JP2012159645A - Wet type image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wet type image formation device capable of shortening time required for adjusting density.SOLUTION: In a developer adjustment section, a high density adjustment liquid tank 55 and a low density adjustment liquid tank 56 respectively have temperature adjustment means 73 and 74 as means to adjust temperatures. The temperature adjustment means 73 and 74 adjust the temperatures of the high density adjustment liquid and the low density adjustment liquid equal to or almost equal to the temperature of liquid developer inside a density adjustment tank 51 based on temperatures measured by thermometers 70, 71 and 72. By adjusting the temperatures of the high density adjustment liquid and the low density adjustment liquid equal to or almost equal to the temperature of liquid developer inside the density adjustment tank 51, an abrupt temperature fluctuation inside the density adjustment tank 51 can be restrained when supplying the density adjustment tank 51 with the high density adjustment liquid or the low density adjustment liquid.

Description

  The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly to a wet image forming apparatus that forms a toner image using a liquid developer.

  An electrophotographic image forming apparatus that forms an electrostatic latent image on a photoconductor (photosensitive drum), attaches toner to the photoconductor, and transfers and fixes the image onto paper or the like is a copying machine, an MFP (multifunctional printer), Widely used in FAX, printers, etc. In these image forming apparatuses, conventionally, a dry development method using a powder toner and a wet development method using a liquid developer have been generally used.

  However, in image forming apparatuses that require higher image quality and higher resolution, such as office printers for large-scale printing and on-demand printing apparatuses, the toner particle diameter is smaller than that of the dry development method using powder toner. A wet development method using a liquid developer that is less likely to be disturbed has been used.

  Particularly in recent years, a high-viscosity, high-concentration liquid developer is used, which is composed by dispersing toner as a solid content composed of a resin and a pigment in an insulating liquid (carrier liquid) such as silicon oil at a high concentration. Image forming apparatuses have been proposed.

  When developing using this liquid developer, a thin layer of developer is formed on a developer carrier such as a developing roller, and the thinned developer is brought into contact with the photoreceptor. It is desirable to develop. This is particularly conspicuous when a high viscosity liquid developer as described above is used.

  Thus, when developing with a thin layer of liquid developer, in order to stabilize the image density, it becomes an important issue to form a uniform thin layer with a constant concentration of developer. In general, the liquid developer remains on the developing roller even after the latent image on the photosensitive member is developed. If this reaches the developing area again in the state as it is, it adversely affects the next development. In order to cope with such a problem, a technique for cleaning the developer on the developing roller remaining after development has been developed. The remaining developer on the developing roller is generally scraped off with a blade that is in contact with the developing roller.

  However, since the developer collected from the developing roller accumulates, a storage container is required even if the developer is collected and discarded. Therefore, a technique has been proposed in which such a container is not required by reusing the collected developer, and the developer can be effectively used.

  However, the developer used for development is a high-concentration developer, but after developing the latent image on the image carrier, a considerable part of the toner is consumed, so the density of the residual developer changes. There are many cases. If this is poured into the developer tank as it is, the concentration of the developer in the developer tank changes, and it becomes difficult to ensure a predetermined concentration. In order to deal with these problems, before the collected developer is poured into the developer tank, the developer for density adjustment (such as high-density developer or low-density developer) is supplied and collected in the density adjustment tank. A technique for adjusting the developer density has been proposed (Patent Document 1).

JP 2008-209716 A

  When adjusting the recovered liquid developer to a desired toner concentration in the concentration adjustment tank, the developer for adjusting the concentration (high concentration developer) or the carrier liquid (low concentration developer) is supplied while measuring the toner concentration. The target value is adjusted.

  However, when the temperature difference between the collected developer in the density adjustment tank and the developer for density adjustment is large, if the developer for density adjustment is supplied, the temperature may fluctuate rapidly in the density adjustment tank. There is sex. At the time of toner density adjustment, the temperature of the liquid in the density adjustment tank is measured and the target current value (load torque) is corrected. Therefore, there is a problem that the density detection accuracy decreases due to temperature fluctuation. As a result, the toner density falls outside the target toner density range, and density adjustment is required again, which increases the time required for density adjustment.

  Further, the viscosity changes due to the temperature fluctuation of the developer for concentration adjustment, and the supply amount fluctuates, so there is a problem that the density adjustment accuracy is lowered, and it takes time to reach the target toner density range. There was also a problem.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a wet image forming apparatus capable of shortening the time required for density adjustment.

  A wet image forming apparatus according to an aspect of the present invention includes a density adjustment tank that contains a liquid developer for density adjustment, a developer temperature measuring unit that measures the temperature of the liquid developer contained in the density adjustment tank, and a density Concentrated liquid tank containing at least two kinds of concentration adjusting liquids for adjustment, adjusted liquid temperature measuring means for measuring the temperature of the concentrated liquid stored in the concentrated liquid tank, and stored in the concentrated liquid tank A toner concentration adjusting means for supplying the concentration adjusting liquid from the concentration adjusting liquid tank to the concentration adjusting tank to measure the toner concentration of the liquid developer and adjusting the toner concentration to a desired toner concentration; The temperature of the liquid developer stored in the density adjusting tank measured by the developer temperature measuring means and the temperature of the density adjusting liquid measured by the adjusting liquid temperature measuring means and supplied by the toner density adjusting means are approximately. Adjust to be the same And a temperature adjustment means because.

  Preferably, the temperature adjusting unit adjusts the temperature of the concentration adjusting liquid stored in the concentration adjusting liquid tank so as to be the temperature of the liquid developer stored in the concentration adjusting tank.

  In particular, the temperature adjusting means is provided in a path for supplying the concentration adjusting liquid stored in the concentration adjusting liquid tank to the concentration adjusting tank.

  Preferably, the temperature adjusting means adjusts the temperature of the liquid developer accommodated in the concentration adjusting tank so as to be the temperature of the concentration adjusting liquid accommodated in the concentration adjusting liquid tank.

  Preferably, the temperature adjusting unit adjusts the temperature of the liquid developer stored in the concentration adjusting tank and the concentration adjusting liquid stored in the concentration adjusting liquid tank to a desired temperature.

