CN101546163A - Development device conveying liquid developer, image forming apparatus and image forming method - Google Patents

Abstract

Provided are a developing device, an image forming device, and an image forming method, comprising a developer carrier (20Y) on which a liquid developer including toner and carrier liquid is loaded, and a developer carrier (20Y) A developer supply member (32Y) for supplying liquid developer, a developer carrier cleaning member (21Y) for recovering liquid developer on the developer carrier (20Y), a developer carrier cleaning member (21Y) for storing ) the recovery storage part (31aY) of the liquid developer recovered from the recovery storage part (31aY), the supply part (31bY) that makes the liquid developer flow to the recovery storage part (31aY), and the liquid developer recovered by the recovery storage part (31aY) to the first direction ( X) The conveying member (34Y) for conveying and the conveying amount adjusting part (39bY) for adjusting the conveying amount of the conveying member (34Y).

Description

Developing device, image forming device, and image forming method

technical field

The present invention relates to a developing device, an image forming device, and an image forming method using a liquid developer containing a toner in a carrier liquid.

Background technique

Currently, a wet image forming apparatus develops an electrostatic latent image formed on an image carrier (image carrier) with a thin layer of liquid developer formed by a developing device, and transfers the developed image to a recording medium. On the medium, the structure of the wet image forming apparatus has: a developing unit, which is equipped with a developer carrier for supplying a thin layer of liquid developer to the image carrier; a developer carrier cleaning unit, which removes and recovers the developed The liquid developer on the developer carrying body; and the liquid developer storage part, which can accommodate the liquid developer of the developing part.

The developing unit has a developer recovery unit that recovers the removed undeveloped liquid developer on the developer carrier and transports it to the liquid developer storage unit (Patent Document 1).

Patent Document 1: Japanese Patent Laid-Open No. 2001-125383

However, in the technique described in Patent Document 1, when the recovered liquid developer is transported to the liquid developer storage unit, the developer remains in the developer recovery unit, and there is agitation between the developed developer and the new developer. and reduced dispersion. In addition, depending on the state of the recovered liquid developer, the concentration of the liquid developer transported to the liquid developer storage part fluctuates greatly, and as a result, the concentration fluctuation in the liquid developer storage part may increase, and the agitation and dispersibility may decrease. .

Contents of the invention

In order to solve the above problems, an object of the present invention is to provide a developing device capable of improving agitation and dispersibility of liquid developer in a developer container without adding new components or substantially changing the structure. Another object of the present invention is to provide an image forming apparatus and an image forming method with good image quality and low cost. Furthermore, it is another object of the present invention to provide a developing device, an image forming device, and an image forming method that reduce sudden fluctuations in the concentration of a liquid developer in a developer container.

The developing device of the present invention is characterized in that it includes: a developer carrier on which a liquid developer including toner liquid and carrier liquid is loaded; and the liquid is supplied to the developer carrier. A developer supply part for developer; a developer carrier cleaning part for recovering the liquid developer of the developer carrier; a recovery storage for storing the liquid developer recovered by the developer carrier cleaning part a supply unit that makes the liquid developer flow to the recovery storage unit; a transport member that transports the liquid developer recovered by the recovery storage unit in a first direction; and a transport unit that adjusts the transport amount of the transport member Quantity Adjustment Department.

The image forming apparatus of the present invention is characterized in that it has:

a developing unit including a developer carrier on which a liquid developer including a toner liquid and a carrier liquid is placed; a developer supply unit that supplies the liquid developer to the developer carrier; components, a developer carrier cleaning member that recovers the liquid developer of the developer carrier, a recovery storage unit that stores the liquid developer recovered by the developer carrier cleaning member, and a liquid developer a supply unit that flows into the recovery storage unit, and a transport member that transports the liquid developer recovered from the recovery storage unit in a first direction;

a conveying amount adjustment unit that adjusts the conveying amount of the conveying member;

a latent image carrier, which develops a latent image through the developer carrier;

a charging section that charges the latent image carrier;

an exposure unit that exposes the latent image carrier charged by the charging unit to form the latent image; and

A transfer member that transfers the image developed on the latent image carrier by the developing unit.

In addition, the image forming apparatus has:

an image information detecting unit, which detects image information; and

The liquid developer concentration determination unit determines the toner concentration of the liquid developer collected by the developer carrier cleaning member based on the detection result of the image information detection unit.

In addition, the liquid developer concentration determination unit calculates the toner concentration of the liquid developer recovered by the developer carrier cleaning member based on the detection result of the image information detection unit.

In addition, the image information detection unit calculates an image occupancy rate based on the number of dots printed on one transfer material.

In addition, the conveying amount adjusting unit adjusts the conveying amount of the conveying member based on the toner concentration determined by the liquid developer concentration determining unit.

In addition, the image forming apparatus includes a speed changing unit that is controlled by the conveying amount adjusting unit to adjust the rotational speed of the conveying member.

In addition, the image forming apparatus includes: an opening through which the liquid developer in the recovery storage unit is discharged; and a discharge rate adjustment member controlled by the conveyance rate control unit to cover the opening.

In addition, the discharge amount adjusting member includes a cover that covers the opening and a cam that moves the cover.

In addition, the conveying member is an auger having helical blades.

In addition, the image forming apparatus includes a liquid developer concentration determination unit that measures the concentration of the liquid developer in the recovery storage unit and determines the concentration of the liquid developer recovered by the developer carrier cleaning member.

The image forming method of the present invention is characterized in that when the developer carrier is used to develop the latent image after the exposed portion on the latent image carrier is exposed, and transfer the developed image to the transfer material When an image is formed, image information is detected, the toner concentration of the liquid developer in the recovery storage portion of the developer container is determined based on the detection result of the image information, and the recovery storage unit is controlled to transport the liquid developer in accordance with the determined toner concentration. The delivery amount of the delivery member of the liquid developer in the section.

In addition, the toner concentration of the liquid developer in the recovery storage portion of the developer container is calculated based on the detection result of the image information.

The developing device of the present invention can improve the agitation and dispersibility of the liquid developer in the developer container without adding new parts or greatly changing the structure, and can reduce the sharp concentration fluctuation of the liquid developer, so the concentration can be adjusted. Stablize.

