JP2001183908A - Image forming device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized image forming device which reduces the stress given to particles for image formation and is small in power consumption. SOLUTION: The particles 2 for image formation are floated on the surface of liquid 1 stored in a liquid vessel 16 and uniformly dispersed on the liquid surface by vibrating the particles with a vibrating device 3. A cylindrical particle carrier 4 is disposed in the liquid vessel 16 so as to expose one part of peripheral surface thereof out of the liquid surface and is rotatively driven. When the peripheral surface of this particle carrier is protruded from the liquid surface, the particles 2 on the liquid surface are stuck on the peripheral surface of the particle carrier and a uniform particle layer is formed. On the other hand, an electrostatic latent image is formed on the peripheral surface of an image carrier 8 by the uniform electrification with an electrifier 9 and the irradiation with image light by means of a image writing device 10 and, on the position where the particle layer is opposed to the image carrier, the particles are transitted to a latent image, which is visualized. The visualized image formed on the image carrier is transferred on a sheet of paper 12 and fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an image forming method for forming a visible image using colored particles, such as a copying machine, a printer and a facsimile, and more particularly, to a method for forming a uniform particle layer on a particle carrier. The present invention relates to an image forming apparatus and an image forming method for forming an image by forming the image and flying the image by an electric field.

[0002]

2. Description of the Related Art Conventionally, two-component developing systems and one-component developing systems are widely used as electrophotographic developing systems. In the two-component developing method, the colored particles (toner) and the carrier, which is a magnetic particle, are stirred by a mechanical force, and the two-component developer is magnetically adsorbed on the peripheral surface of the developing roll to face the photoreceptor. It is transported to the developing section. In the developing section, a developing electric field is applied between the photoconductor and the developing roll,
Particles (toners) on the developing roll are selectively adhered to the electrostatic latent image on the photoreceptor surface to form a visible image. Such a two-component developing method has been used for many copying machines, printers, and the like since ancient times. Since the toner is charged in advance by stirring the toner and the carrier, a high-speed copying machine,
It is fully compatible with printers.

On the other hand, the one-component developing system can be further classified into a magnetic one-component developing system and a non-magnetic one-component developing system. The magnetic one-component system transports colored magnetic particles using magnetic force. In the non-magnetic one-component developing method, a predetermined charge is applied to the particles by a blade or the like pressed against the developing roll, and the particles are conveyed while being attached to the surface of the developing roll. In recent years, the one-component developing system has been widely used in low- and medium-speed copying machines because of the simpler structure of the apparatus and the elimination of the use of a carrier as compared with the two-component developing system.

[0004]

As described above, the electrophotographic system has various particle conveying means, but each has the following problems. The two-component development method
A magnetic roll and an auger for transporting the two-component developer while stirring them are required, so that the number of parts is large, the cost is high, and it is difficult to miniaturize the apparatus. Further, a mechanism for adjusting the concentration between the toner and the carrier is required.

[0005] In the magnetic one-component system, since the particles contain a magnetic substance, it is difficult to form a color. Further, since the blade is used as the layer regulating member, the stress applied to the particles is large. Similarly, in the non-magnetic one-component system, since a blade is used as the layer regulating member, a large stress is applied to the toner.

[0006] Further, as a common problem of the electrophotographic system,
Since a large amount of heat is required when the particles are melted and fixed on an image holding medium such as paper, there is a problem that energy consumption is large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to form a high-quality image with a small number of parts without increasing the size of the entire apparatus. An object of the present invention is to provide an image forming apparatus and an image forming method capable of reducing stress applied to image forming particles and achieving low power consumption.

[0008]

According to a first aspect of the present invention, there is provided a container for accommodating a liquid, and supplying particles for image formation to a surface of the liquid in the container. A part of an endless peripheral surface is immersed in the liquid, and when the peripheral surface moves around and moves from below the surface of the liquid to the surface, the particle is supplied to the peripheral surface. An image forming apparatus comprising: a particle carrier that adheres to a surface to form a particle layer; and a developing unit that selectively flies and transfers the particle layer on the particle carrier to the image carrier. I will provide a.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the particle supply means convects the liquid in the container or circulates the liquid using a path outside the container. A circulation flow forming means is included.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the image forming apparatus further includes a vibrating means for vibrating the liquid in the container.

According to a fourth aspect of the present invention, in the image forming apparatus according to the first or second aspect, the image forming apparatus further includes a stirring means for stirring the liquid in the container.

According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects,
The particles have been subjected to a liquid-phobic treatment.

According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects,
It is assumed that the particle carrier is formed of a porous material.

According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects,
The angle formed between the outer peripheral surface of the particle carrier and the liquid surface outside the particle carrier is 90 ° or more.