  Preferably, the temperature adjustment means adjusts the temperature of the liquid developer accommodated in the concentration adjustment tank, and the second temperature adjustment unit adjusts the temperature of the concentration adjustment liquid accommodated in the concentration adjustment liquid tank. The first and second temperature adjustment units so that the temperature of the liquid developer accommodated in the concentration adjustment tank and the concentration adjustment liquid accommodated in the concentration adjustment liquid tank become a desired temperature. adjust.

  A wet image forming apparatus according to another aspect of the present invention includes a density adjustment tank that contains a liquid developer for density adjustment, a density adjustment liquid tank that contains at least two density adjustment liquids for density adjustment, and a density A toner concentration adjusting means for measuring the toner concentration of the liquid developer contained in the adjustment tank and supplying the concentration adjustment liquid from the concentration liquid adjustment tank to the concentration adjustment tank in order to adjust the toner concentration to a desired toner concentration; Prepare. The toner concentration adjusting means includes an adjusting liquid temperature measuring means for measuring the temperature of the concentration adjusting liquid stored in the concentration adjusting liquid tank, and a supplying means for supplying the concentration adjusting liquid from the concentration adjusting liquid tank to the concentration adjusting tank. Including. The supply means supplies the concentration adjustment liquid from the concentration adjustment liquid tank based on the temperature of the concentration adjustment liquid stored in the concentration adjustment liquid measured by the adjustment liquid temperature measurement means when adjusting the toner concentration. To control.

  Preferably, a memory for storing an adjustment table for adjusting a supply amount of the concentration adjustment liquid provided in advance in association with the temperature of the concentration adjustment liquid is provided, and the supply means refers to the adjustment table of the memory, The supply amount for supplying the concentration adjusting liquid is controlled.

  In the wet image forming apparatus according to an aspect of the present invention, when adjusting the toner concentration, the temperature of the liquid developer stored in the density adjusting tank measured by the developer temperature measuring means and the adjustment liquid temperature measuring means are measured. In addition, temperature adjusting means for adjusting the temperature of the density adjusting liquid supplied by the toner density adjusting means to be substantially the same is provided. By this means, it is possible to suppress rapid temperature fluctuations when the concentration adjusting liquid is supplied to the concentration adjusting tank, and it is possible to suppress the decrease in concentration detection accuracy and shorten the time required for concentration adjustment.

It is the schematic explaining the structure of the image formation part in the wet image forming apparatus according to embodiment of this invention. FIG. 6 is a diagram illustrating a configuration of a developer adjusting unit that adjusts a liquid developer supplied to the image forming unit according to the first embodiment of the present invention. FIG. 10 is a flowchart illustrating a density adjustment process of developer adjusting unit 54 according to the first embodiment of the present invention. It is a diagram illustrating a temperature adjusting unit of developer adjusting unit according to the first embodiment of the present invention. It is a figure explaining the temperature adjustment means of the developer adjustment part 54 according to the modification 1 of Embodiment 1 of this invention. It is a figure explaining the temperature adjustment means of the developer adjustment part 54 according to the modification 2 of Embodiment 1 of this invention. It is a figure explaining the temperature adjustment means of the developer adjustment part 54 according to the modification 3 of Embodiment 1 of this invention. It is a figure explaining the temperature adjustment means of the developer adjustment part 54 according to the modification 4 of Embodiment 1 of this invention. It is a figure explaining the temperature adjustment means of the developer adjustment part 54 according to the modification 5 of Embodiment 1 of this invention. It is a figure explaining the temperature adjustment means of the developer adjustment part 54 according to the modification 6 of Embodiment 1 of this invention. It is a flowchart explaining the density adjustment process of the developer adjustment part 54 according to Embodiment 2 of this invention. It is a figure explaining the high concentration adjustment liquid time / temperature table according to Embodiment 2 of this invention. It is a figure explaining the low concentration adjustment liquid time / temperature table according to Embodiment 2 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

(Embodiment 1)
FIG. 1 is a schematic diagram illustrating a configuration of an image forming unit in a wet image forming apparatus according to an embodiment of the present invention. FIG. 1 is a schematic cross-sectional view of an image forming unit in the wet image forming apparatus.

Referring to FIG. 1, the photosensitive drum 1 functions as an image carrier.
The image forming unit 10 has a charging device 2 that uniformly charges the surface of the photosensitive drum 1 disposed around the photosensitive drum 1 around the photosensitive drum 1, and LED light or light on the charged photosensitive drum 1. An exposure device 3 that forms an electrostatic latent image by irradiating a laser beam, a liquid developing device 4 that develops the electrostatic latent image using a liquid developer, and a developed toner image are transferred to a transfer material. The image forming apparatus includes a transfer device 5 and a cleaning device 6 for removing the liquid developer remaining on the surface of the photosensitive drum 1 after the transfer.

  In addition, before and after the liquid developing device 4, it is possible to provide a device for applying or collecting a part of the liquid developer in advance.

  The transfer material may be a recording material such as recording paper as it is, or may be configured such that the transfer material is transferred again to the recording material using an intermediate transfer belt or the like as the transfer material.

  In general, the liquid developing device 4 bears a thin layer of a liquid developer on the surface, a developing roller 41 that develops a latent image on the photosensitive drum 1 that is an image bearing member, and a developing roller 41. A transfer roller 42 for transferring the liquid developer whose liquid amount is adjusted to the surface thereof, and a supply roller 43 for contacting the transfer roller 42 and supplying the liquid developer 8 in the developer tank 44 to the surface thereof. Including.

  The supply roller 43 is provided with a regulating blade 45 for regulating the amount of pumping up the liquid developer 8. The developing roller 41 is provided with a cleaning device 46 for removing the liquid developer remaining after being developed on the photosensitive drum 1.

  In FIG. 1, only one liquid developing device 4 is disposed, but a plurality of liquid developing devices 4 may be disposed for color image formation. Further, the color development method, the presence / absence of intermediate transfer, and the like may be arbitrarily set, and an arbitrary arrangement according to the configuration can be taken.

  The photosensitive drum 1 rotates in the direction of the arrow shown in FIG. 1, and the charging device 2 charges the surface of the rotating photosensitive drum 1 to about several hundred volts by corona discharge or the like.

  On the downstream side of the charging device 2 in the rotation direction of the photosensitive drum 1, an electrostatic latent image having a surface potential lowered to about 100 V or less is formed by the laser beam emitted from the exposure device 3.

