JPH01170969A - Developing device - Google Patents

Abstract

PURPOSE:To perform development of high picture quality by providing a means which detects an operation time, a 1st applying means which applies a voltage between a charge holder and a developer carrier, and a means which controls the voltage of the 1st applying means according to the operation time of the detecting means. CONSTITUTION:This developing device is provided with the detecting means 64 which detects the operation time of the developing device, the 1st voltage applying means 57 which applies the voltage between the charge holder 22 and developer carrier 29, and the control means 65 which controls the voltage of the 1st voltage applying means 57 according to the operation time of the detecting means 64. The specific density is maintained by controlling the voltage of the 1st applying means 57 by the control means 65 according to the relational expression between image density and the voltage of the 1st applying means 57 between the latent image holder and developer carrier 29 corresponding to the voltage of the developer carrier 29.

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 Application Laid-Open No. 54-43038 and US Pat. No. 4,083,326, and its construction is shown in FIGS. 18 and 19.

In Figure 18 (Japanese Unexamined Patent Publication No. 54-43038),
1 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 l 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 l.
coated on the surface of Next, charged toner 2
When facing the electrostatic latent image on the photoreceptor 5, it is blown away and developed.

In FIG. 19 (US Pat. No. 4,083,326), 13 is a developing roller, 14 is a toner, 15 is a hopper,
16 is a blade, 17 is a sheet-like photoreceptor, 18.19
20 is a conductive fur brush in sliding contact with the developing roller 13;
is a first power supply that applies voltage to the hopper 15 and the conductive fur brush 18, and 2! is a second power source that applies voltage to the conductive fur brush 18 and the developing roller.

Further, the voltage applied by the second power supply 2I is the same as that of the first power supply 20.
The voltage is set higher than the voltage applied by the photoreceptor 17 and lower than the voltage applied to the electrostatic latent image on the photoreceptor 17. The toner 14 triboelectrically charged by the fur brush 18 is supplied to the first and second power sources 20 .
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 toner 14 on the developing roller 13 after development 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, with such a system, there is a problem in that the image density decreases as the operating time of the developing device increases, making it difficult to reproduce high-quality images.

In view of this point, the present invention provides a developing device capable of reproducing high image quality.

Means for Solving the Problems The developing device of the present invention includes a detecting device for detecting a leap during operation of the developing device, and a first voltage applying device for applying a voltage between a charge holding member and a developer carrying member. Further, a control means is provided for controlling the voltage of the first voltage application means in response to the operating jump of the detection means.

action The effect of this technical means is as follows.

The relationship between the voltage of the first applying means corresponding to the operating time of the developing device and the image density is checked in advance, and the voltage of the first applying means is adjusted by the control means in response to the operating time of the developing device detected by the detecting means. By controlling this, a predetermined density can be maintained, and as a result, high-quality image development becomes possible.

Embodiment FIGS. 1 to 6 show examples in which the developing device according to the first embodiment of the present invention is 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 holding member 22 is a photosensitive drum, in which a photoconductor 24 made of zinc oxide, selenium, organic photoconductive material, etc. is supported on the surface of an aluminum base 23. (Therefore, the charge holding body 22 will be referred to as a photosensitive drum 22 hereinafter.) Reference numeral 25 denotes a charger that uses a first DC high voltage power source 26 to charge the photoconductor 24 on the photosensitive drum 22, for example, negative in the case of zinc oxide, In the case of selenium, a positive corona is applied to charge the entire surface of the photoconductor 24.

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, and for example, a metal roller made of stainless steel, aluminum, etc., a roller whose surface is coated with resin, etc. is used. Preferably, as shown in FIG. The outer circumferential surfaces 29a and 29b are smooth at both ends, and the center surface 29c has a rough surface with minute irregularities, and is installed at a constant distance from the photosensitive drum 22, for example, in a counterclockwise direction as shown in FIG. Rotate it. A cylindrical elastic body 30 is a first supply means for supplying the developer 28 to the developing roller 29. The cylindrical elastic body 30 is a fur brush, a roller made of a sponge, etc., and is applied to the outer peripheral surface of the mandrel 31. A layer of elastic material 32 is formed.

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, comes into sliding contact with the surface of the developing roller 29, and is rotated, for example, in a clockwise direction 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, as shown in FIG. 3, the fibers of the fur brush 30 are formed in a spiral shape in a direction in which the developer 28 moves from the outer periphery of both ends of the fur brush 30 to the center when the fur brush 30 is rotated. Reference numeral 34 denotes a developer storage means, which is composed of a storage section 35 that stores the developer 28 and a second supply means 36 that supplies the developer to the first supply means 30 . Further, the storage section 35 has an opening 37 for replenishing the developer 28 at one end, and is formed of 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 which is a circulation means and is provided between the first supply means 30 and the second supply means 36, and the developer 28 is provided between the first supply means 30 and the second supply means 36.
0 and the second supply means 36
It has. Reference numeral 42 is formed by a part of the scraping plate or the like body 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 partition plate,
The developer roller 29 is provided between the developer roller 29 and the second supply means 36 at a position where the developer 28 in the storage section 35 is not directly supplied to the developer carrier 29. Furthermore, a gap δ is provided between one end of the partition plate 44 and the outer peripheral surface of the fur brush 30. Good performance was achieved when the gap δ was 0.5 to 311II11. Reference numeral 62 denotes a remaining amount detection means for detecting the remaining amount of the developer 28, and is provided between the partition plate 44 and the partition plate 40. The remaining amount detecting means 62 is a well-known sensor that detects the amount of developer by vibration, transmittance, etc. As shown in FIG. 2, 45 is a bearing for the developing roller, and 46 is a bearing for the fur brush 30.

