JPS63172290A - Developing device - Google Patents

Abstract

PURPOSE:To regulate a developer to a uniform and prescribed layer thickness and to obtain an image of high quality free from unevenness in density by means of a simple constitution without requiring highly accurate adjustment by constituting a press contact part of a layer thickness regulating means of a bag sealing fluid. CONSTITUTION:At least the press contact part of a blade 49 for regulating the layer thickness of the developer 28 is constituted of the bag 49b sealing fluid 49a and for instance the bag 49b made of an urethane sheet and sealing air 49a is fitted to one end of a fitting plate 49c consisting of a phosphobronze plate for a spring. Thereby, the adhesion of the developer 28 on a developing roll 29 to the bag 49b can be improved and the contact pressure of the surface of the developer 28 with the blade 49 can be fixed, so that the layer thickness can be uniformly regulated in the axial direction of the roll 29. Consequently, an image of high quality free from unevenness in the density can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developing device in an image forming apparatus such as the present invention.

BACKGROUND OF THE INVENTION Conventionally, developing methods using dry developers are roughly divided into seven types: methods using two-component developers and methods using one-component developers.

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

This developing method is described in, for example, Japanese Patent Application Laid-Open No. 54-43038,
JP-A-56-110968, U.S. Patent No. 4,083
, No. 326 specification, etc., and the configuration thereof is shown in FIGS. 10, 11, and 12.

In FIG. 10 on page 7 (Japanese Unexamined Patent Publication No. 54-4.3038), 1 is a developing roller, 2 is a toner, 3 is a hopper, 4 is a rubber blade, and 5 is a photoreceptor. The developing roller 1 is made of a metal material with an uneven surface, and toner 2 is supplied from a hopper 3 to the developing roller 1 . Next, when the developing roller 1 rotates in the direction of the arrow, the blade 4 that comes into sliding contact with the surface of the developing roller 1
As a result, the toner 2 is charged to a predetermined polarity and 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.

In FIG. 11 (Japanese Unexamined Patent Application Publication No. 58-110963), 6 is a photoreceptor, 7 is a developing roller made of a conductive urethane material that is in sliding contact with the photoreceptor 6, and development rollers 8a and 8b are conductive fur brushes. is in sliding contact with the developing roller 7. 9 is a power source that applies voltage to the fur brushes 8a, 8b and the developing roller 7; 10 is a voltage divider that adjusts the voltage of the power source 9;
Reference numeral 1 includes a hopper containing toner 12.

Toner 1 supplied from the hopper 11 to the fur brush 8b
2 is supplied from the fur brush 8b to the fur brush 8a and is triboelectrically charged, and then the fur brush 8a is charged by the voltage of the power source 9.
The electrostatic latent image is coated onto the developing roller 7, and then adhered to the electrostatic latent image on the photoreceptor 6 for development. If a predetermined developed density is not obtained as a result of this development, the voltage divider 10 is used to adjust the density.

In FIG. 12 (U.S. Pat. No. 4,083,326), 13 is a developing roller in sliding contact with the photoreceptor, 14 is toner, 15 is a hopper, 16 is a blade, 17 is a sheet-like photoreceptor, 18.19 20 is a first power source that applies voltage to the hopper 15 and the conductive fur brush 18; 21 is a conductive fur brush that applies voltage to the conductive fur brush 18 and the developing roller 7; This is the second power source. Further, the voltage applied by the second power source 21 is configured to be higher than the voltage applied by the first power source 20 and lower than the voltage of the electrostatic latent image on the photoreceptor 17.

The toner 14 is triboelectrically charged by the fur brush 18.
Hoppers 15 to 9 due to the potential difference between
The toner is supplied to the developing roller 13 via the page conductive fur brush 18, smoothed by the blade 16, and then attached to the electrostatic latent image on the photoreceptor 17 for development. Next, the toner 14 on the developing roller 13 after development is scraped off using a conductive fur brush 19.

Problems to be Solved by the Invention However, in this type of system, there is a problem in forming a uniform layer thickness of the developer (toner) on the developing roller.

In other words, since the blade shown in FIG. 10 is a plate-shaped elastic blade, if the amount of toner adhering to the developing roller is not constant, the adhesion between the toner on the developing roller and the blade will be poor, and the layer thickness will increase on the developing roller. There was a problem that unevenness occurred and density unevenness occurred during development.