[0015] The invention according to claim 8 is a container for accommodating transport particles having a specific gravity greater than that of the image forming particles,
Gas supply means for sending gas into the gap between the transport particles, particle supply means for supplying particles for image formation having a lower specific gravity than the transport particles, to the surface of the powder layer comprising the transport particles, When a part of the endless peripheral surface comes into contact with the transport particles and the peripheral surface moves around and moves from below the surface of the powder layer made of the transport particles to the surface, the image forming is performed. Forming a particle layer by adhering particles for use on the peripheral surface to form a particle layer; and developing means for selectively flying and transferring the particle layer on the particle carrier to the image carrier. Provide equipment.

According to a ninth aspect of the present invention, in the image forming apparatus according to the eighth aspect, the particle supply means convects the transport particles in the container or circulates the particles using a path outside the container. It shall include a circulating flow forming means for moving.

According to a tenth aspect of the present invention, in the image forming apparatus according to the eighth or ninth aspect, the image forming apparatus further includes a vibrating means for vibrating the transport particles in the container.

[0018] According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the eighth to tenth aspects, the particle size of the image forming particles is smaller than the particle size of the transporting particles. Is also large.

According to a twelfth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, the particles for image formation have liquid ink sealed in a capsule. .

According to a thirteenth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, the particles for forming an image are colored foamed particles.

According to a fourteenth aspect of the present invention, there is provided a particle carrier having an endless peripheral surface, wherein a liquid is stored in a container, particles for image formation are supplied to the surface of the liquid in the container. Part is immersed in the liquid, and when moving around the peripheral surface and moving from below the surface of the liquid to the surface, the particles are attached to the peripheral surface to form a particle layer, There is provided an image forming method characterized by selectively developing a particle layer on a particle carrier onto an image carrier.

According to a fifteenth aspect of the present invention, a carrier particle having a specific gravity larger than that of an image forming particle is accommodated in a container, a gas is sent into a gap between the carrier particles, Particles for image formation with small specific gravity
The carrier particles are supplied to the surface of the powder layer, and a part of the particle carrier having an endless peripheral surface is brought into contact with the carrier particles. When moving from below the surface of the powder layer to the surface, the particles for image formation are attached to the peripheral surface to form a particle layer, and the particle layer on the particle carrier is transferred to the image carrier. An image forming method characterized by selectively flying and developing.

As described above, according to the present invention, the particles for image formation are dispersed and filled on the surface of the fluid without using a complicated apparatus configuration or control means, and are conveyed onto the particle carrier to form an image. An image forming method is proposed. As a feature of the image forming apparatus or the image forming method according to the present invention, as shown in FIG. 2, the surface of a fluid (liquid or vapor-phase fluidized powder) 101 in which particles 102 for image formation are contained in a container 100. Floating in The particles 102 floating on the fluid are dispersed on the surface of the fluidized bed because it is most stable in terms of energy to uniformly disperse them on the surface of the fluidized bed. Therefore, it is possible to easily obtain a layer of colored particles that are substantially evenly dispersed, and to fly this particle layer from the surface of the particle carrier to a latent image due to, for example, a difference in electrostatic potential, thereby enabling uniform density development. Becomes

As the above-mentioned particles, besides those having a specific gravity lower than that of a liquid, those having a specific gravity slightly higher than that of a liquid can be used. However, when the specific gravity is larger than the liquid, a liquid-phobic substance is used, and the liquid is dispersed on the liquid surface by the surface tension of the liquid. The particles having a specific gravity lower than that of the liquid may be lyophilic.

The particles 102 for forming an image preferably have low adhesion between the particles and have good fluidity. When the adhesion between the particles is large or the fluidity is not so good, the particles often adhere and aggregate by electrostatic force or Van der Waals force as shown in FIG. Even if it is sprayed alone, it may not be uniformly dispersed and filled.

In such a case, a minute vibration is applied vertically from below the fluid 101 as shown in FIG. 5A, or the fluid 101 is moved right and left as shown in FIG. By vibrating the particles, the particles move to a more stable arrangement (fine packing). Further, as shown in FIG. 5C, a liquid stirring means 108 may be provided. In the present invention, by applying this principle, it is possible to form a state in which the particles are dispersed without agglomeration and are closely packed on the surface of the fluidized bed. Then, these particles are conveyed onto the particle carrier 104 and used for image formation.

According to the invention described in claim 1 or 14, the particles for image formation are supplied to the surface of the liquid by the particle supply means, and are uniformly dispersed and filled. The particle carrier is partially immersed in the liquid and is moving around.When the peripheral surface moves from below the surface of the liquid to the surface, the particles adhere to the peripheral surface. A layer can be formed. The particle layer is conveyed to a position facing the image carrier by the orbital movement of the particle carrier, and is selectively fly on the image carrier by applying, for example, a developing electric field, and is transferred to the image carrier to be visible. Form an image.

