JP5273346B2 - Image forming method and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming method and an image forming apparatus uniformity for the concentration of liquid developer in a developer container, or the like, is made high, and proper image quality and cost reduction are attained, without requiring drastic changes in the constitution. <P>SOLUTION: The developer container 31Y has: a supply part 31aY reservoiring liquid developer, to be supplied to a developer carrier 20Y by a developer supply member 32Y; a collection part 31bY for collecting the liquid developer collected by a developer carrier cleaning member 21Y; and a partition part 37Y, provided between the supply part 31aY and the collection part 31bY and constituted so that the liquid developer can move therein, where the amount of the liquid developer moving in the partition part 37Y is adjusted, based on discrimination by a discriminating means 112. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an image forming method and an image forming apparatus using a liquid developer in which toner is dispersed in a carrier liquid.

2. Description of the Related Art Conventionally, a developing device has a structure having a tank part for storing a liquid developer, a primary storage part, and a partition wall between the tank part and the primary storage part.

  In this structure, when the amount of the liquid developer in the tank portion that stores the liquid developer supplied to the developing roller or the like exceeds a predetermined amount, the liquid developer is discharged to the primary storage portion beyond the partition wall. Thereafter, the liquid developer in the primary storage unit is collected in the developer adjusting unit, the density is adjusted, and the like, and the circulation path is returned to the tank unit.

JP 2002-258620 A

  However, in the technique described in Patent Document 1, the concentration in the developer adjusting unit suddenly changes greatly according to the concentration of the collected liquid developer, and the concentration in the tank unit may become uneven.

  In order to solve the above-described problems, the present invention does not require a significant change in configuration, increases the uniformity of the concentration of the liquid developer in the developer container, and provides an image forming method with good image quality and low cost. An object of the present invention is to provide an image forming apparatus.

In the image forming method of the present invention, a latent image carrier that carries a latent image, a charger that charges the latent image carrier, an exposure unit that exposes the latent image carrier to form the latent image , A developer carrying member carrying a liquid developer containing toner and carrier liquid, a developer supply member having a spiral groove and supplying the liquid developer to the developer carrying member, and cleaning the developer carrying member. A developer carrying member cleaning member and a developer container for storing a liquid developer, a developing unit for developing the latent image formed on the latent image carrier, and an image developed on the latent image carrier There comprising a transfer member to be transferred, and discriminating means for discriminating the images information, and the developer container is supplied portion in which the developer supply member for storing the liquid developer supplied to the developer carrying member, Liquid recovered by the developer carrier cleaning member Recovery unit for recovering the developer, and has a liquid developer partition portion movable provided between the supply part and the collecting part, moving the partition portion based on the determination of the determination means Since the amount of liquid developer is adjusted, there is no need to change the configuration significantly, the uniformity of the concentration of liquid developer in the developer container is increased, and an image forming method with good image quality and low cost is provided. It becomes possible to do.

  The determining means is a means for comparing a predetermined value determined in advance with a line rate of the print image, and when the image line rate of the print image is larger than the predetermined value, Since the amount of the liquid developer that moves is increased, the uniformity of the concentration of the liquid developer in the recovery unit can be increased.

Furthermore, in the image forming apparatus of the present invention, a latent image carrier that carries a latent image, a charger that charges the latent image carrier, and an exposure unit that exposes the latent image carrier to form the latent image. A developer carrying member for carrying a liquid developer containing toner and a carrier liquid, a developer supply member having a spiral groove and supplying the liquid developer to the developer carrying member, and the developer carrying member. A developer carrier cleaning member to be cleaned, a supply unit for storing the liquid developer supplied to the developer carrier by the developer supply member, and a recovery for storing the liquid developer recovered by the developer carrier cleaning member And developing the latent image formed on the latent image carrier, having a partition part for partitioning the supply part and the supply part and moving the liquid developer from the supply part to the recovery part. A developing unit, A liquid developer storing portion for storing a liquid developer for supplying the liquid developer to the portion, a transfer member to which the developed image is transferred to the latent image carrier, a determining means for determining image information, and the determination And an adjustment unit that adjusts the amount of the liquid developer that moves the partition based on the determination of the means, so that there is no need to make a significant configuration change and liquid development in a developer container or the like with a simple configuration It becomes possible to provide a low-cost image forming apparatus with high image quality uniformity and high image quality.

Further, the partition portion has an overflow plate that moves in the vertical direction, and overflow member moving means that moves the overflow plate in the vertical direction, and the adjustment portion moves the overflow plate in the vertical direction by the overflow plate moving means. Since it is moved, there is no need to make a significant change in configuration, and with a simple configuration, the uniformity of the concentration of the liquid developer in the developer container is increased, and an image forming apparatus with good image quality and low cost is provided. It becomes possible to do.

Also, an agitation member for agitating the liquid developer disposed in the supply unit and stored in the supply unit, and an overflow amount control member for controlling the amount of liquid developer disposed in the supply unit and moving through the partition unit And an overflow amount control member driving means for driving the overflow amount control member, and the adjustment portion drives the overflow amount control member drive means to move the partition portion. since adjusting, must be a significant configuration change without, with increasing the homogeneity of the concentration of the liquid developer in the developer container or the like with a simple structure, provides a quality good, low-cost image forming apparatus It becomes possible.

A stirring member that is disposed in the supply unit and that transports the liquid developer stored in the supply unit from a central part to both axial end sides; and a stirring member driving unit that drives the stirring member. The partition unit includes a moving unit that moves the liquid developer from the supply unit to the recovery unit on both ends in the axial direction, and the adjustment unit drives a stirring member driving unit that drives the stirring member. Since the amount of liquid developer that moves through the partition is adjusted, there is no need to make a significant change in configuration, the liquid developer concentration uniformity in the developer container and the like can be increased with a simple configuration, and image quality can be improved. It is possible to provide a good and low-cost image forming apparatus.

And a squeeze portion for collecting the liquid developer by squeezing the latent image carrier developed in the developing portion, and the liquid developer recovered by the squeeze portion is recovered by the recovery portion. Therefore, the liquid developer on the surface of the developer carrying member cleaning member easily flows, and it is not necessary to add a member for that purpose. Therefore, the apparatus can be downsized and the cost can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing main components constituting the image forming apparatus according to the embodiment of the present invention. Each color of the latent image carrier 10Y that is disposed in a central portion of the image forming apparatus, 10M, 10C, to 10K, developing units 30Y as a developing unit, 30M, 30C, 30K, developer recovery replenishing device 70Y, 70M, 70C , 70K are arranged in a lower part of the image forming apparatus, the intermediate transfer belt 40, a secondary transfer unit 60 as a transcription member is disposed on top of the image forming apparatus.

Around the latent image carriers 10Y, 10M, 10C, and 10K, chargers 11Y, 11M, 11C, and 11K, and exposure units 12Y, 12M, 12C, and 12K as exposure units are provided. The exposure units 12Y, 12M, 12C, and 12K include line heads and the like in which LEDs are arranged, and the latent image carriers 10Y, 10M, 10C, and 10K are uniformly charged by the chargers 11Y, 11M, 11C, and 11K. The exposure units 12Y, 12M, 12C, and 12K irradiate a modulated laser beam based on the input image signal, and electrostatic latent images on the charged latent image carriers 10Y, 10M, 10C, and 10K. Form an image.

