CN101364074A - Developer conveying mechanism and image forming apparatus using the developer conveying mechanism - Google Patents

Abstract

The present invention provides a developer conveying mechanism capable of smoothly performing a conveying process of surplus liquid developer, and an image forming apparatus using the developer conveying mechanism. The developer conveying mechanism of the present invention includes: a developer storage part (310), storing liquid developer; a developer conveying screw (320), arranged in the developer storage part (310), and conveying the liquid developer; and a hollow path embedded with a developer conveying screw (320) and conducting the liquid developer conveyed by the developer conveying screw (320).

Description

Developer conveying mechanism and image forming apparatus using the developer conveying mechanism

The present invention is made by reference to Japanese application No. 2007-197448 filed on July 30, 2007 and Japanese application No. 2008-36760 filed on February 19, 2008, including the specification, drawings and claims in their entirety Include these.

technical field

The present invention relates to a developer conveying mechanism used in a conveying process for conveying surplus liquid developer generated in an image forming process and stored in a developer storage portion or the like, and an image forming apparatus using such a developer conveying mechanism.

Background technique

There have been proposed wet image forming apparatuses that develop a latent image using a high-viscosity liquid developer obtained by dispersing a toner composed of a solid component in a liquid solvent, thereby making the electrostatic latent image visible . The above developer used in a wet image forming apparatus is formed by dispersing solid components (toner particles) in an organic solvent (carrier liquid) made of silicone oil, mineral oil, edible oil, etc. Formed and having electrical insulation properties and high viscosity, the toner particles have a particle diameter of about 1 μm, which is very fine. In a wet image forming apparatus, by using such fine toner particles, higher image quality can be realized than in a dry image forming apparatus using powdery toner particles having a particle diameter of about 7 μm. The carrier liquid that constitutes the developer not only prevents the toner particles with a particle diameter of about 1 μm from scattering, but also has the function of making the toner particles in a more uniformly dispersed state by making the toner particles in a charged state, and also plays a role in developing and transferring. The role of enabling toner particles to move easily under the action of an electric field in the printing process.

In such an image forming apparatus, it is necessary to use a developer conveying mechanism specially designed for conveying liquid developer. As a developer conveyance mechanism, for example, a conveyance mechanism disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 5-57993) is known. The developer conveying mechanism disclosed in Patent Document 1 performs mixing with new developer supplied from the developer supply port while supplying the developer containing toner to the developing position, and specifically has a structure that it passes the developing The developer is conveyed by the rotation of the agent conveying screw, and the developer is circulated between the adjacent developer mixing/conveying section and the developer storage section for storing the developer supplied from the developing roller to the photoreceptor. agent for the remaining developer after development. When the developer is circulated between the adjacent developer mixing/transporting section and the developer storage section, a control means capable of controlling the flow rate of the developer is also provided.

Contents of the invention

In the above Patent Document 1, a structure in which the developer is circulated in a closed loop between the adjacent developer mixing/conveying section and the developer storage section is disclosed. Therefore, there is a problem that although the new developer replenished from the developer supply port The agent is smoothly flowed and supplied into the developer mixing/conveying portion by gravity, but the conveying process of the remaining liquid developer generated in the image forming process is not considered.

In addition, there is also a problem that the remaining liquid developer generated in the image forming process and stored in the developer storage section etc. is charged to aggregate the toner particles, or the toner density is in a non-uniform state, so it is difficult to handle. .

In addition, there is a problem that, since the remaining liquid developer is in a charged state, the remaining liquid developer is electrostatically adsorbed on the developer conveying screw or the surface of the developer mixing/conveying portion and cannot be conveyed.

That is, when the developer conveying mechanism disclosed in Patent Document 1 is applied to an image forming apparatus, there is a problem that recycling and disposal of excess liquid developer cannot be smoothly performed.

The purpose of the present invention is to solve the above problems. The developer conveying mechanism of the present invention is characterized in that it includes: a developer storage part for storing liquid developer; a shaft rotates to convey the liquid developer; and a hollow path in which the conveying member is embedded and conducts the liquid developer conveyed by the conveying member.

In addition, in the developer conveying mechanism of the present invention, the developer storage portion includes a storage base forming a groove portion and a conveyance base configuring the hollow path.

In addition, when the radius of the outer peripheral portion of the conveying member is r1, the radius of the conveying port is r2, and the radius of curvature of the groove portion is r3, the developer conveying mechanism of the present invention has r1< The relationship of r2<r3.

In addition, in the developer conveying mechanism of the present invention, the conveying member is a screw.

In addition, in the developer conveying mechanism of the present invention, the conveying member has a helical blade.

Also, in the developer conveying mechanism of the present invention, an end portion of the conveying member is connected to a spring member embedded in the hollow path.

In addition, an image forming apparatus according to the present invention includes: a roller holding a liquid developer; a roller cleaning blade abutting on the roller and scraping off the liquid developer held on the roller; and a developer conveying mechanism; Wherein, the developer conveying mechanism includes: a developer storage part that receives the liquid developer scraped off by the roller cleaning blade; the liquid developer; and a hollow path embedded with the conveying member and conducting the liquid developer conveyed by the conveying member.

In addition, in the image forming apparatus of the present invention, the roller is a developing roller.

In addition, in the image forming apparatus of the present invention, the roller is an image carrier pressing roller that abuts on the image carrier.

In addition, in the image forming apparatus of the present invention, the conveying member is a screw.

In addition, the image forming apparatus according to the present invention is characterized in that the pitch of the screw for conveying the liquid developer scraped off from the image carrier and the pitch of the screw for conveying the liquid developer scraped off from the developing roller Are not the same.

In addition, the image forming apparatus according to the present invention is characterized in that the rotational speed of the screw conveying the liquid developer scraped off from the image carrier and the rotational speed of the screw conveying the liquid developer scraped off from the developing roller are Are not the same.

In addition, in the image forming apparatus according to the present invention, a plurality of the developer storage portions are provided.

In addition, in the image forming apparatus according to the present invention, the developer storage portion includes a storage base forming the groove portion and a delivery base connected to the hollow path.

In addition, in the image forming apparatus according to the present invention, an end portion of the transport member is connected to a spring member substantially embedded in the hollow path.

According to the developer conveying mechanism of the present invention, it is possible to smoothly carry out a process of conveying the aggregated toner particles in the charged state or the remaining liquid developer in which the toner concentration is uneven. As a result, recycling and disposal of excess liquid developer can be smoothly performed.

In addition, according to the developer conveying mechanism of the present invention, since the toner particles of the charged remaining liquid developer are prevented from being electrostatically adsorbed to the surface of the constituent members of the conveying portion, there is no problem that the remaining liquid developer cannot be conveyed. .

In addition, according to the image forming apparatus using the developer conveying mechanism provided by the present invention as described above, the conveying efficiency of the remaining liquid developer is improved and the developer is freed from the structure of closed-loop circulation of the developer, so that the developer can be temporarily removed from the developing The part is transported to move to another part to be mixed with new developer, or to perform desired dispersion by eliminating aggregation of toner particles and unevenness of toner concentration, or to discard as unnecessary developer.

The following embodiments can also be provided within the scope of the present invention, and these embodiments will be referred to as reference embodiments below. That is, the developer transport mechanism according to the reference embodiment is characterized in that it includes: a storage base for storing a liquid developer obtained by dispersing toner particles in a carrier; a transport base provided in the longitudinal direction of the storage base. On one end, a liquid developer stored in the storage base is sucked; a delivery screw is supported to be rotatable in contact with the storage base, and a helical blade is formed with a predetermined pitch; The radius of curvature of the groove portion of the conveying screw covering the storage base is small, and the radius of curvature of the groove is formed on the conveying base, and the screw blade is basically embedded in the conveying base; wherein the conveying A screw extends into the interior of the transport base.

In addition, the developer conveying mechanism related to the reference embodiment has the following features: a pipe member communicating with the suction inlet is provided at the end of the conveying base where the storage base is not provided, and the conveying screw is arranged so as to extend to inside the pipe.

In addition, the developer conveying mechanism according to the reference embodiment is characterized in that a spring member substantially embedded in the pipe is attached to an end portion of the conveying screw extending into the pipe.

In addition, the image forming apparatus according to the reference embodiment is characterized in that it uses a plurality of the above-described developer conveying mechanisms.

In addition, the image forming apparatus according to the reference embodiment is characterized in that a developer conveying structure for conveying the liquid developer scraped off from the image carrier and a developer conveying structure for conveying the liquid developer scraped off from the developing roller are provided. structure.

In addition, the image forming apparatus according to the reference embodiment is characterized in that the pitch of the screw used in the developer conveying structure for conveying the liquid developer scraped off from the image carrier and the pitch of the screw used in conveying the liquid developer scraped off from the developing roller are characterized in that The pitches of the screws used in the developer conveying structure of the developer are different.

In addition, the image forming apparatus related to the reference embodiment is characterized in that the rotation speed of the screw used in the developer conveying structure for conveying the liquid developer scraped off from the image carrier and the speed of rotation of the screw used in conveying the liquid developer scraped off from the developing roller are characterized. The rotation speeds of the screws used in the developer conveying structure of the developer are different.

According to the developer transport mechanism according to the reference embodiment, it is possible to smoothly carry out the process of transporting the aggregated toner particles in the charged state or the remaining liquid developer in the state of non-uniform toner concentration. As a result, recycling and disposal of the remaining liquid developer can be smoothly carried out.

In addition, according to the developer conveying mechanism according to the reference embodiment, since toner particles of the charged remaining liquid developer are prevented from being electrostatically adsorbed to the surface of the constituent members of the conveying portion, failure to convey the remaining liquid developer does not occur. The problem.

In addition, according to the image forming apparatus using the developer conveyance mechanism according to the above-mentioned reference embodiment, the conveyance efficiency of the excess liquid developer is improved, and the developer can be temporarily transported out of the closed-loop circulation structure of the developer. It is transported from the developing part to another part to be mixed with new developer, or the desired dispersion is performed by eliminating the aggregation of toner particles and the unevenness of toner concentration, or it is discarded as unnecessary developer.

Description of drawings

FIG. 1 is a diagram showing main components constituting an image forming apparatus using a developer conveying mechanism according to an embodiment of the present invention;

2 is a cross-sectional view showing main components of an image forming unit and a developing unit;

FIG. 3 is a diagram illustrating compression of the toner compression roller 22Y;

FIG. 4 is a diagram illustrating development of the developing roller 20Y;

FIG. 5 is a diagram illustrating the squeezing action of the image carrier squeezing roller 13Y;

FIG. 6 is a diagram illustrating the pressing action of the intermediate transfer body pressing device 52Y;

Fig. 7 is a figure showing the appearance shape of an anilox roll;

Fig. 8 is a schematic diagram showing the situation when the rotating body drive transmission mechanism is applied in the developing unit;

Fig. 9 is a diagram showing a cross-section when the rotating body drive transmission mechanism is connected;

FIG. 10 is a diagram showing a cross section before connecting the rotating body drive transmission mechanism;

Fig. 11 is a cross-sectional view showing the components of the rotating body drive transmission mechanism before they are fully fitted;

Fig. 12 is a sectional view showing the connection of the rotating body drive transmission mechanism;

13A to 13D are diagrams illustrating a polygonal shape of a torque transmission member and a detailed relationship between a rotation driven member and a rotation transmission member;

14A and 14B are diagrams illustrating the polygonal shape of the torque transmission member and the detailed relationship between the rotation driven member and the rotation transmission member;

FIG. 15 is a perspective view showing a developer conveying mechanism in the developer storage portion 18Y;

16 is a schematic diagram showing a cross section of a main part of the developer conveying mechanism according to the embodiment of the present invention;

17A to 17C are schematic diagrams showing sections at three positions in the length direction of the developer conveying mechanism according to the embodiment of the present invention;

FIG. 18 is a diagram showing main components constituting an image forming apparatus using a developer conveying mechanism according to an embodiment of the present invention;

FIG. 19 is a cross-sectional view showing main components of an image forming unit and a developing unit;

FIG. 20 is a perspective view showing a developer conveying mechanism in the developer storage portion 18Y;

21 is a perspective view of components constituting the developer conveying base 330 and the developer storage base 310;

22 is a perspective view of components constituting the developer conveying base 330 and the developer storage base 310;

23 is a schematic diagram showing a cross section of a main part of a developer conveying mechanism according to another embodiment of the present invention;

FIG. 24 is a perspective view showing a developer conveying mechanism in the developer storage portion 24Y.