  A liquid developing device 4 is disposed further downstream of the exposure device 3, and the electrostatic latent image formed on the photosensitive drum 1 is developed using the liquid developer 8.

  In the liquid developing device 4, a liquid developer 8 in which toner is dispersed in an insulating solvent (hereinafter also referred to as carrier liquid) is accommodated in a developer tank 44, and the surface of the conveying roller 42 is supplied by a supply roller 43. Is supplied with a liquid developer 8. The conveying roller 42 conveys a thin layer of the liquid developer 8 and transfers it to the developing roller 41.

  A thin layer of the liquid developer 8 is carried on the developing roller 41. Further, due to the potential difference between the developing roller 41 and the electrostatic latent image on the photosensitive drum 1, the toner particles in the thin layer of the liquid developer 8 carried on the developing roller 41 become electrostatic latent on the photosensitive drum 1. Moving to the image, the electrostatic latent image is developed.

  In the transfer device 5, the developed toner image on the photosensitive drum 1 is applied onto the transfer material by charging the transfer material conveyed at the same speed as the peripheral speed of the photosensitive drum 1 or applying a voltage. Transcribed.

  A cleaning device 6 for removing the liquid developer 8 remaining on the surface of the photosensitive drum 1 is disposed on the downstream side of the transfer device 5. The cleaning device 6 removes the liquid developer 8 remaining on the photosensitive drum 1.

  The cleaning blade of the cleaning device 6 may be a rubber body or a rigid body. Examples of the rubber body include urethane rubber, NBR rubber, and fluorine rubber. In the case of a rigid body, resins such as polypropylene, ABS, and polycarbonate, and metals such as aluminum, anodized, SUS, and brass can be used.

  In addition, although the structure which removes the remaining carrier liquid using a cleaning blade is described, the so-called remaining carrier liquid is removed while the web roll-shaped paper, cloth, etc. are pressed against the photoreceptor and moved up and down. It is also possible to employ web cleaning. Further, a toner may be attracted by applying a bias.

  If the transfer material on which the toner image has been transferred by the transfer device 5 is a recording material, it is conveyed to a fixing device (not shown), and is discharged after heating and fixing.

  If the transfer material is an intermediate transfer member such as an intermediate transfer belt, then the toner image is re-transferred to the recording material, and the recording material to which the toner image has been transferred is also conveyed to the fixing device, Discharged.

  Next, the liquid developer 8 used for development will be described. In the liquid developer 8, colored toner particles are dispersed at a high concentration in a carrier liquid as a solvent. Further, additives such as a dispersant and a charge control agent may be appropriately selected and added to the liquid developer 8.

  The liquid developer includes, as main components, an insulating liquid that is a carrier liquid, a toner that develops an electrostatic latent image, and a dispersant that disperses the toner.

  The carrier liquid can be used without particular limitation as long as it is generally used for an electrophotographic liquid developer. For example, as the carrier liquid, an isoparaffin-based isopar (G, H, L, M, etc.) can be used. (Exxon Mobile), IP solvent (1620, 2028, 2835, etc.) (Idemitsu Kosan) and paraffinic Moresco White (P-40, P-70, P-120) (Matsumura Oil Research Institute). it can. It is also possible to use silicon oil or mineral oil.

  The toner particles are mainly composed of a resin and a pigment or dye for coloring. The resin has a function of uniformly dispersing pigments and dyes in the resin and a function as a binder when fixing on a recording sheet.

  The toner particles can be used without any particular limitation as long as they are generally used for electrophotographic liquid developers. As the toner binder resin, for example, a thermoplastic resin such as polystyrene resin, styrene acrylic resin, acrylic resin, polyester resin, epoxy resin, polyamide resin, polyimide resin, or polyurethane resin can be used. It is also possible to use a mixture of a plurality of these resins.

  Also, commercially available pigments and dyes used for coloring the toner can be used. For example, carbon black, bengara, titanium oxide, silica, phthalocyanine blue, phthalocyanine green, sky blue, benzidine yellow, lake red D, etc. can be used as the pigment. Solvent red 27, acid blue 9, or the like can be used as the dye.

  As a method for adjusting the liquid developer, it can be adjusted based on a commonly used technique. For example, the binder resin and the pigment are melt-kneaded using a pressure kneader, a roller mill or the like at a predetermined blending ratio and uniformly dispersed, and the obtained dispersion is finely pulverized by, for example, a jet mill. By classifying the obtained fine powder with, for example, an air classifier, a colored toner having a desired particle diameter can be obtained. The obtained toner particles are mixed with an insulating liquid as a carrier liquid at a predetermined blending ratio. This mixture can be uniformly dispersed by a dispersing means such as a ball mill to obtain a liquid developer.

  The average particle diameter of the toner can be 0.1 μm to 5 μm because the wet image forming method is adopted. If the particle size is less than 0.1 μm, the developability is greatly reduced, and if the particle size is larger than 5 μm, the image quality is lowered.

  The ratio of the toner particle mass to the liquid developer mass is suitably about 10 to 50%.

  If it is less than 10%, the toner particles are likely to settle, and there is a problem with the stability over time during long-term storage, and it is necessary to supply a large amount of liquid developer in order to obtain the required image density. The carrier liquid adhering to the recording paper is increased, and there is a possibility that the vapor processing when dried at the time of fixing becomes a problem. On the other hand, when it exceeds 50%, the viscosity of the liquid developer becomes too high, and it may be difficult to handle in production.

  The clay of the liquid developer is preferably 0.1 mPa · s or more and 10,000 mPa · s or less at 25 ° C. If it exceeds 10,000 mPa · s, it becomes difficult to handle the liquid developer such as stirring and feeding, and the load on the apparatus for supplying a uniform liquid developer may increase.

  FIG. 2 is a diagram illustrating a configuration of developer adjusting unit 54 that adjusts the liquid developer supplied to image forming unit 10 according to the first embodiment of the present invention.

  With reference to FIG. 2, the developer adjustment unit 54 includes a recovery tank 53, a concentration adjustment tank 51, a high concentration adjustment liquid tank 55, a low concentration adjustment liquid tank 56, a developer storage tank 52, and a pump 62. , 64, 66, 68, 69, a stirring blade 65, a motor 61, a measurement unit 60, thermometers 70, 71, 72, and a control unit 100 that controls the entire developer adjustment unit 54. Each tank is provided with a stirring blade and a motor for driving the stirring blade as in the case of the concentration adjustment tank 51. Although not shown, it is assumed that the thermometers 70, 71, 72, the measuring unit 60, the motor 61, and the pumps 62, 64, 66, 68, 69 are connected to the control unit 100.