  The developing units 30Y, 30M, 30C, and 30K are roughly composed of developing rollers 20Y, 20M, 20C, and 20K as developer carriers, yellow (Y), magenta (M), cyan (C), and black (K). Developer containers 31Y, 31M, 31C, and 31K that store liquid developers of the respective colors, and development that supplies the liquid developers of these colors from the developer containers 31Y, 31M, 31C, and 31K to the developing rollers 20Y, 20M, 20C, and 20K Developer supply rollers 32Y, 32M, 32C, and 32K as agent supply members are provided, and the electrostatic latent images formed on the latent image carriers 10Y, 10M, 10C, and 10K are developed with liquid developers of respective colors.

  The intermediate transfer belt 40 is an endless belt member and is wound around and stretched between a driving roller 41 and a tension roller 42, and the latent image carriers 10Y, 10M, and 50K are primary transfer units 50Y, 50M, 50C, and 50K. It is rotationally driven by the drive roller 41 while abutting 10C and 10K. The primary transfer units 50Y, 50M, 50C, and 50K are arranged such that the primary transfer rollers 51Y, 51M, 51C, and 51K face each other with the intermediate transfer belt 40 sandwiched between the latent image carriers 10Y, 10M, 10C, and 10K. The developed toner image of each color on the latent image carriers 10Y, 10M, 10C, and 10K is sequentially superimposed and transferred onto the intermediate transfer belt 40 using the contact position with 10Y, 10M, 10C, and 10K as a transfer position. A full-color toner image is formed.

  In the secondary transfer unit 60, a secondary transfer roller 61 is disposed opposite to the belt driving roller 41 with the intermediate transfer belt 40 interposed therebetween, and a cleaning device including a secondary transfer roller cleaning blade 62 and a developer recovery unit 63 is disposed. The In the secondary transfer unit 60, the sheet material conveyance path L is adjusted in accordance with the timing at which a full-color toner image or a single-color toner image formed by superimposing colors on the intermediate transfer belt 40 reaches the transfer position of the secondary transfer unit 60. Then, a sheet material such as paper, film or cloth is conveyed and supplied, and a single-color toner image or a full-color toner image is secondarily transferred to the sheet material. A fixing unit (not shown) is disposed in front of the sheet material conveyance path L, and a single color toner image or a full color toner image transferred onto the sheet material is fused and fixed to a recording medium (sheet material) such as paper. Image formation on the final sheet material is completed.

  On the side of the tension roller 42 that stretches the intermediate transfer belt 40 together with the belt drive roller 41, a cleaning device including an intermediate transfer belt cleaning blade 46 and a developer recovery unit 47 is disposed along the outer periphery thereof. The intermediate transfer belt 40 that has passed through the unit 60 proceeds to the winding portion of the tension roller 42, the intermediate transfer belt cleaning blade 46 performs cleaning on the intermediate transfer belt 40, and again proceeds to the primary transfer unit 50. .

  Developer collecting and replenishing devices 70Y, 70M, 70C and 70K adjust the concentration of the liquid developer collected from the latent image carriers 10Y, 10M, 10C and 10K and the developing units 30Y, 30M, 30C and 30K, and Supply to 31Y, 31M, 31C, 31K.

  Next, the latent image carriers 10Y, 10M, 10C, and 10K and the developing units 30Y, 30M, 30C, and 30K will be described. FIG. 2 is a cross-sectional view showing the main components of the periphery of the latent image carrier 10Y and the developing unit 30Y. 3 is a diagram for explaining the developer supply member, FIG. 4 is a diagram for explaining the compression of the developer by the developer compressing device 22Y, FIG. 5 is a diagram for explaining the development by the developing roller 20Y, and FIG. 6 is by the squeeze roller 13Y. It is a figure explaining a squeeze effect | action. Since the configurations of the latent image carriers 10Y, 10M, 10C, and 10K for each color and the developing units 30Y, 30M, 30C, and 30K are the same, the following description is based on the periphery of the latent image carrier 10Y for yellow (Y) and the developing unit 30Y. I will explain.

The periphery of the latent image carrier 10Y is arranged along the rotational direction of the outer periphery of the latent image carrier 10Y along with a discharging device 16Y, a cleaning device including a latent image carrier cleaning blade 17Y and a developer recovery unit 18Y, a charger 11Y, and an exposure unit. 12Y, the developing of the development unit 30Y roller 20Y, a second squeeze section consisting of a first squeezing roller 13aY and the first squeezing portion 13Y and the second squeezing roller 14aY and the second squeezing roller cleaning blade 14bY consists first squeezing roller cleaning blade 13bY 14Y is arranged. In the developing unit 30Y, a developing roller cleaning blade 21Y as a developer carrier cleaning blade and a developer supply roller 32Y using an anilox roller are arranged on the outer periphery of the developing roller 20Y. A liquid developer stirring auger 36Y and a developer supply roller 32Y as a stirring member are accommodated. A primary transfer roller 51Y of the primary transfer portion is disposed along the intermediate transfer belt 40 at a position facing the latent image carrier 10Y.

  The latent image carrier 10Y is a photosensitive drum made of a cylindrical member having a width wider than about 320 mm of the developing roller 20Y and having a photosensitive layer formed on the outer peripheral surface. For example, as shown in FIG. Rotate. The photosensitive layer of the latent image carrier 10Y includes an organic latent image carrier or an amorphous silicon latent image carrier. The charger 11Y is disposed upstream of the nip portion between the latent image carrier 10Y and the developing roller 20Y in the rotation direction of the latent image carrier 10Y, and has a bias having the same polarity as the charging polarity of the developing toner particles from a power supply device (not shown). Is applied to charge the latent image carrier 10Y. The exposure unit 12Y exposes the latent image carrier 10Y charged by the charger 11Y downstream of the charger 11Y in the rotation direction of the latent image carrier 10Y, and forms a latent image on the latent image carrier 10Y. To do.

The developing unit 30Y includes a developing roller 20Y that carries the liquid developer, a developing roller cleaning blade 21Y that cleans the developing roller 20Y, a developer compression member 22Y that forms a compressed state on the developer on the developing roller 20Y, and liquid development. The toner is dispersed in an approximately 25% weight ratio in the carrier liquid by the developer supply roller 32Y and the developer regulating blade 33Y for stirring and maintaining the agent in a uniform dispersed state and supplying it to the developing roller 20Y. A developer container 31Y for storing the liquid developer in a state; The developer container 31Y includes a supply unit 31aY and a recovery unit 31bY. The supply unit 31aY is a stirring auger 36Y that stirs the developer in the developer container 31Y, and a liquid developer storage unit 71Y described later in the stirring auger 36Y. The collecting unit 31bY collects the liquid developer scraped off by the developing roller cleaning blade 21Y, the first squeeze roller cleaning blade 13bY, and the second squeeze roller cleaning blade 14bY. and has a collection auger 34Y such as a carrying member having a spiral blade to be sent to the liquid developer reservoir 71Y.