Reference numeral 47 denotes a blade which is a layer thickness regulating means for regulating the layer thickness of the developer 280. In this embodiment, a rubber blade made of an elastic material such as urethane rubber is used, but other rubber materials or polyethylene may be used as the blade material. It may be made of an elastic synthetic resin such as terephthalate, an elastic metal such as phosphor bronze or spring steel, or an elastic metal or synthetic resin coated with a fluororesin. Also, blade 47
The accuracy and mounting position of the end face of the blade 47 have a great influence on the formation of a uniform thin layer of the developer 28, so the end of the blade 47 is precisely finished with a straightness of 0.15 mm or less, and the mounting is The blade 47 is positioned in pressure contact with the developer carrier at a surface including at least the downstream edge of the blade 47 with respect to the moving direction of the developer roller 29 . Furthermore, the width of the 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 FIG. 48.49
is a sealing material that prevents the developer 28 from leaking, and is made of an elastic material such as woven fabric, nonwoven fabric (felt), sponge, or rubber. Also, the sealing material 48 and 49 are the developing roller 2.
9 and both end surfaces of the blade 47. Reference numeral 50 denotes a spill prevention means for the developer 28, which is provided upstream from the opposing position of the developing roller 29 and the fur brush 30 with respect to the moving direction of the fur brush 30 and below the developing roller 29. The spill prevention means 50 is composed of a U-shaped leak prevention member 51 and a leak prevention sheet 52 whose one end is fixed to the leak prevention member 51 and the other end is in light contact with the surface of the developing roller 29. Note that one end of the leak prevention sheet 52 of the spill prevention means 50 may be provided on the housing 33. Further, the width of the leak prevention sheet 52 is set to a length such that it comes into contact with the outer circumferential surfaces 29a and 29b at both ends of the developing roller 29, and both ends thereof are formed by sealing materials 48 provided at both ends of the developing roller 29, as shown in FIG. Developing roller 29 by 49
It is in pressure contact with the Furthermore, the end of the leak prevention sheet 52 on the side that lightly contacts the surface of the developing roller 29 is connected to the fur brush 30.
The developing roller 29 and the fur brush 30
It is located upstream from the line connecting the centers of the The leak prevention sheet 52 is made of an elastic material such as polyethylene terephthalate or urethane rubber. In this embodiment, urethane rubber has good adhesion to the developing roller 29.
(preferably about 0 to 200 μm). The leak prevention member 51 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 52, 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 52, the capacity of the leakage prevention member 51 may be small. 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, fur brush 3o
has a specific resistance of about 1018Ω or less, preferably 103Ω
It is better to use a conductive material with a conductivity of 107 Ωcm to 107 Ωcm.

Furthermore, as the fur brush 30, other conductive fibers may be used instead of just conductive rayon fibers as in this embodiment, or a fur brush made by electrostatic flocking may be used to make the coating uniform. It is also effective to use

Furthermore, it goes without saying that the aforementioned 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 3° cylindrical elastic material 32. . Note that when the developer 28 is a one-component magnetic toner, a magnetic roller is used as the mandrel 31, a magnetic brush is formed on the outer periphery, and a cylindrical elastic body 3 is formed.
It is also effective to set it to 0. 64 is a detection means for detecting the operating time of the developing device. In this embodiment, the operating time of the developing device is detected based on, for example, the rotation time of the developing roller 29. Further, the detection means 64 is provided on the side of the housing 33 as shown in FIG. 2, and detects the rotation of the developing roller 290 using, for example, a well-known electronic counter, and converts the rotation time into an electrical output.

A first applying means 57 applies a voltage between the photosensitive drum 22 and the developing roller 29, and applies, for example, a DC bias voltage. 65 is a control means for controlling the voltage of the first application means 57 in accordance with the rotation time of the detection means 64. Note that the control means 65 adjusts in advance the relationship between the voltage of the first application means 57 and the density corresponding to the operating time of the developer roller 29, and the control means 65 adjusts the relationship between the voltage of the first application means 57 and the density corresponding to the operating time of the developer roller 29, and A predetermined concentration is maintained by controlling the voltage of one applying means 57.

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 photosensitive drum 22
The upper photoconductor 24 is an organic photoconductive material, and the cylindrical elastic body 3
0 is a fur brush in which about 3,600 rayon fibers with a specific resistance of about 105Ω are implanted on an aluminum core 31 and contain carbon as an elastic material 32;
The surface roughness of the developing roller 29 is 2 μmRmax, and the linear pressure of the blade 47 that presses against the developing roller 29 is 60 g/am.
, the gap between the photosensitive drum 22 and the developing roller 29 is 0.
15, photoreceptor and developing roller peripheral speed is 150n+m/S
The peripheral speed of the fur brush was 225+wsw/s, and the developer 28 was an ordinary positively charged non-magnetic one-component toner.

In FIG. 1, a first high-voltage DC power supply 26 is connected to a charger 25.
A high voltage of about -6 kV is applied, and the entire surface of the photosensitive drum 22 is negatively charged to about -800 V 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.

Meanwhile, the developer 28 in the storage section 35 is transferred to the second supply means 3.
6 into the fur brush 30 through the opening 41. Since the developer 28 is not directly supplied to the developing roller 29 by the partition plate 44 during this supply, the uncharged developer 28 does not adhere to the developing roller 29. Next, the excess developer 28 in the fur brush 30 is removed by a scraping plate 42.
It is scraped off and supplied in an appropriate amount, and is positively charged by friction with the scraping plate 42 and the housing 33. Next, the developing roller 29 is activated by the charged developer 28 in the fur brush 30.
An electric field is generated between the developing roller 2 and the fur brush 30.
9 is coated with a charged developer 28. At this time, the developer 28 supplied in an appropriate amount is further uniformly charged positively by friction with the surface of the developing roller 29 due to the rotation of the fur brush 30. At this time, the developing roller 2
9 and the fur brush 30, and the housing 33 is electrically insulated from the fur brush 30, so that a strong voltage that generates an electric field is applied between them. It does not occur that the charged developer 28 is easily transferred. Therefore, the developing roller 2
9 is coated with a uniformly charged developer 28, making it possible to obtain a high quality image.

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. Subsequently, as the developing roller 29 rotates, the charged developer 28 on the surface of the developing roller 29 is removed.
When passing through the blade 47, a part of it is scraped off by the blade 47, resulting in a predetermined layer thickness of about 40 μm (
The layer thickness at this time is preferably regulated to about 10 to 70 μm. In addition, the end face of the blade 47 is finished with a straightness of 0.15+sm or less, and the blade 47 is installed with respect to the moving direction of the developing roller 29 as shown in FIG.
Since the surface 47B including at least the gill 47A on the downstream side is pressed against the developer roller 29, the layer thickness and charge amount of the developer 28 on the developer roller 29 become uniform. As a result, density unevenness and developer spillage do not occur.

The blade position will be explained in more detail based on FIG. 5.