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing main components constituting an image forming apparatus using a developer conveying mechanism according to an embodiment of the present invention. The developing units 30Y, 30M, 30C, and 30K are arranged at the lower part of the image forming apparatus, and the intermediate transfer body 40 and the secondary transfer portion 60 are arranged at The upper part of the image forming unit.

The image forming unit includes image carriers 10Y, 10M, 10C, and 10K; charging rollers 11Y, 11M, 11C, and 11K; and exposure units 12Y, 12M, 12C, and 12K (not shown). The exposure units 12Y, 12M, 12C, and 12K have semiconductor lasers, polygon mirrors, F-θ lenses, and the like. The image forming section uniformly charges the image carriers 10Y, 10M, 10C, and 10K with the charging rollers 11Y, 11M, 11C, and 11K, and irradiates laser light modulated based on input image signals through the exposure units 12Y, 12M, 12C, and 12K, thereby forming Electrostatic latent images are formed on the charged image carriers 10Y, 10M, 10C, and 10K.

The developing units 30Y, 30M, 30C, 30K roughly include: developing rollers 20Y, 20M, 20C, 20K; storing liquids of each color formed from yellow (Y), magenta (M), cyan (C), and black (K); developer containers (reservoirs) 31Y, 31M, 31C, 31K of the developer; and supply of these liquid developers of each color from the developer containers 31Y, 31M, 31C, 31K to the developing rollers 20Y, 20M, 20C, 20K The anilox rollers 32Y, 32M, 32C, 32K, etc., develop the electrostatic latent images formed on the image carriers 10Y, 10M, 10C, 10K with liquid developers of each color. Each of these developing units 30Y, 30M, 30C, and 30K is configured to be detachably attached to the image forming apparatus.

The image carrier squeeze rollers 13Y, 13M, 13C, 13K are abutted against the image carriers 10Y, 10M, 10C, 10K to exert a squeezing action thereon, and directional rollers 20Y, 20M, 20C, 20K are provided around These developing rollers are toner compression rollers 22Y, 22M, 22C, 22K that exert a compression effect. These toner compression rollers 22Y, 22M, 22C, and 22K may be in contact with the developing rollers 20Y, 20M, 20C, and 20K, or may remain in a non-contact state.

The intermediate transfer body 40 is an endless belt, which is wound and stretched between the drive roller 41 and the tension roller 42, and is connected to the image carriers 10Y, 10M, 10C, 10K at the primary transfer portions 50Y, 50M, 50C, 50K. The abutting state is rotationally driven by the drive roller 41 . In the primary transfer sections 50Y, 50M, 50C, and 50K, the primary transfer rollers 51Y, 51M, 51C, and 51K and the image carriers 10Y, 10M, 10C, and 10K are opposed to each other with the intermediate transfer body 40 interposed therebetween. The abutting positions of the image carriers 10Y, 10M, 10C, and 10K are used as transfer positions, and the toner images of each color on the developed image carriers 10Y, 10M, 10C, and 10K are successively overlapped and transferred onto the intermediate transfer body 40 , thereby forming a full-color toner image.

In the secondary transfer unit 60 , the secondary transfer roller 61 and the belt drive roller 41 are disposed opposite to each other with the intermediate transfer belt 40 interposed therebetween, and a secondary transfer roller cleaning blade 62 and a developer storage portion 63 are further disposed. cleaning device. At the transfer position where the secondary transfer roller 61 is arranged, the single-color toner image or the full-color toner image formed on the intermediate transfer body 40 is transferred to paper conveyed through the sheet conveyance path L, on recording media such as sheets and cloth.

Further, a fixing unit (not shown) is arranged in front of the sheet transport path L for fusing and fixing a single-color toner image or a full-color toner image transferred to a recording medium such as paper on paper or the like for recording. on the medium.

The tension roller 42 hangs the intermediate transfer body 40 together with the belt drive roller 41 , and the cleaning device including the intermediate transfer body cleaning blade 46 and the developer storage portion 47 abuts and is arranged at a position where the intermediate transfer body 40 is hung by the tension roller 42 place.

Next, the image forming unit and the developing unit will be described. 2 is a cross-sectional view showing main components of an image forming unit and a developing unit. FIG. 3 is a diagram illustrating compression of the toner compression roller 22Y. FIG. 4 is a diagram illustrating development of the developing roller 20Y. FIG. 5 is a diagram illustrating the pressing action of the image carrier pressing roller 13Y. FIG. 6 is a diagram illustrating the pressing action of the intermediate transfer body pressing device 52Y. Since the configurations of the image forming section and developing unit are the same for each color, the following description will be based on the image forming section and developing unit for yellow (Y).

The image forming section is arranged along the rotational direction of the outer periphery of the image carrier 10Y: a latent image eraser 16Y, a cleaning device including an image carrier cleaning sheet 17Y and a developer storage section 18Y, a charging roller 11Y, an exposure unit 12Y, a developing unit 30Y. roller 20Y, and a cleaning device including an image carrier squeeze roller 13Y and an image carrier squeeze roller cleaning sheet 14Y as an accessory member thereof. Arranged around the developing roller 20Y in the developing unit 30Y are a cleaning device including a developing roller cleaning blade 21Y and a developer storage portion 24Y, an anilox roller 32Y, and a toner compression roller 22Y.

A carrier amount regulating blade 23Y is provided on the outer periphery of the toner compression roller 22Y. A part of the liquid developer roller 34Y and the anilox roller 32Y is housed in the liquid developer container 31Y. Also, a primary transfer roller 51Y of the primary transfer portion is arranged at a position facing the image carrier 10Y along the intermediate transfer body 40 , and an intermediate transfer body pressing device 52Y is arranged on the downstream side in the moving direction thereof, The intermediate transfer body pressing device 52Y includes an intermediate transfer body pressing roller 53Y, a backup roller 54Y, an intermediate transfer body pressing roller cleaning blade 55Y, and a developer storage portion 56Y.

The image carrier 10Y is a photosensitive drum constituted by a cylindrical member wider than a width of about 320 mm of the developing roller 20Y, and has a photosensitive layer formed on the outer surface. For example, as shown in FIG. 2, the image carrier 10Y rotates clockwise. The photosensitive layer of this image carrier 10Y is composed of an amorphous silicon image carrier or the like. The charging roller 11Y is disposed upstream of the nip portion between the image carrier 10Y and the developing roller 20Y in the rotational direction of the image carrier 10Y, and is supplied with the same polarity as the toner charging polarity from a power supply unit (not shown). The bias voltage is applied to charge the image carrier 10Y. The exposure unit 12Y irradiates laser light to the image carrier 10Y charged by the charging roller 11Y on the downstream side of the charging roller 11Y in the rotational direction of the image carrier 10Y, thereby forming a latent image on the image carrier 10Y.

The developing unit 30Y has: a toner compression roller 22Y; a developer container 31Y for storing a liquid developer in a state in which about 20% by weight of toner is dispersed in a carrier; roller 20Y; an anilox roller 32Y, a restricting sheet 33Y, and a supply roller 34Y for supplying the liquid developer to the developing roller 20Y in a state of maintaining uniform dispersion after stirring; the liquid developer carried on the developing roller 20Y becomes a toner compression roller 22Y in a compressed state; and a developing roller cleaning blade 21Y for cleaning the developing roller 20Y.

Fig. 7 is a diagram showing an external shape of an anilox roll. The anilox roll 32Y and the supply roll 34Y constitute a structure that rotates in opposite directions to each other. If the anilox roller 32Y and the supply roller 34Y are configured to rotate in opposite directions to each other, a uniform film of the liquid developer can be formed from the supply roller 34Y to the anilox roller 32Y.

The liquid developer contained in the developer container 31Y is a high-concentration and high-viscosity non-volatile liquid developer having a non-volatile property at normal temperature. That is, the liquid developer in the present invention is obtained by adding solid particles having an average particle diameter of 1 μm obtained by dispersing a colorant such as a pigment in a thermoplastic resin to a liquid such as an organic solvent, silicone oil, mineral oil, or edible oil, together with a dispersant. A high-viscosity (about 30 to 10,000 mPa·s) liquid developer with a solid toner concentration of about 20% in a solvent.

In the developer container 31Y, toner particles in a liquid developer having a positive charge are agitated by the supply roller 34Y and sucked from the developer container 31Y as the anilox roller 32Y rotates.

The restricting piece 33Y is composed of an elastic piece covered with an elastic body, a rubber part, and a plate member such as metal supporting the rubber part. The rubber part is formed of urethane rubber or the like in contact with the surface of the anilox roller 32Y. The restricting sheet 33Y restricts and adjusts the film thickness and amount of the liquid developer carried and conveyed by the anilox roller 32Y formed of an anilox roller, thereby adjusting the amount of liquid toner supplied to the developing roller 20Y.

The developing roller 20Y is a cylindrical member having a width of about 320 mm, which rotates counterclockwise as shown in FIG. 2 around the rotation axis. In this developing roller 20Y, an elastic layer such as urethane rubber, silicone rubber, or NBR is provided on the outer periphery of an inner core made of metal such as iron. The developing roller cleaning blade 21Y is made of rubber or the like that contacts the surface of the developing roller 20Y, and the developing roller 20Y is arranged on the downstream side of the nip portion that contacts the image carrier 10Y in the rotational direction of the developing roller 20Y, and scrapes off the surface of the developing roller 20Y. Residual liquid developer.

As shown in FIG. 3, the toner compression roller 22Y is a cylindrical member. Like the developing roller 20Y, it is an elastic roller formed by covering an elastic body 22-1Y, and is configured to have a metal roller base on the surface layer. The structure of the conductive resin layer or rubber layer, for example, as shown in FIG. 2 , rotates in the direction opposite to that of the developing roller 20Y, that is, in the clockwise direction. The toner compression roller 22Y has means for increasing the charging bias on the surface of the developing roller 20Y, as shown in FIGS. The side of the toner compression roller 22Y applies a bias electric field to the developer conveyed by the developing roller 20Y toward the developing roller 20Y. The application of this bias voltage will be described in detail later. The toner compression roller 22Y may not be in contact with the developing roller 20Y as long as it can perform the toner compression function.

As shown in FIG. 3, this causes the toner T uniformly dispersed in the carrier C to move and aggregate to the side of the developing roller 20Y, forming a so-called toner compressed state T', and a part of the carrier C and the untoned A small amount of toner T″ compressed by the toner is carried on the toner compression roller 22Y to rotate in the direction of the arrow in the figure, scraped off by the carrier amount regulating blade 23Y, and merged with the developer in the reservoir 31Y before being reused. On the other hand, as shown in FIG. 4 , the developer D carried on the developing roller 20Y and compressed by the toner is applied to the image by applying a desired electric field at the developing nip portion where the developing roller 20Y abuts against the image carrier 10Y. The latent image of the carrier 10Y is developed.

The image carrier pressing device is opposed to the image carrier 10Y and arranged on the downstream side of the developing device 20Y, for recovering the remaining developer of the toner image developed on the image carrier 10Y, and as shown in FIGS. 2 and 5 , it It includes an image carrier pressing roller 13Y, which is an elastic roller member covered with an elastic body 13-1Y on its surface and rotates in sliding contact with the image carrier 10Y, and a cleaning sheet 14Y. The carrier pressing roller 13Y presses and makes sliding contact to clean the roller surface. As shown in FIG. 5, the image carrier pressing device has the function of improving the content of the developed image by recovering the remaining carrier C and originally unnecessary cloudy toner (capritona—) T" from the developer D developed on the image carrier 10Y. function of the toner particle ratio. The recovery ability of the remaining carrier C can be determined by the rotational direction of the image carrier squeeze roller 13Y, and the relative peripheral speed difference of the image carrier 10Y surface with respect to the peripheral speed of the image carrier squeeze roller 13Y surface. To set the desired recovery capacity, if the image carrier squeeze roller 13Y is rotated in reverse with respect to the image carrier 10Y, the recovery capacity can be improved, or setting a large peripheral speed difference can also improve the recovery capacity, and it can also be used synergy of the two.