In the case shown in FIG. 11, the charged toner on the fur brush adheres to the developing roller and becomes a thin layer due to the electric field between the fur brush and the developing roller.

Therefore, if the amount of toner supplied to the fur brush is not constant for -10 pages, the thickness of the toner on the developing roller will vary, resulting in the problem of uneven density during development.

In the case shown in Fig. 12, a gap is provided between the developing roller and the blade, and as the developing roller rotates, the toner adhering to the developing roller in a layer is scraped off by the blade and passes through the gap to become a thin layer. be done. Therefore,
The gap between the developing roller and the blade needs to be made with high precision, which poses a problem in that the processing cost and assembly cost of the parts are high.

The present invention solves the conventional problems and makes it possible to form a uniform layer thickness of the developer on the developer carrier with a simple structure without requiring high-precision adjustment. It is an object of the present invention to provide a developing device that can obtain high-quality images.

Means for Solving the Problems The developing device of the present invention includes an endless developer carrier,
A supplying means for supplying the developer onto the developer carrier, and a layer thickness regulating means that is in pressure contact with the developer carrier and regulates the developer to a predetermined layer thickness; At least the pressure contact portion of the thickness regulating means is constituted by a fluid-tight bag.

By configuring the pressure contact part of the working layer thickness regulating means with a fluid-tight bag, it is possible to improve the adhesion with the toner on the developer carrier, and also to improve the layer thickness between the developer surface and the layer thickness on the developer carrier. Since the contact pressure with the regulating member can be kept constant, the developer can be regulated to a uniform predetermined layer thickness. Therefore, a high-quality image without density unevenness can be obtained with a simple configuration without requiring highly accurate adjustment.

Embodiment FIGS. 1 to 3 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, 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.

29 is a developing roller which is a developer carrier, and the developing roller 2
9 is a metal roller made of stainless steel, aluminum, or the like, or a metal roller whose surface is coated with resin. Preferably, as shown in FIG. A rough surface with fine irregularities is formed on the surface 29e, 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. 30 is the developing roller 2
The first supply means for supplying the developer 28 to the core 31 is a cylindrical elastic body. 32 layers were formed. In this embodiment, the cylindrical elastic body 30 is a fur brush, and the elastic material 32 is made of conductive fur using carbon-containing rayon fibers. Further, the fur brush 30 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 of the developing roller 29 or higher. Furthermore, the fibers of the fur brush 30 are
As shown in the figure, the developer 28 is transferred to the fur brush 30 during rotation.
Both ends are shaped like a spiral in the direction of movement from the outer periphery to the center. 33 is a developer storage means, which stores the developer 28.
The second toner supply means 35 supplies toner to the fur brush 30. Further, the storage section 34 is formed by a part of the storage space 37 and has an opening 36 for replenishing the developer 28 at one end. Further, the toner supply means 35 fixes one end of a sheet-like elastic member 39 made of polyethylene terephthalate or the like with a thickness of about 30 μm to the outer peripheral surface of the mandrel 38, and rotates or swings the mandrel 38 to supply the developer 28. It is supplied to the fur brush 30. In this embodiment, the mandrel 38 rotates clockwise in the clockwise direction. A partition plate 40 is provided between the first developer supply means 30 and the second developer supply means 35, and the developer 28 is separated between the first developer supply means 30 and the second developer supply means 35. It has an opening 41 for inflow and outflow between the two. 42 is formed by a part of the scraping plate 37, which comes into sliding contact with the fur brush 30 and removes the developer 2 inside the fur brush 30.
This is to make the amount of the developer 8 uniform and to scrape off the overcharged developer 28 in the fur brush 30. 43 is a lid of the replenishment opening 36. As shown in FIG. 2, 44 is a bearing for the developing roller 29, and 45 is a bearing for the fur brush 30. Reference numeral 46 denotes a second DC high-voltage power source serving as a voltage applying means, which applies a voltage between the developing roller 29 and the fur brush 30. 47 is a detection means for detecting the current value of the second DC high voltage power supply 46 and detecting the presence or absence of the developer 28. 48 is integrally formed with the fixed plate support 37 which is a flying means, 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. 4, the tip of the fur brush 30 is deformed 1.
It is 5 pages long. Therefore, the fur flage 30 rotates and the fixed plate 4
8, the developing roller 2 is moved by the restoring force of the fur brush 30.
9" The developer 28 can be attached to the second part in a flying manner. A blade 49 is a layer thickness regulating means for regulating the layer thickness of the developer 28, and is brought into pressure contact with the developing roller 29 to regulate the layer thickness of the developer 28 so as not to require highly accurate adjustment. Further, the blade 49 connects at least the pressure contact portion with the fluid 49.
A is made up of a sealed bag 49b. In this embodiment, a bag 49b made of a urethane sheet and sealed with an air fluid 49a is provided at one end of a mounting plate 49C made of a phosphor bronze plate for a spring. The fluid 49a may be made of a gas such as nitrogen, water, an aqueous solution of a low-molecular organic substance such as ethylene glycol,
Any liquid may be used as long as it is a liquid such as a polymer dispersion aqueous solution or a polymer solution. The material of the bag 49b may be a resin sheet such as polyethylene terephthalate, Teflon, or vinyl chloride resin, or other rubber sheet material. Also, the mounting plate 49
The material c may be an elastic material such as spring steel, resin, or rubber, or a rigid material such as aluminum, steel, or resin.