In addition, the image forming apparatus of the present invention can improve the agitation and dispersibility of the liquid developer in the developer container without adding new components or greatly changing the structure, and can reduce sudden concentration fluctuations of the liquid developer. A device with good image quality and low cost can be provided.

Other contents and advantages of the present invention will be more clearly apparent from the description.

The present invention accordingly includes the examples set forth below to illustrate structural features, component combinations, and structural arrangements, and the claims define the scope of the invention.

Description of drawings

The present invention can be further explained from the following description of the drawings, where the same symbols represent the same components, wherein,

FIG. 1 is a diagram showing an embodiment of an image forming apparatus;

2 is a sectional view showing the periphery of the latent image carrier and the main constituent elements of the developing unit;

FIG. 3 is a schematic sectional view showing a part of the developing unit 30Y;

Fig. 4 is the figure of the A-A side of Fig. 3 seen from the arrow place;

Fig. 5 is the figure of the BB face of Fig. 3 seen from arrow place;

Figure 6 is a diagram representing a recovery auger;

Figure 7 is a diagram showing the recovery auger;

Figure 8 is a diagram showing a recovery auger;

FIG. 9 is a diagram showing a block diagram of a liquid developer conveying speed control device;

Fig. 10 is a graph showing the relationship between the image occupancy rate (screen occupancy rate) and the concentration of the liquid developer recovered by the developing roller cleaning blade;

11 is a diagram showing a flow chart of a first embodiment of the liquid developer transport speed control by the transport speed control means;

12 is a diagram showing a flow chart of a second embodiment of the liquid developer delivery speed control by the delivery speed control device;

13 is a cross-sectional view showing the periphery of a latent image carrier and main components of a developing unit according to another embodiment;

14 is a cross-sectional view showing the periphery of a latent image carrier and main components of a developing unit according to another embodiment;

FIG. 15 is a diagram showing the configuration of the developing unit recovery path 72Y.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a diagram showing main components constituting an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view showing main components around a latent image carrier 10Y and a developing unit 30Y as a developing device. Since the structures of the latent image carriers 10Y, 10M, 10C, and 10K and the developing units 30Y, 30M, 30C, and 30K of each color are the same, the following is based on the yellow (Y) latent image carrier 10Y and the developing unit 30Y. Be explained.

In the developer container 31Y, the toner particles in the liquid developer are positively charged, the liquid developer is stirred by the stirring auger 36Y, and is discharged from the developer by the rotation of the developer supply roller 32Y as a developer supply member. The agent container 31Y is drawn up.

The developer regulating plate 33Y is in contact with the surface of the developer supply roller 32Y, and the liquid developer remains in the concave and convex grooves of the anilox pattern formed on the surface of the developer supply roller 32Y, and other redundant components are extracted. The amount of liquid developer supplied to the developing roller 20Y as a developer carrier is limited. With this limitation, the film thickness of the liquid developer applied to the developing roller 20Y is quantified to be about 6 μm. The liquid developer picked up by the developer regulating plate 33Y falls back into the developer container 31Y due to gravity, and the liquid developer not picked up by the regulating plate 33Y is accommodated in the concave-convex grooves on the surface of the developer supply roller 32Y. It is connected to the developing roller 20Y and is coated on the surface of the developing roller 20Y.

The developing roller 20Y to which the liquid developer is applied by the developer supply roller 32Y faces the developer compressing device 22Y downstream of the nip portion with the developer supply roller 32Y. A bias voltage of approximately +400 V is applied to the developing roller 20Y, and a bias voltage higher than that of the developing roller 20Y and the same polarity as the charging polarity of the toner is applied to the developer compressing device 22Y. For example, a bias of about +4 kV is applied to the developer compressing device 22Y.

The latent image carrier 10Y is made of amorphous silicon, and after the surface is charged to about +600V by the charger 11Y upstream of the nip portion with the developing roller 20Y, the potential of the image portion is set to +25V by the exposure unit 12Y. way to form a latent image. In the developing nip portion formed between the developing roller 20Y and the latent image carrier 10Y, the latent image on the latent image carrier 10Y (image portion+25V) , non-image portion +600V), the toner particles selectively move to the image portion on the latent image carrier 10Y, thereby forming a toner image on the latent image carrier 10Y. In addition, since the carrier liquid is not affected by an electric field, it separates at the exit of the developing nip between the developing roller 20Y and the latent image carrier 10Y, and adheres to both the developing roller 20Y and the latent image carrier 10Y. The developing roller 20Y that has passed through the developing nip is cleaned by the developing roller cleaning blade 21 that is a developer carrier cleaning member, and the liquid developer is recovered.

The latent image carrier 10Y that has passed through the developing nip passes through squeeze rollers (squeeze rollers) 13Y. The squeeze roller 13Y has the function of recovering the remaining carrier liquid and the active toner (cabritona) that is not necessary from the developer developed on the latent image carrier 10Y, and increasing the ratio of toner particles in the image. . The recoverability of the remaining carrier liquid can be determined according to the rotational direction of the first squeeze roller 13aY and the second squeeze roller 14aY and the peripheral speed of the surface of the first squeeze roller 13aY and the second squeeze roller 14aY relative to the latent image carrier 10Y. The difference of the relative peripheral speed of the peripheral speed of the surface is set as the desired recovery ability, if it is rotated to the counter direction with respect to the latent image carrier 10Y, then the recovery ability improves, in addition, even if the peripheral speed difference is set larger , the recycling capacity is also improved, and this synergistic effect is also possible.

In the present embodiment, as an example, the first squeeze roller 13aY and the second squeeze roller 14aY are rotated together at substantially the same peripheral speed with respect to the latent image carrier 10Y, and from the latent image carrier The remaining carrier liquid with a weight ratio of about 5% to 10% is recovered from the developer D developed on the body 10Y to reduce the rotational driving load of both sides, and at the same time, the external disturbance of the latent image carrier 10Y to the developed toner image is also suppressed. effect.