  The liquid developer accommodated in the developer container 31Y is a low concentration (about 1 to 2 wt%) and low viscosity, which is conventionally used, using Isopar (trademark: Exxon) as a carrier liquid. It is not a volatile liquid developer having volatility, but a non-volatile liquid developer having a high concentration and high viscosity and having non-volatility at room temperature. That is, in the liquid developer in the present invention, a solid having an average particle diameter of 1 μm in which a colorant such as a pigment is dispersed in a thermoplastic resin is introduced into a liquid solvent such as an organic solvent, silicon oil, mineral oil, or edible oil. It is a liquid developer having a high viscosity (about 30 to 10,000 mPa · s) which is added together with a dispersant and has a toner solid content concentration of about 25%.

  As shown in FIG. 3, the developer supply roller 32 </ b> Y is a cylindrical member, and an uneven surface formed by a groove such as a spiral as a fine and uniform moving means on the surface so as to easily carry the developer on the surface. The anilox roller is formed, for example, and rotates in the counterclockwise direction as shown in FIG. The groove dimensions are such that the groove pitch is about 130 μm and the groove depth is about 30 μm. The developer supply roller 32Y supplies the liquid developer from the developer container 31Y to the developing roller 20Y. The stirring auger 36 </ b> Y and the developer supply roller 32 </ b> Y may be in sliding contact with each other, but may be separated from each other.

  The developer regulating blade 33Y supports a metal blade, an elastic blade having a surface covered with an elastic body, a rubber portion made of urethane rubber or the like that contacts the surface of the developer supply roller 32Y, and the rubber portion. It consists of a metal plate. Then, the film thickness and amount of the liquid developer carried and conveyed by the developer supply roller 32Y composed of an anilox roller are regulated and adjusted, and the amount of liquid developer supplied to the developing roller 20Y is adjusted. Note that the rotation direction of the developer supply roller 32Y may be the opposite direction instead of the arrow direction shown in FIG. 2, and the developer regulating blade 33Y at that time requires an arrangement corresponding to the rotation direction.

  The developing roller 20Y is a cylindrical member having a width of about 320 mm, and rotates counterclockwise around the rotation axis as shown in FIG. The developing roller 20Y is provided with an elastic layer made of polyurethane rubber, silicon rubber, NBR or the like 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 comes into contact with the surface of the developing roller 20Y, and is arranged downstream of the developing nip portion where the developing roller 20Y comes into contact with the latent image carrier 10Y in the rotation direction of the developing roller 20Y. The liquid developer remaining on the developing roller 20Y is scraped off and removed.

  The developer compressing device 22Y applies corona discharge from a corona discharger. As shown in FIG. 4, the developer compressing device 22Y moves the toner T uniformly dispersed in the carrier liquid C to the developing roller 20Y side and aggregates it to form a so-called developer compressed state T ′.

  As shown in FIG. 5, the developer D carried by the developing roller 20Y and compressed by the developer is applied to the latent image carrier by applying a desired electric field at the developing nip where the developing roller 20Y contacts the latent image carrier 10Y. Development is performed corresponding to the latent image of 10Y. The undeveloped developer D is scraped off and removed by the developing roller cleaning blade 21Y and collected on the developer collection auger 34Y side in the developer container 31Y. Note that the carrier liquid and toner to be merged are not in a mixed color state.

Next, the squeeze part as a carrier liquid removal part is demonstrated. The squeeze unit of the present embodiment includes a first squeeze unit 13 and a second squeeze unit 14, and is disposed on the downstream side of the developing roller 20Y so as to face the latent image carrier 10Y. The excess developer of the developed toner image is recovered by contact.

As shown in FIG. 6, the first squeeze portion 13 includes a first squeeze roller 13aY made of an elastic roller member that covers a surface of the first elastic body 13a-1Y and rotates in sliding contact with the latent image carrier 10Y. As shown in FIG. 2, it comprises a first squeeze roller cleaning blade 13bY that presses and slides against the first squeeze roller 13aY to clean the surface.

Similarly to the first squeeze part 13 shown in FIG. 6, the second squeeze part 14 is covered with a second elastic body 14a-1Y on its surface, and is an elastic roller member that rotates in sliding contact with the latent image carrier 10Y. 2 and a second squeeze roller cleaning blade 14bY that presses and slides against the second squeeze roller 14aY to clean the surface, as shown in FIG.

The squeeze portions 13 and 14 have a function of collecting excess carrier liquid C and originally unnecessary fog toner T ″ from the developer D developed on the latent image carrier 10Y, and increasing the toner particle ratio in the visible image. The recovery ability of the surplus carrier liquid C is relative to the rotation direction of the first squeeze roller 13aY and the second squeeze roller 14aY and the surface of the first squeeze roller 13aY and the second squeeze roller 14aY with respect to the peripheral speed of the surface of the latent image carrier 10Y. It is possible to set the desired recovery capability according to the peripheral speed difference, and the recovery capability increases if the latent image carrier 10Y is rotated in the counter direction. In addition, this synergistic effect is possible.

  The excess carrier liquid C and unnecessary fog toner T ″ collected by the first squeeze roller 13aY and the second squeeze roller 14aY are removed by the action of the first squeeze roller cleaning blade 13bY and the second squeeze roller cleaning blade 14bY. 13aY and the second squeeze roller 14aY are collected on the developer collection auger 34Y side of the developer container 31Y. The collected excess carrier liquid C and fog toner T ″ are collected from a dedicated isolated latent image carrier 10Y. Since it is collected, color mixing phenomenon does not occur in all locations.

  Further, the liquid developer collected by the first squeeze roller 13aY and the second squeeze roller 14aY is dropped on the developing roller cleaning blade 21Y, and the liquid developer dropped on the developing roller cleaning blade 21Y and the developing roller cleaning blade 21Y are cleaned. The liquid developer thus obtained may be further dropped onto the collection unit 31bY.

  In the primary transfer unit 50Y, the developer image developed on the latent image carrier 10Y is transferred to the intermediate transfer belt 40 by the primary transfer roller 51Y. Here, the latent image carrier 10Y and the intermediate transfer belt 40 are configured to move at the same speed, so that the driving load of rotation and movement is reduced, and the disturbance effect on the visible toner image of the latent image carrier 10Y is suppressed. doing.

  The developer recovery and supply device 70Y stores the recovered liquid developer, supplies a high concentration developer from the developer tank 74Y, and supplies a carrier liquid from the carrier liquid tank 77Y, and adjusts the concentration thereof. Have

In the present embodiment, the liquid developer is recovered from the developing unit 30Y and the latent image carrier 10Y. The liquid developer recovered on the developer recovery auger 34Y side of the development unit 30Y is recovered in the liquid developer storage portion 71Y via the development unit recovery path 72Y as a recovery path. Further, the liquid developer recovered from the latent image carrier 10Y by the latent image carrier cleaning device 15Y including the latent image carrier cleaning blade 17Y and the developer recovery unit 18Y passes through the latent image carrier recovery path 73Y. The developer is collected in the developer reservoir 71Y.

  Further, 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. Further, the carrier liquid is supplied from the carrier liquid tank 77Y to the liquid developer storage section 71Y via the carrier liquid supply path 78Y and the carrier liquid pump 79Y. In addition, it is good also as a structure which replenishes by opening and closing of a valve | bulb etc. using gravity instead of a pump.