The position of the surface 47B including at least the downstream edge 47A of the blade 27 with respect to the moving direction of the developing roller 29 is the nip surface 47B when the edge 47A of the blade 47 is not in contact with the surface of the developing roller 29, as shown in FIG. occurs, and the edge 47A is provided within the range of the nip surface 47B. Next, the developer 28 partially scraped off by the blade 47 is moved from the center of the developing roller 29 toward both ends, and is moved from both ends of the fur brush 30 to the center by rotation of the spiral-shaped fur brush 30. Go to section. Therefore, the developing roller 29 and the fur brush 30
There is no increase in the amount of developer 28 near both ends of the storage section 35, and the height of the developer 28 in the storage section 35 is kept constant. Furthermore, since the sealing material 48, 49 that is in contact with both end surfaces of the blade 470 is in contact with the smooth surfaces of the outer circumferential surfaces 29a and 29b at both ends of the developing roller 29, even when the developing roller 29 rotates, wear is extremely low. There is no scattering or leakage of the developer 28. Further, the joint surface of the sealing material 49 that contacts the blade 47 and the developing roller 29 is a smooth surface, and no gap is generated in the joint portion. Therefore, the developing roller 29
There is no leakage of the developer 28 due to the component force pushed in the axial direction. That is, 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. The detection means 64 detects the rotation time of the zero-order developing roller 29, which allows a high-quality image to be obtained, and the control means 65 applies a voltage corresponding to the rotation time to the first developing roller 29 and the photosensitive drum 22. is applied to the applying means 57. The control method of the control means 65 will be explained in more detail based on the experimental results shown in FIG. FIG. 7 shows the relationship between the voltage of the first applying means 57 and the image density after the rotation time of the developing roller 29 is initial w4 (at the start) and one hour later. From this, the voltage of the applying means 57 of - By varying the density, the density can be controlled, and a relational expression between the rotation time of the developing roller 29 and the voltage of the first application means 57 to maintain a predetermined density can be determined.

Based on the above results, an example of the control method of the control means 65 will be briefly explained using FIG. 7.

For example, in order to maintain the predetermined concentration=1, the voltage of the first application means 57 is controlled so as to apply -580V initially and -210V after one hour. Therefore, by controlling the voltage corresponding to the rotation time of the current I1 roller 29 by the control means 65, it is possible to always maintain a predetermined density. Therefore, high-quality image reproduction becomes possible. It should be noted that the developing device having this configuration can also be adapted to the case where the voltage of the first voltage applying means 57 is an AC voltage or a DC voltage with an AC voltage superimposed thereon. Next, when the negatively charged electrostatic latent image on the photosensitive drum 22 faces the positively charged developer 28 on the developing roller 29, the developer 28 flies away due to the electrostatic force of the electrostatic latent image on the photosensitive drum 22. Then, the latent image can be developed. Next, the surplus developer 28 that was not used for development is transferred to the developing roller 2.
While still attached to the surface of the leak prevention sheet 52, it is carried further downstream and passes through the leak prevention sheet 52. At this time, since the leak prevention sheet 52 is in light contact with the developing roller 29, the developer 28 is carried as it is into the housing 33 by electrostatic adhesion, and after passing through the leak prevention sheet 52, it is removed again. It won't leak. Next, the developer 2 adhering to the surface of the developing roller 29
8 with the fur brush 30 and the developing roller 29
Clear your history. Therefore, a high-quality image without ghosts can be obtained. Next, the developer 28 scraped off by the fur brush 30 is transported by the fur brush 30, then scraped off by the scraping plate 42, and returned to the storage section 35 through the opening 41, so that it is placed on the developer roller 29. The developer 28 is not overcharged. Therefore, high-quality development is possible. In this developing state, there is a developer 2 in the storage section 35.
Therefore, when the second supply means 36 supplies the developer 28, the developer 28 is applied to the partition plate 44 and the partition plate 40.
8 accumulates, the remaining amount detecting means 62 detects that the developer 28 is present. Next, the second supply means 36 repeats the developing process, and even if the amount of developer 28 in the storage section 35 decreases, the sheet-like elastic member 39 continues to rotate clockwise, so that the image shown in FIG. The developer 28 can be constantly supplied into the fur brush 30 through the opening 41 by being displaced as shown. Therefore, even if the inclination angle of the bottom surface of the storage section 35 is made small, the developer 28 in the storage section 35 can be supplied to the fur brush 30 without any problem. Furthermore, since the developer 28 is stirred within the storage section 35 by a sheet-like elastic member 39, there is an effect that the height of the developer 28 within the storage section 35 is kept constant. Next, when the developer 28 runs out in the storage section 35, the developer 28 does not accumulate on the partition plate 44 and the partition plate 40m, so the remaining amount detecting means 62 detects the developer 28.
Detects the absence of . 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.

In this developing device, since the developer is not directly supplied to the developing roller by the partition plate, uncharged developer does not adhere 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 is possible. Further, since a single fur brush can supply developer to the developing roller and scrape off the developer on the developing roller after development, the structure can be simplified and the apparatus 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. 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.

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. The second supply means 36 has at least two blades 39a and 39b on the outer circumferential surface of the mandrel 38, and the storage portion 35
It has a structure that rotates inside. Also, the blades 39a and 39b
The blade 39a on the downstream side in the rotational direction of the blade has a larger elastic force than the blade 39b on the upstream side, and one end of the blade 39b is brought into slight contact with the inner wall of the storage section 35, and one end of the blade 39a is brought close to the inner wall of the storage section. It is set up. Furthermore, the blade 39a is provided with an opening hole 39c. In this embodiment, the blade 39b is made of a sheet-like elastic material made of polyethylene terephthalate or the like with a thickness of approximately 30 μm, but the elastic material may be a rubber material such as urethane or neoprene, or an elastic synthetic material such as polystyrene or Teflon. It may also be a resin film or an elastic metal such as phosphor bronze or spring steel. Further, although the blade 39a is made of a rigid material such as an aluminum plate, the rigid material may also be metal such as stainless steel, a material coated with fluororesin, hard resin, ceramics, or the like. Moreover, the mandrel 38 rotates clockwise. In this embodiment, the layer thickness regulating means 47 is in pressure contact with the developing roller 29 to regulate the layer thickness of the developer 28 so that highly accurate adjustment is not required. Further, the blade 47 has a structure of at least two layers in the pressure contact direction, and the layer 4 on the side that contacts the developing roller 29? The elastic modulus of layer a is made smaller than that of the other layer 47b. In this embodiment, layer 47a is made of urethane rubber and layer 47b is made of urethane rubber.
Although the layer 47b is formed integrally with an elastic material such as a phosphor bronze plate, other rubber materials or elastic synthetic resins may be used as the material for the layer 47b. An elastic metal such as steel may also be used. Further, the peripheral speed of the fur brush 30 is set lower than the peripheral speed of the developing roller 29.