Further, the blade 49 is brought into pressure contact with the surface of the developing roller 29 at a position downstream from the position where the developing roller 29 and the fur brush 30 face each other and upstream from the position facing the photosensitive drum 22 with respect to the rotating direction of the developing roller 29. It is a provision. Furthermore, the width of the blade 49 is determined by the width of the developing roller 29 as shown in FIG.
The length is such that both ends thereof come into contact with the outer circumferential surfaces 29a and 29b. A sealing material 50 and 51 prevents the developer 28 from leaking, and is made of an elastic material such as felt, sponge, or rubber. Further, the sealing material 50.51 is the developing roller 29.
The outer circumferential surfaces 29a and 29b of both ends of the blade 49 are in contact with the outer circumferential surfaces 29a and 29b of the blade 49.

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, for the fur brush 30, it is preferable to use a conductive material having a specific resistance of about 1010 Ωcm or less, preferably 103 Ωem 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 17 pages. Furthermore, it goes without saying that the above-mentioned 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 its outer periphery to form the cylindrical elastic body 31.

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 made of zinc oxide, and the cylindrical elastic body 30 is made of 3 rayon fibers containing carbon and having a specific resistance of about 105 Ωem as an elastic material 32 on an aluminum core 31.
A fur brush with approximately 600 hairs/cm2 flocked, the surface roughness of the developing roller 29 may be 5 μmRmay, the linear pressure of the blade 49 in pressure contact with the developing roller 29 is 25 g/cm, the gap between the photosensitive drum 22 and the developing roller 29 is 0° 15 mm,
As the developer 28, an ordinary positively charged non-magnetic one-component toner was used in the experiment.

In FIG. 1 on page 18, the charger 27 is connected to the first high voltage DC power supply 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 charge is removed to a residual potential close to approximately O■, forming a positive electrostatic latent image.

Meanwhile, the developer 28 in the storage section 34 is transferred to the second supply means 3.
5 into the fur brush 30 through the opening 41. 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 developer 37. Further, the developer 28 is conveyed to a position facing the developing roller 29 by the rotation of the fur brush 30 . The developer 28 supplied in an appropriate amount is blown onto the developing roller 29 by the restoring force of the fur brush 30 when the tip of the fur brush 30 passes through the fixing plate 48 from the deformed state as shown in FIG. 4 due to the rotation of the fur brush 30. Attach 19 pages. At this time, a voltage is applied between the developing roller 29 and the fur brush 30 by the second DC high voltage power supply 46,
The layer thickness of the charged developer 28 on the surface of the developing roller 29 is adjusted. Note that the layer thickness of the second DC high voltage power supply 46 can be adjusted by applying a voltage of approximately ±30V to ±250V. At this time, for example, if a voltage with the fur brush 30 side being positive is applied between the developing roller 29 and the fur brush 30 using the second DC high voltage power supply 46, the developer 28 is transferred from the fur brush 30 to the developing roller due to the electric field therebetween. 2
When the developer 28 is transferred to the developer 9, for example, even if there is an uncharged developer 28 or a developer 28 charged with an opposite sign, the uncharged developer or the charged developer is difficult to be transferred, and the normally charged developer is Only agent 28 is selected and contributes to development. Therefore, a good image can be obtained. In this development 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 47 is small.