Next, the latent image carrier 10Y passes through a nip portion with the intermediate transfer belt 40 in the primary transfer 50Y to perform primary transfer of the developed toner image to the intermediate transfer belt 40 . About −200 V of the polarity opposite to the charging characteristic of the toner particles is applied to the primary transfer roller 51Y, whereby the toner is primarily transferred from the latent image carrier 10Y to the intermediate transfer belt 40 , thereby Only the carrier liquid remains on the latent image carrier 10Y. On the downstream side of the rotation direction of the latent image carrier 10Y than the primary transfer part, after the primary transfer, the latent image carrier 10Y is erased by a static elimination device 16Y composed of an LED or the like, and the electrostatic latent image remains. The carrier liquid on the latent image carrier 10Y is extracted by the latent image carrier cleaning plate 17Y, and recovered by the developer recovery unit 18Y.

A plurality of toner images formed on the latent image carrier 10 are sequentially primary transferred and superimposed, and the toner images on the intermediate transfer belt 40 carried thereon advance to the secondary transfer unit 60 , And enter the nip portion between the intermediate transfer belt 40 and the secondary transfer roller 61 . The nip width at this time was set to 3 mm. In the secondary transfer unit 60, −1200 V is applied to the secondary transfer roller 61 and +200 V is applied to the belt drive roller 41, whereby the toner image on the intermediate transfer belt 40 is transferred to On recording media (sheet materials) such as paper.

However, when the supply of the sheet material is troublesome such as clogging, not all toner images are transferred to the secondary transfer roller and recovered, but a part remains on the intermediate transfer belt. During the secondary transfer process, the toner image on the intermediate transfer belt is not 100% secondary transferred and moved to the sheet material, but a few percent of the secondary transfer residue occurs. In particular, when the supply of the sheet material is troublesome such as a jam, the toner image is transferred in contact with the secondary transfer roller 61 without the sheet material being sandwiched, and the back surface of the sheet material is soiled.

For these unnecessary toner images, in this embodiment, the carrier liquid is recovered (squeezed) on the side of the secondary transfer roller 61, and the intermediate transfer by the intermediate transfer belt cleaning blade 46 and the developer recovery part 47 is performed. Cleaning on the printing belt 40 , and cleaning of the secondary transfer roller 61 by the secondary transfer roller cleaning plate 62 .

Such an image forming method of the image forming apparatus of the present embodiment roughly includes the following steps: a step in which the developer supply roller 32Y sucks the liquid developer from the supply portion 31aY in the developer container 31Y storing the liquid developer; 32Y is a step of supplying liquid developer to the developing roller 20Y; a step of charging the latent image carrier 10Y by the charger 11Y; a step of exposing the latent image carrier 10Y by the exposure device 12Y; placing the developing roller 20Y on the A step of applying a liquid developer to the latent image carrier 10Y and developing it; a step of transferring the image on the latent image carrier 10Y to the intermediate transfer belt 40; and a developing roller cleaning blade 21Y cleaning the developing roller 20Y steps on liquid developer.

Next, the developer container 31Y and the developer recovery and replenishment device 70Y of this embodiment will be described in detail.

The developer recovery and replenishment device 70Y has a liquid developer storage unit 71Y that stores recovered liquid developer, supplies high-concentration developer from a developer tank 74 as a supply unit, and supplies carrier liquid from a carrier liquid tank 77 as a supply unit. , thereby adjusting the density.

The liquid developer stored in the liquid developer storage unit 71Y is not a low-concentration (about 1 to 2 wt %) and low-viscosity liquid developer that is generally used at present and uses Isopar (trademark: Exxon) as a carrier liquid, and has volatilization at room temperature. It is not a volatile liquid developer, but a high-concentration, high-viscosity, non-volatile non-volatile liquid developer at room temperature. That is to say, the liquid developer of the present invention is a thermoplastic resin in which a solid substance having an average particle diameter of 1 μm including a colorant such as a pigment is mixed with a dispersant in a liquid solvent such as an organic solvent, silicone oil, mineral oil, or edible oil. A high-viscosity (about 30 to 10,000 mPa·s) liquid developer having a toner solid content concentration of about 25% is added.

In this embodiment, the liquid developer is recovered from the developing unit 30Y and the latent image carrier 10Y.

The developing unit 30Y has a developer container 31Y for supplying and recovering liquid developer, and the like. The developer container 31Y has a supply part 31aY and a recovery part 31bY. The supply part 31aY has a stirring auger 36Y which is a stirring member for stirring the developer in the developer container 31Y, and supplies liquid developer from a liquid developer storage part 71Y described later to the stirring auger 36Y. The liquid developer communication portion 35Y, etc., the recovery portion 31bY has a recovery auger 34Y as a conveying member, and the recovery auger 34Y has the developing roller cleaning blade 21Y, the first squeezing roller cleaning blade 13bY, and the second squeezing roller cleaning blade 13bY. The liquid developer scraped off by the cleaning blade 14bY is conveyed in the first direction X, and sent to the helical blade of the liquid developer storage portion 71Y.

The liquid developer recovered to the recovery portion 31bY side of the developing unit 30Y is recovered to the liquid developer storage portion 71Y via the developing unit recovery path 72Y as a recovery path or a developing device recovery path arranged on one end side of the recovery auger 34Y. . In addition, the liquid developer recovered from the latent image carrier 10Y by the latent image carrier cleaning device 15Y is recovered to the liquid developer storage part 71Y through the latent image carrier recovery path 73Y, in which the latent image carrier The cleaning device 15Y is composed of a latent image carrier cleaning plate 17Y and a developer recovery unit 18Y.

Then, the high-concentration developer is supplied from the developer tank 74Y to the liquid developer storage portion 71Y via the developer supply path 75Y and the developer pump 76Y. In addition, the carrier liquid is supplied from the carrier liquid tank 77Y to the liquid developer storage portion 71Y via the carrier liquid supply path 78Y and the carrier liquid pump 79Y. Furthermore, instead of a pump or the like, it may be a configuration in which the supply is replenished by opening and closing a valve or the like using gravity.

The liquid developer stored in the liquid developer storage portion 71Y is supplied to the developer container 31Y via the connecting portion 35Y through the developer supply path 81Y and the developer supply pump 82Y.