In this embodiment, as an example, as shown in FIG. 5, the image carrier squeeze roller 13Y is rotated at substantially the same peripheral speed together with the image carrier 10Y, and the weight is recovered from the developer D developed on the image carrier 10Y. The remaining carrier C ratio is about 5 to 10%, thereby reducing the rotational driving load of both sides, and suppressing the disturbing effect on the developed toner image of the image carrier 10Y. The remaining carrier C and unnecessary blurred toner T″ recovered by the image-carrier squeeze roller 13Y are recovered from the image-carrier squeeze roller 13Y by the action of the cleaning blade 14Y.

In the primary transfer portion 50Y, the developer image developed on the image carrier 10Y is transferred onto the intermediate transfer body 40 by the primary transfer roller 51Y. Here, the image carrier 10Y and the intermediate transfer body 40 move at the same speed, thereby suppressing the disturbing effect on the developed toner image of the image carrier 10Y while reducing the driving load of rotation and movement. In the primary transfer portion 50Y of the first color, since the primary transfer is performed for the first time, color mixing does not occur, but from the second color, since the toner image that has been primary transferred Different toner images are further transferred on the part to perform color overlap, so the toner of the transfer is reversed by the so-called reverse transfer phenomenon in which the toner is transferred from the intermediate transfer body 40 to the image carrier 10 (M, C, K). Toner and transfer remaining toner are mixed and carried on the image carrier 10 (M, C, K) together with the remaining carrier to move, and then removed from the image carrier by the action of the cleaning sheet 17 (M, C, K). Recycle and concentrate.

The intermediate transfer body pressing device 52Y is disposed on the downstream side of the primary transfer portion 50Y, and performs a process of removing excess carrier liquid from the intermediate transfer body 40 to increase the ratio of toner particles in a developed image. The intermediate transfer body pressing device 52Y is provided as a device that, when the carrier amount of the developer (toner dispersed in the carrier body) transferred onto the intermediate transfer body 40 in the primary transfer portion 50Y does not reach The approximate toner weight ratio in the desired dispersion state of the liquid developer is about 40% to 60%, and the remaining carrier is further removed from the intermediate transfer body 40 so as to be transferred to the sheet in the final stage described above. Afterwards, it enters the stage of the fixing process (not shown in the figure), so that a good secondary transfer function and a fixing function can be exerted. Like the image carrier pressing device, the intermediate transfer body pressing device 52Y includes an intermediate transfer body pressing roller 53Y composed of an elastic roller covered with an elastic body on its surface and rotating in a state of sliding contact with the image carrier 40 . Component configuration: backup roller 54Y, which is disposed opposite to the intermediate transfer body pressing roller 53Y with the image carrier 40 interposed therebetween; cleaning sheet 55Y, which comes into pressure sliding contact with the intermediate transfer body pressing roller 53Y to clean its surface; and developing The agent storage part 56Y. As shown in FIG. 6 , the intermediate transfer body pressing device 52Y has a function of recovering the remaining carrier C and originally unnecessary blurred toner T″ from the developer D primarily transferred on the intermediate transfer body 40 . The developer storage portion 56Y also serves as a recovery mechanism for recovering a carrier liquid in the magenta image carrier squeeze roller cleaning blade 14M disposed downstream thereof.

With regard to the recoverability of the remaining carrier C, desired recovery can be set by the rotational direction of the intermediate transfer body squeeze roller 53Y and the relative peripheral speed difference between the surface of the intermediate transfer body 40 and the surface of the intermediate transfer body squeeze roller 53Y. If the recovery capacity is increased by reversely rotating the squeeze roller 53Y with respect to the intermediate transfer body, or the recovery capacity is also increased by setting a large peripheral speed difference, further, this double action is also possible. In this embodiment, as an example, the intermediate transfer body squeeze roller 53Y is rotated together with the intermediate transfer body 40 at substantially the same peripheral speed, and recovered from the developer primarily transferred on the intermediate transfer body 40 The remaining carrier is about 5 to 10% by weight, so as to reduce the rotational driving load of both sides and suppress the disturbing effect on the toner image on the intermediate transfer body 40 .

In the extrusion part of the intermediate transfer body of the first color, because it is the first time the intermediate transfer body is extruded, the color mixing phenomenon does not occur, but starting from the second color, due to the first transfer Different toner images are further transferred to the toner image portion to perform color overlap, so the toner when the toner is transferred from the intermediate transfer body 40 to the intermediate transfer body squeeze roller 53Y is mixed with each other and mixed with the remaining toner. The carriers are carried together on the intermediate transfer body pressing roller 53Y to move, and then recovered and collected from the intermediate transfer body pressing roller 53Y by the action of the cleaning sheet. In addition, when the above-mentioned squeezing ability of the image carrier 40 and the squeezing ability of the image carrier squeezing roller 53Y on the primary transfer portion on the upstream side of the intermediate transfer body squeezing process are sufficient, it is not necessarily necessary at all An intermediate transfer body pressing device is provided on the downstream side of the primary transfer process.

In the liquid development image forming apparatus using a developer obtained by dispersing toner in a carrier according to this embodiment, a developer obtained by dispersing 20% of toner in a carrier having an approximate weight ratio of 80% is used. And it is controlled to achieve the following goal: After going through various processes, the toner weight ratio (solid content ratio) at the position to be transferred to the sheet secondarily, that is, the so-called second transfer position, is within a thin coating In the case of smooth paper such as paper, it is about 45%, in the case of plain paper, it is about 55%, and in the case of rough paper such as recycled paper with a large mesh size of paper fibers, it is about 60%. The developer initially stored in the developer container 31Y is in a state where approximately 20% by weight of toner is dispersed in the carrier. However, in the development to the image carrier 10Y, if the image duty ) is large in development, the toner consumption ratio is large, and on the contrary, in development with a small image duty ratio, the toner consumption ratio is small. That is, since the toner weight ratio of the developer stored in the developer container 31Y changes moment by moment as the development to the image carrier 10Y is performed, it is necessary to constantly monitor this change and perform control so as to maintain the dispersion at 20Y. The state of the rough toner weight ratio of the % degree.

The restriction piece 33Y abuts against the surface of the anilox roller 32Y, thereby retaining the liquid developer in the concave-convex grooves of the mesh pattern formed on the surface of the anilox roller 32Y and scraping off other excess liquid developer, thereby restricting the development of the liquid developer. The amount of liquid developer supplied by the developing roller 20Y. With such a limitation, the film thickness of the liquid developer applied to the developing roller 20Y is fixed to about 6 μm. The liquid developer scraped off by the restricting sheet 33Y falls back into the developer container 31Y by gravity, and the liquid developer not scraped off by the restricting sheet 33Y is accommodated in the concave-convex grooves on the surface of the anilox roller 32Y, and passes through the contact with the developing roller. 20Y is pressure-contacted and coated onto the surface of the developing roller 20Y.

The developing roller 20Y to which the liquid developer is applied via the anilox roller 32Y contacts the toner compression roller 22Y downstream of the nip portion with the anilox roller 32Y. The developing roller 20Y is applied with a predetermined bias, and the toner compression roller 22Y is applied with a bias higher than that of the developing roller 20Y and having the same polarity as the charged polarity of the toner. The application of the bias voltage will be described later.

Since the bias voltage is applied as described above, the toner particles in the liquid developer on the developing roller 20Y, as shown in FIG. The roller 20Y moves on one side. Thus, the toner particles are slowly combined with each other and aggregated to form a film state, and when developing to the image carrier 10Y, the movement of the toner particles from the developing roller 20Y to the image carrier 10Y becomes fast, thereby improving the image density. .

The image carrier 10Y is made of amorphous silicon. The image carrier 10Y is charged by the charging roller 11Y upstream of its nip with the developing roller 20Y, and then passes through the exposure unit 12Y to form a latent image. As shown in FIG. 4, at the developing nip formed between the developing roller 20Y and the image carrier 10Y, the toner particles T are formed in accordance with the bias voltage applied to the developing roller 20Y and the latent image on the image carrier 10Y. The electric field selectively moves to the image portion on the image carrier 10Y, thereby forming a toner image on the image carrier 10Y. Since the carrier liquid C is not affected by an electric field, as shown in FIG. 4 , it separates at the outlet of the developing nip between the developing roller 20Y and the image carrier 10Y and adheres to both the developing roller 20Y and the image carrier 10Y. As shown in FIG. 5 , the image carrier 10Y passing through the development nip passes through the image carrier squeeze roller 13Y portion, and is subjected to a process of removing the remaining carrier liquid C to increase the ratio of toner particles in the developed image.

Next, the image carrier 10Y primary transfers the developed toner image onto the intermediate transfer body 40 through its nip portion with the intermediate transfer body 40 in the primary transfer portion 50Y. The toner is primarily transferred from the image carrier 10Y to the intermediate transfer body 40 by applying a bias voltage having a polarity opposite to that of the charged polarity of the toner particles to the primary transfer roller 51Y, and only the toner remains on the image carrier 10Y. carrier fluid. On the downstream side of the rotation direction of the image carrier 10Y of the primary transfer section, a latent image eraser 16Y formed of a lamp or the like erases an electrostatic latent image on the image carrier 10Y after the primary transfer, and an image carrier cleaning sheet 17Y scrapes off the image carrier 10Y. The scraped-off carrier liquid is recovered by the developer storage section 18Y.

The toner image first transferred onto the intermediate transfer body 40 in the primary transfer portion 50Y passes through the intermediate transfer body pressing device 52Y in order to scrape off the remaining carrier on the intermediate transfer body 40 . A predetermined bias voltage is applied to the intermediate transfer body pressing roller 53Y and the intermediate transfer body pressing back-up roller 54Y of the intermediate transfer body pressing device 52Y to generate a pressurization of the toner toward the intermediate transfer body 40 side. The electric field of the particles. Therefore, as shown in FIG. 6, the toner particles are not recovered, and only the carrier liquid which is not affected by the electric field is separated from the toner particles between the intermediate transfer body 40 and the intermediate transfer body squeeze roller 53Y and It is collected on the intermediate transfer body squeeze roller 53Y.

The toner image on the intermediate transfer body 40 next advances toward the secondary transfer unit 60 and enters the nip portion of the intermediate transfer body 40 and the secondary transfer roller 61 . The occlusal width at this time was set to 3 mm. In the secondary transfer unit 60 , predetermined bias voltages are respectively applied to the secondary transfer roller 61 and the belt drive roller 41 , thereby transferring the toner image on the intermediate transfer belt 40 to a recording medium such as paper.

After passing through the secondary transfer unit 60, the intermediate transfer body 40 advances toward the winding part of the tension roller 42, and the intermediate transfer body 40 is cleaned by the intermediate transfer body cleaning sheet 46, and then the intermediate transfer body 40 is again It proceeds to the primary transfer unit 50 .

Next, the pressing function of the secondary transfer roller 61 will be described. The sheet is supplied in synchronization with the timing at which the toner image superimposed on the intermediate transfer body 40 reaches the secondary transfer position, and the toner image is secondarily transferred onto the sheet. The sheet is then subjected to a fixing process not shown to end image formation on the sheet. However, when a sheet supply failure such as a paper jam occurs, the toner image comes into contact with the secondary transfer roller 61 and is transferred without the sheet, resulting in contamination of the back surface of the sheet. The secondary transfer roller 61 of the present embodiment is composed of an elastic roller whose surface is covered with an elastic body. It should be noted that the intermediate transfer body 40 employs an elastic belt by sequentially primary transferring toner images formed on a plurality of photoreceptors and superimposedly carrying them and then collectively secondary transferring onto a sheet so that even A sheet whose surface is not smooth due to a fiber material or the like can conform to the surface of the rough sheet to improve secondary transfer characteristics. The use of the elastic roller for the secondary transfer roller 61 in this embodiment is also for the same purpose as above. The secondary transfer roller cleaning sheet 62 is used as means for removing the developer (toner dispersed in the carrier) transferred on the secondary transfer roller 61 , which is recovered from the secondary transfer roller 61 and collected developer. The concentrated developer is in a multi-color mixed state, and sometimes contains impurities such as paper dust.