  The liquid collected from the cleaning device 46 of the liquid developing device 4 has a toner concentration that has changed from a predetermined toner concentration due to the development process. Therefore, it is necessary to readjust the toner concentration. Operate.

  The recovered developer or the like that needs to readjust the toner concentration is temporarily stored in the recovery tank 53. Then, at a predetermined timing, the collected developer is sent to the concentration adjustment tank 51 via the pump 68.

In the density adjustment tank 51, the toner density is measured and adjusted.
Here, the amount of liquid in the density adjustment tank 51 at the time of measuring the toner density needs to be kept constant. The density adjustment tank 51 is provided with an opening 51a at a predetermined position, and excess liquid developer is opened. The amount of liquid overflowing from the part 51a is kept constant.

The liquid developer overflowing from the opening 51 a is recovered in the recovery tank 53.
The concentration adjustment tank 51 is provided with a stirring blade 65, a motor 61 that rotates the stirring blade 65, and a measurement unit 60 that measures the motor consumption current of the motor 61. The measurement result of the measurement unit 60 is output to the control unit 100.

  Since the viscosity of the liquid developer depends on the toner concentration, the measuring unit 60 measures the motor consumption current that changes depending on the stirring torque of the stirring blade 65 that stirs the liquid developer, and the toner concentration can be measured.

  Further, since the viscosity varies depending on the temperature of the liquid developer, a thermometer 70 is provided in the density adjusting tank 51, and the toner density is measured according to the temperature table of the toner density stored in advance while measuring the temperature of the liquid developer. Is detected. It is assumed that the temperature table is stored in the memory of the control unit 100 although not shown. Based on the measurement result from the measurement unit 60 and the temperature measured by the thermometer 70, the control unit 100 measures the toner density according to the temperature table stored in the memory.

  The control unit 100 adjusts the toner concentration of the liquid developer in the density adjustment tank 51 to a desired value or a desired range according to the measured toner density, so that the high density adjustment liquid tank 55 or the low density adjustment liquid tank. A concentration adjusting liquid is supplied from 56 to the concentration adjusting tank 51. Specifically, the pump 62 or the pump 64 is instructed to supply a desired concentration adjusting liquid to the concentration adjusting tank 51.

  Then, the toner concentration is measured and adjusted again in the density adjustment tank 51, and the liquid developer that has been readjusted is stored in the developer storage tank 52 via the pump 66 and then passed through the pump 69. Then, it is sent to the developer tank 44 and used again in the development process.

  Each tank is provided with a stirring blade and a motor for rotating the stirring blade so that the developer or the like is not solidified, and is constantly rotating according to an instruction from the control unit 100. To do.

Here, the temperature adjustment means is not shown.
FIG. 3 is a flowchart illustrating the density adjustment processing of developer adjusting unit 54 according to the first embodiment of the present invention. This process is mainly executed based on an instruction from the control unit 100 to each unit.

  Referring to FIG. 3, first, density adjustment is started (step S2). Specifically, a predetermined amount of liquid developer is supplied to the density adjusting tank 51 via the pump 68.

Next, a temperature adjustment process is performed (step S3). The temperature adjustment process will be described later.
Next, the toner density in the density adjusting tank 51 is measured (step S4). Specifically, the motor consumption current that varies depending on the stirring torque of the stirring blade 65 is measured by the measuring unit 60. Then, the control unit 100 measures the toner density based on the measurement result.

  Next, it is determined whether or not the measured toner density is within a predetermined density range (step S6).

  If it is determined in step S6 that the measured toner density is within the predetermined density range (YES in step S6), the density adjustment process ends (end).

  On the other hand, if it is determined in step S6 that the measured toner density is not within the predetermined density range (NO in step S6), it is determined whether the measured toner density is less than the predetermined density range (step S8). .

  If it is determined in step S8 that the measured toner density is less than the predetermined density range (YES in step S8), a high concentration adjusting liquid is supplied to the concentration adjusting tank 51 (step S10).

Then, the process returns to step S4 again, and the toner density in the density adjusting tank 51 is measured.
On the other hand, if it is determined in step S8 that the measured toner density is not less than the predetermined density range, that is, not less than the predetermined density range (NO in step S8), the low concentration adjustment liquid is supplied to the concentration adjustment tank 51. (Step S14).

Then, the process returns to step S4 again, and the toner density in the density adjusting tank 51 is measured.
In step S6, it is determined whether the measured toner density is within a predetermined density range, and the above-described processing is repeated until the toner density reaches the predetermined density.

  Next, temperature adjustment processing in developer adjusting unit 54 according to the first embodiment of the present invention will be described.

  FIG. 4 is a diagram illustrating temperature adjusting means of developer adjusting unit 54 according to the first embodiment of the present invention.

  Referring to FIG. 4, in developer adjusting unit 54 according to the first embodiment of the present invention, temperature adjusting means 73 and 74 are used as temperature adjusting means in high concentration adjusting liquid tank 55 and low concentration adjusting liquid tank 56, respectively. The structure which provided each is shown. In addition, about the structure of a pump, a control part, etc., it abbreviate | omits. The same applies to the following drawings.

  Based on the temperatures measured from the thermometers 70, 71, 72, the control unit 100 controls the temperature of the high concentration adjusting liquid and the low concentration adjusting liquid by the temperature adjusting means 73, 74 of the liquid developer in the concentration adjusting tank 51. The temperature is adjusted so as to be the same or substantially the same as the temperature.

  The high concentration adjusting solution or the low concentration adjusting solution is supplied to the concentration adjusting tank 51 by making the temperature of the high concentration adjusting liquid and the low concentration adjusting liquid and the temperature of the liquid developer in the concentration adjusting tank 51 the same or substantially the same. It is possible to suppress a rapid temperature fluctuation in the concentration adjusting tank 51 at the time, and it is possible to suppress a decrease in concentration detection accuracy. When the density detection accuracy decreases, the density adjustment result falls outside the allowable range as a result, and it is necessary to perform density adjustment again. With this method, it is possible to shorten the toner density adjustment time. Further, if the time for density adjustment increases, in the worst case, the liquid developer in the developer storage tank 52 becomes empty, and the image forming operation stops, so that productivity is greatly impaired. become. This situation can also be avoided.