Next, flow of the liquid developer in the developer container 31Y will be described. 3 is a schematic sectional view of the developing unit 30Y, FIG. 4 is a view of the A-A plane of FIG. 3 seen from the arrow, and FIG. 5 is a view of the BB plane of FIG. 3 seen from the arrow.

The developing container 31Y of this embodiment is provided with a liquid level adjustment plate 37Y as a partition between the supply portion 31aY and the recovery portion 31bY. The liquid level adjustment plate 37Y is arranged in the second direction Y perpendicular or substantially perpendicular to the first direction X with respect to the recovery auger 34Y, and has a first flow part 38aY through which the liquid developer flows from the supply part 31aY and a first flow part 38aY. The second flow portion 38bY. For example, by arranging the first wall high portion 37aY having the first wall height on the central side of the liquid level adjustment plate 37Y, and arranging the first flow portion 38aY on the upper portion on the developing unit recovery path 72Y side, a liquid level adjustment plate 37Y having a height lower than the central side is provided. The second wall height portion 37bY having the second wall height is provided by disposing the second flow portion 38bY on the upper part on the opposite side of the developing unit recovery path 72Y, and a third wall height having a third wall height lower than that on the central side is provided. Part 37cY.

In addition, it is also possible to form a structure in which the wall heights of the liquid level adjustment plates 37Y are all the same, a hole is provided as the first flow portion 38aY on the side of the developing unit recovery path 72Y, and a second flow portion is formed on the opposite side of the developing unit recovery path 72Y. 38bY setting hole. In addition, a structure having a wall lower than the central side and a structure having a hole may be combined.

The liquid developer is pumped up from the liquid developer storage portion 71Y shown in FIG. 2 by the developer supply pump 82Y, and supplied to the supply portion 31aY of the developer container 31Y through the developer supply path 81Y and the communication portion 35Y. As shown in FIG. 4, the communication portion 35Y is provided at the substantially central portion in the axial direction, and the liquid developer supplied to the supply portion 31aY is diffused from the substantially central portion in the axial direction to both sides by the rotation of the agitating auger 36Y as indicated by the arrows. end.

If the amount of the liquid developer in the supply portion 31aY increases, the liquid developer overflows from the first flow portion 38aY or the second flow portion 38bY provided at the end of the liquid level adjustment plate 37Y shown in FIG. ) to the recovery section 31bY. In the recovery part 31bY, the liquid developer is sent to the developing unit recovery path 72Y by the rotation of the recovery auger 34Y, and is recovered into the liquid developer storage part 71Y through the developing unit recovery path 72Y.

And, as shown in FIG. 4 , the developing roller 20Y is driven together with the developing roller gear 20aY and the developing roller shaft 20bY by the developing roller driving motor 23Y as the driving source of the developer carrier and through the developing roller driving motor gear 23aY. In addition, the developer supply roller 32Y is driven together with the developer supply roller gear 32aY and the developer supply roller respectively by the developer supply section motor 39aY which is a common developer supply section driving source, and through the developer supply section motor gear 39bY. Shaft 32bY, and together drive agitating auger 36Y with agitating auger gear 36aY and agitating auger shaft 36bY. In addition, the recovery auger 34Y is driven together with the recovery auger gear 39dY and the recovery auger shaft 39eY by a developer recovery unit motor 39cY not shown as a driving source of the developer recovery unit.

The liquid developer flowing from the first flow portion 38aY or the second flow portion 38bY of the liquid level adjusting plate 37Y, the liquid developer flowing from other parts of the liquid level adjusting plate 37Y, and the liquid developer recovered from the developing roller cleaning plate 21Y Since it is agitated while being conveyed by the recovery auger 34Y, if the second flow portion 38bY is arranged on the opposite upstream side from the developing unit recovery path 72Y side, the agitation distance becomes longer, and the agitation and dispersibility are improved. Therefore, when the liquid developer is recovered into the liquid developer storage portion 71Y, it is in a state of being easily mixed with liquid developers of other concentrations.

FIG. 6 is a diagram showing the recovery auger 34Y. The recovery auger 34Y conveys the liquid developer, and, as shown in FIG. 6 , has a helical blade. In this way, by having the helical blade, a portion for conveying the liquid developer is formed, and the agitation and dispersibility are improved.

FIG. 7 is a diagram showing a recovery auger 34Y according to another embodiment. The recovery auger 34Y has portions with different pitches, for example, the pitch gradually increases toward the developing unit recovery path 72Y as shown in FIG. 7 . In this manner, by having portions with different pitches, portions with different conveying speeds of the liquid developer are formed, thereby improving agitation performance.

In addition, as shown in FIG. 8 , a recovery auger 34Y of another embodiment can also be applied. The recovery auger 34Y shown in FIG. 8 has a first conveying pitch portion 34aY as a first conveying portion at a lower position corresponding to the first flow portion 38aY, and has a pitch ratio of the second on the upstream side opposite to the developing unit recovery path 72Y side. The second conveyance pitch part 34bY, which is a second conveyance part with a small conveyance pitch part 34aY and a slow conveyance speed, has a third conveyance pitch part 34cY, which is a third conveyance part, at a lower position corresponding to the second flow part 38bY.

In this configuration, the conveying amount per unit length of the second conveying pitch portion 34bY is smaller than that of the first conveying pitch portion 34aY, and the amount of liquid developer conveyed from the first conveying pitch portion 34aY to the developing unit recovery path 72Y is also smaller. The amount of the liquid developer transported from the second transport pitch portion 34bY to the first transport pitch portion 34aY is larger than that of the liquid developer, and therefore, stagnation of the liquid developer in the vicinity of the lower portion of the first flow portion 38aY can be reduced.

Furthermore, the conveying amount per unit length of the third conveying pitch portion 34cY is larger than that of the second conveying pitch portion 34bY, and the amount of liquid developer conveyed from the second conveying pitch portion 34bY to the first conveying pitch portion 34aY is also larger than that from the second conveying pitch portion 34bY. The amount of liquid developer transported by the three transport pitch portion 34cY to the second transport pitch portion 34bY is small, so that the stagnation of the liquid developer near the lower side of the second flow portion 38bY can be reduced, but there is a possibility that the liquid developer may remain in the second flow portion 38bY. Concerns about conveying the pitch portion 34bY.