Therefore, the developer 28 adhering to the surface of the developing roller 29 can be scraped off after the developing process. Reference numeral 53 denotes a second DC high voltage power source which is a second voltage applying means, and applies a voltage between the developing roller 29 and the fur brush 30 to adjust the layer thickness of the developer 28 charged on the surface of the developing roller 29. It is for adjustment. 54 is a detection means for detecting the current value of the second DC high voltage power supply 53 and detecting the presence or absence of the developer 28. Reference numeral 55 denotes a fourth voltage applying means, which applies a voltage between the fur brush 30 and the leak prevention member 51 so that the developer 28 is attracted to the fur brush 30 side, thereby preventing the developer 28 from leaking. It is something to do.

Next, the operation of the second embodiment of the present invention will be explained.

The second supply means 36 supplies the fur brush 30 through the opening 41 . At this time, the feeding method is such that most of the developer 28 in the storage section 35 is transported by the highly elastic blades 39a, and the developer 28 on the inner wall of the storage section 35 is lightly axially transported by the low elastic blades 39b. Therefore, the developer 28 can be supplied into the fur brush 30 to the end without being damaged. Furthermore, since the blade 39a is provided with the opening hole 39c, the developer 28 is disposed between the blade 39a and the blade 39b.
will not get caught. Therefore, the transport of developer 28 becomes more constant. In this embodiment, one end of the blade 39b is placed in slight contact with the inner wall of the storage section 35, and one end of the blade 39a is provided close to the inner wall of the storage section 35, but two blades 39a are provided.
, 39b may be arranged so that one end thereof faces the inner wall of the storage section 35, and the length of the blade 39b is made longer in the direction of the inner wall of the storage section 35 than the blade 39a, and the blade 39b is provided close to the inner wall of the storage section 35. In this operation, the bending angle of the blade 39b having low elastic force changes depending on the amount of developer 28 in the storage section 35. Therefore, when there is a large amount of developer 28 in the storage section 35, the developer 28
8, the blade 39b bends and most of the developer is transported by the blade 39a. Next, the developer 28 in the storage section 35
When the amount is small, the blade 39b returns to its original position due to the elastic force of the blade, and the developer 28 on the inner wall of the storage portion 35 can be easily conveyed.

Therefore, the developer 28 can be supplied into the fur brush 30 to the end without being damaged. 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 housing 33. Further, this developer 28 is applied to the developing roller 2 by rotating the fur brush 300 times.
The developing roller 29 is conveyed to a position opposite to the developing roller 29, and the surface of the developing roller 29 is coated with the charged developer 28. Next, a voltage is applied between the developing roller 29 and the fur brush 30 by the second DC high voltage power source 53 to adjust the layer thickness of the charged developer 28 on the surface of the developing roller 29. The second DC high voltage power supply 53 applies a voltage of ±30v to ±250v.
The layer thickness can be adjusted by approximately v. At this time, for example, if a voltage is applied between the developing roller 29 and the fur brush 30 using the second DC high voltage power supply 53 with the fur brush 30 side being positive, the developer 28 is transferred from the fur brush 30 to the developing roller due to the electric field therebetween. When the developer 2 is transferred to the
For example, uncharged developer 28 and oppositely charged developer 28
Even if there is, uncharged developer and charged developer are difficult to be transferred, and only properly charged developer 28 is selected and contributes to development. Therefore, a good image can be obtained. In this developing state, there is an appropriate amount of developer 28 in the fur brush 30, and therefore the contact resistance between the fur brush 30 and the developing roller 29 is high, so the current value of the detection means 54 is small. Next, the developing process is repeated and the storage section 35
When the developer 28 in the fur brush 30 and the developer 28 in the fur brush 30 are used up, the contact resistance becomes lower and the current value of the detection means 54 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 54. Further, the developer 28 is contained in the storage section 35 by the blades 39.
Since a and 39b are agitated and rotated, there is an effect that the height of the developer 28 in the storage section 35 is kept constant. Here, the layer thickness of the developer 28 on the surface of the developing roller 29 coated by voltage adjustment of the second DC high voltage power supply 53 is greater than a predetermined thickness, and there is some variation.

Further, since the developer 28 in the fur brush 30 is splashed onto the developing roller 29 by the voltage of the second DC high voltage power supply 53, it takes 1 time for the developer 28 to rise to a predetermined layer thickness. Since it can be done quickly within seconds, no extra waiting time is required. Next, as the developing roller 29 rotates, the charged developer 28 on the surface of the developing roller 29 is further positively charged by the blade 47 as it passes through the blade 47, and a portion is scraped off to regulate the layer thickness to a predetermined thickness. Ru. The reason for this is the layer 4 on the side that comes into contact with the developing roller 29? Since the layer a is formed of a urethane rubber layer with a small elastic modulus, it has good adhesion to the developer 28 on the developing roller 29, and the other layer 47b is a phosphor bronze layer with a high elastic modulus and presses the developing roller 29. Therefore, the angle θ between the surface of the developer 28 on the developing roller 29 and the blade surface in contact with the surface can be increased, and the accumulation of the developer 28 between the developing roller 29 and the blade 47 can be reduced, and the condensation can be improved. The generation of the agent can be reduced, and as a result, the development roller 29
The developer 28 supplied above can be regulated to have a uniform, predetermined layer thickness. Therefore, a high-quality image without density unevenness can be obtained. Next, when the negatively charged electrostatic latent image on the photosensitive drum 22 faces the positively charged developer 28 on the developing roller 29, the developer 28 flies away due to the electrostatic force of the electrostatic latent image on the photosensitive drum 22. Then, the latent image can be developed.

After development, the developer 28 adhering to the surface of the developing roller 29 is scraped off with a fur brush 30.
Delete the history of 9. Therefore, a high-quality image without ghosts can be obtained. Next, the developer 28 scraped off by the fur brush 30 is conveyed by the fur brush 30, then scraped off by the scraping plate 42, and returned to the storage section 35 through the opening 41, onto the developing roller 29. The developer 28 is not overcharged. Therefore, high-quality development becomes possible.

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

In FIGS. 9 and 10, members having the same functions as in the second embodiment of the present invention are given the same numbers. As shown in FIG. 1O, the layer thickness regulating means 47 has at least the pressure contact portion with the developing roller 29 formed in a convex shape, and the convex twill line 62 of the fur brush 30 is connected to the developing roller 29 with a small gap L (L). is preferably 0.05 to 0.51111). Further, the peripheral speed i of the fur brush 30 is the same as the peripheral speed of the developing roller 29. A second voltage applying means 53 is provided between the developing roller 29 and the fur brush 30.
A voltage obtained by superimposing a positive DC voltage on the C 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.