  The thermometers 71 and 72 may be thermocouples. The temperature control means 73 and 74 may be, for example, a cartridge heater as a heating means and a Peltier element as a cooling means. Either one or both may be provided.

  In this example, the case where the temperature adjustment process is executed after the start of the density adjustment in step S2 has been described. However, the temperature adjustment process may be executed after step S8. Specifically, when the toner concentration of the liquid developer in the density adjustment tank 51 is equal to or higher than a predetermined density, the temperature of the low density adjustment liquid is the same as or substantially the same as the temperature of the liquid developer in the density adjustment tank 51. When the temperature is adjusted and the toner concentration of the liquid developer in the density adjustment tank 51 is less than a predetermined density, the temperature of the high density adjustment liquid is the same as or substantially the same as the temperature of the liquid developer in the density adjustment tank 51. Adjust it.

  FIG. 5 is a diagram illustrating temperature adjusting means of developer adjusting unit 54 according to the first modification of the first embodiment of the present invention.

  Referring to FIG. 5, developer adjusting unit 54 according to the first modification of the first embodiment of the present invention is different from the configuration of FIG. 4 in that thermometer 75 is also provided in collection tank 53. . Since the other points are the same, detailed description thereof will not be repeated.

  Until the concentration adjustment is performed (while the collected developer is accommodated in the collection tank 53), the control unit 100 performs the high concentration adjustment liquid based on the temperatures measured from the thermometers 75, 71, and 72. The temperature of the low concentration adjusting solution is adjusted to be the same as or substantially the same as the temperature of the collected developer in the collecting tank 53. After the concentration adjustment is started, the temperature is measured from the thermometers 70, 71, 72. Based on this, the temperature of the high concentration adjusting solution and the low concentration adjusting solution is adjusted so as to be the same as or substantially the same as the temperature of the liquid developer in the concentration adjusting tank 51.

  In this case, the temperature of the high concentration adjusting liquid and the low concentration adjusting liquid is adjusted to the temperature of the collected developer in the collecting tank 53 in advance, so that the temperatures of the high concentration adjusting liquid and the low concentration adjusting liquid are adjusted to the concentration adjusting tank 51. It is possible to further shorten the time for adjusting the developer temperature in the toner and shorten the toner density adjustment time.

  FIG. 6 is a diagram illustrating temperature adjusting means of developer adjusting unit 54 according to the second modification of the first embodiment of the present invention.

  Referring to FIG. 6, in developer adjusting unit 54 according to the second modification of the first embodiment of the present invention, temperature adjusting means 73 and 74 are deleted as compared with the configuration of FIG. The difference is that 76 is provided in the concentration adjustment tank 51. Since the other points are the same, detailed description thereof will not be repeated.

  Based on the temperature measured from the thermometers 70, 71, 72, the control unit 100 controls the temperature of the liquid developer in the concentration adjustment tank 51 with the temperature adjustment means 76 provided in the concentration adjustment tank 51. The temperature is adjusted to be the same as or substantially the same as the temperature of the concentration adjusting solution. By providing the temperature adjusting means 76 in the concentration adjusting tank 51, it becomes possible to adjust the temperature of the liquid developer in the concentration adjusting tank 51 to the temperature of the high concentration adjusting liquid or the low concentration adjusting liquid. It is possible to suppress rapid temperature fluctuations in the concentration adjustment tank 51 when the liquid or the low concentration adjustment liquid is supplied to the concentration adjustment tank 51.

  Note that the temperature adjustment process in this case is executed after the process in step S8, that is, before supplying the high concentration adjustment liquid or before supplying the low concentration adjustment liquid in the flowchart illustrated in FIG. . For example, when the toner concentration of the liquid developer in the concentration adjusting tank 51 is equal to or higher than a predetermined concentration, the temperature of the liquid developer is adjusted so as to be the same as or substantially the same as the temperature of the low concentration adjusting liquid, thereby adjusting the concentration. When the toner concentration of the liquid developer in the tank 51 is less than a predetermined concentration, the temperature of the liquid developer may be adjusted so as to be the same as or substantially the same as the temperature of the high concentration adjusting liquid.

  With this configuration, the high-concentration adjustment liquid or the low-concentration adjustment liquid is made the same as or substantially the same as the temperature of the liquid developer in the concentration-adjustment tank 51 so that the high-concentration adjustment liquid or the low-concentration adjustment liquid It is possible to suppress rapid temperature fluctuations in the concentration adjustment tank 51 when supplied to 51, and to suppress a decrease in concentration detection accuracy.

  FIG. 7 is a diagram illustrating temperature adjusting means of developer adjusting unit 54 according to the third modification of the first embodiment of the present invention.

  Referring to FIG. 7, in developer adjusting unit 54 according to the third modification of the first embodiment of the present invention, temperature adjusting means 73 and 74 are further provided with high concentration adjusting liquid tank 55 as compared with the configuration in FIG. The difference is that each is provided in the low concentration liquid tank 56. Since the other points are the same, detailed description thereof will not be repeated.

  Based on the temperatures measured from the thermometers 70, 71, 72, the control unit 100 uses the temperature adjusting means 73, 74, 76 to adjust the liquid developer in the concentration adjustment tank 51 and the high concentration in the high concentration adjustment liquid tank 55. The temperature of the adjustment liquid or the low concentration adjustment liquid in the low concentration adjustment liquid tank 56 is adjusted.

  By providing the temperature adjusting means 73 and 74 in the high concentration adjusting liquid tank 55 and the low concentration adjusting liquid tank 56, the temperature adjusting means is provided in the three tanks, and the time required for temperature adjustment can be shortened. Also, temperature stability is improved. For example, the time required for temperature adjustment can be shortened by controlling the temperature control means so that the temperature of the concentration adjustment tank 51, the high concentration adjustment liquid tank 55, and the low concentration adjustment liquid tank 56 becomes the average value. It becomes. In addition, it is not restricted to an average value, For example, considering the amount of liquid accommodated in each tank, you may make it adjust to the appropriate temperature that the time of temperature adjustment becomes the minimum.