However, since the amount of liquid developer flowing from the first wall high portion 37aY on the central side is small compared to the amount of liquid developer flowing from the first flow portion 38aY and the second flow portion 38bY, if the recovery portion 31bY as a whole, the amount of liquid developer is averaged with respect to the first direction, and the balance is good.

In addition, the second conveying pitch portion 34bY of the recovery auger 34Y shown in FIG. 8 may be formed in a structure in which the conveying speed becomes gradually smaller as it goes toward the upstream side opposite to the developing unit recovery path 72Y side. structure.

In addition, although the second conveying pitch portion 34bY of the recovery auger 34Y shown in FIG. on the structure. At this time, the second conveying pitch portion 34 bY may be configured such that the conveying speed gradually becomes smaller toward the upstream side opposite to the developing unit recovery path 72Y side.

Next, the conveying speed control of the liquid developer will be described. In this embodiment, the rotation speed of the recovery auger 34Y and the conveyance speed of the liquid developer are controlled based on image information.

FIG. 9 is a block diagram showing the conveyance speed control device 100 of the liquid developer. The transport speed control device 100 has a recovered liquid developer concentration estimation unit 101, a recovered liquid developer concentration determination unit 102, and a transport speed indication unit 103. A signal is input to control the rotational speed of the developer recovery section motor 39cY as a speed changing mechanism, thereby controlling the rotational speed of the recovery auger 34Y.

In this embodiment, an image occupancy rate is used as image information. The image occupancy rate is the ratio of the number of printed dots to the total number of dots (the sum of printed dots and unprinted dots) included in one page, and the image occupancy is detected by calculating image data or the like using the image occupancy rate detection mechanism 110 Rate.

The recovered liquid developer concentration estimation means 101 estimates the concentration of the liquid developer recovered by the developing roller cleaning blade 21Y from the image occupancy rate detected by the image occupancy rate detection means 101 based on the prediction table shown in FIG. 10 .

The recovered liquid developer concentration determination means 102 determines in which range the concentration of the liquid developer estimated by the recovered liquid developer concentration estimation means 101 falls.

The transport speed instruction means 103 determines the rotation speed of the recovery auger 34Y based on the concentration of the liquid developer recovered by the developing roller cleaning plate 21Y determined by the recovered liquid developer concentration determination means 102 .

FIG. 11 is a flowchart showing a first embodiment of the liquid developer transport speed control performed by the transport speed control device 100 . In the first embodiment, there are the following steps: a step of detecting the image occupancy rate; a step of determining the concentration of the liquid developer collected by the developing roller cleaning blade into the recovery portion 31aY in the developer container 31Y with respect to the detection result of the image occupancy rate ; A step of controlling the transport speed of the recovery auger 34Y for transporting the liquid developer in the recovery unit 31bY based on the determined concentration. Hereinafter, a specific description will be given.

First, in the first step, the image occupancy rate is detected by the image occupancy rate detection means 110 (ST1). Next, in the second step, the concentration of the liquid developer recovered by the developing roller cleaning blade 21Y is determined by the recovered liquid developer concentration determination mechanism 102 ( ST2 ).

Next, in the third step, the recovered liquid developer concentration judging means 102 judges whether or not the concentration of the liquid developer is within ±3% with respect to the desired concentration of the liquid developer (ST3). In the third step, if the determined concentration of the liquid developer is within ±3% with respect to the desired concentration of the liquid developer, the conveying speed indicating mechanism 103 ends the conveying speed control without changing the rotational speed of the recovery auger 34Y. . In the third step, if the determined concentration of the liquid developer exceeds ±3% with respect to the expected concentration of the liquid developer, then in the fourth step, the recovered liquid developer concentration determination mechanism 102 determines the concentration of the determined liquid developer. Whether the concentration is in the range of +3% to +10% or in the range of -3% to -10% with respect to the desired concentration of the liquid developer (ST4).

In the fourth step, if the determined concentration of the liquid developer is within the range of +3% to +10% or -3% to -10% relative to the expected concentration of the liquid developer, then in the fifth step In this process, the conveyance speed instruction mechanism 103 decelerates the developer recovery section motor 39bY so that the rotational speed of the recovery auger 34Y becomes 1/2 (ST5), and the conveyance speed control ends. In the fourth step, if the concentration of the determined liquid developer is not within the range of +3% to +10% or -3% to -10% relative to the expected concentration of the liquid developer, that is, in excess of +10% or less than −10%, in the sixth step, the conveying speed indicating mechanism 103 decelerates the developer collecting part motor 39cY so that the rotating speed of the collecting auger 34Y becomes 1/3 (ST6), and the conveying speed is terminated. control.

FIG. 12 is a flowchart showing a second embodiment of the liquid developer transport speed control performed by the transport speed control device 100 . In this second embodiment, it has the following steps: a step of detecting the image occupancy rate; the liquid developer concentration estimation mechanism pre-estimates the recovery of the developing roller cleaning blade 21Y into the developer container 31Y based on the detection result of the image occupancy rate Concentration of the liquid developer in the part 31bY; and a step of controlling the conveyance speed of the recovery auger 34Y for conveying the liquid developer in the recovery part 31bY based on the detection result of the image occupancy rate corresponding to the estimated concentration. Hereinafter, a specific description will be given.

In the present embodiment, the estimated liquid developer concentration being within ±3% of the expected liquid developer concentration corresponds to the image occupancy being within the range of 27% to 33%. In addition, the estimated concentration of the liquid developer is within the range of +3% to +10% or within the range of −3% to −10% with respect to the desired concentration of the liquid developer corresponding to an image occupancy of 15%. In the range of more than and less than 27%, or in the range of more than 33% and less than 45%. Also, when the estimated concentration of the liquid developer is not within the range of +3% to +10% or within the range of -3% to -10% with respect to the expected concentration of the liquid developer, that is, it exceeds +10% or is lower than The case of —10% corresponds to a case where the image occupancy rate is less than 15% or the image occupancy rate exceeds 45%.