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

  Next, the operation of the image forming apparatus of the present invention will be described. Subsequently, with respect to the latent image carriers 10Y, 10M, 10C, and 10K and the developing units 30Y, 30M, 30C, and 30K, the four latent image carriers 10Y, 10M, 10C, and 10K and the developing units 30Y, 30M, and 30C, A description will be given by taking the periphery of the latent image carrier 10Y of yellow and the developing unit 30Y as an example.

  In the developer container 31Y, the toner particles in the liquid developer have a positive charge. This liquid developer is stirred by the stirring auger 36Y, and the developer supply roller 32Y rotates, whereby the developer container 31Y. Pumped from.

  The developer regulating blade 33Y is in contact with the surface of the developer supply roller 32Y, leaving the liquid developer in the uneven grooves of the anilox pattern formed on the surface of the developer supply roller 32Y, and other excess liquid developer. The amount of liquid developer supplied to the developing roller 20Y is regulated. By such regulation, the film thickness of the liquid developer applied to the developing roller 20Y is quantified so as to be about 6 μm. The liquid developer scraped by the developer regulating blade 33Y is dropped back into the developer container 31Y by gravity, and the liquid developer that has not been scraped by the regulating blade 33Y is uneven on the surface of the developer supply roller 32Y. Is applied to the surface of the developing roller 20Y by being pressed against the developing roller 20Y.

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

  The latent image carrier 10Y is made of amorphous silicon, and after the surface is charged to about +600 V by the charger 11Y upstream of the nip portion with the developing roller 20Y, the potential of the image portion is +25 V by the exposure unit 12Y. A latent image is formed. In the developing nip portion formed between the developing roller 20Y and the latent image carrier 10Y, the bias + 400V applied to the developing roller 20Y and the latent image on the latent image carrier 10Y (image portion + 25V, non-image portion + 600V). 5), the toner particles T are selectively moved to the image portion on the latent image carrier 10Y as shown in FIG. 5, thereby forming a toner image on the latent image carrier 10Y. The Further, since the carrier liquid C is not affected by the electric field, as shown in FIG. 5, it is separated at the developing nip exit between the developing roller 20Y and the latent image carrier 10Y, and the developing roller 20Y and the latent image carrier 10Y are separated. Adhere to both.

  The latent image carrier 10Y that has passed through the developing nip portion passes through the squeeze roller 13Y portion. As shown in FIG. 6, the squeeze roller 13Y collects excess carrier liquid C and originally unnecessary fog toner T ″ from the developer D developed on the latent image carrier 10Y, and increases the toner particle ratio in the visible image. The surplus carrier liquid C can be collected in the surface of the first squeeze roller 13aY and the second squeeze roller 14aY with respect to the rotation direction of the first squeeze roller 13aY and the second squeeze roller 14aY and the peripheral speed of the surface of the latent image carrier 10Y. It is possible to set the desired recovery capability according to the relative peripheral speed difference between them, and the recovery capability increases when the latent image carrier 10Y is rotated in the counter direction, and the peripheral speed difference is set large. In addition, the recovery capability is increased, and this synergistic effect is also possible.

  In the present embodiment, as shown in FIG. 6, as an example, the first squeeze roller 13aY and the second squeeze roller 14aY are rotated with respect to the latent image carrier 10Y at substantially the same peripheral speed, and developed to the latent image carrier 10Y. The excess carrier liquid C having a weight ratio of about 5 to 10% is recovered from the developer D to reduce both rotational driving loads and suppress the disturbance effect on the visible toner image of the latent image carrier 10Y. Yes.

  Next, the latent image carrier 10Y passes through the nip portion with the intermediate transfer belt 40 in the primary transfer 50Y, and primary transfer of the visible toner image to the intermediate transfer belt 40 is performed. The primary transfer roller 51Y is applied with about -200 V having the opposite polarity to the charging characteristics of the toner particles, so that the toner is primarily transferred from the latent image carrier 10Y to the intermediate transfer belt 40, and is transferred to the latent image carrier 10Y. Only the carrier liquid remains. On the downstream side in the rotation direction of the latent image carrier 10Y from the primary transfer portion, the latent image carrier 10Y after the primary transfer is erased by the static eliminator 16Y composed of an LED or the like, and the latent image carrier 10Y is placed on the latent image carrier 10Y. The remaining carrier liquid is scraped off by the latent image carrier cleaning blade 17Y and recovered by the developer recovery unit 18Y.

  The toner images on the intermediate transfer belt 40 on which the toner images formed on the plurality of latent image carriers 10 are successively primary-transferred and carried are then transferred to the secondary transfer unit 60 where the intermediate transfer belt 40 and the secondary transfer belt 40 are secondary-transferred. It enters the nip portion with the transfer roller 61. The nip width at this time is 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 driving roller 41, whereby the toner image on the intermediate transfer belt 40 is a recording medium such as paper. Transferred to (sheet material).

  However, when a sheet material supply trouble such as a jam occurs, not all toner images are transferred to the secondary transfer roll and collected, and a part of the toner image remains on the intermediate transfer belt. Even during the transfer process, the toner image on the intermediate transfer belt is not 100% secondary transferred and transferred to the sheet material, and a secondary transfer residue of several percent occurs. In particular, when a sheet material supply trouble such as a jam occurs, the toner image is transferred in contact with the secondary transfer roller 61 without the sheet material interposed, and the back surface of the sheet material is stained.

  In the present embodiment, the carrier liquid is recovered (squeezed) on the secondary transfer roller 61 side with respect to these unnecessary toner images, and the intermediate transfer belt cleaning blade 46 and the developer recovery unit 47 clean the intermediate transfer belt 40. The secondary transfer roller 61 is cleaned by the secondary transfer roller cleaning blade 62.

  Next, the circulation path of the liquid developer of this embodiment will be described. FIG. 7 is a schematic cross-sectional view showing a part of the developing unit 30Y and the developer collecting and supplying device 70Y. The developing unit 30Y and the developer recovery and supply device 70Y form a circulation path by the supply unit 31aY and the recovery unit 31bY of the developer container 31Y, the development unit recovery path 72Y, the liquid developer storage part 71Y, and the developer supply path 81Y. ing.

  In this circulation path, the liquid developer is recovered in the recovery part 31bY of the developer container 31Y, and is recovered by the recovery auger 34Y in the liquid developer storage part 71Y via the development unit recovery path 72Y. The liquid developer collected in the liquid developer reservoir 71Y is replenished with a high-concentration developer from the developer tank 74Y and a carrier liquid from the carrier liquid tank 77Y, and is stored by being driven by a reservoir agitating motor 71aY or the like. The density is adjusted by the part stirring member 71bY. The liquid developer whose density has been adjusted is supplied to the supply portion 31aY of the developer container 31Y via the developer supply path 81Y and the developer supply pump 82Y.

  As shown in FIG. 7, the developing container 31Y of this embodiment is provided with a liquid level adjusting plate 37Y as a partition between the supply unit 31aY and the recovery unit 31bY. The liquid level adjusting plate 37Y can adjust the amount of the liquid developer that moves from the supply unit 31aY to the recovery unit 31bY beyond the liquid level adjusting plate 37Y.