  With this configuration, the high concentration adjusting solution or the low concentration adjusting solution and the temperature of the liquid developer in the concentration adjusting tank 51 are made the same or substantially the same, so that the high concentration adjusting solution or the low concentration adjusting solution is placed in the concentration adjusting tank. It is possible to suppress rapid temperature fluctuations in the concentration adjustment tank 51 when supplied to 51, and to suppress a decrease in concentration detection accuracy.

  In this example as well, the temperature adjustment process may be executed after step S8. Specifically, when the toner concentration of the liquid developer in the density adjustment tank 51 is equal to or higher than a predetermined density, the temperature of the low density adjustment liquid and the temperature of the liquid developer in the density adjustment tank 51 are the same or substantially the same. When the toner concentration of the liquid developer in the density adjustment tank 51 is less than a predetermined density, the temperature of the high density adjustment liquid and the temperature of the liquid developer in the density adjustment tank 51 are the same. Or what is necessary is just to adjust temperature so that it may become substantially the same.

  FIG. 8 is a diagram illustrating a temperature adjustment unit of developer adjustment unit 54 according to the fourth modification of the first embodiment of the present invention.

  Referring to FIG. 8, in developer adjusting unit 54 according to the fourth modification of the first embodiment of the present invention, thermometers 71 and 72 and temperature adjusting means 73 and 74 are deleted as compared with the configuration in FIG. Instead, the means is provided in the flow path for supplying the adjustment liquid. Since the other points are the same, detailed description thereof will not be repeated.

  Specifically, temperature control means 79 and 80 are provided in the middle of the flow path from the high concentration adjusting liquid tank 55 and the low concentration adjusting liquid tank 56 to the concentration adjusting tank 51, respectively. Further, the thermometers 77 and 78 are provided on the downstream side of the temperature adjusting means 79 and 80 in the concentration adjusting liquid supply direction.

  Based on the temperature measured from the thermometers 70, 77, 78, the control unit 100 controls the temperature of the high concentration adjusting liquid or the low concentration adjusting liquid by the temperature adjusting means 79, 80 of the liquid developer in the concentration adjusting tank 51. Adjust the temperature so that it is the same or substantially the same as the temperature.

  As a material of the tube used for the flow path, a Tygon tube from the viewpoint of flexibility and chemical resistance, or a Viton tube may be used in consideration of heat resistance. In consideration of thermal conductivity, an aluminum metal pipe may be used. A resistance heating element and a Peltier element may be built in the metal pipe. When the amount of the concentration adjustment liquid assumed is small, the concentration adjustment is possible only with the amount of liquid in the temperature adjusting means 79 and 80 provided in the middle of the flow path, and the temperature adjustment time can be further shortened. That is, the toner density adjustment time can be shortened.

  Note that the temperature adjustment process in this case is executed after the process in step S8, that is, before supplying the high concentration adjustment liquid or before supplying the low concentration adjustment liquid in the flowchart illustrated in FIG. . For example, when the toner concentration of the liquid developer in the concentration adjusting tank 51 is equal to or higher than a predetermined concentration, the temperature is adjusted so that the temperature of the low concentration adjusting liquid is the same as or substantially the same as the temperature of the liquid developer. When the toner concentration of the liquid developer in the tank 51 is less than a predetermined concentration, the temperature may be adjusted so that the temperature of the high concentration adjusting liquid is the same as or substantially the same as the temperature of the liquid developer.

  FIG. 9 is a diagram illustrating temperature adjusting means of developer adjusting unit 54 according to the fifth modification of the first embodiment of the present invention.

  Referring to FIG. 9, in developer adjusting unit 54 according to the fifth modification of the first embodiment of the present invention, temperature adjusting means 79 and 80 and a thermometer are respectively provided in the middle of the flow path as compared with the configuration of FIG. Instead of providing 77 and 78, a difference is that a buffer is provided. Since the other points are the same, detailed description thereof will not be repeated.

  Specifically, buffers 81 and 82 are provided in the middle of the flow path, and thermometers 83 and 84 and temperature control means 85 and 86 are provided, respectively. With this configuration, it is possible to arbitrarily set the concentration adjustment liquid amount that can be adjusted in temperature. As temperature control means, a resistance heating element and a Peltier element may be built in the wall surface of the buffer.

  Based on the temperature measured from the thermometers 70, 83, and 84, the control unit 100 controls the temperature of the high concentration adjusting solution or the low concentration adjusting solution by the temperature adjusting means 85 and 86 of the liquid developer in the concentration adjusting tank 51. Adjust the temperature so that it is the same or substantially the same as the temperature.

  In the case where the amount of the concentration adjustment liquid assumed is small, the concentration adjustment can be performed only with the amount of liquid in the buffers 81 and 82 provided in the middle of the flow path, and the temperature adjustment time can be further shortened. That is, the toner density adjustment time can be shortened.

  Note that the temperature adjustment process in this case is executed after the process in step S8, that is, before supplying the high concentration adjustment liquid or before supplying the low concentration adjustment liquid in the flowchart illustrated in FIG. . For example, when the toner concentration of the liquid developer in the concentration adjustment tank 51 is equal to or higher than a predetermined concentration, the temperature adjustment is performed so that the temperature of the low concentration adjustment liquid in the buffer 82 is the same as or substantially the same as the temperature of the liquid developer. When the toner concentration of the liquid developer in the concentration adjusting tank 51 is less than a predetermined concentration, the temperature adjustment is performed so that the temperature of the high concentration adjusting liquid in the buffer 81 is the same as or substantially the same as the temperature of the liquid developer. Just do it.

  FIG. 10 is a diagram illustrating temperature adjusting means of developer adjusting unit 54 according to the sixth modification of the first embodiment of the present invention.

  Referring to FIG. 10, developer adjusting unit 54 according to the sixth modification of the first embodiment of the present invention is different from the configuration of FIG. 8 in that temperature adjusting means 76 is further provided. Since the other points are the same, detailed description thereof will not be repeated.

  Based on the temperature measured from the thermometers 70, 77, 78, the control unit 100 uses the temperature adjusting means 76, 79, 80 to develop the temperature of the high concentration adjusting liquid or the low concentration adjusting liquid and the liquid development in the concentration adjusting tank 51. The temperature is adjusted so that the temperature of the agent is the same or substantially the same.