In such a configuration, since little stress is applied to the particles during layer formation, particles having a low melting point can be used, and the temperature of the fixing device can be lowered. For this reason, it is possible to reduce the power consumption of a fixing device that requires a large amount of power in an image forming apparatus using toner.

According to the second aspect of the invention, the liquid is convected in the container or circulated using a path outside the container, and the liquid is used to transport and supply the particles. For example, as shown in FIG. 2, if there is no flow on the liquid surface, it is difficult to efficiently guide particles onto the particle carrier 104. Therefore, as shown in FIG.
For example, the particles are collected on the downstream side by the circulation pipe 106 and the like, and a flow is created in the container (particularly on the surface) so as to return to the upstream again, so that the particles 102 can be efficiently supplied and replenished. Also, with such a configuration,
It is possible to easily adjust the height of the liquid surface. If the specific gravity of the particles is larger than the specific gravity of the liquid, the particles will not float on the liquid surface if the particles and the liquid are mixed. Therefore, the recovery of the particles 112 and the circulation of the liquid
For example, as shown in FIG. 3 (b), the particles and the liquid are once separated and each is separately circulated. Then, the particles are returned from the toner supply unit onto the liquid surface, and the liquid is returned from the liquid supply unit into the tank.

According to a third aspect of the present invention, particles on the surface of the liquid are vibrated by vibrating the liquid by vibrating means. The particles supplied on the liquid are uniformly dispersed without any external force when the fluidity is high, but by further applying vibration from the bottom surface or side surface of the container 100 by the vibration means 103 as shown in FIG. FIG. 5 (a) and FIG. 5 (b)
As shown in (2), even when the particles adhere to each other and a uniform layer is not formed, the particles can be promptly dispersed and uniformized. The vibration means may be a means for mechanically vibrating a plate-like member or the like, or a means for electrically generating vibration using a piezoelectric element or the like.

According to the fourth aspect of the present invention, the liquid in which the particles are floated is stirred by the stirring means, so that even if the particles adhere to each other and a uniform layer is not formed, the particles are quickly dispersed and made uniform. It becomes possible. This stirring means
For example, as shown in FIG. 5C, a small wave is generated on the surface of the liquid, whereby the particles on the surface of the liquid have a stable arrangement (fine packing).

According to a fifth aspect of the present invention, particles whose surfaces are subjected to a liquid-phobic treatment are used. Liquidphobicity means that particles have a property that they are less compatible with the liquid, and the particles move so as to avoid contact with the liquid when introduced into the liquid. For example, when water is used as the liquid, if the surface is hydrophilic, FIG.
Water covers the particles 102 as shown in FIG. When the surface of the particles is made hydrophobic, water does not cover the particles 112 as shown in FIG. 6B, so that the particles 112 can be smoothly transported to the particle carrier. In addition, by using particles subjected to the liquid-phobic treatment, even when particles having a specific gravity higher than that of the liquid are used, the particles can be dispersed on the surface of the liquid by the surface tension of the liquid. In addition,
When oil, for example, is used as the liquid, the same effect can be obtained by making the particle surface hydrophilic.

In the invention according to claim 6, the particle carrier is formed of a porous material. That is, a cylindrical body having an endless peripheral surface using a porous material, or a porous film having a cylindrical or endless belt shape can be used. This porous material is a material through which a liquid easily penetrates and has pores to such an extent that particles do not cause clogging or the like.

If the particle carrier is made of a material having poor permeability, when the particle layer on the surface of the liquid is guided to the surface of the particle carrier, the liquid is moved by weight as shown in FIG. Try to return to For this reason, evenly arranged particles on the surface of the liquid tend to return together with the liquid, so that a uniform layer may not be guided to the particle carrier. However, by making the particle carrier porous, as shown in FIG.
The liquid quickly permeates into the particle carrier, a liquid layer is not formed between the particle layer and the surface of the particle carrier, and the particle layer can be reliably held on the surface of the particle carrier.

According to a seventh aspect of the present invention, as shown in FIGS. 8 (b) and 8 (c), the angle between the surface of the particle carrier and the liquid surface is 90 ° or more. Preferably, 1
35 ° or more. And, although this angle cannot be more than 180 °, the particles floating on the liquid are pulled up above the liquid surface, and a particle layer can be formed on the peripheral surface, and this particle layer is opposed to the image carrier. The angle may be close to 180 ° as long as an area for development can be secured.

As shown in FIG. 8A, when the angle between the peripheral surface of the particle carrier and the liquid surface is less than 90 °, the liquid layer including the particle layer guided to the particle carrier becomes As shown in (a), an attempt is made to return into the container by gravity or the like, and the particle layer on the particle carrier is disturbed. However, by making the angle between the peripheral surface of the particle carrier and the liquid surface 90 ° or more, the liquid is prevented from flowing down from the surface of the particle carrier so as to hang down, as shown in FIG. 9B. A good particle layer can be obtained.