Next, a cleaning device for the intermediate transfer body 40 will be described. When a sheet supply failure such as paper jam occurs, not all toner images are transferred to the secondary transfer roller 61 to be collected, but some of the toner images remain on the intermediate transfer body 40 . Moreover, in the usual secondary transfer process, the toner image on the intermediate transfer body 40 is not 100% completely transferred to the sheet by secondary transfer, but a few percent of the toner image will be generated. Secondary transfer residue. For the next image formation, the above two types of unnecessary toner images are recovered and collected by the intermediate transfer body cleaning blade 46 and the developer storage portion 47 arranged on the downstream side in the moving direction of the intermediate transfer body 40 .

Next, the driving force transmission in the developing units 30Y, 30M, 30C, and 30K using the rotary body drive transmission mechanism according to the embodiment will be described in detail. The rotating body drive transmission mechanism of the present invention is used to transmit rotational driving force from the main body of the image forming apparatus to image carriers and rollers on the side of the developing units 30Y, 30M, 30C, and 30K detachably mounted on the main body.

Fig. 8 is a schematic diagram showing the situation in which the rotary body drive transmission mechanism is applied in the developing unit, Fig. 9 is a sectional view showing the connection of the rotary body drive transmission mechanism, and Fig. 10 is a diagram showing the state before the rotary body drive transmission mechanism is connected Sectional view, Fig. 11 is a sectional view showing the components of the rotating body drive transmission mechanism before they are fully fitted.

In FIG. 8, reference numeral 100 denotes a rotating body drive transmission mechanism. In this embodiment, the rotating body drive transmission mechanism 100 is used to transmit rotation to the image carrier 10Y, the image carrier squeeze roller 13Y, the developing roller 20Y, and the anilox roller 32Y. driving force. In this embodiment, the rotating body drive transmission mechanism 100 is applied to each of the above-mentioned rollers, but it may be applied to only one of the above-mentioned rollers, or may be applied to any combination of the above-mentioned rollers. Furthermore, the rotating body drive transmission mechanism 100 may be used for rollers other than the above-mentioned respective rollers. In addition, this embodiment shows an example in which the rotating body drive transmission mechanism 100 is applied to an image forming apparatus using liquid developer, but the present invention is not limited thereto, and can also be applied to an image forming apparatus using dry toner. middle.

In FIGS. 9 to 11 , numeral 110 denotes a torque transmission member, numeral 120 denotes a rotation transmission member, numeral 112 denotes a spring member, numeral 113 denotes a flange portion, and numeral 114 denotes a key member. Reference numeral 130 denotes abutting surface for transmission, reference numeral 140 denotes a rotating body driving source part, reference numeral 150 denotes a rotating driven member, reference numeral 151 denotes a rotating body mounting flange part, reference numeral 152 denotes a ball bearing, reference numeral 153 denotes a support member, and reference numeral 160 Indicates a concave part for mating.

FIGS. 9 to 11 are diagrams showing the structure of a rotary body drive transmission mechanism 100 having a rotary body (image carrier 10Y) rotatably supported in the axial direction of the rotary body (image carrier 10Y). It includes a rotation transmission member 120 and the like, and a rotary body drive source 140 for rotating the rotary body in the direction of the rotary shaft rotates the rotary body by transmitting drive to drive the rotary body in rotation.

In the examples of FIGS. 9 to 11, the image carrier 10Y as a rotating body is shown to receive a rotational driving force from a rotating body drive source 140 such as a motor, but the image carrier squeeze roller 13Y, developing roller 20Y, anilox When another roller such as the roller 32Y receives a rotational driving force as a rotating body, it may be configured in the same manner.

The rotational driving force is transmitted from the key member 114 of the rotating body drive source 140 to the rotation transmission member 120 via the flange portion 113 fixed to the key member 114 .

A polygonal hole is formed in the rotation transmission member 120 , and a rotational force is transmitted to the torque transmission member 110 by a transmission contact surface 130 having the same polygonal shape as an inner wall of the hole. The torque transmission member 110 urged by the spring member 112 protrudes from the polygonal hole of the rotation transmission member 120 .

The rotation driven member 150 is provided with a hole having the same polygonal shape for receiving the rotational force via the torque transmission member 110 , and the torque transmission member 110 is engaged with the engaging concave portion 160 as the inner wall thereof.

The rotation driven member 150 is fixed to the rotation body mounting flange portion 151 by predetermined fixing means, and the rotation body (image carrier 10Y) mounted on the rotation body mounting flange portion 151 rotates together with the rotation driven member 150 . The rotating body mounting flange part 151 is mounted on the support member 153 via the ball bearing 152, and is in a freely rotatable state.

Fig. 10 shows the situation that the rotation driven component 150 is installed on the rotation transmission component 120 along the direction of the arrow in the figure, the torque transmission component 110 loosely fitted on the rotation transmission component 120 remains completely free without any restriction .

11 shows the scene where the rotation driven member 150 is installed at a predetermined position of the rotation transmission member 120, and shows the following state: the polygonal shape of the torque transmission member 110 loosely fitted with the rotation transmission member 120 and the torque transmission member 110 formed in the In a state where the relative phases of the abutting surfaces on the torque transmission member 110 do not match, the end surface of the rotational driven member 150 abuts against the end surface of the torque transmission member 110 facing thereto, and the torque transmission member 110 resists the force of the spring member 112. Move by pushing force.

FIG. 12 shows a state in which the polygonal shape of the torque transmission member 110 loosely fitted to the rotation transmission member 120 and the relative phase of the mating concave surface 160 formed on the rotation driven member 150 are driven by the rotation of the rotation transmission member 120. Fitting, and by the urging force of the spring member 112 , the state where the torque transmission member 110 is fitted into the rotation driven member 150 during rotation.

Here, a predetermined gap into which the torque transmission member 110 can fit in the rotation direction and the direction perpendicular to the rotation axis may be provided in the fitting concave surface 160 of the hole of the rotation driven member 150 . With regard to the loose fit relationship between the rotation driven part 150 and the torque transmission part 110 of the rotation transmission part 120 , especially for a predetermined clearance provided in the direction of rotation, it can be set so that when the rotation body is rotationally driven from the rotation transmission part 120 (image carrier 10Y) is a gap into which the torque transmission member 110 can fit toward the moving pressure side as it rotates.

The rotation driven member 150 is rotatably supported by the ball bearing 152 supported by the rotating body mounting flange portion 151 pressed into one end of the cylindrical rotating body (image carrier 10Y), and the rotating driven member 150 is screwed. It is fixed to this rotating body mounting flange portion 151 to define a position in the sliding direction.

On the other hand, the rotating body drive source unit 140 (detailed illustration is omitted) is disposed opposite to the rotating body (image carrier 10Y) in the direction of the rotating body rotation axis, and is configured as a key for driving the rotation of the rotating body driving source unit 140 . A structure in which the member 114 is transmitted to the driving flange portion 113 . Further, the rotation transmission member 120 is mounted on the drive flange portion 113, and constitutes a rotation body drive transmission portion together with the rotation driven member 150 facing it.

This rotary body drive transmission portion has a structure including a columnar torque transmission member 110 extending in the rotation axis direction of the rotary body (image carrier 10Y) and forming a polygonal shape, and is formed corresponding to the polygonal shape of the torque transmission member 110. The plurality of abutting faces (fitting concave portion 160 ) that the polygonal faces abut on share the torque transmission member 110 with predetermined gaps in the rotation direction and the direction perpendicular to the rotation axis.

Next, the relationship between the polygonal shape of the torque transmission member 110 , the polygonal hole provided on the rotation transmission member 120 , the polygonal hole provided on the rotation driven member 150 , and the rotating body drive of the present invention will be described. Rotary drive force transmission mechanism in the transmission mechanism.

13A to 13D are diagrams for explaining the polygonal shape of the torque transmission member 110 and the detailed relationship between the rotation driven member 150 and the rotation transmission member 120 , and the drawings show the AA cross section of FIG. 12 .

In FIGS. 13A to 13D , the polygonal shape of the torque transmission member 110 and the contact surfaces of the rotation driven member and the rotation transmission member are configured so as not to include surfaces parallel to each other.

13A to 13D schematically show an example in which the polygonal shape of the torque transmission member 110 and the abutment surfaces of the rotation driven member 150 and the rotation transmission member 120 are formed in an odd number relationship. FIG. 13A schematically shows Although it does not conform to the representation method of the A-A cross-sectional view, it is preferable to use the two-dot chain line to show the rotation in consideration of the expressive effect of the figure to show the state in which the rotation driven member 150 is rotationally driven from the rotation transmission member 120 via the torque transmission member 110. driven part 150 .

Fig. 13B shows that the torque transmission component 110, the rotation driven component 150, and the rotation transmission component 120 are in a non-rotational driving state, and the torque transmission component 110 is provided with a predetermined gap in the rotation direction and the direction at right angles to the rotation axis to be connected to the rotation driven component 150. 1. The rotation transmission part 120 is loosely fitted. In FIGS. 13A and 13B , the polygonal shape of the torque transmission member 110 and the contact surfaces of the rotation driven member 150 and the rotation transmission member 120 are formed in a pentagonal relationship.

Similarly, in FIGS. 13C and 13D , the polygonal shape of the torque transmission member 110 and the contact surfaces of the rotation driven member 150 and the rotation transmission member 120 are configured in a triangular relationship.

13A to 13D show an example in which the polygonal shape of the torque transmission member 110 and the shapes of the abutment surfaces of the rotation driven member 150 and the rotation transmission member 120 are different, but the common points in the entire relationship are: When the torque transmission member 110, the rotation driven member 150, and the rotation transmission member 120 are in a non-rotational driving state, the torque transmission member 110 is provided with a predetermined gap in the direction of rotation and a direction perpendicular to the rotation axis to be connected to the rotation driven member 150, The rotation transfer part 120 is a loose fit.

Moreover, when the rotation transmission member 120 is rotated in the direction of the arrow in the drawing to rotationally drive the rotation driven member 150 via the torque transmission member 110, the abutting surface of the rotation transmission member 120 abuts against the torque transmission member 110, and the torque transmission member 110 abuts against the abutting surface of the rotation driven member 150 to be rotationally driven.

When the above-mentioned rotational driving is performed, the torque transmission member 110 loosely fitted with the abutting surface of the rotational driven member 150 and the rotation transmission member 120 automatically moves from the loosely fitted state to a stable position and automatically adjusts the rotation axis.

Therefore, it is possible to easily prevent the rotation variation due to the use of one rotation transmission portion as described in the conventional example, and it is not necessary to configure each part with particularly high precision.

On the other hand, if the polygonal shape of the torque transmission member 110 and the contact surfaces of the rotation driven member 150 and the rotation transmission member 120 have a structure including parallel surfaces, due to the multiple contact surfaces of the rotation driven member 150 and the rotation A plurality of abutment surfaces of the transmission member 120 have a parallel relationship with each other. Therefore, when the rotational driving state is carefully observed, for example, the torque transmission member 110 that automatically moves from a loose fit state to a position that is conducive to self-stabilization and automatically adjusts the rotation axis is affected. Under the influence of disturbances such as slight transmission torque fluctuations and vibrations, small movements along the parallel abutment surfaces may result in an unavoidable unstable state, and this may cause slight fluctuations in the rotational speed for one rotation cycle.

Therefore, the polygonal shape of the torque transmission member 110 illustrated in FIGS. 13A to 13D and the abutment surfaces of the rotation driven member 150 and the rotation transmission member 120 are configured in an odd number relationship, and the plurality of abutment surfaces of the rotation driven member 150 and the rotation transmission The abutment surfaces of the member 120 do not form a parallel relationship with each other, so when the rotational driving state is carefully observed, the torque transmission member 110 that automatically moves from the loose fit state to a position that is conducive to its own stability and automatically adjusts the axis of rotation Affected by disturbances such as slight transmission torque fluctuations or vibrations, it will not move, and the self-aligning state can be maintained, so that it will not cause a small rotation speed fluctuation in one rotation cycle.

