carrier by the first supply means. As a result, high-quality development becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of essential parts of a developing device in a first embodiment of the present invention, FIGS. 2 to 6 are configuration diagrams of each part of the developing device in the first embodiment, and FIG. FIG. 8 is a cross-sectional view of a main part of a developing device according to the first embodiment of the present invention, FIG. 8 is a cross-sectional view of a main part of a developing device according to a second embodiment of the present invention, and FIGS. FIG. 2 is a sectional view of a main part of a developing device using a developer. 28...Developer, 29...Developer carrier, 30...
・First supply means, 36...Second supply means, 44.
...Developer reservoir. Name of agent: Patent attorney Toshio Nakao Idiot 1 person 28-...
Current 1-punishment? ? -fi ｜ 雾 切但轻体 J - ``First offering g + stage 2nd figure et al. 0 M 4 Figure 9 Figure 1 □

Claims (7)

[Claims] (1) An endless developer carrier, a first supply means for supplying developer to the developer carrier, a second supply means for supplying developer to the first supply means, and a developer reservoir. The development reservoir is located above the first supply means between the developer carrier and the second supply means, and the developer from the second supply means is transferred through the developer reservoir. A developing device characterized in that the developing device is configured to supply the first supplying means with the first supplying means. (2) The developing device according to claim 1, further comprising a circulation means for flowing the developer into and out between the first supply means and the second supply means. (3) The first supply means is composed of a cylindrical elastic body, and the excess developer on the elastic body is scraped off by sliding contact with the cylindrical elastic body, and the developer on the elastic body is scraped to make the developer uniform on the elastic body. 2. The developing device according to claim 1, further comprising a plate. (4) The first supply means is composed of a cylindrical elastic body, a partition plate having an opening through which the developer flows in and out is provided between the cylindrical elastic body and the second supply means, and the opening 2. The developing device according to claim 1, wherein is provided at a position where the developer from the second supply means is supplied in a tangential direction to the outer periphery of the cylindrical elastic body. (5) The first supply means is composed of a cylindrical elastic body, and a partition plate having an opening through which the developer flows in and out is provided between the cylindrical elastic body and the second supply means, and a developer reservoir is provided. 2. The developing device according to claim 1, wherein the end of the developer carrier side is disposed with a gap between the outer peripheral surface of the cylindrical elastic body and the gap is smaller than the opening area of the opening. (6) The first supply means is composed of a cylindrical elastic body, the developer carrier and the cylindrical elastic body are brought into contact, and the developer carrier and the cylindrical elastic body are moved in the forward direction at the contact position. 2. The developing device according to claim 1, wherein the circumferential speed of the cylindrical elastic body is faster than the circumferential speed of the developer carrier. (7) The developing device according to claim 1, wherein the first supply means is constituted by a cylindrical fur brush.