In the image forming apparatus according to the eighth aspect or the image forming method according to the fifteenth aspect, transporting particles having a specific gravity larger than that of the image forming particles are contained in the container.
A gas-injected gas is blown into two types of particles with different specific gravities to form a solid-gas two-phase flow state, and the particles for image formation with a low specific gravity emerge on the surface of the powder layer composed of particles for transport by buoyancy and are uniformly dispersed. And filled. Then, when the particle carrier moves from below the surface of the powder layer made of the particles for transport onto the surface, the particles for image formation adhere to the peripheral surface of the particle carrier, and a uniform particle layer is formed. You. By selectively flying and transferring the particles for image formation from the particle layer to the image carrier, it becomes possible to form a visible image having a uniform density.

Further, in such a method, since little stress is applied to the particles at the time of forming the layer, particles having a low melting point can be used, the temperature of the fixing device can be lowered, and toner is used. It is possible to reduce the power consumption of the fixing device that requires a large amount of power in the image forming apparatus.

According to the ninth aspect of the present invention, the particles for transportation are convected in the container or circulated by using a path outside the container, so that the flow of the particles for transportation is generated. Thus, it becomes possible to efficiently supply and replenish the particles for image formation to the surface of the powder layer composed of the particles for transportation.

According to a tenth aspect of the present invention, there is provided a vibrating means for vibrating the particles for conveyance, and the vibrating means comprises particles for image formation supplied to the surface of the powder layer comprising the particles for conveyance. Vibrates. The particles for image formation supplied on the powder layer composed of particles for conveyance in a gas-solid two-phase flow state are uniformly dispersed without external force when the fluidity is high,
Further, as shown in FIG. 5, by applying vibration from the bottom and side surfaces of the container, even when particles for image formation adhere to each other and a uniform layer is not formed, the particles are quickly dispersed and uniformized. can do.

According to the eleventh aspect of the present invention, by making the particle size of the particles for image formation larger than the particle size of the particles for conveyance, the particles for image formation are formed on the surface of the powder layer composed of the particles for conveyance. Is more likely to appear. If the particles for image formation having a lower specific gravity are smaller than the particles for transport having a higher specific gravity, the contact pressure between the particles pushing up each particle from below is less likely to act upon forming the gas phase flow, and the gas phase flow It is hard to float on the body surface.

According to the twelfth aspect of the present invention, as the particles for forming an image, particles obtained by enclosing a liquid ink in a capsule are used. In the above configuration, since no pressure is applied to the particles using a blade or the like at the stage of forming the layer, the layer can be formed even if the particles for image formation are soft. In addition, by using such particles for image formation, fixing can be performed only by applying pressure, and fixing can be performed with a small amount of energy.

According to the thirteenth aspect of the present invention, by using colored foamed particles as the particles for image formation, the density of the particles can be reduced while the range of selection of the material of the particles is widened. It becomes possible.

By using the image forming apparatus or the image forming method as described above, it is possible to reduce the stress applied to the particles and to form a uniform particle layer on the particle carrier. Further, since no stress is applied to the particles, the selection range of the particles for image formation is widened, and the fixing energy can be reduced when low-melting particles are used. Furthermore, when a liquid is used, particle scattering (cloud), which has been a problem in the past, does not occur, and an image without image quality degradation can be formed.

[0045]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an image forming apparatus according to an embodiment of the present invention described in claim 1, claim 2, claim 3, claim 5, claim 6, or claim 7. This image forming apparatus includes a liquid tank 16 containing the liquid 1, particles 2 supplied to the surface of the liquid 1, a vibrating device 3 for vibrating the liquid 1 at the bottom of the liquid tank 16, and a part of the peripheral surface. Is immersed in the liquid 1, the peripheral surface of which moves around the cylindrical particle carrier 4, and a particle charging device 5 that charges the particles 2 attached to the peripheral surface at a position facing the particle carrier 4. Have. Further, the circulation device 6 collects the particles 2 in the liquid tank 16 from the downstream side in the transport direction and returns the particles 2 to the upstream side in the liquid tank 16.
And a controller 7 for adjusting the particle concentration, the flow rate of the liquid 1, and the like.

Above the particle carrier 4, an image carrier 8 on which an electrostatic latent image is formed by uniform charging and irradiation of image light is formed.
Are arranged around the image carrier 8, a charging device 9 for charging the surface of the image carrier 8 almost uniformly, and a laser beam is applied to the charged image carrier 8 to electrostatically charge the image carrier 8. An image writing device 10 for forming a latent image, and a developing bias applying device 1 for applying a developing bias between the particle carrier 4 and the image carrier 8
1, a transfer roller 13 for transferring a particle image formed on the image carrier 8 onto a sheet 12, an image carrier 8 and a transfer roller 1
3 is provided with a transfer bias applying device 14 for applying a transfer bias, and a fixing device 15 for fixing the particle image on the paper 12 by pressing and heating.