Next, the developing process is repeated, and the developer 28 inside the housing 37 is
When the developer 28 in the fur brush 30 runs out, the contact resistance decreases and the current value of the detection means 47 increases. Therefore, the presence or absence of the developer 28 in the housing 37 can be detected based on the current value of the detection means 47.

Further, the second supply means 35 repeats the development process,
Even if the amount of developer 28 in the storage section 34 decreases, since the sheet-like elastic member 39 rotates clockwise, it is displaced as shown in FIG. It can be supplied into the fur brush 30 through the. Therefore, even if the angle of inclination of the bottom surface of the storage section 34 is small, the developer 28 in the storage section 34 can be supplied to the fur brush 30 without any problem. Further, the developer 28 is stored in the storage section 3.
Since the developer 28 is stirred by a sheet-like elastic member 39 within the storage section 4, the height of the developer 28 within the storage section 34 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 46 is greater than a predetermined thickness, and there is some variation. Next, as the developing roller 29 rotates, the charged developer 28 on the surface of the developing roller 29 passes through the blade 49 and is further positively charged by the blade 49 on page 21, and a portion is scraped off to form a predetermined amount. The layer thickness is about 40μm (the layer thickness at this time is 10-70μm)
(preferably on the order of μm).

The reason why the layer thickness can be controlled to be uniform in the axial direction of the developing roller 29 is as follows.
Since the pressure contact portion with the developing roller 29 is constituted by the bag 49b in which at least the fluid 49a is sealed, it is possible to improve the adhesion between the developer 28 on the developing roller 29 and the bag 49b. This is because the contact pressure between the upper surface of the developer 28 and the layer thickness regulating member 49 can be kept constant. Therefore, a high-quality image without density unevenness can be obtained. Next, the developer 28 that has come into contact with the blade 49 moves from the center of the developing roller 29 toward both ends, and moves from both ends of the fur brush 30 to the center due to the rotation of the spiral-shaped fur brush 30. do. Therefore, the developer 28 in the vicinity of both ends of the developing roller 29 and the fur brush 30 does not increase, and the developer 28 in the housing 37 does not increase.
This has the effect of keeping the height constant. Furthermore, the blade 49
Since the sealing materials 50 and 51 that are in contact with both end surfaces of the developing roller 29 are in contact with the smooth surfaces of the outer circumferential surfaces 29a and 29b of the developing roller 29, there is very little wear even when the page 22 developing roller 29 rotates. There is no scattering or leakage of the developer 28. In addition, sealing materials 50, 5
1, the joint surface that contacts the blade 49 and the developing roller 29 is a smooth surface, and no gap is generated in the joint portion. Therefore, there is no leakage of the developer 28 due to the force pushed in the axial direction of the developing roller 29. In addition, the storage section 34 for the developer 28 is not provided near the opposing position upstream of the opposing position between the developing roller 29 and the fur brush 30 with respect to the moving direction of the developing roller 29, and is not provided near the opposing position. Since the fixing plate 48 is provided on the upstream side, leakage and scattering of the developer 28 are further eliminated. That is,
This developing device is capable of uniformly charging the developer 28 on the developing roller 29 and making the layer thickness uniform.Furthermore, the developer 28 is free from scattering or leaking, and is high quality with no fogging or density unevenness. You can get a good image. Furthermore, since the circumferential speeds of the developing roller 29 and the photosensitive drum 22 are made the same, edge effects can be eliminated when developing a latent image. Further, in this developing device, the developer 28 in the fur brush 30 is
Since the developer 28 is blown onto the developing roller 29 by the voltage of the defining plate 48 and the second DC high voltage power supply 46, the rise time for the developer 28 to reach a predetermined layer thickness is as fast as within lsee. There is no need for extra waiting time.