For the most preferable form in which the polygonal shape of the torque transmission member 110 and the abutting surfaces of the rotation driven member 150 and the rotation transmission member 120 are formed in an odd-numbered relationship, in consideration of production efficiency, the simplest shape of three equal parts is preferable. triangle shape.

The polygonal shape of the torque transmission member 110 shown in FIGS. 13A to 13D and the shape of the abutting surface of the rotation driven member 150 and the rotation transmission member 120 are examples of the same shape of the torque transmission member 110, but the torque transmission member may be formed. The shape of 110 is such that the shape of the portion loosely fitted with the rotation driven member 150 is different from the shape of the portion loosely fitted with the rotation transmission member 120 . In addition, an example in which the torque transmission member 110 is loosely fitted and contained in the rotation driven member 150 and the rotation transmission member 120 was shown, but it is also possible to constitute an external structure on the contrary.

In addition, in FIGS. 9 to 12, a spring is used to move and press the torque transmission member 110 in one direction, so that it is in a state of automatically adjusting the rotation axis and stabilizing the axial position, but the configuration of the spring is not indispensable condition.

Next, a case where the rotary body drive transmission mechanism of this embodiment is applied to a plurality of rollers of an image forming apparatus will be discussed. In this embodiment, the rotating body drive transmission mechanism 100 is used to transmit the rotational driving force to the image carrier 10Y, the image carrier squeeze roller 13Y, the developing roller 20Y, and the anilox roller 32Y. The corners of the polygonal shape of the engaging concave portion 160 and the like of the driven member 150 are set so as not to be parallel to each other. This is because if there is a phase coincident position such as the corners in the respective rollers being parallel to each other, the image will be disturbed by noise due to resonance. Here, a corner refers to a vertex of a polygonal shape such as the engaging concave portion 160 .

In addition, especially when the rotating body drive transmission mechanism 100 is applied to the image carrier 10Y or the anilox roller 32Y, it is preferable to set the corners of the polygonal shape so that they are not parallel to each other. This is because in the image forming apparatus, it is necessary to finely change the rotation speed of the anilox roller 32Y according to paper quality, room temperature, etc., and especially to prevent linkage with the image carrier 10Y.

14A and 14B are diagrams for explaining the polygonal shape of the torque transmission member 110 and the detailed relationship between the rotation driven member 150 and the rotation transmission member 120 , and their structures are the same as those shown in FIGS. 13A to 13D . What is different from what is shown in FIGS. 13A to 13D is that the relative eccentric state of the rotation driven member 150 and the rotation transmission member 120 is exaggeratedly shown. The illustration of the non-rotated state is omitted therein. Furthermore, although it does not conform to the AA cross-sectional diagram representation method, it is preferable to omit the cross-hatching of the rotation transmission member 120 and to show the rotation driven member 150 with a two-dot chain line in consideration of the expressive effect of the diagram. In addition, symbol G1 in the figure represents the rotation axis of the rotation transmission member 120, symbol G2 represents the rotation axis of the rotation driven member 150, and symbol G3 represents the virtual rotation axis of the entire rotary body drive transmission mechanism.

In Fig. 14A and Fig. 14B, the rotation axis of the rotation transmission member 120 and the rotation axis of the rotation driven member 150 become a relatively eccentric state as shown in the figure, and one end of the torque transmission member 110 automatically moves to the rotation transmission member 120, The other end automatically moves to a stable position based on the mechanism described in FIGS. 13A-13D , and automatically adjusts the rotation axis.

That is, the torque transmission member 110 transmits rotational drive from the rotation transmission member 120 to the rotation driven member 150 in a state tilted by the relative eccentricity amount, and in this state, the virtual rotation axis G3 of the torque transmission member 110 falls on the above-mentioned relative eccentricity. Rotational drive transmission is performed at the middle position of the relative eccentricity, that is, about 1/2 of the relative eccentricity.

In the structure shown in the conventional example, the rotation speed change of one rotation cycle occurs according to the relative eccentricity of the driving side and the driven side, but according to the above-mentioned structure of the present embodiment, the virtual rotation axis center of the torque transmission member 110 falls on the Since the rotation drive is transmitted at the intermediate position of the relative eccentricity, that is, the position of about 1/2 of the relative eccentricity amount, it is possible to reduce the variation of the rotational speed in one rotation cycle by half.

According to the above-mentioned structure, it is possible to provide a rotary body drive transmission mechanism which does not need to be constructed with very high precision and which has a simple structure and even if the axis centers of the driving side and the driven side are different It is possible to prevent the rotational speed of one rotation cycle from changing even if the rotational drive is performed in a stable state, so that the rotational drive transmission can be performed stably.

In addition, according to the above-mentioned structure, even if there is a certain degree of dimensional error, it will not become a defective product, so it can contribute to improving the yield rate in mass production.

In addition, according to the image forming apparatus using the above-mentioned rotary body drive transmission mechanism, jitters do not occur in one rotation period of the rotary body drive transmission mechanism, so that image disturbance and instability do not occur.

Next, the developer transport mechanism applied to the developer storage portion 18Y of the image carrier 10Y and the developer storage portion 24Y of the developing roller 20Y of the image forming apparatus will be described.

FIG. 15 is a perspective view showing a developer conveying structure in the developer storage portion 18Y, and FIG. 16 is a schematic cross-sectional view showing a main part of the developer conveying mechanism according to the embodiment of the present invention. Fig. 16 is the BB section of Fig. 2 . The structure of the developer conveying mechanism used in the developer storage portion 24Y is also basically the same.

In FIGS. 15 and 16, reference numeral 200 denotes a developer conveying mechanism, reference numeral 210 denotes a developer storage base, reference numeral 211 denotes a groove portion of a developer storage base, reference numeral 220 denotes a developer conveying screw, and reference numeral 230 denotes a developer conveying base. , Reference numeral 231 indicates a suction port, reference numeral 240 indicates a pipe fitting, reference numeral 241 indicates a pipe joint, reference numeral 242 indicates a mounting portion, and reference numeral 250 indicates a spring member.

As shown in FIG. 2 , the developer is first transferred from the image carrier 10Y to the intermediate transfer body 40 , and the remaining developer is scraped off by the image carrier cleaning blade 17Y and stored in the developer storage portion 18Y. The developer is temporarily stored in the developer storage base 210 of the developer transport mechanism 200 constituting the developer storage portion 18Y, and is sent from the developer storage base 210 to the developer transport provided at one end in the longitudinal direction thereof. In the base body 230 .

In the developer storage base groove portion 211 of the developer storage base 210 is arranged a developer transport screw 220 formed on the outer periphery of a cylindrical base portion thereof to constitute a structure in which the developer is transported in the axial direction. A helical blade with a predetermined pitch is integrally rotatably supported. The developer storage base groove portion 211 is formed in a shape covering the developer conveying screw 220 , and its radius of curvature is set to be slightly larger than that of the suction port 231 .

The developer storage portion 18Y is formed with a substantially U-shaped developer storage base groove portion 211 that is opened upwardly in order to store the developer scraped off from the image carrier 10Y, and constitutes an axis along the axis from one end of the developer storage base 210 . To discharge the developer, a circular developer suction port 231 is formed on the developer transport base 230 at one end of the developer storage base 210, and the developer transport screw 220 is inserted into the suction port 231 to rotate. structure. The diameter of the suction port 231 has a size to the extent that the developer conveying screw 220 extending from the developer storage base groove portion 211 to the inside of the suction port 231 of the developer transport base 230 can be substantially fitted inside, thus significantly It functions as a pump that sucks the developer into the suction port 231.

When the developer conveying screw 220 is rotated with the upper side of the developer storage base 210 opened to convey the developer to the portion where the developer conveying screw 220 is inserted into the suction port 231, a pump action is exerted on the developer at this portion, Thus, the developer is pressed to the desired position.

A hole communicating with the suction port 231 is formed in the developer conveying base 230, and a pipe member 240 is installed at one end of the hole through a pipe joint 241 as shown in the figure. The developer conveying screw 220 extends into the pipe 240 , the spring member 250 is mounted on the developer conveying screw 220 through the mounting portion, and the outer periphery of the spring member 250 is in sliding contact with the inner side of the pipe 240 .

On the other hand, the developer stored in the developer storage portion 18Y shown in FIG. 2 is the developer scraped from the image carrier, and the developer is in a charged state, so that the toner particles are aggregated, or the toner particles are easily Static cling to other parts. Therefore, when the developer is pressure-fed by the above-mentioned pumping action, there is a possibility that the toner particles are electrostatically adsorbed to the inner surface of the conveyance path.

Therefore, in the present embodiment, the spring member 250 formed with a predetermined pitch is installed on the protruding end of the developer conveying screw 220, and the spring member 250 is supported rotatably integrally with the developer conveying screw 220, and is mounted on the spring member 250. A slight gap is provided between the outer peripheral surface of the developer discharge port and the inner surface of the developer discharge port, so that even if the toner particles are electrostatically adsorbed to the inner surface of the conveying path due to sliding and rotating at many places, the toner particles can be scraped off, Thereby, stable developer pressure feeding can be realized.

FIG. 16 shows that the developer is conveyed to a desired position by forming a developer conveying path by installing a pipe member 240 such as a developer conveying hose using a pipe joint 241 and connecting it to the suction port 231 of the developer storage base 210. state. As described above, the developer conveying screw 220 and the spring member 250 are inserted into the pipe member 240 with a slight gap from the inner surface thereof, thereby improving the pressure-feeding capability of the image carrier and functioning to scrape the pipe member 240. The action of the toner particles adsorbed on the inner surface enables stable developer pressure feeding.

The developer conveying screw 220 may be lengthened without using the spring member 250 to push the developer to a desired position, but in this case, the developer conveying passage needs to be formed in a straight shape. In the structure in which the spring member 250 is inserted into the developer conveyance passage, the purpose can be achieved even if the developer conveyance passage is formed with curvature, and there are few restrictive conditions for forming the developer conveyance passage.

In this embodiment, an example of conveying the developer scraped off from the image carrier 10 has been described, but the present invention is not limited to this example, and may be applied to the locations provided in various places in FIG. 1 .

Next, the case where the developer transport mechanism is applied to the developer storage portion 18Y of the image carrier 10Y and the case where it is applied to the developer storage portion 24Y of the developing roller 20Y will be described.

The viscosity of the liquid developer scraped off by the image carrier cleaning blade 17Y of the image carrier 10Y is greater than that of the liquid developer scraped off by the developing roller cleaning blade 21Y of the developing roller 20Y.

In the developer conveying mechanism 200 , conveying a low-viscosity liquid developer requires a greater conveying processing capacity. Therefore, it is preferable to make the blade pitch of the developer conveying screw 220 in the developer conveying mechanism 200 of the developer reservoir 24Y smaller than the blade pitch of the developer conveying screw 220 in the developer conveying mechanism 200 of the developer reservoir 18Y.

In addition, the rotational speed of the developer conveying screw 220 in the developer conveying mechanism 200 of the developer storage portion 24Y is preferably set to be higher than the rotational speed of the developer conveying screw 220 in the developer conveying mechanism 200 of the developer storage portion 18Y.

Also, the blade pitch of the developer conveyance screw 220 in the developer conveyance mechanism 200 of the developer storage portion 24Y can be made smaller than the blade pitch of the developer storage portion 18Y, and the developer conveyance mechanism 200 of the developer storage portion 24Y can be made The rotational speed of the developer conveying screw 220 in is greater than the rotational speed of the developer storage portion 18Y thereof.

Next, the improvement of the developer conveying capability in the developer conveying mechanism will be described. 17A to 17C are schematic diagrams showing cross-sections at three positions in the longitudinal direction of the developer conveying mechanism 200 according to the embodiment of the present invention.

In FIGS. 17A to 17C, when viewed along the length direction of the developer storage base 210, FIG. 17A shows a section closest to the developer carrying base 230, and FIG. Figure 17B shows a cross section approximately in the middle of the two. The difference between FIGS. 17A to 17C is that the developer storage base groove portion 211 covers the range of the developer conveying screw 220 .

This range can be defined by the arc angle α in the figure. That is, an angle α centered on the circle O of the cross section of the developer conveying screw 220 is used to define how much of the cross section of the developer conveying screw 220 is covered by the developer storage base groove portion 211 .