  Here, the amount of the liquid developer supplied from the liquid developer storage unit 71Y to the supply unit 31aY of the developer container 31Y is A, and the developing roller from the supply unit 31aY of the developer container 31Y via the developer supply roller 32Y. The amount of liquid developer applied to 20Y is B. Of the liquid developer supplied to the developing roller 20Y from the supply portion 31aY of the developer container 31Y via the developer supply roller 32Y, the latent image carrier 10Y The amount of the liquid developer used for developing the latent image is C, and among the liquid developers supplied from the supply unit 31aY of the developer container 31Y to the developing roller 20Y via the developer supply roller 32Y, the developing roller cleaning blur is set. -The amount of the liquid developer recovered by the recovery unit 31bY of the developer container 31Y by the nozzle 21Y is transferred from the supply unit 31aY to the recovery unit 31bY beyond the liquid level adjustment plate 37Y. When the amount of the liquid developer is X, the amount of the liquid developer is recovered to the liquid developer reservoir 71Y is, X = A-B, from D = B-C, the X + D = A-C.

  The concentration of the liquid developer in the liquid developer reservoir 71Y may change abruptly depending on the amount and concentration of the liquid developer collected in the liquid developer reservoir 71Y. In the present embodiment, the concentration of the liquid developer collected in the liquid developer reservoir 71Y is made as close as possible to the concentration in the liquid developer reservoir 71Y so that the liquid developer in the liquid developer reservoir 71Y Reduce sudden changes in concentration. For this reason, in the present embodiment, the recovery unit from the supply unit 31aY in accordance with the image line rate as an example of image information having a large correspondence with the amount C of the liquid developer used for developing the latent image on the latent image carrier 10Y. The amount X of liquid developer that moves beyond the liquid level adjusting plate 37Y to 31bY is adjusted.

  Here, the image line rate is the number of dots to be printed with respect to the total number of dots included in one page (the total number of dots to be printed and the number of dots not to be printed). In the present embodiment, calculation can be performed by a CPU or the like inside the image forming apparatus or an external calculator. The calculation of the image line ratio is executed in units of one page of paper such as one page of A3 size paper or one page of A4 size paper. Note that it is also possible to calculate the amount of used developer by accumulating the image area ratio and to estimate the amount of liquid developer in the developer reservoir 71Y.

  FIG. 8 is a graph showing the relationship between the image line rate and the amount D of the liquid developer collected in the collecting unit 31bY of the developer container 31Y by the developing roller cleaning blade 21Y, and FIG. 6 is a graph showing the relationship between the concentration of liquid developer recovered by the recovery unit 31bY of the developer container 31Y by the roller cleaning blade 21Y. However, the amount B of the liquid developer applied from the supply part 31aY of the developer container 31Y to the developing roller 20Y via the developer supply roller 32Y is 30 g / min, the liquid developer reference concentration is 20%, and the carrier liquid amount 20 g / min, solid content 6 g / min.

  As shown in FIG. 8, when the image line ratio is increased, the amount of liquid developer recovered by the recovery roller 31bY of the developer container 31Y by the developing roller cleaning blade 21Y decreases substantially linearly. Further, as shown in FIG. 9, when the image area ratio is increased, the concentration of the liquid developer recovered in the recovery unit 31bY of the developer container 31Y by the developing roller cleaning blade 21Y decreases.

  In the present embodiment, the control is performed so that the amount X of the liquid developer that moves from the supply unit 31aY to the recovery unit 31bY beyond the liquid level adjusting plate 37Y increases as the image line ratio increases. By controlling in this way, it is possible to bring the concentration of the liquid developer collected in the liquid developer storage portion 71Y closer to the concentration of the liquid developer originally stored in the liquid developer storage portion 71Y. .

  FIG. 10 is a graph showing the amount X of the liquid developer that moves from the supply unit 31aY to the recovery unit 31bY according to the image line rate of the embodiment. FIG. 11 shows the image line rate and the recovery unit 31bY in the example of FIG. 10 is a graph showing a change in the concentration of the liquid developer recovered from the liquid developer storage unit 71Y.

  For example, in this embodiment, the control is set so as to correspond to FIG. 8, and as shown in FIG. 10, it is collected in the collecting unit 31bY of the developer container 31Y by the image line ratio and the developing roller cleaning blade 21Y. From the recovery unit 31bY, the amount D of the liquid developer to be added and the amount X of the liquid developer that moves over the liquid level adjusting plate 37Y from the supply unit 31aY to the recovery unit 31bY according to the image line ratio of the embodiment are added. The amount of the liquid developer collected in the liquid developer reservoir 71Y is made constant.

  By controlling the amount of the liquid developer that moves beyond the liquid level adjusting plate 37Y from the supply unit 31aY to the recovery unit 31bY in accordance with the image line rate, the image line rate increases as shown in FIG. Even in this case, the decrease in the concentration of the liquid developer recovered from the recovery unit 31bY to the liquid developer storage unit 71Y is reduced, and the rapid change in the concentration of the liquid developer in the liquid developer storage unit 71Y is reduced. Can do.

  Next, a specific structure for controlling the amount of liquid developer that moves from the supply unit 31aY to the recovery unit 31bY beyond the liquid level adjustment plate 37Y according to the image line ratio will be described.

  12 is a cross-sectional view showing the first embodiment, FIG. 13 is a cross-sectional view of the first embodiment viewed from a direction orthogonal to FIG. 12, and FIG. 14 is a block diagram of the first embodiment.

  As shown in FIGS. 12 and 13, in the first embodiment, the liquid developer is pumped up from the liquid developer reservoir 71Y shown in FIG. 7 by the developer supply pump 82Y, and the developer supply path 81Y and the communication portion are connected. 35Y is supplied to the supply part 31aY of the developer container 31Y. The communication portion 35Y is provided at a substantially central portion in the axial direction, and the liquid developer supplied to the supply portion 31aY spreads from the substantially central portion in the axial direction to both ends by the rotation of the stirring auger 36Y as indicated by an arrow. .

  A liquid level adjustment plate 37Y is provided between the supply unit 31aY and the recovery unit 31bY, and a first low wall portion 37aY and a second low wall portion 37bY as moving portions are provided on the end side of the liquid level adjustment plate 37Y. Is provided. When the amount of the liquid developer in the supply part 31aY increases, the liquid developer moves to the recovery part 31bY over the first low wall part 37aY and the second low wall part 37bY. In the collection unit 31bY, the liquid developer is conveyed to the development unit collection path 72Y by the rotation of the collection auger 34Y, and is collected in the liquid developer storage unit 71Y illustrated in FIG. 7 via the development unit collection path 72Y.

In the first embodiment, an overflow plate 137Y as an overflow member is provided on the first low wall portion 37aY and the second low wall portion 37bY so that the height can be adjusted. The overflow plate 137Y has a plate-like portion 137aY, and a moving shaft 137bY having one end side provided on the plate-like portion 137aY and a rack portion 137cY formed on the other end side. The overflow plate 137Y is driven by an overflow plate drive motor 138Y as an overflow member moving means having a pinion gear 138aY that meshes with the rack portion 137cY, and is movable in the vertical direction. A restraining spring 139Y is installed below the overflow plate 137Y between the developer container 31Y and the overflow plate 137Y.