  Specifically, by providing the temperature adjusting means 76 in the concentration adjusting tank 51, the temperature of the liquid developer in the concentration adjusting tank 51 can be adjusted, and three temperature adjusting means are provided. As described above, the time required for temperature adjustment can be shortened, and the temperature stability is also improved. That is, the toner density adjustment time can be shortened.

(Embodiment 2)
In the first embodiment, the temperature of the liquid developer and the temperature of the supplied density adjustment liquid are made substantially the same, thereby suppressing the decrease in density detection accuracy and shortening the toner density adjustment time. explained.

  On the other hand, the viscosity of the concentration adjusting liquid varies with temperature. Therefore, even when a predetermined amount of density adjusting liquid is replenished at the time of toner density adjustment, the supply amount varies depending on the temperature. Therefore, there is a problem that the density adjustment accuracy is lowered, and there is also a problem that it takes time to reach the target toner density range.

  In the second embodiment of the present invention, a method capable of solving the above-described problem and reducing the toner density adjustment time will be described.

  As a specific configuration, it is possible to use a configuration in which the temperature adjusting means described in FIG. 2 is not provided.

  FIG. 11 is a flowchart illustrating the density adjustment processing of developer adjusting unit 54 according to the second embodiment of the present invention. This process is mainly executed based on an instruction from the control unit 100 to each unit.

  Referring to FIG. 11, first, density adjustment is started (step S2). Specifically, a predetermined amount of liquid developer is supplied to the density adjusting tank 51 via the pump 68.

  Next, the toner density in the density adjusting tank 51 is measured (step S4). Specifically, the motor consumption current that varies depending on the stirring torque of the stirring blade 65 is measured by the measuring unit 60. Then, the control unit 100 measures the toner density based on the measurement result.

  Next, it is determined whether or not the measured toner density is within a predetermined density range (step S6).

  If it is determined in step S6 that the measured toner density is within the predetermined density range (YES in step S6), the density adjustment process ends (end).

  On the other hand, if it is determined in step S6 that the measured toner density is not within the predetermined density range (NO in step S6), it is determined whether the measured toner density is less than the predetermined density range (step S8). .

  If it is determined in step S8 that the measured toner density is less than the predetermined density range (YES in step S8), the temperature of the high concentration adjusting liquid is measured (step S20).

Specifically, the control unit 100 acquires the temperature of the high concentration adjustment liquid from the thermometer 71.
Next, the pump drive time is corrected from the high concentration adjusting solution time / temperature table according to the measured temperature (step S22). It is assumed that the high concentration adjustment liquid time / temperature table and the low concentration adjustment liquid time / temperature table are stored in a memory (not shown) in the control unit 100.

  FIG. 12 is a diagram illustrating a high concentration adjusting liquid time / temperature table according to the second embodiment of the present invention.

  Referring to FIG. 12, here, the pump driving time corresponding to the temperature when the liquid temperature is T ° C. is shown. Specifically, when T ≦ reference temperature−20 ° C., the pump driving time is corrected from the reference time by multiplying the reference time by the coefficient A.

  When the condition of reference temperature−20 ° C. <T ≦ reference temperature−15 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by the coefficient B.

  When the condition of reference temperature−15 ° C. <T ≦ reference temperature−10 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient C.

  When the condition of reference temperature−10 ° C. <T ≦ reference temperature−5 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient D.

When the condition of reference temperature−5 ° C. <T <reference temperature + 5 ° C. is satisfied, the reference time is set.
When the condition of reference temperature + 5 ° C. ≦ T <reference temperature + 10 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by the coefficient E.

  When the condition of reference temperature + 10 ° C. ≦ T <reference temperature + 15 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by the coefficient F.

  When the condition of reference temperature + 15 ° C. ≦ T <reference temperature + 20 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient G.

  When the condition of reference temperature + 20 ≦ T is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient H.

  The relationship among the coefficients A, B, C, D, E, F, G, and H is A> B> C> D> 1> E> F> G> H.

Here, the reference temperature is about room temperature as an example.
Since the temperature of the liquid developer is also variable, the relationship between the reference temperature and the reference time is not fixed. For example, the reference time may be changed according to the temperature of the liquid developer. For example, a separate table for setting the reference time according to the temperature of the liquid developer may be provided.

  The controller 100 refers to the high concentration adjusting liquid time / temperature table stored in advance in the memory and corrects the pump driving time according to the acquired temperature of the high concentration adjusting liquid.

  Referring to FIG. 11 again, next, a high concentration adjusting liquid whose pump driving time is corrected is supplied to the concentration adjusting tank 51 (step S10).

Then, the process returns to step S4 again, and the toner density in the density adjusting tank 51 is measured.
On the other hand, if it is determined in step S8 that the measured toner density is not less than the predetermined density range, that is, not less than the predetermined density range (NO in step S8), the temperature of the low density adjustment liquid is measured (step S24). ). Specifically, the control unit 100 acquires the temperature of the low concentration adjustment liquid from the thermometer 72.

  Next, the pump driving time is corrected from the low concentration adjusting liquid time / temperature table according to the measured temperature (step S26).

  FIG. 13 is a diagram illustrating a low concentration adjusting liquid time / temperature table according to the second embodiment of the present invention.

  Referring to FIG. 13, here, the pump drive time corresponding to the temperature when the liquid temperature is T ° C. is shown. Specifically, when T ≦ reference temperature−20 ° C., the pump driving time is corrected from the reference time by multiplying the reference time by the coefficient I.

  When the condition of reference temperature −20 ° C. <T ≦ reference temperature −15 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient J.

  When the condition of reference temperature−15 ° C. <T ≦ reference temperature−10 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient K.

  When the condition of reference temperature −10 ° C. <T ≦ reference temperature −5 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient L.

When the condition of reference temperature−5 ° C. <T <reference temperature + 5 ° C. is satisfied, the reference time is set.
When the condition of reference temperature + 5 ° C. ≦ T <reference temperature + 10 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient M.

  When the condition of reference temperature + 10 ° C. ≦ T <reference temperature + 15 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient N.

  When the condition of reference temperature + 15 ° C. ≦ T <reference temperature + 20 ° C. is satisfied, the pump driving time is corrected by multiplying the reference time by a coefficient O.