The liquid 1 is a fluid having a specific gravity larger than that of the particles 2, and in this embodiment, distilled water is used. Note that the liquid is not limited to water, and can be appropriately selected, such as silicone oil.

The particles 2 are colored particles having a particle size of 10 μm and a density of 0.8 g / cm 3, the surface of which is subjected to a hydrophobic treatment. By performing the hydrophobic treatment on the surface of the particle 2, the particle 2 floats on the liquid surface in the state shown in FIG. 6B, the mutual force with the liquid is reduced, and the particle is easily moved from the liquid to the particle carrier. Further, the particles 2 have such physical properties that they are melted at a lower melting point than the developer (toner) used in conventional electrophotography. In the image forming apparatus of the present embodiment, since the stress applied to the particles is smaller than that of the conventional electrophotographic method, it is possible to use an image forming apparatus having a lower melting point than the conventional particles (toner).

The particle carrier 4 is formed by adhering a porous film endlessly, and has a structure in which a liquid can penetrate well. Then, the peripheral surface is driven so as to move around.

The circulating device 6 collects the liquid 1 containing the particles 2 from above the liquid tank 16 and introduces the liquid 1 containing the particles 2 again from the lower part of the liquid tank 16 via the controller 7, thereby obtaining the liquid 1. Is circulated in the direction of the arrow shown in FIG. Thereby, a circulating flow is generated in the liquid 1 in the liquid tank 16 and the particles 2 can be transported. Further, the circulation device 6 is provided with a concentration detecting means (not shown) for measuring the concentration of the particles 2, based on which the controller 7 controls the supply amount of the particles 2, the flow rate of the liquid 1, and the like. . The controller 7 includes a concentration adjusting device for supplying the particles 2, a flow rate measuring means for the liquid 1, a flow rate controlling means, and the like.

The image carrier 8 is obtained by coating an organic photoreceptor layer on the surface of an aluminum roll having a diameter of φ30.
Is charged to about -350 V by the image writing device 1
By 0, an electrostatic latent image (latent image potential-100 V) is written. Although not shown in the figure, the apparatus also includes an apparatus for transporting the sheet 12, an image processing apparatus, and the like. In the present embodiment, the image forming speed is 50 mm /
sec (about 10 sheets / min), but if the image writing speed is increased, it is possible to form an image at a higher speed.

Next, the operation of the image forming apparatus will be described.
An image forming method according to an embodiment of the present invention will be described. The liquid 1 stored in the liquid tank 16 is circulated by the circulation device 6 in the direction of the arrow shown in FIG. 1, and a flow is generated in the liquid tank. When the liquid 1 circulates, the particles 2 are supplied into the circulation device, and the flow rate and the particle concentration are adjusted by the controller 7. Since the specific gravity of the particles 2 is smaller than that of the liquid 1, the particles 2 introduced into the liquid tank 16 are
Floats on the surface of the liquid and accumulates in layers on the liquid surface. At this time,
The liquid 1 is vibrated by the vibrating device 3, and the vibrations cause the particles to adhere to each other and move so as to be densely packed, so that almost one layer of particles is formed on the surface of the liquid.

The particles 2 thus uniformly dispersed and filled are conveyed toward the particle carrier 4 by the flow of the liquid 1. When the peripheral surface of the particle carrier 4 moves above the liquid surface in the same direction as the particle transport direction, and the peripheral surface of the particle carrier 4 moves from below the surface of the liquid 1 to the surface, the particles 2 Adhere to the peripheral surface of the particle carrier 4 to form a uniform particle layer. At this time, the liquid 1 and the particles are both
Guided above, the particle carrier is porous,
The liquid permeates into the particle carrier and only the particle layer remains on the peripheral surface of the particle carrier 4.

The particle layer formed on the particle carrier 4 is charged to a negative polarity by the particle charger 5 and the image carrier 8 is charged.
Is transported to the developing section opposite to. In the developing section, a developing electric field acts between the particle carrier 4 and the image carrier 8, and the particles 2 on the particle carrier 4 fly to the image carrier 8 to visualize the electrostatic latent image. . The particle image formed on the image carrier 8 is conveyed to a position facing the transfer roller 13 by rotation of the image carrier 8, and is transferred onto the sheet 12 conveyed at a predetermined timing by the action of a transfer electric field. You. The particle image transferred onto the sheet 12 is heated and pressed by the fixing device 15, and the particle image is melted and fixed on the sheet.

On the other hand, the particles 2 that have not contributed to the development are returned to the surface of the liquid 1 by the orbital movement of the particle carrier 4, and are collected in the circulation device 6 by circulating the liquid 1 in a certain direction. Then, the concentration of the particles 2 is detected, and the particles 2 are added as necessary by the controller 7.
6 is introduced.