First, in the eleventh step, the image occupancy rate is detected by the image occupancy rate detecting means 110 (ST11). Next, in the twelfth step, the recovered liquid developer concentration judging means 102 judges whether or not the image occupancy rate is in the range of 27% or more and 33% or less (ST12). In the twelfth step, if the image occupancy rate is within the range of 27% to 33%, the conveyance speed instruction mechanism 103 ends the conveyance speed control without changing the rotation speed of the recovery auger 34Y. In the twelfth step, when the image occupancy rate is not within the range of 27% or more and 33% or less, in the thirteenth step, the recovered liquid developer concentration judging unit 102 judges whether the image occupancy rate is above 15% and Within the range of less than 27% or within the range of over 33% and 45% or less (ST13).

In the thirteenth step, if the image occupancy rate is within the range of 15% or more and less than 27% or exceeds the range of 33% and 45% or less, then in the fourteenth step, the conveying speed indicating mechanism 103 controls the developing The agent recovery part motor 39cY decelerates so that the rotation speed of the recovery auger 34Y becomes 1/2 (ST14), and the conveyance speed control ends. In the thirteenth step, when the image occupancy rate is not within the range of 15% or more and less than 27% or exceeds the range of 33% and 45% or less, that is, the image occupancy rate is less than 15% or the image occupancy rate exceeds 45% In the case of %, in the fifteenth step, the conveyance speed instruction mechanism 103 decelerates the developer recovery unit motor 39cY so that the rotational speed of the recovery auger 34Y becomes 1/3 (ST15), and the conveyance speed control ends.

Thus, the developing unit 30Y of this embodiment includes the developing roller 20Y on which the liquid developer is placed, the developer supply roller 32Y that supplies the liquid developer to the developing roller 20Y, and the developing roller cleaning blade 21Y that recovers the liquid developer on the developing roller 20Y. , a recovery part 31aY that recovers the liquid developer recovered by the developing roller cleaning plate 21Y, a supply part 31bY that makes the liquid developer flow to the recovery part 31aY, and a transport member that transports the liquid developer recovered by the recovery part 31aY in the first direction X 34Y, and the developer recovery section motor 39cY that changes the conveying speed of the conveying member 34Y, therefore, the agitation and dispersion of the liquid developer in the developer container 31Y can be improved without adding new parts or greatly changing the structure. sex.

In addition, the image forming apparatus according to this embodiment includes the developing unit 30Y, the developer recovery unit motor 39cY that changes the conveying speed of the conveying member 34Y, the latent image carrier 10Y that develops the latent image by the developing roller 20Y, and the latent A charger 11Y for charging the image carrier 10Y, an exposure device 12Y for exposing the latent image carrier 10Y, a transfer member 40 for transferring an image on the latent image carrier 10Y, an image information detection mechanism 110 for detecting image information , the liquid developer concentration determining means 102 that determines the concentration of the liquid developer recovered by the developing roller cleaning blade 21Y with respect to the detection result of the image information detecting means 110, and the concentration of the developer based on the concentration determined by the liquid developer concentration determining means 102. The collecting section motor 39cY instructs the conveying speed indicating mechanism 103 to change the conveying speed of the conveying member 34Y, so that the agitation of the liquid developer in the developer container 31Y can be improved without adding new parts or greatly changing the structure. and dispersibility, it is also possible to provide a device with good image quality and low cost.

In addition, the image forming apparatus of the present embodiment includes the developing device 30Y, the developer recovery unit motor 39cY for changing the conveying speed of the conveying member 34Y, the latent image carrier 10Y for developing the latent image by the developing roller 20Y, and the latent image carrier 10Y for developing the latent image. A charger 11Y for charging the image carrier 10Y, an exposure device 12Y for exposing the latent image carrier 10Y, a transfer member 40 for transferring an image on the latent image carrier 10Y, an image information detection mechanism 110 for detecting image information , the liquid developer concentration estimating means 101 which estimates in advance the concentration of the liquid developer recovered by the developing roller cleaning plate 21Y with respect to the detection result of the image information detecting means 110, and the liquid developer concentration estimating means 101 based on the The detection result of the image information detection means 110 corresponding to the concentration instructs the developer recovery part motor 39cY to change the transport speed instructing means 103 of the transport member 34Y. Therefore, there is no need to add new parts or significantly change the transport speed. With this configuration, the agitation and dispersibility of the liquid developer in the developer container 31Y can be improved, and a low-cost device with good image quality can be provided.

In addition, since the image information detection unit 110 detects the image occupancy rate, which is to obtain the number of printed dots relative to one transfer material, for example, the total number of dots included in one page, it is possible to provide better image quality and low cost device.

In addition, since there is a developing device recovery path 72Y for recovering the liquid developer at one end side of the conveyance member 34Y, there is a partition 37Y between the supply portion 31bY and the recovery portion 31aY, and the partition 37Y has a first wall height portion 37aY higher than the second wall. The first high wall portion 37aY is disposed closer to the first direction X side, and the second high wall portion 37bY is disposed on the opposite side of the first direction X than the first high wall portion 37aY and the second high wall portion 37bY. The three-wall high portion 37cY has a second wall high portion 37bY arranged in the second direction Y perpendicular to or substantially perpendicular to the first direction X with respect to the conveying member 34Y to allow the liquid developer to flow from the supply portion 31aY. The first flow portion 38aY of the third wall height portion 37cY is arranged in the second direction Y perpendicular to or substantially perpendicular to the first direction X with respect to the conveying member 34Y, so that the liquid developer flows from the supply portion 31aY. The flow of the second flow portion 38bY, therefore, can reduce the liquid leakage from the developer container 31Y.

Moreover, since the conveyance member 34Y has the recovery auger 34Y, and the recovery auger 34Y has a helical blade, it can convey more well-balanced with a simple structure.

Next, the embodiment will be described in more detail.