The liquid developer in which toner particles are dispersed in the carrier liquid has a surface tension corresponding to the liquid, and thus has a characteristic of being adsorbed on the outer peripheral surface of the developer conveying screw 220 and a part of the developer storage base 210, and therefore, The developer adsorbed on the outer peripheral surface of the developer conveying screw 220 rotates and moves together with the developer conveying screw 220 , and the developer adsorbed on the developer storage base 210 tends to stay at the attached position.

Therefore, the developer conveying function of the developer conveying screw 220 formed with predetermined pitch helical blades on the outer periphery of the cylindrical base portion and integrally rotated is realized by the part where the developer conveying screw 220 cooperates with the arcuate surface along its outer peripheral surface, So it's important to expand the area of that collaboration.

The inventors of the present application conducted various experiments based on this principle, and as a result, concluded that a desired developer transportability can be obtained when the arc angle α shown in FIGS. 17A to 17C is 180° or more.

Needless to say, the larger the angle α, the longer the portion where the developer conveying screw 220 interacts with the arcuate surface along its outer peripheral surface becomes longer, thereby improving the developer conveying ability.

17A to 17C are implementations based on this recognition. Observing the developer storage base 210 in the longitudinal direction, it can be seen that the portion near the developer delivery base 230 where the scraped developer is accumulated is required to carry the developer. Therefore, as shown in FIGS. In Fig. 17A, the angle α is set to be larger and larger.

Next, the case where the developer transport mechanism is applied to the developer storage portion 18Y of the image carrier 10Y and the case where it is applied to the developer storage portion 24Y of the developing roller 20Y will be described.

As described above, the viscosity of the liquid developer scraped off from the image carrier 10Y is greater than that of the liquid developer scraped off from the developing roller 20Y.

In the developer conveying mechanism 200 , conveying a low-viscosity liquid developer requires a greater conveying processing capacity. Therefore, it is preferable to set the arc angle α in the developer storage portion 24Y for conveying the low-viscosity liquid developer to be larger than the arc angle α in the developer storage portion 18Y.

That is, if the arc angle of the developer storage base groove portion 211 of the developer storage base groove portion 211 of the developer transport mechanism 200 that transports the liquid developer scraped off from the image carrier 10Y, and the developer that transports the liquid developer scraped off from the developing roller 20Y Compared with the arc angle of the developer storage base groove portion 211 of the transport mechanism 200 on a plane perpendicular to the developer transport direction, the latter arc angle is preferably set larger than the former arc angle.

As described above, according to the configuration of the present invention, it is possible to smoothly carry out the conveyance process of the aggregated toner particles in the charged state or the surplus liquid developer in the non-uniform state of the toner concentration. As a result, recycling and disposal of excess liquid developer can be smoothly performed.

In addition, according to the structure of the present invention, since the toner particles of the charged residual liquid developer are prevented from being electrostatically adsorbed to the surface of the constituent members of the conveyance portion, there is no problem that the residual liquid developer cannot be conveyed.

In addition, according to the image forming apparatus using the developer conveying mechanism constituted as above, the conveying efficiency of the surplus liquid developer is improved, and the developer can be temporarily conveyed from the developing part by being freed from the structure of closed-loop circulation of the developer. Move to other parts to mix with new developer, or perform desired dispersion by eliminating aggregation of toner particles and unevenness of toner concentration, or discard as unnecessary developer.

Next, other embodiments of the present invention will be described. 18 is a diagram showing main components constituting an image forming apparatus using a developer transport mechanism according to an embodiment of the present invention, and FIG. 19 is a cross-sectional view showing main components of an image forming unit and a developing unit. picture.

In FIG. 18, for each color of yellow (Y), magenta (M), cyan (C), and black (K), the same The constituent parts of , use the same designation and add Y, M, C, K for each color. Among them, FIG. 19 shows the configurations of an image forming section, a developing unit, and an intermediate transfer body pressing device for yellow (Y). Hereinafter, details of each image forming section, developing unit, and intermediate transfer body pressing device will be described with reference to FIG. 19 .

The image forming section is arranged along the rotational direction (moving direction) of the outer periphery of the image carrier 10Y: a latent image eraser 16Y, a cleaning device including an image carrier cleaning blade 17Y and a developer storage portion 18Y, a charging roller 11Y, an exposure unit 12Y, a developing The developing roller 20Y of the unit 30Y, and the cleaning device including the image carrier pressing roller 13Y and, as its accessory members, the image carrier pressing roller cleaning blade 14Y and the developer storage portion 15Y.

The developing unit 30Y is arranged around the developing roller 20Y: a cleaning blade 21Y, a developer supply roller 32Y using an anilox roller, a restricting sheet 33Y for restricting the amount of developer supplied, a developer compressing roller 22Y, and a scraper on the surface thereof. A cleaning sheet 23Y for the developer, and a developer agitating roller 34Y for agitating the developer into a uniformly dispersed state is arranged in a developer container (reservoir) 31Y containing liquid developer. Further, the primary transfer roller 51Y of the primary transfer portion 50Y is disposed at a position facing the image carrier 10Y with the intermediate transfer body 40 interposed therebetween, and along the downstream side of the intermediate transfer body 40 in the moving direction thereof, The intermediate transfer body pressing device 52Y, the primary transfer section 50 (M, C, K) of each color, and the intermediate transfer body pressing device 52 (M, C, K) are disposed on the side. The intermediate transfer body pressing device 52Y includes an intermediate transfer body pressing roller 53Y, a backup roller 54Y, a cleaning blade 55Y for the intermediate transfer body pressing roller, and a developer storage portion 56Y.

The liquid developer contained in the developer container 31Y is not a low-concentration (about 1 to 2 wt %) and low-viscosity volatile liquid that uses Isopar (trademark: Exon) as a carrier and has a volatile property at normal temperature, which is generally used in the past. The developer is a liquid developer in which a high-concentration and high-viscosity non-volatile solvent having non-volatile properties at normal temperature is used as a carrier. That is, the liquid developer in this embodiment is obtained by adding solid particles having an average particle diameter of 1 μm obtained by dispersing a colorant such as a pigment in a thermoplastic resin to an organic solvent, silicone oil, mineral oil, edible oil, etc. A high-viscosity (about 30 to 10,000 mPa·s) liquid developer with a solid toner concentration of about 25% in a liquid solvent. The liquid developer accommodated in the developer container 31Y is a liquid developer obtained by dispersing the toner weights from the developer cartridge 72Y, respectively, according to the concentration of the developer that changes as the image carrier is developed. For a high-concentration developer with a ratio of about 35% to 55%, the carrier is replenished from the carrier cartridge 71Y to the developer container 31Y, and stirred by the liquid developer stirring roller 34Y to form a uniformly dispersed state. Approximate weight ratio liquid developer with 25% toner dispersed in 75% vehicle.

In the image forming section and developing unit 30Y, the image carrier 10Y is uniformly charged by the charging roller 11Y, and irradiated based on the input image signal modulation by the exposure unit 12Y having an optical system such as a semiconductor laser, a polygon mirror, and an F-θ lens. The subsequent laser light forms an electrostatic latent image on the charged image carrier 10Y. Then, from the developer container 31Y storing the liquid developer of each color (here, yellow), the amount of the developer supplied is regulated by the regulation sheet 33Y and the developer is supplied to the developing roller 20Y by the developer supply roller 32Y, thereby forming the image carrier 10Y. The electrostatic latent image on the surface is developed.

The intermediate transfer body 40 is an endless elastic belt that is wound and stretched between the driving roller 41 and the tension roller 42 and is formed in contact with the image carriers 10Y, 10M, 10C at the primary transfer portions 50Y, 50M, 50C, 50K. , 10K is driven to rotate by the driving roller 41 in a contact state. In the primary transfer sections 50Y, 50M, 50C, and 50K, the primary transfer rollers 51Y, 51M, 51C, and 51K and the image carriers 10Y, 10M, 10C, and 10K are opposed to each other with the intermediate transfer body 40 interposed therebetween. The abutting positions of the image carriers 10Y, 10M, 10C, and 10K are used as transfer positions, and the toner images of each color on the developed image carriers 10Y, 10M, 10C, and 10K are successively overlapped and transferred onto the intermediate transfer body 40 , thereby forming a full-color toner image. As described above, the toner images formed on the plurality of image carriers (photoreceptors) 10Y, 10M, 10C, and 10K are superimposed and carried on the intermediate transfer body 40 by sequential primary transfer, and then transferred by the intermediate transfer body 40 Uniform secondary transfer onto sheet. Therefore, an elastic belt member is used as a material that conforms to the non-smooth surface even if the surface of the sheet is not smooth due to fiber material or the like when the toner image is transferred to the sheet in the secondary transfer process. A means of improving the secondary transfer characteristics of the sheet surface.

In the secondary transfer unit 60 , the secondary transfer roller 61 and the belt driving roller 41 are disposed opposite to each other with the intermediate transfer belt 40 interposed therebetween, and a cleaning blade 62 including the secondary transfer roller and a developer storage portion are disposed. 63 cleaning device. In the secondary transfer unit 60 , in synchronization with the timing at which the full-color toner image or the single-color toner image formed by overlapping colors on the intermediate transfer body 40 reaches the transfer position of the secondary transfer unit 60 , A sheet of paper, sheet, cloth, or the like is conveyed and supplied through the sheet conveyance path L, and a single-color toner image or a full-color toner image is secondarily transferred onto the sheet. In front of the sheet conveyance path L is arranged a fixing unit (not shown) that fuses and fixes a single-color toner image or a full-color toner image transferred on a sheet to a recording medium such as paper ( sheet), the final image formation on the sheet is completed. The secondary transfer roller 61 is also composed of an elastic roller covered with an elastic body on the surface so that even if the surface of the sheet is not smooth due to fiber material or the like, the secondary transfer roller 61 can conform to the surface of the rough sheet to improve the secondary transfer roller. Secondary transfer characteristics of the device. This is also for the same purpose as the case where the elastic belt member is used for the intermediate transfer body 40 which sequentially first transfers and carries the toner images formed on the plurality of image carriers 10Y, and then collectively Primary and secondary transfer to sheet.

On the side of the tension roller 42 that hangs the intermediate transfer body 40 together with the belt drive roller 41 , a cleaning device including a cleaning blade 46 and a developer storage portion 47 is disposed along its outer periphery on the downstream side in the moving direction of the intermediate transfer body 40 . device. The intermediate transfer body 40 that has passed the secondary transfer unit 60 advances toward the winding portion of the tension roller 42 , and is cleaned by the cleaning sheet 46 on the intermediate transfer body 40 , and then the intermediate transfer body 40 moves toward the primary transfer body again. Section 50 advances.

In the developer container 31Y, the toner particles in the liquid developer are positively charged, and the developer is stirred into a uniformly dispersed state by the stirring roller 34Y, and is discharged from the developer container 31Y with the rotation of the developer supply roller 32Y. After being drawn up, the amount of the developer is regulated by the regulation sheet 33Y and supplied to the developing roller 20Y. The developer initially stored in the developer container 31Y is in the state of uniformly dispersing the toner in the carrier at an approximate weight ratio of about 25%. However, in developing the image carrier 10Y, if the image duty ratio is large The toner consumption ratio is large when the development is small, and on the contrary, the toner consumption ratio is small when the image duty ratio is small. That is, since the toner weight ratio of the developer stored in the developer container 31Y changes moment by moment as the development to the image carrier 10Y is performed, it is necessary to constantly monitor this change and control so as to maintain a dispersion of 25 The state of the rough toner weight ratio of the % degree.

In order to control the concentration of the developer in the developer container 31Y, a transmission type optical sensor (not shown) for detecting the dispersion weight ratio of the toner, or a developer agitating roller for detecting A torque detecting means of stirring torque of 34Y, etc., and a reflective optical sensor for detecting the liquid level of the developer in the developer container 31Y, etc., are used as means for detecting the concentration. In addition, when the dispersed weight ratio of the toner in the predetermined amount of developer becomes small, a predetermined amount of dispersed toner at a high concentration of about 35% to 55% by weight is replenished from the developer cartridge 72Y into the developer container 31Y. the developer. Contrary to this, when the dispersed weight ratio of the toner becomes large, a predetermined amount of carrier is replenished from the carrier cartridge 71Y into the developer container 31Y. The rough toner weight ratio is controlled at about 25% by the above supplement. In addition, the concentration control of the developer may also be performed as follows: in the controller (CPU) that manages the image signal, the concentration of the developer in the developing unit 30Y is predicted based on the output image density, and then the concentration of the developer from the developer cartridge is predicted and controlled. 72Y and supplementary amounts of vector box 71Y. Through such predictive control, control response performance and reliability can be improved.