As described above, in the image forming apparatus of the present embodiment, the particles uniformly dispersed and filled in the liquid are moved onto the particle carrier, and the particles are charged by the charging device on the particle carrier. It is characterized by being developed by flying by an electric field. By using this method, it is possible to simply replace the developing method in the conventional electrophotographic method. Compared with the conventional electrophotographic developing method, the present image forming apparatus has a uniform particle (toner) layer on the particle carrier, so that a more uniform and fine image can be formed. There is an advantage that the particles do not come into contact with the layer forming blade during the formation, so that no stress is applied to the particles.

FIG. 10 is a diagram showing particles used in an image forming apparatus according to an embodiment of the present invention. The particles 122 are obtained by enclosing a liquid ink 122b in a capsule 122a. In the image forming apparatus shown in FIG. 1, since pressure is not applied to the particles using a blade or the like at the stage of layer formation, a layer can be formed even if the particles are soft. Therefore, it is possible to use the particles 122 in which the liquid ink 122b is sealed as described above, and it is only necessary to apply pressure at the time of fixing, so that fixing can be performed with little energy.

FIG. 11 is a diagram showing particles used in an image forming apparatus according to an embodiment of the present invention. The particles 132 are made of colored foamed particles. By using such expanded particles in the image forming apparatus shown in FIG. 1, it is possible to reduce the density of the particles while widening the range of selection of the material of the particles. For this reason, particles can be stably and uniformly dispersed and filled on the liquid surface.

FIG. 12 shows claims 8, 9, and 1 of the present invention.
FIG. 12 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. The configuration of this image forming apparatus is almost the same as the configuration of the image forming apparatus shown in FIG. This apparatus comprises an image forming particle 52 and a conveying particle 5 having a smaller particle size than the particle 52.
1, a powder tank 66 for accommodating a large number of transfer particles 51, a vibration device 53, a particle carrier 54, a particle charging device 55
, Circulating device 56, controller 57, image carrier 5
8, a charging device 59, a latent image writing device 60, a developing bias application device 61, a transfer roll 63, a transfer bias application device 64, and a fixing device 65, etc., constitute a main part.

The circulating device 56 is provided with a density detecting means (not shown) for measuring the density of the particles 52 for image formation. The flow rate of the particles 51 is controlled. The controller 57 includes a concentration adjusting device for supplying the particles 52, a flow rate measuring means, a flow rate controlling means, and a fan for introducing air into the circulation device 56.

The particles 51 for conveyance have a particle diameter of 0.1.
1 μm and a density of 2.4 g / cm 3 are used. The particles 52 for image formation have a particle diameter of 10 μm.
and colored particles having a density of 0.8 g / cm @ 3. Further, the image forming particles 52 have such physical properties that they are melted at a lower melting point than a developer (toner) conventionally used in electrophotography. Since the image forming apparatus according to the present embodiment exerts less stress on particles for forming an image as compared with a conventional electrophotographic system, it is possible to use an image forming apparatus having a lower melting point than conventional particles (toner). is there. In this embodiment, the image forming speed is 50 mm /
sec (about 10 sheets / min), but higher speed image formation is possible by increasing the speed of image writing. The other configuration of the image forming apparatus is the same as that of the image forming apparatus shown in FIG.

Next, the operation of the image forming apparatus will be described.
An image forming method according to an embodiment of the present invention will be described. The controller 5 in the circulation device 56
Air is introduced by 7, and the transport particles 51 stored in the powder tank 66 circulate in the direction of the arrow shown in FIG. 12 and a circulating flow is also generated in the powder tank 66. Circulation device 5
In 6, the image forming particles 52 are supplied to the conveying particles 51, and air is fed into two types of particles having different particle diameters and specific gravities to form a solid-gas two-phase flow state. As a result, the particles 52 for image formation having a small specific gravity float on the surface of the powder layer composed of the particles 51 for conveyance by buoyancy, and a layer of the particles 52 is formed on the surface. At this time, the transporting particles 51 are vibrated by the vibrating device 53, and the vibration causes the adhesion of the particles 52 to be broken, so that the particles 52 are uniformly dispersed and filled.

The particles 52 are transported in the direction of the particle carrier 54 by the flow of the transporting particles 51,
When the peripheral surface of No. 4 moves from below the surface of the powder layer composed of the particles for transport 51 to above the surface, the particles 52 adhere to the peripheral surface of the particle carrier 54 to form a uniform particle layer.

The particle layer formed on the particle carrier 54 is
The toner is charged to a negative polarity by the particle charging device 55 and transported to the developing unit. In the developing section, the particles 5 on the particle carrier 54
2 flies to the image carrier 58 by the developing electric field, and the electrostatic latent image is developed. The particle image formed on the image carrier 58 is transferred onto a sheet 62 conveyed at a predetermined timing, and the particle image on the sheet 12 is fixed by a fixing device 65 by heating and pressing. On the other hand, particles 5 which did not contribute to development
2 is collected by circulating the transport particles 51 in a certain direction, and is reused via the circulation device 56.