Further, since the developer 28 in the fur brush 30 is attached to the developing roller 29 by the fixing plate 48, the developer 28
8 The cohesion of comrades will disappear. 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 will fly 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 the fur brush 3o.
9 Delete history. 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 34 through the opening 41. is not overcharged. Therefore, high-quality development is possible. Furthermore, this developing device has a simple configuration and is compact because a single fur brush can supply developer to the developing roller and scrape off the developer on the developing roller after development. Since the structure is free from scattering and 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. 6 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 FIG. 6, the layer thickness regulating member 49 includes a urethane sheet bag 49b that seals an air fluid 49a at one end of a rigid mounting plate 49C made of stainless steel. Further, the mounting plate 49c is brought into contact with the developing roller 29 by the elastic force of the pressing spring 52. The peripheral speed of the fur brush 30 is slower than the 25-page peripheral speed of the developing roller 29. The second direct high voltage power supply 46 applies a voltage obtained by superimposing a positive DC voltage to an AC voltage between the developing roller 29 and the fur brush 30 to the fur brush 30 side. The other configurations are the same as the first embodiment.

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

In FIG. 6, by constructing the mounting plate 49c of the layer thickness regulating means 49 from a rigid metal body, for example, the contact area between the developing roller 29 and the bag 49b can be made more uniform in the axial direction of the developing roller 29. More uniform developer 2
8 thin layers are formed. Furthermore, by making the peripheral speed of the fur brush 30 slower than the peripheral speed of the developing roller 29, the fur brush 3σ during the developing process is bent in one direction due to the load of the developer 28 and the contact portion of the scraping plate 42. After that, it is bent in the opposite direction at the sliding contact portion with the developing roller 29. Therefore, the fur brush 30 is never bent in one direction. Therefore, the fibers of the fur brush 30 are prevented from collapsing, and the stirring action with the developer 28 is ensured, making it possible to obtain a long-term stable image with a high quality of 26 pages. Further, in the second DC high voltage power supply 46, by superimposing a DC voltage on the AC voltage, the surface of the developing roller 29 is coated with the developer 28 to a predetermined layer thickness or more, and the surface of the developing roller 29 after development is The developer 28 adhering to the top is reciprocated between the fur brush 30 and the developing roller 29 by the AC voltage, erasing the history of the developing roller 29, causing the developer 28 to coagulate and develop onto the developing roller 30. Prevents high adhesion of agents.

Therefore, a high-quality image without ghosts can be obtained.

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

FIG. 6 shows a third embodiment of the invention, in which parts having the same functions as in the first embodiment of the invention are given the same numbers. In FIG. 6, 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. It is easily understood that even if a conductive sponge is used as the cylindrical elastic body 300 and the elastic material 32, the effects of frictional charging, page 27 coating, etc. described in the first embodiment can be effectively performed. In this embodiment, the developing roller 29 and the cylindrical elastic body 30 are spaced at a constant distance (this space is 0.1-0.
5mm is preferable) and face each other at a close position. 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. A bias voltage applying means 53 applies a DC bias voltage between the photosensitive drum 22 and the developing roller 29.

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

When the charged developer 28 on the cylindrical elastic body 30 rotates and comes to a position facing the developing roller 29, the cylindrical elastic body 30 returns as it passes through the fixed plate 48 as in the first embodiment. The developing roller 29 is coated with a thickness thicker than a predetermined thickness due to the force and the electric field generated by the second DC high voltage power supply 46.
The layer thickness regulating means 49 regulates the thickness to a predetermined value. Next, when facing the electrostatic latent image on the photosensitive drum 22, the bias voltage applying means 53 connects the photosensitive drum 22 and the developing roller 29.
A DC bias voltage is applied between the two and developed. By applying a bias voltage, the developer 28 is blown away due to the synergistic effect of the electrostatic force caused by the electrostatic latent image and the electric field caused by the DC bias, so that more effective development can be achieved.

Incidentally, in the developing device of this configuration, the bias voltage is AC voltage or D
A C voltage superimposed with an AC voltage can also be used, and it is possible to do this without using a bias application means.

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

FIG. 8 shows a fourth embodiment of the present invention, in which parts having the same functions as in the third embodiment of the present invention are given the same numbers. In FIG. 8, the mounting plate 49 of the layer thickness regulating means 49
C is a blade that is an elastic body or a rigid body; in this embodiment, an elastic body is used, and the material is the same as in the first embodiment. This blade 49 has one end connected to the developing roller 29 and the cylindrical elastic body 3 with respect to the rotating direction of the developing roller 29.
The surface of the developing roller 29 is brought into pressure contact with the surface of the developing roller 29 downstream of the facing position of 0 and upstream of the facing part of the photosensitive drum 22, and the other end is brought into pressure contact with the surface of the developing roller 29 when the developing roller 29 rotates. Accordingly, the one end portion is fixed to the retainer 37 at a position where it acts to bite into the developing roller 29 side. Therefore, there is an effect of preventing aggregation or solidification of the developer 28. Further, in this embodiment, the blade 49 has a convex shape so that the pressure contact portion with the developing roller 29 is shaped like a convex portion. Therefore,
The facing distance between the developing roller 29 and the blade 49 after regulating the layer thickness is increased, and the charged developer 28 on the developing roller 29 does not fly to the blade 49. Therefore, more uniform coating can be achieved.