Next, the operation of the third embodiment of the present invention will be described.

In FIG. 9, by providing a second voltage applying means 53 that superimposes a DC voltage on an AC voltage, the developer 28 can be coated on the developing roller 29 to a predetermined layer thickness or more, and furthermore, the developing roller 29 can be coated with the developing agent 28 after development. Developer 2 attached on the surface of 29
8 is reciprocated by the fur brush 30 and the developing roller 29 using the AC voltage, the history of the developing roller 29 is erased, and the aggregation of the developer 28 and the high adhesion of the developer 28 to the developing roller 29 are prevented. can be done. Therefore, a high-quality image without ghosts can be obtained. Further, the blade 47, which is a layer thickness regulating means, has a small gap to equalize the amount of developer 28 supplied onto the developing roller 29, and then regulates the developer to a uniform predetermined layer thickness with the pressure contact surface of the convex portion. can.

Furthermore, the developer 28 that was partially scattered by the blade 47 is
The force of the subsequent developer 280 changes the flow along the wall surface of the convex portion of the blade 47 in the direction of arrow A, and the fur brush 30
Fall to the side. As a result, the developer 28 flows back to the area where the developing roller 29 and the blade 47 face each other in the vicinity of the pressure contact area, so that more uniform coating can be achieved. Therefore, it is possible to obtain a high-quality image without density unevenness with a simple configuration without requiring highly accurate adjustment. Further, by rotating the mandrel 38 of the second supply means 36 in the counterclockwise direction, when one end of the blade 39a faces the opening 41, the blade 39
A space can be formed between a and the blade 39b. Therefore, the developer 28 on the developing roller 29 after development is conveyed by the fur brush 30, then scraped off by the scraping plate 42, returned to the space in the storage section 35 through the opening 41, and then returned to the space in the storage section 35. The developer 28 in the part is moved to the blade 39 by the elastic force of the blade 39b.
It can flow out from the funnel hole 39c of a. Therefore, overcharging of the developer 28 can be further prevented, and the scraping effect of the scraping plate 42 can be enhanced.

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

In FIG. 11, members having the same functions as in the second embodiment of the present invention are given the same numbers. Also,
The second supply means 36 are the same as in the first embodiment of the invention. Further, the second voltage applying means 53 between the developing roller 29 and the fur brush 30 applies a voltage higher than a predetermined voltage when applying a voltage, and applies a voltage to a predetermined voltage after applying a voltage. be. The layer thickness regulating means 47 is a rigid body made of metal such as stainless steel, coated with fluororesin, or hard resin.
It is made of ceramics or the like and is brought into contact with the developing roller 30 by the elastic force of a pressing spring 56.

Next, the operation of the fourth embodiment of the present invention will be described.

In FIG. 11, the developing roller 29 and the fur brush 30
The second voltage applying means 53 applies a voltage higher than a predetermined voltage when applying a voltage to increase the amount of developer 28 supplied from the fur brush 30, and after applying a voltage, the second voltage applying means 53 applies a voltage higher than a predetermined voltage. Apply voltage to fur brush 30
By increasing the ability to supply the developer 28 from the developer 28, it is possible to eliminate a decrease in image density at the initial stage of development and after the initial stage of development. Furthermore, by configuring the layer thickness regulating means 47 with a rigid body such as metal, a smoother surface can be obtained compared to rubber or the like, and by bringing this into contact with the developing roller 29, a uniform surface without streaks or unevenness can be obtained. A thin layer of developer material 28 is formed. Further, by superimposing the AC voltage on the DC voltage using the second voltage applying means 53, the developer 28 adhering to the surface of the developing roller 29 after development is removed from the fur brush 30 and the developing roller 29 by the AC voltage. The history of the developing roller 29 is erased, the developer 28 is agglomerated, and the developer 28 is moved back and forth between the developing roller 29 and the developing roller 29.
prevent high adhesion of Therefore, a high-quality image without ghosts can be obtained.

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

FIG. 12 shows a fifth embodiment of the present invention, in which parts having the same functions as in the fourth embodiment of the present invention are given the same numbers. In FIG. 12, a cylindrical elastic body 30 uses a conductive sponge as an elastic material 32, and is formed into a cylindrical roller around an aluminum mandrel 31. In addition, a cylindrical elastic body 300 and an elastic material 32
It is easy to understand that even if a conductive sponge is used as the material, the effects of frictional charging, coating, etc. described in the first embodiment can be effectively performed. In this example, development,
The roller 29 and the cylindrical elastic body 30 face each other at a close position with a constant interval (this interval is preferably in the order of 0.1 to 0.5). Needless to say, even with such a gap, the charged developer 28 is transferred to the developing roller 29 as described in the first embodiment. In addition, the layer thickness regulating means 4
Reference numeral 7 uses a blade made of an elastic body, and this blade 47 has one end thereof positioned downstream of the position where the developing roller 29 and the cylindrical elastic body 30 face each other with respect to the rotating direction of the developing roller 29.
The other end is brought into pressure contact with the surface of the developing roller 29 on the upstream side of the part facing the photosensitive drum 22, and the one end part bites into the developing roller 29 side due to the frictional force received at the pressed part when the developing roller 29 rotates. It is fixed to the structure 33 at a position where it acts. Further, the shape of the developing roller 29 and the pressure contact portion is formed into a convex shape, and the convex portion is constituted by a bag 47d in which the fluid 47c is sealed. In this embodiment, a urethane sheet bag 47d that seals an air fluid 47c is provided at one end of the urethane rubber mounting plate 47e. still,
The material of the fluid 40c may be any gas such as nitrogen, water, an aqueous solution of a low-molecular organic substance such as ethylene glycol, an aqueous polymer dispersion solution, or a liquid such as a polymer solution.

The material of the bag 47d may be a resin sheet such as polyethylene terephthalate, Teflon, or vinyl chloride resin, or other rubber sheet material.

Further, the mounting plate 47e may be made of an elastic material such as spring steel, resin, or rubber, or a rigid material such as aluminum, steel, or resin. Further, the voltage of the second voltage applying means 53 is gradually increased so as to supply a fixed amount of the charged developer 28 on the cylindrical elastic body 30 onto the developing roller 29 when the voltage is applied.

Next, the operation of the fifth embodiment of the present invention will be described.