In this manner, in the developer recovery system of the present embodiment, the developer container 31Y is supplied with high-concentration developer from the developer cartridge 72Y to the developer container 31Y according to the developer concentration that changes with the development on the image carrier. As for the developer, the carrier is supplied from the carrier cartridge 71Y to the developer container 31Y, and 25% toner is uniformly dispersed in 75% carrier in approximate weight ratio. After using this developer, an image is formed through various processes and secondarily transferred to a sheet in the final stage. Next, the stage of the fixing process (not shown in the figure) is entered. In order to exert a good secondary transfer function and a fixing function, the liquid developer is preferably in a dispersed state with an approximate weight ratio of about 40% to 60%. For this reason, the image carrier pressing device (13-15), the image carrier cleaning device (17, 18), the intermediate transfer body pressing device (52-15) having the above-mentioned cleaning sheets are arranged at appropriate multiple positions. 55), intermediate transfer body cleaning devices (46, 47), and secondary transfer roller cleaning devices (62, 63), etc., as so-called developer recovery devices for removing and recovering residual developer and residual carrier .

In the present embodiment, for example, the developer of the first color scraped off by the cleaning sheet 14Y and collected in the developer storage section 15Y, the developer scraped off by the cleaning sheet 44 and collected in the developer storage section 45, and The developer scraped off by the cleaning blade 46 and recovered in the developer storage portion 47 is collected in the same flow path. And, the developer scraped off by the cleaning blade 18Y and recovered into the developer storage portion 17Y, and the developer scraped off by the cleaning blade 55Y and the cleaning blade 14M of the next color and recovered into the developer storage portion 56Y are collected in the In the same flow path, and after the second color, the recovered developer is collected in the same flow path in the same way. In addition, the developer of the fourth color scraped off by the cleaning blade 17K and recovered in the developer storage portion 18K, and the developer scraped off and recovered in the developer storage portion 56K by the cleaning blade 55K are collected in the same flow path. . Furthermore, these collected flow paths and the flow paths of the developer scraped off by the cleaning blade 62 and recovered in the developer storage portion 63 are combined on the developer recovery flow path 70, and then the developer recovery flow path 70 is pumped into the developer recovery flow path 70. The developer is sent to the filter device 77.

The developer scraped off and recovered by each cleaning blade in this way is stored in the carrier buffer tank 74 via the filter device 77 from the recovery flow path 70 incorporating the delivery flow path so as to be reusable. If the developed developer is recovered from a plurality of developing units, the toner becomes a mixed color state and cannot be directly reused in the recovered state. Therefore, a filter device 77 is provided on the transport path to filter out toner particles to only Make the carrier reusable. The carrier stored in the carrier buffer tank 74 is dispatched into the carrier cartridge 71Y via the developer delivery path 78, and then replenished from the carrier cartridge 71Y to the developer container (reservoir) together with replenishment of the developer from the developer cartridge 72Y. In 31Y, the reuse of the carrier in the carrier buffer tank 74 is realized by this.

The filtering device 77 is used for filtering to separate the toner solid content and paper powder from the carrier components after the flows of the developer recovered by the respective developer recovery devices are merged onto the recovery flow channel, and the filtering device 77 can be, for example, used Filter paper, electrostatic filter or other filter. The carrier that becomes reusable due to separation of the toner and the like is stored in the carrier buffer tank 74, and the carrier temporarily stored in the buffer is dispatched to the carrier cassettes 71Y of a plurality of developing units, respectively, to be reused. The system utilized can achieve even and stable reuse of carriers. Therefore, the pump 76 for conveying the developer functions together with the filter device 77 , and a simple and inexpensive structure can be realized together with the conveying path. In addition, since the developer recovered from the cleaning device of the secondary transfer roller 61 and the intermediate transfer body 40 may contain impurities, paper dust, etc., it may be discarded without recycling. However, by providing a filtering process to also filter out impurities, paper dust, etc. as in this embodiment, the recovered developer from each part can be reused. The filter function can be stably maintained by configuring a system that removes mixed toner, impurities, paper dust, and the like removed from the filter device 77 based on the detection result of the filter state detection device (not shown).

When the weight of toner replenished from the developer cartridge 72Y is relatively high, the carrier component is relatively insufficient. Conversely, when the weight of toner replenished from the developer cartridge is relatively low, the carrier component is relatively excessive. When the carrier component is insufficient, in the present embodiment, the developer cartridge 72Y and the developer cartridge 72Y are configured together with the carrier cartridge 71 detachable from the carrier conveyance path, so that replenishment can be easily performed. In addition, not only when the toner weight ratio is low, but also when performing image development with a large image duty ratio, the toner weight ratio to be replenished from the developer cartridge 72Y is about 35% to 55% as the developer is consumed. In the secondary transfer and fixing, the toner weight ratio is increased to about 40% to 60%. Therefore, the recovery amount of the carrier increases, and the carrier component gradually becomes relatively excessive. In this way, since the developer cartridge 72Y contains the developer dispersed at a high concentration of about 35% to 55% by weight of the toner, if the developer is consumed by performing image development with a large image duty ratio, The recovery of the corresponding carrier components would then become relatively redundant. In the case of excess carrier components, in this embodiment, a detachable carrier storage tank 73 is provided separately from the carrier storage tank 74 to form a structure that can remove the full carrier storage tank 73 and the carrier together. Therefore, the full carrier storage tank can be replaced with an empty carrier storage tank for storage, so the carrier can be effectively reused without waste, and it is not necessary to set the volume of the carrier buffer tank 74 to be very large, which is advantageous. Device miniaturization.

In addition, the carrier cartridge 71Y may be omitted, and the developer container 31Y may be appropriately replenished with the carrier directly from the carrier buffer tank 74 . When the carrier case 71Y detachable with respect to the carrier conveyance path is constituted at the same time as the developer cartridge 72Y, and the carrier case 71Y is configured so as to be interchangeable with the carrier accommodating tank 73, the empty carrier case 71Y can be directly used as The carrier accommodates the tank 73 so that convenience can be improved. Although the carrier can flow into and out of the carrier box 71Y and the carrier tank 73 in two directions along the carrier transport path, if a one-way valve function is provided and connected as a structure to prevent the outflow, the loading and unloading operation will also be facilitated.

On the other hand, with regard to the preparation of the developer, although it is also possible to use a preparation bottle provided separately from the developing unit and supply it to the developer container 31Y after the preparation, in order to avoid changes in the concentration of the developer in the developer container 31Y which changes from time to time, The control generates a time lag and needs to be considered accordingly. As described in the present embodiment, the developer dispersed to a high concentration and the carrier are replenished by constituting the detection content based on the detection means for detecting the toner dispersion weight ratio in the developing unit and the detection means for detecting the amount of the developer. Into the developer container 31 and stirred into a uniformly dispersed structure, stable concentration control without concentration control time lag can be realized.

As described above, in this embodiment, the developer is scraped off and recovered by the cleaning device included in the developer recovery device, and the developer is delivered to the developing unit 30Y for reuse. Here, each developer recovery device is further explained. In the developer unit 30Y, there are a cleaning sheet 23Y for cleaning the toner compression roller 22Y which develops the liquid carried on the development roller 20Y, and a cleaning sheet 21Y for cleaning the developing roller 20Y. The toner of the agent is pressed into a compressed state. The cleaning blade 21Y is arranged on the downstream side of the development nip formed by the abutment of the development roller 20Y and the image carrier 10Y in the rotation direction of the development roller 20Y, and scrapes off the developer remaining on the development roller 20Y. The cleaning blade 23Y scrapes off the developer on the toner compression roller 22Y rotating in the direction of the arrow in the drawing, and the scraped off developer is merged (combined) with the developer in the reservoir 31Y and reused. These confluent carriers and toners are not in a state where the colors are mixed.

The image carrier pressing device is arranged opposite to the image carrier 10Y and is located on the downstream side of the developing roller 20Y in the rotation direction of the image carrier 10Y, and includes: an image carrier pressing roller 13Y, a cleaning blade 14Y, and a developer storage portion 15Y. The sheet 14Y is in pressure sliding contact with the image carrier pressing roller 13Y to clean the roller surface. The image carrier pressing device has a function of recovering the remaining carrier and originally unnecessary blurred toner from the developer developed on the image carrier 10Y to increase the ratio of toner particles in the developed image. In this embodiment, the image carrier squeeze roller 13Y and the image carrier 10Y are rotated at substantially the same peripheral speed, and the remaining carrier with a weight ratio of about 5 to 10% is recovered from the developer developed on the image carrier 10Y to reduce the pressure on both sides. The rotation drives the load, and suppresses the disturbing effect on the developed toner image of the image carrier 10Y. The remaining carrier and unnecessary blurred toner recovered by the image carrier squeeze roller 13Y are recovered from the image carrier squeeze roller 13Y by the action of the cleaning blade 14Y and collected into the developer storage portion 15Y. Since the recovered residual carrier and blurred toner are recovered from the dedicated and individually provided image carrier 10Y, color mixing does not occur in the image forming portions of the respective colors.

In the primary transfer portion 50Y, the image carrier 10Y and the intermediate transfer body 40 move at the same speed, and the developer image developed on the image carrier 10Y is transferred onto the intermediate transfer body 40 by the primary transfer roller 51Y, This reduces the driving load for rotation and movement, and suppresses the disturbing effect on the developed toner image of the image carrier 10Y. In the primary transfer portion 50Y of the first color, since the primary transfer is performed for the first time, color mixing does not occur, but from the second color, since the toner image that has been primary transferred Different toner images are further transferred on the part to perform color overlap, so the toner of the transfer is reversed by the so-called reverse transfer phenomenon in which the toner is transferred from the intermediate transfer body 40 to the image carrier 10 (M, C, K). Toner and transfer remaining toner are mixed and carried on the image carrier 10 (M, C, K) together with the remaining carrier to move, and then removed from the image carrier by the action of the cleaning sheet 17 (M, C, K). Recycle and concentrate.

After the secondary transfer to the final sheet, it enters the stage of the fixing process (not shown in the figure). In order to exert a good secondary transfer function and fixing function, the developer (toner dispersed in the carrier) The preferred dispersion state is roughly 40% to 60% by weight of the toner as described above. The intermediate transfer body pressing device 52Y serves as a device for further removing the remaining carrier from the intermediate transfer body 40 when the developer does not reach a preferred dispersed state in this final stage. The intermediate transfer body pressing device 52Y is arranged on the downstream side of the intermediate transfer body 40 moving direction of the primary transfer portion 50Y, and includes: an intermediate transfer body pressing roller 53Y; a backup roller 54Y, and an intermediate transfer body pressing roller 53Y is disposed opposite to each other with the intermediate transfer body 40 in between; the cleaning sheet 55Y is in pressure sliding contact with the intermediate transfer body pressing roller 53Y to clean the surface of the roller; and the developer storage portion 15M. The intermediate transfer body pressing device 52Y has functions of recovering the remaining carrier from the developer primarily transferred on the intermediate transfer body 40, increasing the ratio of toner particles in the developed image, and recovering originally unnecessary blurred toner. Function. The developer storage portion 15M is a recovery mechanism for recovering the carrier from the magenta image carrier squeeze roller cleaning sheet 14M arranged on the downstream side in the moving direction of the intermediate transfer body 40 and is also used for cleaning the intermediate transfer body squeeze roller 53Y. part on sheet 55Y. In this way, by using the developer storage portion 15 (M, C, K) of the image carrier pressing device for the second color and subsequent colors as the primary transfer unit of the previous color arranged in the moving direction of the intermediate transfer body 40 The developer storage part of the intermediate transfer body pressing device 52 (M, C, K) on the downstream side of the printing part 50 (M, C, K) can be limited to a fixed interval, so that the structure can be simplified. miniaturization.