In such a structure, in the first embodiment, as described above, the height of the overflow plate 137Y is adjusted according to the line drawing rate. As shown in FIG. 14, when print data is transmitted from a personal computer 101 or the like, the data is temporarily stored in the buffer memory 111 in the printer 110, and a signal is transmitted to the CPU 112 as a determination unit. The CPU 112 calculates the line drawing rate from the transmitted signal, obtains the height of the overflow plate 137Y requested from the line drawing rate, and instructs the motor drive circuit 113 to determine the correction amount from the current height of the overflow plate 137Y. To do. The motor drive circuit 113 drives the overflow plate 137Y to a predetermined height by the overflow plate drive motor 138Y. Note that at least one of the CPU 112, the motor drive circuit 113, the overflow plate drive motor 138Y, and the overflow plate 137Y adjusts the amount of liquid developer that moves the liquid level adjustment plate 37Y based on the determination of the CPU 112. Configure.

  As a result, the overflow plate 137Y adjusts the height of the first low wall portion 37aY and the second low wall portion 37bY, and from the supply portion 31aY to the recovery portion 31bY, the first low wall portion 37aY and the first low wall portion 37aY of the liquid level adjustment plate 37Y. 2 It is possible to control the amount of the liquid developer that moves beyond the low wall portion 37bY.

  In the first embodiment, the liquid level adjusting plate 37Y is provided with the first low wall portion 37aY and the second low wall portion 37bY, but instead of the first low wall portion 37aY and the second low wall portion 37bY, an opening is provided. And the liquid developer may move in the opening. At that time, the overflow plate 137Y is disposed at a position where the opening can be opened and closed, and the amount of the liquid developer moving from the supply unit 31aY to the recovery unit 31bY can be controlled by adjusting the opening area.

  Next, Example 2 will be described. 15 is a cross-sectional view showing the second embodiment, FIG. 16 is a cross-sectional view of the second embodiment when viewed from a direction orthogonal to FIG. 15, and FIG. 17 is a block diagram of the second embodiment.

  As shown in FIGS. 15 and 16, in the second embodiment, the liquid developer is pumped up from the liquid developer storage unit 71Y shown in FIG. 7 by the developer supply pump 82Y, and the developer supply path 81Y and the communication unit are connected. 35Y is supplied to the supply part 31aY of the developer container 31Y. The communication portion 35Y is provided at a substantially central portion in the axial direction, and the liquid developer supplied to the supply portion 31aY spreads from the substantially central portion in the axial direction to both ends by the rotation of the stirring auger 36Y as indicated by an arrow. .

  A liquid level adjusting plate 37Y is provided between the supply unit 31aY and the recovery unit 31bY. When the amount of the liquid developer in the supply unit 31aY increases, the liquid developer moves over the liquid level adjusting plate 37Y to the recovery unit 31bY. In the collection unit 31bY, the liquid developer is conveyed to the development unit collection path 72Y by the rotation of the collection auger 34Y, and is collected in the liquid developer storage unit 71Y illustrated in FIG. 7 via the development unit collection path 72Y.

  In the second embodiment, an overflow amount control screw 237Y as an overflow amount control member is provided in the supply unit 31aY near the liquid level adjusting plate 37Y. The overflow amount control screw 237Y rotates by driving an overflow amount control screw drive motor 238Y as an overflow amount control screw drive means.

In such a structure, in the second embodiment, as described above, the number of rotations of the overflow amount control screw 237 is adjusted according to the image line rate. As shown in FIG. 17, when print data is transmitted from a personal computer 101 or the like, the data is temporarily stored in the buffer memory 111 in the printer 110, and a signal is transmitted to the CPU 112 as a determination unit. The CPU 112 calculates the line drawing rate from the transmitted signal, obtains the number of rotations of the overflow amount control screw 237 requested from the line drawing rate, and drives the correction amount from the current number of rotations of the overflow amount control screw 237 to drive the motor. Instruct the circuit 113. The motor drive circuit 113 drives the overflow amount control screw 237 at a predetermined rotational speed by the overflow amount control screw drive motor 238Y. Note that at least one of the CPU 112, the motor drive circuit 113, the overflow amount control screw drive motor 238Y, and the overflow amount control screw 237 determines the amount of liquid developer that moves the liquid level adjustment plate 37Y based on the determination of the CPU 112. An adjustment unit to be adjusted is configured.

  As a result, the overflow amount control screw 237 can control the amount of liquid developer that moves beyond the liquid level adjusting plate 37Y from the supply unit 31aY to the recovery unit 31bY by adjusting the rotational speed.

  Next, Example 3 will be described. 18 is a cross-sectional view showing the third embodiment, FIG. 19 is a cross-sectional view of the third embodiment when viewed from a direction orthogonal to FIG. 18, and FIG. 20 is a block diagram of the third embodiment.

  As shown in FIGS. 18 and 19, in the third embodiment, the liquid developer is pumped up from the liquid developer reservoir 71Y shown in FIG. 7 by the developer supply pump 82Y, and the developer supply path 81Y and the communication portion are connected. 35Y is supplied to the supply part 31aY of the developer container 31Y. The communication portion 35Y is provided at a substantially central portion in the axial direction, and the liquid developer supplied to the supply portion 31aY spreads from the substantially central portion in the axial direction to both ends by the rotation of the stirring auger 36Y as indicated by an arrow. .

  A liquid level adjustment plate 37Y is provided between the supply unit 31aY and the recovery unit 31bY, and a first low wall portion 37aY and a second low wall portion 37bY as moving portions are provided on the end side of the liquid level adjustment plate 37Y. Is provided. When the amount of the liquid developer in the supply part 31aY increases, the liquid developer moves to the recovery part 31bY over the first low wall part 37aY and the second low wall part 37bY. In the collection unit 31bY, the liquid developer is conveyed to the development unit collection path 72Y by the rotation of the collection auger 34Y, and is collected in the liquid developer storage unit 71Y illustrated in FIG. 7 via the development unit collection path 72Y.

  In the third embodiment, the stirring auger 36Y is applied as an overflow amount control member without particularly increasing the number of members, and the rotational speed of the stirring auger 36Y is controlled. As shown in FIG. 19, the stirring auger 36Y sets the direction of the screw so as to convey the liquid developer supplied into the supply part 31aY from the substantially central part in the axial direction through the connecting part 35Y toward both end parts. doing. Further, a first low wall portion 37aY and a second low wall portion 37bY are provided as moving portions on the end side of the liquid level adjusting plate 37Y.

  Therefore, if the rotation speed of the stirring auger 36Y is increased, the amount of the liquid developer in the supply unit 31aY conveyed toward both ends increases, and the first low wall portion 37aY and the second low wall portion 37aY are supplied from the supply unit 31aY. The liquid developer that moves over the wall portion 37bY to the recovery portion 31bY can be increased. Conversely, if the rotation speed of the agitating auger 36Y is decreased, the amount of the liquid developer in the supply unit 31aY conveyed toward both ends is reduced, and the first low wall portion 37aY and the supply unit 31aY are reduced. The liquid developer that moves beyond the second low wall portion 37bY to the recovery portion 31bY can be reduced. The stirring auger 36Y rotates by driving the stirring auger drive motor 338Y.