In FIG. 12, the developing roller 29 and the cylindrical elastic body 3
By gradually increasing the voltage between 0 and 0 to a predetermined voltage by the second voltage applying means 53, the charged developer 28 on the cylindrical elastic body 30 is A fixed amount can be supplied onto the developing roller 29. Therefore, the surface of the developing roller 29 can be uniformly coated with the charged developer 28 . Further, the pressure contact portion with the developing roller 29 is at least the fluid 47c.
The developing roller 29 is configured with a sealed bag 47d.
The adhesion between the upper developer 28 and the bag 47d can be improved, and the contact pressure between the surface of the developer 28 on the developer roller 29 and the layer thickness regulating means 47 can be kept constant. Further, since the pressure contact portion of the blade 47 is provided at a position where it acts to bite into the developing roller 29 side, the developer 28 does not accumulate between the developing roller 29 and the blade 47. Therefore, there is an effect of preventing aggregation or assimilation of the developer 28. Further, the blade 47 has a convex shape at the portion in pressure contact with the developing roller 29. Therefore, the facing distance between the developing roller 29 and the blade 47 after regulating the layer thickness is increased.
The charged developer 28 on the developing roller 29 is transferred to the blade 47.
There is nothing to fly to. Therefore, more uniform coating can be achieved.

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

FIG. 13 shows a sixth embodiment of the present invention, in which parts having the same functions as in the fifth embodiment of the present invention are given the same numbers. In FIG. 13, the layer thickness regulating member 47 includes a urethane sheet bag 47d that seals an air fluid 47c at one end of a rigid mounting plate 47e made of stainless steel. Further, the mounting plate 47e is attached to the developing roller 2 by a pressing spring 58 made of an elastic material such as spring steel, resin, or rubber.
It is in contact with 9.

Further, the layer thickness regulating member 47 has one end thereof connected to the developing roller 29.
in pressure contact with the surface of the developing roller 29 on the downstream side of the opposing position of the developing roller 29 and the cylindrical elastic body 30 and on the upstream side of the opposing part with the photosensitive drum 22, with respect to the rotation direction of
The other end is fixed to the housing 33 at a position where the one end tends to escape from the surface of the developing roller 29 due to the frictional force received at the pressure contact part when the developing roller 29 rotates, and the shape of the developing roller 29 and the pressure contact part is adjusted. It has a convex shape.

Next, the operation of the sixth embodiment of the present invention will be described.

In FIG. 13, the contact area between the developing roller 29 and the bag 47d can be made more uniform in the axial direction of the developing roller 29 by constructing the mounting plate 47e of the layer thickness regulating means 47 from a rigid metal body, for example. Further, by making the shape of the pressure contact portion with the developing roller 29 into a convex shape, the developer 28 that has been partially scraped off by the layer thickness regulating means 47 is removed by the force of the succeeding developer 28 from the convex portion of the layer thickness regulating means 47. The flow changes along the wall surface in the direction of the arrow and falls toward the cylindrical elastic body 30. As a result, the developer 28 flows back to the area where the developing roller 29 and the layer thickness regulating means 47 face each other in the vicinity of the pressure contact area, so that a rough and uniform coating can be achieved.

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

14 to 16 show a seventh embodiment of the present invention. In FIG. 16, parts having the same functions as in the second embodiment are given the same numbers. Developing roller 2
The outer peripheral surfaces 29a and 29b at both ends of 9 are smooth surfaces, and the central surface 2
A rough surface with fine irregularities is formed on the surface 9c. Further, as shown in FIGS. 15 and 16, the uneven rough surface 29c is formed by the developer 2.
8 When the grain size is D, the predetermined layer thickness is h, and the depth of the uneven portion is H, the relationship is O≦h−D<H. The depth H of the uneven portion is defined as the distance from the bottom surface of the lowermost layer of the developer 28 within the unevenness to the uppermost surface of the developing roller 29. 5
Reference numeral 9 denotes a fixed plate serving as a flying means, which is integrally formed with the housing 33 and is brought into contact with the outer periphery of the fur brush 30 on the upstream side of the contact position between the developing roller 29 and the fur brush 30 with respect to the moving direction of the fur brush 30. , and as shown in FIG. 14, the tip of the fur brush 30 is deformed.

Next, the operation of the seventh embodiment of the present invention will be described.

In FIG. 14, the fur brush 30 rotates and the fixed plate 59
The restoring force of the fur brush 30 causes the developing roller 29 to
A developer 28 can be splashed onto the surface as shown in FIG. Therefore, since the developer 28 is attached in a flying manner, there is no aggregation of the developer 28 and the rise time for the developer 28 to reach a predetermined layer thickness can be made faster, so no extra waiting time is required. . Furthermore, since the fixing plate 59 is provided in contact with the fur brush 30 on the upstream side near the facing position, leakage of the developer 28 is further prevented. Further, as shown in FIG. 15 or 16, the developer 28 is regulated to a predetermined layer thickness in a state in which it adheres to the uneven portions and the outermost surface of the developing roller 29.

Therefore, the reproducibility of fine line images is improved by the developer 28 on the outermost surface, and by keeping the amount of developer 28 in the recesses constant, an image with uniform density can be obtained.

Next, an eighth embodiment of the present invention will be described.

In FIG. 17, parts having the same functions as in the seventh embodiment are given the same numbers. A third voltage applying means 60 applies a DC voltage between the developing roller 29 and the fixed plate 59 so that the developer 28 is blown toward the developing roller 29 side. Although a DC voltage is used as the third voltage applying means, a DC voltage superimposed on an AC voltage may also be used, and the fixing plate 59 is a U-shaped leak prevention member 5.
A similar effect can be obtained even if it is composed of a part of 1. A relay 61 is connected to St during development, and connected to 82 so as to apply a voltage of opposite polarity to that during development between the developing roller 29 and the fur brush 30 during non-development.

Next, the operation of the eighth embodiment of the present invention will be described.
- In FIG. 17, by applying a voltage between the developing roller 29 and the fixed plate 59 using the third voltage applying means 60, the amount of the developer 28 flying from the fur brush 30 can be further adjusted. When the developer 28 is transferred from the fur brush 30 to the developing roller 29 by the electric field of the leapfrog, even if there is, for example, uncharged developer 28 or developer 28 charged with the opposite sign in the developer 28, the uncharged developer or the developer 28 is not charged. The charged developer is difficult to be transported, and only the properly charged developer 28 is selected and contributes to development. Therefore, a good image can be obtained. In addition, by connecting S2 with the relay 61 during non-development, the surplus developer 28 on the developing roller 29 can be attracted to the fur brush 30 side by an electric field, and the development history on the developing roller 29 can be erased. Since there is no developer 28, there is no adverse effect of developer humidity or the like.