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

FIG. 9 shows a fifth embodiment of the present invention, in which parts having the same functions as in the third embodiment of the present invention are given the same numbers. In FIG. 9, layer thickness regulating means 49
The mounting plate 49G is an elastic body or a rigid body. The blade is an elastic body or a rigid body, and in this embodiment an elastic body is used, and the material is the same as in the first embodiment. This blade 49 has one end located downstream of the position where the developing roller 30 page 29 faces the cylindrical elastic body 30 and upstream of the facing position of the photosensitive drum 22 with respect to the rotating direction of the developing roller 29. Developing roller 2
9, and the other end is fixed to the support 37 at a position where the one end acts to escape from the surface of the developing roller 29 due to the frictional force received at the pressed portion when the developing roller 29 rotates. In the example, the blade 49 has a convex portion that forms a pressure contact portion with the developing roller 29. Therefore, the developer 28 partially scraped off by the blade 49 is
Due to the force of the following developer 28, the flow is changed along the wall surface of the convex portion of the blade 49 in the direction of arrow A, and the cylindrical elastic body 3
It falls to the 0 side.

As a result, the developer 28 flows back to the area where the developing roller 29 and the blade 49 face each other in the vicinity of the pressure contact area, so that more uniform coating can be achieved.

In the embodiments of the present invention, in addition to the five embodiments described above, many more configurations are possible by combining various elements such as charging of the developer, coating on the developing roller, and regulation of layer thickness. Not even. In addition, the present invention is well suited for non-magnetic component developers, has 31 pages without contact with the latent image carrier, eliminates image cuffing, and uses a direct current electric field to scatter non-magnetic component developers. It has great practical effects, such as being able to perform continuous development and being advantageous for forming color images by overlapping developer agents of multiple colors on a latent image carrier.

Furthermore, the present invention has great practical effects, such as reducing running costs by using a developer with a uniform layer thickness on a developer carrier instead of an ink sheet used in thermal printers. .

As described in detail, in the present invention, the pressure contact portion of the layer thickness regulating means is configured with a fluid-tight bag, which improves the adhesion with the toner on the developer carrier, and also improves the adhesion to the toner on the developer carrier. Since the contact pressure between the surface of the developer on the agent carrier and the layer thickness regulating member can be kept constant, the developer can be regulated to a uniform predetermined layer thickness.

Therefore, it is possible to obtain a high-quality image without density unevenness with a simple and inexpensive configuration without requiring highly accurate adjustment.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of a main part of a developing device according to a first embodiment of the present invention, FIG. 2 is a perspective view of a main part of a developing device according to a first embodiment of the present invention, and FIG. A perspective view of a main part of a fur brush which is an elastic body of a cylindrical test in the first embodiment,
FIG. 4 is an enlarged cross-sectional side view of the main part of the flying means in the first embodiment of the present invention, and FIG. 5 is a cross-sectional side view showing the operating state of the second supply means in the first embodiment of the present invention. , FIG. 6 is a cross-sectional side view of a main part of a developing device according to a second embodiment of the present invention, FIG. 7 is a cross-sectional side view of a main part of a developing device according to a third embodiment of the present invention, and FIG. FIG. 9 is a cross-sectional side view of a main part of a developing device according to a fourth embodiment of the invention; FIG. 9 is a cross-sectional side view of a main part of a developing device according to a fifth embodiment of the invention;
12 are sectional side views of essential parts of a conventional developing device using a one-component developer. 22...Charge carrier, 29...Developer carrier, 30...
First supply means, 49...Layer thickness regulating member, 49a...Fluid, 49b...Bag Name of agent: Patent attorney Toshio Nakachi, 1 person Figure 2 Figure 3 Figure 4 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11

Claims (24)