About 60 cc/min is conveyed from the liquid developer storage part 71Y to the supply part 31aY of this embodiment, and about 30 cc/min of it is passed by the developer supply roller 32Y with a desired developer film thickness (about 65 μm in this embodiment) Coated on the developing roller 20Y. About 30 cc/min of the difference overflows the liquid level adjustment plate 37Y, and flows to the recovery part 31bY. In addition, although depending on the image occupancy rate, about 15 cc/min within about 30 cc/min of coating on the developing roller 20Y is cleaned as a developing residue by the developing roller cleaning blade 21Y. Therefore, the liquid developer recovered by the recovery section 31bY including the liquid developer overflowing the liquid level adjusting plate 37Y and the liquid developer cleaned by the developing roller cleaning plate 21Y is about 45 cc/min, of which about 15 cc/min is Agglomerated toner solids.

The aggregated toner solid content deteriorates the aggregated state by the developer compressing device 22Y shown in FIG. 2 . Since the compressed state changes depending on the characteristics of the liquid developer, whether the operator inputs the aggregation characteristics of the liquid developer or transfers the developed aggregation characteristics through the IC memory card attached to the developer container 31Y, the conveying speed control is updated. The reference speed of the device 100. This reference speed is predetermined and represents a reference speed of the transport speed.

In addition, as shown in FIG. 13 , a squeeze roller recovery path 171Y may be provided for recovering the liquid developer recovered by the first squeeze roller 13aY or the second squeeze roller 14aY. A conveyance auger (not shown) that allows the liquid developer to move in the roller axis direction is disposed on the squeeze roller recovery path 171Y, and is recovered to the liquid developer storage unit 71Y.

In addition, the image occupancy ratio used as image information may be set to be calculated every printing job or every 100 sheets printed. In particular, when the volume of one printing is large, it is not possible to control it for each printing job, so it is preferable to control the conveying speed every 100 sheets.

In addition, in the conveying speed control, the rotation of the recovery auger 34Y may be constant and pulse control may be performed. For example, in the thirteenth step, if the image occupancy rate is in the range of 15% or more and less than 27% or in the range of more than 33% and 45% or less, in the fourteenth step, the developer recovery part motor is controlled. 39cY makes the rotation duty 50% (ST14). In the thirteenth step, when the image occupancy rate is not within the range of more than 15% and less than 27% or exceeds the range of 33% and less than 45%, that is, the image occupancy rate is less than 15% or the image occupancy rate exceeds 45% In this case, in the fifteenth step, the transport speed indicating mechanism 103 may control the developer recovery section motor 39cY so that the rotation duty becomes 30% (ST15).

Furthermore, as shown in FIG. 14 , a density sensor 111Y as an input means is arranged in the recovery part 31bY, and the conveyance amount of the liquid developer can be controlled based on the concentration value of the recovered liquid developer determined by the liquid developer concentration determination means.

For example, the recovery auger 34Y may be driven intermittently by controlling the driving time based on the concentration value measured by the concentration sensor 111Y. Specifically, in the thirteenth step, if the image occupancy rate is within the range of 15% or more and less than 27% or exceeds the range of 33% and 45% or less, then in the fourteenth step, the developer is controlled The recovery part motor 39cY makes the rotation time of the recovery auger 34Y 1/2 (ST14). In the thirteenth step, when the image occupancy rate is not within the range of 15% to less than 27%, or exceeds the range of 33% to 45%, that is, the image occupancy rate is less than 15% or the image occupancy rate exceeds 45%. %, in the fifteenth step, the developer recovery section motor 39cY may be controlled so that the rotation speed of the recovery auger 34Y becomes 1/3 (ST15).

In this case, concentration detection may be performed by measuring the propagation time of sound waves with an ultrasonic sensor, or the amount of transmitted light may be measured. Furthermore, by arranging the concentration sensor 111Y at the most downstream in the conveyance direction of the recovery part 31bY to measure the concentration of the liquid developer after stirring, it is possible to control the allergy slowly without performing allergy control (allergy control), so as to reduce frequent Changes in conveying speed.

In addition, the flow in the case of the pulse control and the intermittent drive control is the same as that in FIG. 11 .

In addition, the image occupancy rate is preferably not the area of one sheet of recording paper as a transfer material, but the amount of the toner layer attached to the photoreceptor 10Y on one sheet as the denominator. That is, it is preferable to use an area including the amount consumed by the interval between sheets due to continuous operation, the printing margin in the width direction, and the like as the denominator. Therefore, even if a better image is printed on the entire surface of the recording paper, it will not be 100% since the spaces between the sheets and in the width direction are not printed. In addition, when printing an image pattern whose image density is read between sheets, it is also counted as an image area.

Next, a specific example in the vicinity of the exit of the developing unit recovery path 72Y will be described. FIG. 15 shows a specific structure of the vicinity of the exit of the developing unit recovery path 72Y. Fig. 15(a) shows a state where the opening is 100% open, Fig. 15(b) shows a state where the opening is 50% open, and Fig. 15(c) shows a state where the opening is 30% open.

As shown in FIG. 15( a ), the developing unit recovery path 72Y has a recovery path opening 72aY as an opening in the vicinity of the exit. The opening area of the recovery path opening 72aY can be adjusted by an opening adjustment cover 172Y serving as a discharge amount adjusting member. The opening adjustment cover 172Y is formed in a cylindrical shape, covers the periphery of the developing unit recovery path 72Y, and has a cover opening 172aY. The lid opening 172aY is formed so as to partially or completely overlap the recovery path opening 72aY. By moving and adjusting the position of the opening adjustment cover 172Y, the area where the cover opening 172aY and the recovery path opening 72aY overlap can be changed, and the amount of liquid developer to be discharged can be adjusted. A cam 173Y serving as a discharge amount adjusting member is in contact with an end portion 172bY of the opening adjusting cover 172Y. The cam 173Y is a circular member, and the rotation center 173aY is arranged eccentrically from the center of the cam 173Y. Furthermore, the opening adjustment cover 172Y is urged toward the cam 173Y by an elastic member such as a spring (not shown).

Therefore, when the rotation angle of the cam 173Y is controlled, the opening adjustment cover 172Y abutting against the cam 173Y moves, and the diameter of the overlapped portion of the cover opening 172aY and the recovery path opening 72aY changes, thereby controlling the flow rate of the liquid developer.