It goes without saying that the present invention is not limited to the eight embodiments described above, but can be configured in many more configurations by combining various elements such as charging the developer, coating the developing roller, regulating layer thickness, etc. . In addition, the present invention is well suited to non-magnetic component developers, and the charge holding member and the developer carrying member are made non-contact, and the first voltage application means is configured to apply a DC bias voltage, thereby retaining the charge. It also becomes possible to form color images by overlapping multiple colors of developer on the body.

As described in detail, the present invention detects in advance the relationship between the latent image carrier and the developer carrier corresponding to the operating time of the developer carrier, in response to the operating time of the developer carrier detected by the detection means. A predetermined density can be maintained by controlling the voltage of the first application means with the control means based on the relational expression between the voltage of the first application means and the image density. 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 according to a first embodiment of the present invention, and FIGS. 6 is a cross-sectional view of the main parts of the developing device in the first embodiment of the present invention. FIG. 7 is a diagram showing the relationship between the voltage of the applying means and the image density, and the essential parts of the eighth developing device. A partial sectional view, FIG. 1θ is an enlarged sectional view of a developing device in a third embodiment of the present invention, FIG. FIG. 13 is a sectional view of essential parts of a developing device in a fifth embodiment of the invention, FIG. 14 is a sectional view of essential parts of a developing device in a sixth embodiment of the invention, and FIG. 15 and 16 are sectional views of main parts of the developing device, respectively, and FIG. 17 is a configuration diagram of each part of the developing device in the seventh embodiment of the present invention, and FIG. 17 is a sectional view of the developing device in the eighth embodiment of the present invention. 18 and 19 are sectional views of essential parts of a developing device using a conventional one-component developer, respectively. 22... Charge carrier, 28... Developer, 29...
...developer carrier, 30...first supply means, 3
4... Developer storage means, 47-... Layer thickness regulating means, 5
7... First voltage application means, 64... Detection means, 6
5... Control means. Name of agent: Patent attorney Toshio Nakao 1 person 22-, 4R supply of 28- 31 developer trough, developer carrier 30, 34-, development storage/&+ throw 47-row Voltage application means 11 57-wire 6s-gJ wholesale means 1ff1 Fig. 2 Fig. 3 45 Fig. 4 Fig. 7 mark #voltage (v) Fig. 10 Fig. 14 Fig. 15 page 418

Claims (64)