As described above, in the image forming apparatus of the present embodiment, the image forming particles 52 uniformly dispersed and filled on the surface of the powder layer composed of the transport particles 51 in the gas phase flow state.
Is moved onto the particle carrier 54, the particles 52 are charged by the charging device 55 on the particle carrier, and the particles 52 are caused to fly by an electric field for development. By using this method, it is possible to simply replace the developing method in the conventional electrophotographic method. Compared with the conventional electrophotographic developing method, the present image forming apparatus has a uniform particle (toner) layer on the particle carrier, so that a more uniform and fine image can be formed. There is an advantage that the particles do not come into contact with the layer forming blade during the formation, so that no stress is applied to the particles.

FIG. 13 is a schematic diagram showing an image forming apparatus according to another embodiment of the present invention. The image forming apparatuses shown in FIGS. 1 and 12 described above are examples relating to single-color image formation.
As shown in FIG. 8, image forming apparatuses 80a, 80b, 80 accommodating respective color particles of yellow, magenta, cyan, and black.
It is also possible to form a full-color image by using those in which c and 80d are arranged in series.

These image forming apparatuses 80a, 80b, 8
Numerals 0c and 80d may be either the configuration shown in FIG. 1 or the configuration shown in FIG. 12, and the fluid tank 96 containing the liquid or the particles for conveyance contains the particle carrier 8 for carrying the particles for image formation.
And an image carrier 88 on the surface of which an electrostatic latent image is formed.

The image forming apparatuses 80a, 80b, 80
Reference numerals c and 80d are arranged so as to face an endless belt-like intermediate transfer body 92 that can move in a circling direction. Inside the intermediate transfer body 92, the particle image on the image carrier 88 is placed on the intermediate transfer body. And a primary transfer device 91 for transferring the image to the primary transfer device. Further, on the downstream side in the circumferential direction of the intermediate transfer member 92, a secondary transfer roll 93 that collectively transfers the particle images superimposed on the intermediate transfer member 92 onto a sheet 94, and fixes the particle image on the sheet. A fixing device 95 is provided. Further, although not shown in the figure, a controller for adjusting the transfer position of the four-color image to the intermediate transfer member is provided as an object necessary for forming a color image.

In such an image forming apparatus, each of the image forming apparatuses 80a, 80b, 80c and 80d operates on the image carrier 88 in the same manner as the apparatus shown in FIG. A black color particle image is formed. These particle images are sequentially transferred at a predetermined timing by the transfer device 91 onto the intermediate transfer member 92 that moves around, and particle images of four colors are superimposed on the intermediate transfer member 92. These particle images are transferred onto a sheet conveyed at a predetermined timing at a position facing the transfer roll 93, and are fixed by a fixing device 95 to form a full-color image on the sheet.

In the present embodiment, since the intermediate transfer member 92 is used, it is possible to improve the retention of particles for image formation regardless of the type of paper, and to prevent image disturbance due to scattering of particles. It is possible to For this reason, the particle image formed well on the intermediate transfer member 92 can be satisfactorily transferred onto the sheet by the transfer roll 93, and a high-quality image can be finally obtained.

[0071]

As described above, in the image forming apparatus and the image forming method according to the present invention, the particles are uniformly dispersed and filled on the surface of the fluid and transported to the particle carrier. A uniform thin particle layer can be formed. Therefore, a more uniform and high-quality image can be formed. Further, since the stress applied to the particles is small and the selection range of the particle material is widened, low melting point particles can be used, and the energy consumption can be reduced as compared with the conventional image forming apparatus. Further, since the configuration of the entire apparatus can be simplified, a small-sized image forming apparatus can be realized.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a state in which a particle layer is formed on a particle carrier in the image forming apparatus according to the first aspect of the invention.

FIG. 3 is a schematic configuration diagram showing an example of a circulating flow forming means used in the image forming apparatus according to the second aspect of the present invention.

FIG. 4 is a schematic configuration diagram showing an example of a vibrating means that can be used in the image forming apparatus according to the third aspect of the present invention.

FIG. 5 is a schematic diagram illustrating the operation of the image forming apparatus according to the third or fourth aspect of the invention.

FIG. 6 is a schematic view showing a state in which particles for image formation are floating on a fluid in the image forming apparatus according to the fifth aspect of the present invention.

FIG. 7 is a schematic view showing a state in which a particle layer is formed on a peripheral surface of a particle carrier in the image forming apparatus according to the invention of claim 6;

FIG. 8 is a schematic view showing the main points of the configuration of the invention according to claim 7;

FIG. 9 is a schematic view showing a state in which a particle layer is formed on a peripheral surface of a particle carrier in the image forming apparatus according to the invention of claim 7;

FIG. 10 is a sectional view showing an example of particles used in the image forming apparatus according to the invention.