In the intermediate transfer body extrusion part of the first color, because of the first intermediate transfer body extrusion, color mixing does not occur, but starting from the second color, due to the toning that has been transferred for the first time Different toner images are further transferred on the toner image portion to perform color overlap, so the toner when the toner is transferred from the intermediate transfer body 40 to the intermediate transfer body squeeze roller 53Y is mixed in color and mixed with the remaining toner. The carrier is carried and moved by the intermediate transfer body squeeze roller 53Y together, and then recovered and collected from the intermediate transfer body squeeze roller 53Y by the action of the cleaning sheet. In addition, when the above-mentioned squeezing ability of the image carrier 10Y and that of the image carrier squeezing roller 53Y on the primary transfer portion located on the upstream side of the intermediate transfer body squeezing process are sufficient, it is not necessarily necessary to be An intermediate transfer body pressing device is provided on the downstream side of the rotation direction of the intermediate transfer body 40 in the transfer process.

The sheet is supplied in synchronization with the timing at which the toner image superimposed on the intermediate transfer body 40 reaches the secondary transfer portion, the toner image is secondarily transferred onto the sheet, and then the sheet is Enters the fusing process to end image formation on the sheet. However, when a sheet supply failure such as paper jam occurs, not all of the toner image is transferred to the secondary transfer roller and collected, but some of the toner image remains on the intermediate transfer body. Moreover, in the usual secondary transfer process, the toner image on the intermediate transfer body is not 100% completely transferred to the sheet by secondary transfer, but a secondary transfer of several percent occurs. Transfer residue. In particular, when a sheet supply failure such as a paper jam occurs, the toner image contacts the secondary transfer roller 61 and is transferred in the absence of the sheet, causing contamination on the back side of the sheet. For these unnecessary toner images, cleaning on the intermediate transfer body 40 is performed by the cleaning sheet 46 for the intermediate transfer body, and cleaning on the secondary transfer roller 61 is performed by the cleaning sheet 62 for the secondary transfer roller. . Thus, the secondary transfer roller cleaning blade 62 is used as means for removing the developer (toner dispersed in the carrier) transferred on the secondary transfer roller 61 , which is recovered from the secondary transfer roller 61 And concentrate the developer. The concentrated developer is in a mixed color state and may contain impurities such as paper dust, but these are separated by the filter device 77 as described above.

Next, the structure of the developer storage unit using the developer transport structure according to this embodiment will be described. 20 is a perspective view showing the developer conveying mechanism in the developer storage portion 18Y, FIG. 21 is a perspective view of components constituting the developer conveying base 330 and the developer storage base 310, and FIG. 22 is viewed from a different angle from FIG. 22. 23 is a schematic diagram showing a cross section of a main part of a developer conveying mechanism according to another embodiment of the present invention. Moreover, FIG. 23 is a BB cross section of FIG. 19 . The structure referred to as a "base" in the description related to FIGS. 15 and 16 is referred to as a "base" in this embodiment, but they are substantially the same part.

In FIGS. 20 to 23, reference numeral 300 denotes a developer conveying mechanism, numeral 310 denotes a developer storage base, numeral 311 denotes a groove portion of the developer storage base, numeral 320 denotes a developer conveying screw, and numeral 330 denotes a developer conveying base. , Reference numeral 331 indicates a suction port, reference numeral 340 indicates a pipe fitting, reference numeral 341 indicates a pipe joint, reference numeral 342 indicates a mounting portion, and reference numeral 350 indicates a spring member.

As shown in FIG. 19 , the developer is first transferred from the image carrier 10Y to the intermediate transfer body 40 , and the remaining developer is scraped off by the image carrier cleaning blade 17Y and stored in the developer storage portion 18Y. The developer is temporarily stored in the developer storage base 310 of the developer transport mechanism 300 constituting the developer storage portion 18Y, and is sent from the developer storage base 310 to the developer transport provided at one end in the longitudinal direction thereof. in the base 330 .

In the developer storage base groove portion 311 of the developer storage base 310, a developer transport screw 320 is arranged to form a structure for transporting the developer in the axial direction, wherein the developer transport screw 320 is formed on the outer periphery of its cylindrical base with a predetermined The pitch of the helical blade is integrally rotatable to support the helical blade. The developer storage base groove portion 311 is formed in a shape covering the developer conveying screw 320 , and its radius of curvature is set to be slightly larger than that of the conveying port 331 . That is, as shown in FIG. 23, when the developer conveying screw 320 is set to r1, the conveying port 331 is set to r2, and the radius of curvature of the groove portion of the developer storage base groove portion 311 is set to r3, the configuration satisfies The structure of the r1<r2<r3 relationship.

The developer storage portion 18Y is formed with a substantially U-shaped developer storage base groove portion 311 that is opened upwardly in order to store the developer scraped off from the image carrier 10Y, and constitutes an axis extending from one end portion of the developer storage base 310. To discharge the developer, a circular developer delivery port 331 is formed on the developer delivery base 330 at one end of the developer storage base 310, and the developer delivery screw 320 is inserted into the delivery port 331 to rotate. structure. The diameter of the delivery port 331 has a size to the extent that the developer delivery screw 320, which extends from the developer storage base groove portion 311 to the inside of the delivery opening 331 of the developer delivery base 330, is substantially fittable, thus significantly It functions as a pump that sucks the developer into the delivery port 331.

When the rotary developer conveying screw 320 is rotated in a state where the developer storage base 310 is opened, thereby conveying the developer to the portion where the developer conveying screw 320 is inserted into the conveying port 331, a pumping action occurs on the developer at this portion. , so that the developer is pressed to the desired position.

A hole communicating with the delivery port 331 is formed in the developer delivery base 330 , and a pipe member 340 is attached to one end of the hole through a pipe joint 341 as shown in the figure. The developer conveying screw 320 extends into the hollow path of the pipe 340 , the spring member 350 is mounted on the developer conveying screw 320 through the mounting portion, and the outer periphery of the spring member 350 is in sliding contact with the inner side of the pipe 340 .

On the other hand, the developer stored in the developer storage portion 18Y shown in FIG. 19 is the developer scraped off from the image carrier, and the developer is in a charged state, so that the toner particles aggregate, or the toner particles Easily electrostatically adsorbed to other components. Therefore, when the developer is pressure-fed by the above-mentioned pumping action, there is a possibility that the toner particles are electrostatically adsorbed to the inner surface of the conveyance path.

Therefore, in this embodiment, the spring member 350 formed with a predetermined pitch is installed on the protruding end of the developer conveying screw 320, and the spring member 250 is supported rotatably integrally with the developer conveying screw 320, and the spring member 250 is supported on the projected end of the developer conveying screw 320. A slight gap is provided between the outer peripheral surface of 350 and the inner surface of the developer discharge port, so that even if the toner particles are electrostatically adsorbed to the inner surface of the conveyance path due to sliding and rotating at many places, the toner particles can be scraped off. , so that stable developer pressure feeding can be realized.

16 shows a state in which a developer delivery passage is formed by installing a pipe member 340 such as a developer delivery pipe through a pipe joint 341 and connecting it to the delivery port 331 of the developer storage base 310 to deliver the developer to a desired position. As described above, the developer conveying screw 320 and the spring member 350 are inserted into the pipe member 340 with a slight gap from its inner surface, thereby improving the pressure-feeding capability of the image carrier and functioning to scrape the pipe member 340. The action of the toner particles adsorbed on the inner surface enables stable developer pressure feeding.

The developer conveying screw 320 may be lengthened without using the spring member 350 to push the developer to a desired position, but in this case, the developer conveying passage needs to be formed in a straight shape. In the structure in which the spring member 350 is inserted into the developer conveying passage, the purpose can be achieved even if the developer conveying passage is formed with curvature, and there are few restrictive conditions for forming the developer conveying passage.

In this embodiment, an example of conveying the developer scraped off from the image carrier 10 has been described, but the present invention is not limited to this example, and may be applied to locations provided in various places in FIG. 1 . The developer conveying mechanism used in the developer storage portion 24Y also has basically the same structure as this. FIG. 24 is a perspective view showing the developer conveying mechanism of the present embodiment applied to the developer storage portion 24Y. In addition, the description regarding FIG. 17 can also be applied to this embodiment.

The developer conveying mechanism of the present embodiment described above can be applied not only to the developer storage portion 18Y and the developer storage portion 24Y but also to the developer storage portion 15Y. Furthermore, needless to say, the developer conveying mechanism of this embodiment can be applied to developer storage portions of other developing units 30M, 30C, and 30K in addition to the yellow developing unit 30Y, and can also be applied to the image forming apparatus. In the developer storage portion 47 near the tension roller 42 , in the developer storage portion 63 in the secondary transfer unit 60 .

As described above, according to the structure according to another embodiment of the present invention, it is possible to smoothly carry out the conveyance process of the aggregated toner particles in the charged state or the surplus liquid developer in the state of non-uniform toner concentration. As a result, recycling and disposal of the remaining liquid developer can be smoothly carried out.

In addition, according to the structure according to the other embodiment of the present invention, since the toner particles of the charged residual liquid developer are prevented from being electrostatically adsorbed to the surface of the constituent members of the conveyance section, there is no possibility that the residual liquid developer cannot be conveyed. question.

In addition, according to the image forming apparatus using the developer conveyance mechanism according to the above-mentioned other embodiments, the conveyance efficiency of the excess liquid developer is improved, and the developer can be temporarily removed from the structure of the closed-loop circulation of the developer. The developing part is conveyed and moved to another part to be mixed with new developer, or to perform desired dispersion by eliminating aggregation of toner particles and unevenness of toner concentration, or to be discarded as unnecessary developer.

Various embodiments have been described above, but embodiments configured by arbitrarily combining components of each embodiment are also included in the present invention.

Claims (15)

1. A developer conveying mechanism, characterized in that it comprises: The developer storage part stores the liquid developer; a transport member provided in the developer storage portion, and transports the liquid developer by rotating about its own axis; and The hollow path is embedded with the conveying member and conducts the liquid developer conveyed by the conveying member. 2. The developer transport mechanism according to claim 1, wherein the developer storage portion includes a storage base forming a groove portion and a transport base configuring the hollow path. 3. The developer conveying mechanism according to claim 2, wherein when the radius of the outer peripheral portion of the conveying member is r1, the radius of the conveying opening is r2, and the curvature of the groove is When the radius is r3, there is a relationship of r1<r2<r3. 4. The developer conveying mechanism according to claim 1, wherein the conveying member is a screw. 5. The developer conveying mechanism according to claim 1, wherein the conveying member has a helical blade. 6. The developer conveying mechanism according to claim 1, wherein an end portion of the conveying member is connected to a spring member embedded in the hollow path. 7. An image forming device, comprising: a roller holding liquid developer; a roller cleaning sheet abutting against the roller and scraping off the liquid developer held on the roller; and developer delivery mechanism; where The developer conveying mechanism includes: a developer storage part that receives the liquid developer scraped off by the roller cleaning blade; the liquid developer; and a hollow path embedded with the conveying member and conducting the liquid developer conveyed by the conveying member. 8. The image forming apparatus according to claim 7, wherein the roller is a developing roller. 9. The image forming apparatus according to claim 7, wherein the roller is an image carrier pressing roller abutting against the image carrier. 10. The image forming apparatus according to claim 7, wherein the transport member is a screw. 11. The image forming apparatus according to claim 10, wherein the screw pitch of the screw conveying the liquid developer scraped off from the image carrier and the pitch of the screw conveying the liquid developer scraped off from the developing roller The pitches of the screws are not the same. 12. The image forming apparatus according to claim 10, wherein the rotational speed of the screw for conveying the liquid developer scraped off from the image carrier and the speed of conveying the liquid developer scraped off from the developing roller The speed of the screw is not the same. 13. The image forming apparatus according to claim 7, wherein a plurality of said developer storage portions are provided. 14. The image forming apparatus according to claim 7, wherein the developer storage portion includes a storage base forming the groove portion and a delivery base connected to the hollow path. 15. The image forming apparatus according to claim 7, wherein an end portion of the transport member is connected to a spring member substantially embedded in the hollow path.

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