[Claims] (1) A developing device that develops an electrostatic image on a charge carrier with a developer on a developer carrier, which includes a detection means for detecting the operating time of the developing device, and a charge carrier and a developer carrier. A developing device comprising: a first application means for applying a voltage between the two times; and a control means for controlling the voltage of the first application means in accordance with the operating time of the detection means. (2) The developing device according to claim 1, wherein the detection means detects the rotation time of the developer carrier. (3) supply means for supplying the developer onto the developer carrier;
A patent providing a layer thickness regulating means for regulating the developer pressed onto the developer carrier to a predetermined layer thickness on the downstream side of the developer supply position of the supply means with respect to the moving direction of the developer carrier. A developing device according to claim 1. (4) The supply means is composed of a first supply means that supplies the developer to the developer carrier, and a second supply means provided in the developer storage means that supplies the developer to the first supply means. A developing device according to claim 3. (5) Claim 4, further comprising a circulation means for the developer to flow in and out between the first supply means and the second supply means.
Developing device described in Section 1. (6) A partition plate is provided between the developer carrier and the second supply means at a position where the developer in the developer storage means is not directly supplied to the developer carrier. Developing device. (7) The developing device according to claim 6, wherein the first supply means is constituted by a cylindrical elastic body, and one end of the partition plate is disposed with a gap from the outer peripheral surface of the elastic body. (8) The gap between the partition plate and the outer circumferential surface of the elastic body is 0.5 to 3 m.
The developing device according to claim 7, in which the number of characters is m. (9) The developing device according to claim 5, wherein the circulation means is constituted by a partition plate having an opening through which the developer flows in and out between the first supply means and the second supply means. (10) The developing device according to claim 9, further comprising a remaining amount detecting means for detecting the presence or absence of developer between the partition plates. (11) The developing device according to claim 4, wherein the second supply means is constituted by at least one blade. (12) The developing device according to claim 4, wherein the second supply means is constituted by at least two blades, and the angle of the two blade surfaces changes depending on the developer load when the developer is supplied. (13) The developing device according to claim 12, wherein the two blades include a blade on the downstream side having a larger elastic force than the blade on the upstream side with respect to the direction in which the developer is supplied to the first supply means. (14) In the two blades, the length of the blade on the downstream side in the direction of supplying the developer to the first supply means is longer than the length of the blade on the upstream side toward the inner wall of the storage section. developing device. (15) The developing device according to claim 12, wherein the upstream blade is provided in slight contact with the inner wall of the storage section. (16) The developer according to claim 12, wherein an opening is provided in the downstream blade, and the developer flows in and out of the opening of the downstream blade by the elastic force of the upstream blade. Device. (17) The blade of the second supply means is configured to rotate from above to the bottom within the storage section with respect to the first supply means to supply the developer to the first supply means, or Developing device according to item 12. (18) The blade of the second supply means is configured to rotate from bottom to top within the storage section relative to the first supply means to supply the developer to the first supply means, or 9th
Developing device described in Section 1. (19) When the developer carrier is formed to have an uneven surface, the developer particle size is D, the predetermined layer thickness is h, and the depth of the uneven portion is H, 0≦h−D< The developing device according to claim 3, which has the following relationship: H. (20) The developing device according to claim 4, further comprising a second voltage application means for applying a voltage between the developer carrier and the first supply means to adjust the amount of developer supplied. (21) When the developer on the developer carrier is not used,
Claim 4: A voltage is applied by the second voltage application means to return the developer on the developer carrier to the first supply means.
Developing device described in Section 1. (22) The developing device according to claim 20, wherein the second voltage applying means is a voltage obtained by superimposing a DC voltage on an AC voltage. (23) The developing device according to claim 20, wherein the voltage of the second voltage applying means is applied at a predetermined voltage or higher when applying the voltage, and subsequently a predetermined voltage is applied. (24) The developing device according to claim 20, wherein the voltage of the second voltage applying means is gradually increased to a predetermined voltage. (25) Let the developer on the cylindrical elastic body fly onto the developer carrier at the upstream side of the position where the developer carrier and the cylindrical elastic body face each other in the moving direction of the cylindrical elastic body. A developing device according to claim 7, further comprising a feeding means. (26) The developing device according to claim 25, further comprising a third voltage applying means for applying a voltage between the developer carrier and the scattering means to adjust the amount of developer spray supplied. (27) The developing device according to claim 26, wherein the third voltage applying means is a voltage obtained by superimposing a DC voltage on an AC voltage. (28) The developing device according to claim 7, further comprising a scraping plate that is in sliding contact with the cylindrical elastic body, scrapes off excess developer on the elastic body, and makes the developer on the elastic body uniform. . (29) The scope of the patent claims that the developer carrier and the cylindrical elastic body are made of a conductive material and brought into contact with each other, and a detection means is provided for detecting the current value of the second voltage application means provided between the developer carrier and the cylindrical elastic body. 21. The developing device according to item 20. (30) Bring the developer carrier into contact with the cylindrical elastic body, move the developer carrier and the cylindrical elastic body in the forward direction at the contact position, and adjust the peripheral speed of the cylindrical elastic body to carry the developer. 21. The developing device according to claim 20, wherein the developing device has a peripheral speed faster than the circumferential speed of the body. (31) Bring the developer carrier into contact with the cylindrical elastic body, move the developer carrier and the cylindrical elastic body in the forward direction at the contact position, and adjust the circumferential speed of the developer carrier by adjusting the cylindrical elastic body. The developing device according to claim 20, which is faster than the circumferential speed of the body. (32) Bringing the developer carrier into contact with the cylindrical elastic body, moving the developer carrier and the cylindrical elastic body in the forward direction at the contact position, and adjusting the circumferential speed of the developer carrier and the cylindrical elasticity. Claim 20 in which the circumferential speed with the body is approximately equal
Developing device as described in section. (33) The developing device according to claim 7, wherein the cylindrical elastic body is a fur brush. (34) The developing device according to claim 7, wherein the cylindrical elastic body is a roller made of sponge. (35) The developing device according to claim 33, wherein the fur brush is conductive. (36) The developing device according to claim 34, wherein the roller made of sponge is electrically conductive. (37) The developing device according to claim 3, wherein the layer thickness regulating means is an elastic blade. (38) The developing device according to claim 3, wherein the layer thickness regulating means is a rigid blade. (39) The developing device according to claim 37 or 38, wherein the straightness of the blade end facing the developer carrier is 0.15 mm or less. (40) The developing device according to claim 37 or 38, wherein the pressure contact portion of the layer thickness regulating means is a surface including at least the downstream edge of the layer thickness regulating means with respect to the moving direction of the developer carrier. Device. (41) Claim 37, wherein the layer thickness regulating means has a structure of at least two layers in the direction of pressure contact with the developer carrier, and the elastic modulus of the layer on the side that contacts the developer carrier is smaller than that of the other layer. The developing device described. (42) The developing device according to claim 37, wherein at least the pressure contact portion of the blade is formed in a convex shape. (43) Claim 4 in which the convex twill line on the first supply means side of the blade is arranged with a small gap between the developer carrier and the developer carrier.
Developing device described in item 2. (44) The developing device according to claim 37, wherein the pressure contact portion of the blade is constituted by a fluid-tight bag. (45) Claim 4, wherein the fluid is made of gas.
Developing device according to item 4. (46) Claim 4, wherein the fluid is composed of a liquid.
Developing device according to item 4. (47) One end of the blade is used as a fulcrum, the other end is brought into pressure contact with the surface of the developer carrier, and the fulcrum acts to bite into the developer carrier side by the frictional force received at the pressure contact portion when the developer carrier moves. Claim 3: The pressure contact portion of the other end has a convex shape.
Developing device according to item 7 or item 38. (48) One end of the blade is used as a fulcrum, the other end is brought into pressure contact with the surface of the developer carrier, and the fulcrum is caused to escape from the surface of the developer carrier by the frictional force received at the pressure contact portion when the developer carrier moves. In addition to providing it in a position where it acts,
39. The developing device according to claim 37 or 38, wherein the pressure contact portion at the other end has a convex shape. (49) Spill prevention that prevents developer from spilling on the upstream side of the opposing position of the developer carrier and the cylindrical elastic body and below the developer carrier with respect to the moving direction of the cylindrical elastic body. A developing device according to claim 7, further comprising means. (50) A patent in which the spillage prevention means comprises a U-shaped developer leakage prevention member and a developer leakage prevention sheet whose one end is fixed to the leakage prevention member and the other end is lightly in contact with the surface of the developer carrier. A developing device according to claim 49. (51) The developing device according to claim 49, wherein the spill prevention means comprises a developer leak prevention sheet having one end fixed to the housing and the other end lightly touching the surface of the developer carrier. (52) The end of the leak prevention sheet on the side that lightly contacts the surface of the developer carrier is upstream from the line connecting the center of the developer carrier and the cylindrical elastic body in the rotational direction of the cylindrical elastic body. A developing device according to claim 50 or 51, which is provided on the side. (53) The developing device according to claim 50, 51, or 52, wherein the leak prevention sheet is made of an elastic material. (54) The developing device according to claim 53, wherein the leak prevention sheet is made of an elastic rubber. (55) The thickness of the rubber of the leak prevention sheet is 50 to 200μ.
55. The developing device according to claim 54, comprising: m. (56) The developing device according to claim 49, wherein a part of the U-shaped developer leakage prevention member is constituted by a flying means. (57) The developing device according to claim 50, further comprising a fourth voltage applying means for applying a voltage between the cylindrical elastic body and the spill prevention member. (58) The developing device according to claim 50, wherein a developer sealing material is provided at both ends of the developer carrier, and the sealing material is pressed against the developer carrier through a leak prevention sheet. (59) Claim 58 in which the sealing material is an elastic body
Developing device described in Section 1. (60) The developing device according to claim 58, wherein the sealing material is made of a cloth such as a woven fabric or a nonwoven fabric. (61) A patent claim in which an electrically insulated housing that surrounds the developer carrier and the cylindrical elastic body is provided, and the voltage is applied at the same potential between the developer carrier and the cylindrical elastic body. Developing device according to scope item 7. (62) The developing device according to claim 3, wherein a charge holding body is provided at a position facing the developer carrying body, so that the developer on the developer carrying body and the charge holding body are not in contact with each other. (63) The developing device according to claim 62, wherein the developer carrier and the charge carrier are moved in the forward direction at the developing position, and the circumferential speeds of the developer carrier and the charge carrier are approximately equal. (64) The developing device according to claim 3, wherein the first voltage application means is means for applying a DC electric field.