In such a structure, in the third embodiment, as described above, the rotation speed of the stirring auger 36Y is adjusted. As shown in FIG. 20, when print data is transmitted from a personal computer 101 or the like, the data is temporarily stored in the buffer memory 111 in the printer 110, and a signal is transmitted to the CPU 112 as a determination unit. The CPU 112 calculates the line drawing rate from the transmitted signal, obtains the requested rotation speed of the stirring auger 36Y from the image drawing ratio, and instructs the motor drive circuit 113 of the correction amount from the current rotation speed of the stirring auger 36Y. To do. The motor drive circuit 113 drives the stirring auger 36Y to a predetermined rotational speed by the stirring auger drive motor 338Y. Note that at least one of the CPU 112, the motor driving circuit 113, the stirring auger driving motor 338Y, and the stirring auger 36Y adjusts the amount of liquid developer that moves the liquid level adjusting plate 37Y based on the determination of the CPU 112. Configure.

  As a result, the agitating auger 36Y adjusts the number of rotations of the liquid developer that moves from the supply unit 31aY to the recovery unit 31bY beyond the first low wall portion 37aY and the second low wall portion 37bY of the liquid level adjusting plate 37Y. The amount can be controlled.

  In the third embodiment, the first low wall portion 37aY and the second low wall portion 37bY are provided on the liquid level adjusting plate 37Y. However, instead of the first low wall portion 37aY and the second low wall portion 37bY, an opening is provided. And the liquid developer may move in the opening.

As described above, in the image forming method of the present embodiment, the latent image carrier 10Y that carries the latent image, the charger 11Y that charges the latent image carrier 10Y, and the latent image carrier 10Y are exposed and exposed. an exposure unit 12Y that forms a toner and a developing roller 20Y that carries liquid developer containing a carrier liquid, spiral has a groove developing roller 20Y developer supplying roller for supplying the liquid developer to 32Y, the developing roller A developing roller cleaning blade 21Y for cleaning the liquid developer on 20Y , and a developer container 31Y for storing the liquid developer , and a developing unit 30Y for developing the latent image formed on the latent image carrier 10Y; includes an intermediate transfer belt 40 on which the image developed on the image carrier 10Y is transferred, a CPU112 for determining an image information, a developer container 31Y is a developer supplying roller 32Y Supply section 31aY for reserving the liquid developer supplied to the developing roller 20Y, is provided between the recovery section 31bY for recovering the liquid developer collected by the developing roller cleaning blade 21Y, and a supply section 31aY and collection section 31bY, Since the liquid developer has a liquid level adjusting plate 37Y to which the liquid developer can move and the amount of the liquid developer that moves the liquid level adjusting plate 37Y is adjusted based on the determination of the CPU 112, there is no need to make a significant configuration change. It is possible to increase the uniformity of the concentration of the liquid developer in the developer container 31Y and the like, and to provide an image forming method with good image quality and low cost.

  Further, the CPU 112 is a means for comparing a predetermined value that is determined in advance with the image line rate of the print image. When the image line rate of the print image is larger than the predetermined value, the liquid level adjusting plate 37Y is moved. Since the amount of the liquid developer that moves is increased, it is possible to increase the uniformity of the concentration of the liquid developer in the recovery unit 31bY.

Further, in the image forming apparatus of the present invention, the latent image carrier 10Y that carries the latent image, the charger 11Y that charges the latent image carrier 10Y, and the exposure that forms the latent image by exposing the latent image carrier 10Y. Cleaning unit 12Y, developing roller 20Y carrying a liquid developer containing toner and carrier liquid, developer supply roller 32Y having a spiral groove and supplying the liquid developer to the developer carrying member, and developing roller 20Y The developing roller cleaning blade 21Y, the supply unit 31aY for storing the liquid developer supplied to the developing roller 20Y by the developer supply roller 32Y, the recovery unit 31bY for storing the liquid developer recovered by the developing roller cleaning blade 21Y, and the supply The liquid developer is moved from the supply part 31aY to the recovery part 31bY while partitioning between the part 31aY and the recovery part 31bY A developing unit 30Y having a position adjusting plate 37Y for developing the latent image formed on the latent image carrier 10Y; a liquid developer storing unit 71Y for storing a liquid developer for supplying the liquid developer to the supplying unit 31aY; The intermediate transfer belt 40 onto which the developed image is transferred to the latent image carrier 10Y, the CPU 112 that determines image information, and the amount of liquid developer that moves the liquid level adjusting plate 37Y is adjusted based on the determination of the CPU 112. Therefore, it is not necessary to make a significant change in the configuration, and with a simple configuration, the uniformity of the concentration of the liquid developer in the developer container or the like is increased, and image formation with good image quality and low cost is achieved. An apparatus can be provided.

Further, the liquid level adjusting plate 37Y has an overflow plate 137Y that moves in the vertical direction and an overflow plate drive motor 138Y that moves the overflow plate 137Y in the vertical direction, and the adjustment unit moves the overflow plate 137Y in the vertical direction by the drive motor 138Y. is performed by moving the, there is no need to make significant configuration changes, the higher the uniformity of the concentration of the liquid developer in the developer container 31Y or the like with a simple configuration, the image quality good, low-cost image forming apparatus Can be provided.

Also, an agitation auger 36Y that agitates the liquid developer stored in the supply unit 31aY and disposed in the supply unit 31aY, and an overflow amount that controls the amount of liquid developer that is disposed in the supply unit 31aY and moves on the liquid level adjusting plate 37Y. A control screw 237Y and an overflow amount control screw drive motor 238Y that drives the overflow amount control screw 237Y, and the adjustment unit drives the overflow amount control screw drive motor 238Y to move the liquid level adjustment plate 37Y. Since the amount of the developer is adjusted, it is not necessary to make a significant change in the configuration, and with a simple configuration, the uniformity of the concentration of the liquid developer in the developer container 31Y and the like is increased, and the image quality is good and the cost is low. A forming apparatus can be provided.

In addition, a stirring auger 36Y that conveys the liquid developer stored in the supply unit 31aY from the center to both axial ends, and a stirring auger drive motor 338Y that drives the stirring auger 36Y are provided. The liquid level adjusting plate 37Y has a first low wall portion 37aY and a second low wall portion 37bY that move the liquid developer from the supply portion 31aY to the recovery portion 31bY on both end sides in the axial direction. Since the amount of liquid developer that moves the liquid level adjusting plate 37Y is adjusted by driving the agitating auger drive motor 338Y that drives the auger 36Y, there is no need to make a significant configuration change, and the developer container 31Y has a simple configuration. It is possible to provide a low-cost image forming apparatus with high image quality and uniformity of the concentration of the liquid developer .

The liquid developer collected by the squeeze units 13Y and 14Y is recovered by squeezing the latent image carrier 10Y developed by the developing unit 30Y to collect the liquid developer. since recovered in part 31bY, the developing roller cleaning blade 21Y made liquid developer tends to flow on the surface, because there is no need for additional members such as for the miniaturization of the apparatus, it is possible to reduce costs.