FIG. 11 is a sectional view showing an example of particles used in the image forming apparatus according to the invention.

FIG. 12 is a schematic configuration diagram illustrating an image forming apparatus according to a second embodiment of the present invention.

FIG. 13 is a schematic configuration diagram illustrating an image forming apparatus according to a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid 2, 52 Particles for image formation 3, 53 Vibration device 4, 54, 84 Particle carrier 5, 55 Particle charging device 6, 56 Circulation device 7, 57 Controller 8, 58, 88 Image carrier 9, 59 Charging device 10, 60 Image writing device 11, 61 Developing bias supply device 12, 62 Paper 13, 63 Transfer roll 14, 64 Transfer bias supply device 15, 65 Fixing device 16 Liquid tank 66 Powder tank 80 Image forming device 91 Primary transfer Apparatus 92 Intermediate transfer body 93 Secondary transfer roll 94 Paper 95 Fixing device 96 Fluid tank 100 Container 101 Fluid 102, 112, 122, 132 Particle 103 Vibration device 104 Particle carrier 106 Circulation device 107 Controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/11 G03G 15/10 114

Claims (15)

[Claims] 1. A container for accommodating a liquid, a particle supply means for supplying particles for image formation on a surface of the liquid in the container, and a part of an endless peripheral surface immersed in the liquid. A particle carrier that adheres the particles on the peripheral surface to form a particle layer when the peripheral surface moves around from the surface of the liquid to the surface, and An image forming apparatus comprising: developing means for selectively flying and transferring the particle layer to the image carrier. 2. The image according to claim 1, wherein the particle supply unit includes a circulating flow forming unit that convects the liquid in the container or circulates and moves the liquid using a path outside the container. Forming equipment. 3. A vibrating means for vibrating the liquid in the container.
An image forming apparatus according to claim 1. 4. The image forming apparatus according to claim 1, further comprising a stirring unit for stirring the liquid in the container. 5. The image forming apparatus according to claim 1, wherein the surface of the particles has been subjected to a liquid-phobic treatment. 6. The image forming apparatus according to claim 1, wherein the particle carrier is formed of a porous material. 7. The method according to claim 1, wherein an angle formed between the outer peripheral surface of the particle carrier and the liquid surface outside the particle carrier is 90 ° or more. The image forming apparatus as described in the above. 8. A container for accommodating transfer particles having a specific gravity higher than that of the image forming particles, a gas supply unit for feeding gas into a space between the transfer particles, and an image having a specific gravity smaller than the transfer particles. Particle supply means for supplying the particles for formation to the surface of the powder layer made of the particles for transportation, and a part of the endless peripheral surface comes into contact with the particles for transportation, and the peripheral surface moves around. A particle carrier that forms a particle layer by adhering the image forming particles on the peripheral surface when moving from below the surface of the powder layer made of the transport particles to the surface; An image forming apparatus, comprising: developing means for selectively flying the upper particle layer onto the image carrier and transferring the same. 9. The method according to claim 8, wherein the particle supply unit includes a circulating flow forming unit that convects the transport particles in the container or circulates the particles using a path outside the container. Image forming apparatus. 10. The image forming apparatus according to claim 8, further comprising a vibrating unit that vibrates the transport particles in the container. 11. The image forming apparatus according to claim 8, wherein a particle size of the image forming particles is larger than a particle size of the transporting particles. 12. The image forming apparatus according to claim 1, wherein the image forming particles are obtained by enclosing liquid ink in a capsule. 13. The image forming apparatus according to claim 1, wherein the image forming particles are colored foamed particles. 14. A liquid is stored in a container, particles for image formation are supplied to the surface of the liquid in the container, and a part of a particle carrier having an endless peripheral surface is immersed in the liquid. When moving around the peripheral surface and moving from below the surface of the liquid to the surface, the particles adhere to the peripheral surface to form a particle layer, and the particle layer on the particle carrier is formed. An image forming method, wherein the toner is selectively fly on an image carrier and developed. 15. A container for transporting particles having a specific gravity higher than that of the particles for image formation is accommodated in a container, a gas is fed into a gap between the particles for transporting, and a gas having a lower specific gravity than the particles for transporting is formed. The particles are supplied to the surface of a powder layer made of the particles for transportation, a part of a particle carrier having an endless peripheral surface is brought into contact with the particles for transportation, and the transportation is performed by moving around the peripheral surface. When moving from below the surface of the powder layer composed of particles for use to the surface, the particles for image formation are attached to the peripheral surface to form a particle layer, and the particle layer on the particle carrier is imaged. An image forming method, wherein the image is selectively fly on a carrier and developed.