In the transport amount control, the diameter of the recovery path opening 72aY may be controlled by keeping the rotation of the recovery auger 34Y constant. For example, in the thirteenth step, if the image occupancy rate is within the range of more than 15% and less than 27% or exceeds the range of 33% and less than 45%, then in the fourteenth step, as shown in Figure 15(b ), the cam 173Y is controlled so that the diameter of the recovery passage opening 72aY becomes 50% (ST14). In the thirteenth step, when the image occupancy rate is not within the range of more than 15% and less than 27% or not within the range of more than 33% and less than 45%, that is, when the image occupancy rate is less than 15% or the image occupancy rate If it exceeds 45%, in the fifteenth step, as shown in FIG. 15(c), the cam 173Y may be controlled so that the diameter of the recovery passage opening 72aY becomes 30% (ST15).

Furthermore, the conveying amount adjustment unit of the present invention includes the conveying speed control device 100 of the embodiment, particularly the conveying speed indicating mechanism 103 . In addition, the liquid developer concentration determination unit includes recovered liquid developer concentration estimation means 101 and recovered liquid developer concentration determination means 102 . Furthermore, the recovery storage unit includes a recovery unit 31bY, and the discharge amount adjustment member includes a developer recovery unit motor 39cY. In addition, the image information detection unit includes an image occupancy ratio detection unit 110 , and the speed change unit includes a transport speed designation unit 103 .

Since the developing device and the developing unit of this embodiment do not need to add new components or greatly change the structure, the agitation and dispersibility of the liquid developer in the developer container are improved, and the rapid concentration fluctuation of the liquid developer is reduced. , so the concentration can be stabilized.

In addition, since the image forming apparatus of this embodiment does not need to add new components or significantly change the structure, the agitation and dispersibility of the liquid developer in the developer container are improved, and the rapid concentration fluctuation of the liquid developer is reduced. Therefore, it is possible to provide a device with good image quality and low cost.

This application is mainly based on the priority of No. 2008-080316 filed on March 26, 2008 and No. 2008-320710 filed on October 17, 2008 in Japan, the entire contents of which are incorporated herein.

Claims (13)

1. developing apparatus is characterized in that it has:

Carry out the developer mounting body of mounting at interior liquid developer to comprising toner liquid and carrier fluid;

Supply the developer replenishing parts of described liquid developer to described developer mounting body;

Reclaim the developer mounting body cleaning member of the described liquid developer of described developer mounting body;

Storage is by the recovery storage part of the liquid developer of described developer mounting body cleaning member recovery;

The supply unit that described liquid developer is flowed to described recovery storage part;

The transfer unit that to carry to first direction by the liquid developer that described recovery storage part reclaims; And

Adjust the operational throughput adjustment part of the operational throughput of described transfer unit.

2. image processing system is characterized in that it has:

Development section, this development section comprise the developer mounting body that the liquid developer that comprises toner liquid and carrier fluid is carried out mounting, supply with the developer replenishing parts of described liquid developer to described developer mounting body, reclaim the developer mounting body cleaning member of the described liquid developer of described developer mounting body, storage is by the recovery storage part of the liquid developer of described developer mounting body cleaning member recovery, the transfer unit that makes supply unit that liquid developer flows to described recovery storage part and will carry to first direction by the liquid developer that described recovery storage part reclaims;

The operational throughput adjustment part, it adjusts the operational throughput of described transfer unit;

Sub-image mounting body, it develops to sub-image by described developer mounting body;

Electro-mechanical part, it makes described sub-image mounting body charged;

Exposure portion, it is to charged described sub-image mounting body exposes and forms described sub-image by described electro-mechanical part; And

Transfer member, it carries out transfer printing to the picture that develops by described development section on described sub-image mounting body.

3. image processing system as claimed in claim 2, wherein, described image processing system has:

The image information test section, it detects image information; And

Liquid development agent concentration detection unit, its testing result according to described image information test section are judged the toner concentration of the liquid developer that described developer mounting body cleaning member reclaims.

4. image processing system as claimed in claim 3, wherein,

Described liquid development agent concentration detection unit calculates the toner concentration of the liquid developer of described developer mounting body cleaning member recovery according to the testing result of described image information test section.

5. image processing system as claimed in claim 3, wherein,

Described image information test section is calculated the image occupation rate according to counting of printing on a transfer materials.

6. image processing system as claimed in claim 3, wherein,

The toner concentration that described operational throughput adjustment part is judged according to described liquid development agent concentration detection unit is adjusted the operational throughput of described transfer unit.

7. image processing system as claimed in claim 6, wherein,

Described image processing system has the speed changing unit of being controlled and adjusted the rotational speed of described transfer unit by described operational throughput adjustment part.

8. image processing system as claimed in claim 6, wherein,

Described image processing system has: the peristome of discharging the liquid developer of described recovery storage part; And the discharge rate adjustment component of controlling, cover described peristome by described operational throughput adjustment part.

9. image processing system as claimed in claim 8, wherein,

Described discharge rate adjustment component has lid that covers described peristome and the cam that described lid is moved.

10. image processing system as claimed in claim 2, wherein,

Described transfer unit is the spiral drill with spiral blade.

11. image processing system as claimed in claim 2, wherein,

Described image processing system has: measure the concentration of the liquid developer of described recovery storage part, and the liquid development agent concentration detection unit judged of the concentration of the liquid developer that described developer mounting body cleaning member is reclaimed.

12. an image forming method is characterized in that,

When utilize developer mounting body to sub-image mounting body on sub-image after the portion of the being exposed exposure develop, and the picture that makes development is when being transferred to image on the transfer materials and forming, detected image information, judge the toner concentration of liquid developer of the recovery storage part of developer reservoir according to the testing result of described image information, control the operational throughput of the transfer unit of the liquid developer of carrying described recovery storage part corresponding to the toner concentration of judging.

13. image forming method as claimed in claim 12, wherein,

Calculate the toner concentration of liquid developer of the recovery storage part of described developer reservoir according to the testing result of image information.

Images