1 is a diagram illustrating an embodiment of an image forming apparatus. FIG. 3 is a cross-sectional view showing the main components of the periphery of the latent image carrier and the developing unit. It is a perspective view of a developer supply member. It is a figure explaining compression of the developer by a developer compression device. It is a figure explaining development by a development roller. It is a figure explaining the squeeze effect | action by a squeeze roller. It is a schematic sectional drawing which shows a developing unit and a circulation path. 6 is a graph showing the relationship between the image line ratio and the amount of liquid developer recovered in the recovery portion of the developer container by the developing roller cleaning blade. 6 is a graph showing a relationship between an image line ratio and a concentration of a liquid developer collected in a collecting unit of a developer container by a developing roller cleaning blade. It is a graph which shows the quantity X of the liquid developer which moves to the collection | recovery part from the supply part according to the image line rate of the Example. FIG. 11 is a graph showing a change in image density and a concentration of liquid developer recovered from the recovery unit to the liquid developer storage unit in the example of FIG. 10. 1 is a diagram illustrating Example 1. FIG. 1 is a diagram illustrating Example 1. FIG. 1 is a block diagram of Example 1. FIG. FIG. 6 is a diagram showing Example 2. FIG. 6 is a diagram showing Example 2. 6 is a block diagram of Embodiment 2. FIG. FIG. 6 is a diagram showing Example 3. FIG. 6 is a diagram showing Example 3. 10 is a block diagram of Example 3. FIG.

Explanation of symbols

10Y, 10M, 10C, 10K ... photosensitive body (latent image carrier), 11Y, 11M, 11C, 11K ... charger, 12Y, 12M, 12C, 12K ... exposure unit (exposure unit) , 13Y ... first squeeze unit , 13aY ... first squeeze roller, 13bY ... first squeeze roller cleaning blade, 14Y ... second squeeze section , 14aY ... second squeeze roller, 14bY ... second squeeze roller cleaning blade, 16Y ... static elimination device, 17Y ... latent image carrier Blade, 18Y ... latent image carrier cleaning liquid recovery section, 20Y, 20M, 20C, 20K ... developing roller (developer carrier), 21Y ... developing roller cleaning blade (developer carrier cleaning member), 22Y ... developer compression Apparatus, 30Y, 30M, 30C, 30K ... Developing unit (developing unit ) , 31Y, 31M, 31C, 31K ... developer container, 31aY ... supply unit, 31bY ... collection unit, 32Y, 32M, 32C, 32K ... developer supply roller (developer supply member), 33Y ... developer regulating blade, 34Y ... collecting auger, 35Y ... communicating portion, 36Y ... stirring auger (stirring member), 37Y ... liquid level adjusting plate (partition portions), 50Y, 50M, 50C, 50K ... primary transfer backup roller, 40 ... intermediate transfer belt (transcription Member), 41 ... belt drive roller, 42 ... tension roller, 46 ... intermediate transfer belt cleaning blade, 47 ... intermediate transfer belt cleaning liquid recovery unit, 50 ... primary transfer unit, 51 ... primary transfer roller, 60 ... secondary transfer unit 61 ... secondary transfer roller, 62 ... secondary transfer roller blade, 63 ... secondary transfer roller cleaning liquid recovery section, 70Y Developer collecting and replenishing device, 71Y ... Liquid developer reservoir, 72Y ... Developing unit collecting path (developing device collecting path), 73Y ... Latent image carrier collecting path, 74Y ... Developer tank, 75Y ... Developer replenishing path, 76Y ... Developer pump, 77Y ... Carrier liquid tank, 78Y ... Carrier liquid supply path, 79Y ... Carrier liquid pump, 81Y ... Developer supply path, 82Y ... Developer supply pump, 112 ... CPU (discriminating means), 137Y ... overflow plate (overflow member), 138Y ... overflow plate driving motor (overflow member moving means), 237Y ... overflow quantity control screw (overflow quantity control member), 238Y ... overflow quantity control screw drive motor (overflow quantity control member Driving means) 338Y: Stirring auger driving motor (stirring member driving means)

Claims (7)

A latent image carrier for carrying a latent image;
A charger for charging the latent image carrier;
An exposure unit that exposes the latent image carrier to form the latent image ;
A developer carrying member carrying a liquid developer containing toner and carrier liquid, a developer supply member having a spiral groove and supplying the liquid developer to the developer carrying member, and cleaning the developer carrying member. A developer carrying member cleaning member, and a developer container for storing a liquid developer, and a developing unit for developing the latent image formed on the latent image carrier;
A transfer member which the developed image on the latent image bearing member is transferred,
Comprising a discriminating means for discriminating the images information, and
The developer container, the recovery unit where the developer supplying member for recovering the developer supply unit for storing the liquid developer to be supplied to the bearing member, the liquid developer collected by the developer carrier cleaning member, and the liquid developer is provided between the supply portion and the recovery unit has a partition portion movable,
An image forming method comprising adjusting the amount of the liquid developer that moves the partition based on the determination by the determination unit. The discriminating means is a means for comparing a predetermined value determined in advance with the image line rate of the print image, and moves the partition when the image line rate of the print image is larger than the predetermined value. the image forming method according to 請 Motomeko 1 you increase the amount of the liquid developer. A latent image carrier for carrying a latent image;
A charger for charging the latent image carrier;
An exposure unit that exposes the latent image carrier to form the latent image;
A developer carrying member carrying a liquid developer containing toner and carrier liquid, a developer supply member having a spiral groove and supplying the liquid developer to the developer carrying member, and cleaning the developer carrying member. A developer carrier cleaning member, a supply unit for storing the liquid developer supplied to the developer carrier by the developer supply member, a recovery unit for storing the liquid developer recovered by the developer carrier cleaning member, And developing the latent image formed on the latent image carrier having a partition that partitions the supply unit and the recovery unit and moves the liquid developer from the supply unit to the recovery unit. And
A liquid developer storage section for storing a liquid developer for supplying the liquid developer to the supply section;
A transfer member onto which the developed image is transferred to the latent image carrier;
Discriminating means for discriminating image information;
An adjustment unit that adjusts the amount of liquid developer that moves the partition based on the determination by the determination unit;
An image forming apparatus comprising: An overflow plate that moves in the vertical direction in the partition; and overflow member moving means for moving the overflow plate in the vertical direction;
The image forming apparatus according to claim 3, wherein the adjustment unit is configured to move the overflow plate in a vertical direction by the overflow plate moving unit. A stirring member that is disposed in the supply unit and stirs the liquid developer stored in the supply unit;
An overflow amount control member that controls the amount of liquid developer that is disposed in the supply unit and moves through the partition unit;
Overflow amount control member driving means for driving the overflow amount control member;
Have
The image forming apparatus according to claim 3, wherein the adjustment unit adjusts an amount of the liquid developer that moves the partition unit by driving an overflow amount control member driving unit. A stirring member that is arranged in the supply unit and conveys the liquid developer stored in the supply unit from the central part to both ends in the axial direction;
A stirring member driving means for driving the stirring member,
The partition unit has a moving unit that moves the liquid developer from the supply unit to the collection unit on both ends in the axial direction.
The image forming apparatus according to claim 3, wherein the adjustment unit adjusts the amount of liquid developer that moves the partition unit by driving a stirring member driving unit that drives the stirring member. A squeeze part for squeezing the latent image carrier developed in the development part to recover the liquid developer,
The image forming apparatus according to claim 3, wherein the liquid developer collected by the squeeze unit is collected by the collection unit.

Images