[Claims] (1) An endless developer carrier facing the charge carrier, a first supply means for supplying the developer onto the developer carrier, and a first supply means that presses onto the developer carrier and supplies the developer to a predetermined amount. A developing device comprising a layer thickness regulating means for regulating the layer thickness, and at least a pressure contact portion of the layer thickness regulating means is constituted by a fluid-tight bag. (2) The developing device according to claim 1, wherein the fluid is made of gas. (3) The developing device according to claim 1, wherein the fluid is a liquid. (4) Using one end of the layer thickness regulating member as a fulcrum, the other end is brought into pressure contact with the surface of the developer carrier, and the fulcrum is bitten into the developer carrier side by the frictional force received at the pressure contact portion when the developer carrier moves. 2. The developing device according to claim 1, wherein the developing device is provided at a position where the other end acts and the pressure contact portion at the other end has a convex shape. (5) Using one end of the layer thickness regulating member as a fulcrum, the other end is brought into pressure contact with the surface of the developer carrier, and the fulcrum is moved from the surface of the developer carrier by the frictional force received at the pressure contact portion when the developer carrier moves. 2. The developing device according to claim 1, wherein the developing device is provided at a position where escape occurs and the pressure contact portion at the other end has a convex shape. (6) The first supply means includes a cylindrical elastic body for transporting the developer, which is provided facing the developer carrier, and an electric field generating means for generating an electric field between the developer carrier and the cylindrical elastic body. A developing device according to claim 1, comprising: (7) Claim 1, further comprising a partition plate having an opening through which the developer flows in and out between the first supply means and the second toner supply means provided in the developer storage means. The developing device described. (8) A patent in which the second developer supply means is constituted by a sheet-like elastic member that rotates or swings within the developer storage means and supplies the developer to the developer carrying means through the opening of the partition plate. A developing device according to claim 7. (9) A patent in which the sheet-like elastic member of the first developer supply means is configured to rotate from bottom to top within the developer storage means relative to the developer carrying means to supply developer to the developer carrying means. A developing device according to claim 8. (10) The first supply means includes a cylindrical elastic body for transporting the developer, which is provided facing the developer carrier, and a cylindrical elastic body that is provided opposite to the developer carrier, and is located upstream from the opposing position with respect to the moving direction of the cylindrical elastic body. 2. The developing device according to claim 1, further comprising a flying means for spraying the developer on the cylindrical elastic body onto the developer carrier. (11) The flying means brings one end into contact with the outer peripheral surface of a cylindrical elastic body to deform the elastic body, and as the elastic body rotates, the developer is sprayed by the elastic body's own restoring force. A developing device according to claim 8. (12) Claim 6, further comprising voltage application means for applying a voltage between the developer carrier and the cylindrical elastic body to adjust the amount of developer supplied onto the developer carrier. developing device. (13) The developing device according to claim 8, further comprising voltage applying means for applying a voltage between the developer carrier and the scattering means to adjust the amount of developer spray supplied. (14) The developing device according to claim 11, wherein the voltage applying means is a voltage obtained by superimposing a DC voltage on an AC voltage. (15) Claim 6, 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. Developing device. (16) Bringing the developer carrier into contact with the cylindrical elastic body,
The developing device according to claim 6, wherein the developer carrier and the cylindrical elastic body are moved in the forward direction at the contact position, and the circumferential speed of the cylindrical elastic body is higher than the circumferential speed of the developer carrier. Device. (17) Bringing the developer carrier into contact with the cylindrical elastic body,
The developing device according to claim 6, wherein the developer carrier and the cylindrical elastic body are moved in the forward direction at the contact position, and the circumferential speed of the developer carrier is faster than the circumferential speed of the cylindrical elastic body. . (18) The developing device according to claim 6, wherein the cylindrical elastic body is a fur brush. (19) The developing device according to claim 6, wherein the cylindrical elastic body is a roller made of sponge. (20) The developing device according to claim 18, wherein the fur brush is conductive. (21) The developing device according to claim 19, wherein the roller made of sponge is electrically conductive. (22) The development according to claim 12, wherein the developer carrier and the cylindrical elastic body are formed of a conductive material, and a detection means for detecting the current value of a voltage application means provided between them is provided. Device (23) The developing device according to claim 1, wherein the developer on the developer carrying means and the charge carrier are not in contact with each other. (24) The developing device according to claim 1, further comprising means for applying a DC electric field between the developer carrying means and the charge carrier.