  When the condition of reference temperature + 20 ≦ T is satisfied, the pump driving time is corrected by multiplying the reference time by the coefficient P.

  The relationship among the coefficients I, J, K, L, M, N, O, and P is I> J> K> L> 1> M> N> O> P.

  The controller 100 refers to the low concentration adjustment liquid time / temperature table stored in advance in the memory, and corrects the pump driving time according to the acquired temperature of the low concentration adjustment liquid.

  Referring to FIG. 11 again, next, the low concentration adjusting liquid whose pump driving time is corrected is supplied to the concentration adjusting tank 51 (step S14).

Then, the process returns to step S4 again, and the toner density in the density adjusting tank 51 is measured.
In step S6, it is determined whether the measured toner density is within a predetermined density range, and the above-described processing is repeated until the toner density reaches the predetermined density.

  As described above, when the concentration adjusting liquid (high concentration adjusting liquid or low concentration adjusting liquid) is supplied from the high concentration adjusting liquid tank 55 or the low concentration adjusting liquid tank 56 to the concentration adjusting tank 51, the concentration is adjusted according to the temperature of the concentration adjusting liquid. The viscosity of the liquid varies.

  The supply of the concentration adjusting liquid is performed using the pump as described above, and the supply amount is set by the flow rate per unit time × the supply time. The flow rate per unit time varies depending on the viscosity variation of the concentration adjusting solution. In other words, the viscosity is weakened at a high temperature, and the viscosity is increased at a low temperature.

  Therefore, the supply amount of the concentration adjustment liquid varies according to the temperature variation, which may lead to a decrease in concentration adjustment accuracy.

  Therefore, in the method according to the second embodiment of the present invention, the drive time of the pump per unit time with respect to the reference supply amount is stored in advance so that the supply amount of the concentration adjusting liquid does not change according to the temperature change. Based on the low concentration adjustment liquid time / temperature table or the high concentration adjustment liquid time / temperature table, the drive time (supply time) is corrected so that the supply amount of the concentration adjustment liquid becomes constant.

  Due to the correction, the supply amount is fixed even when the temperature fluctuation occurs in the concentration adjusting liquid. That is, it is possible to prevent fluctuations in the supply amount of the concentration adjusting liquid due to fluctuations in the viscosity of the concentration adjusting liquid. As a result, it is possible to replenish an appropriate amount of the concentration adjusting liquid, and to shorten the time for adjusting the toner concentration.

  In the above description, the driving time of the pump is corrected according to the temperature. Instead of correcting the driving time, the rotation speed (driving speed) per unit time of the pump may be corrected. It is also possible to correct both the pump driving time and the rotational speed (drive speed).

  In accordance with the method according to the present embodiment, the toner concentration of the desired liquid developer is set to 30%, the high concentration adjusting liquid is set to 40%, the low concentration adjusting liquid is set to the carrier liquid, and the toner concentration adjusting process is executed. did.

  By making the temperature of the concentration adjustment tank and the high concentration adjustment liquid tank or the low concentration adjustment liquid tank the same or substantially the same, it is possible to suppress rapid temperature fluctuations in the concentration adjustment tank during toner concentration adjustment. .

  In addition, by correcting the pump drive time, fluctuations in the supply amount of the density adjustment liquid due to fluctuations in the liquid temperature were suppressed, no decrease in the accuracy of toner density adjustment was observed, and the density adjustment result did not deviate from the target range. .

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Photosensitive drum, 2 Charging apparatus, 3 Exposure apparatus, 4 Liquid developing apparatus, 5 Transfer apparatus, 6 Cleaning apparatus, 8 Liquid developer, 10 Image formation part, 41 Developing roller, 42 Conveyance roller, 43 Supply roller, 44 Development Agent tank, 45 Regulator blade, 46 Cleaning device, 51 Concentration adjustment tank, 51a Opening, 52 Developer storage tank, 53 Recovery tank, 54 Developer adjustment section, 55 High concentration adjustment liquid tank, 56 Low concentration adjustment liquid tank, 60 measurement unit, 61 motor, 65 stirring blade, 81, 82 buffer, 100 control unit.

Claims (8)

A density adjusting tank for storing a liquid developer for density adjustment;
Developer temperature measuring means for measuring the temperature of the liquid developer contained in the density adjusting tank;
A concentration adjusting liquid tank containing at least two kinds of concentration adjusting liquids for concentration adjustment;
Adjusting liquid temperature measuring means for measuring the temperature of the concentration adjusting liquid stored in the concentration adjusting liquid tank;
Toner for measuring the toner concentration of the liquid developer contained in the concentration adjusting tank and supplying the concentration adjusting liquid from the concentration adjusting liquid tank to the concentration adjusting tank in order to adjust the toner concentration to a desired toner concentration Density adjusting means;
When adjusting the toner density, the temperature of the liquid developer stored in the density adjusting tank measured by the developer temperature measuring means, the temperature measured by the adjusting liquid temperature measuring means, and supplied by the toner density adjusting means And a temperature adjusting means for adjusting the temperature of the concentration adjusting liquid to be substantially the same.   The wet image according to claim 1, wherein the temperature adjusting unit adjusts the temperature of the concentration adjusting liquid stored in the concentration adjusting liquid tank so as to be the temperature of the liquid developer stored in the concentration adjusting tank. Forming equipment.   The wet image forming apparatus according to claim 2, wherein the temperature adjusting unit is provided in a path for supplying the concentration adjusting liquid stored in the concentration adjusting liquid tank to the concentration adjusting tank.   The wet image according to claim 1, wherein the temperature adjusting unit adjusts the temperature of the liquid developer accommodated in the concentration adjustment tank so as to be equal to the temperature of the concentration adjustment liquid accommodated in the concentration adjustment liquid tank. Forming equipment.   The temperature adjusting means adjusts the temperature of the liquid developer accommodated in the concentration adjustment tank and the concentration adjustment liquid accommodated in the concentration adjustment liquid tank to a desired temperature. Wet image forming apparatus. The temperature adjusting means is
A first temperature adjusting unit for adjusting the temperature of the liquid developer accommodated in the concentration adjusting tank;
A second temperature adjustment unit that adjusts the temperature of the concentration adjustment liquid stored in the concentration adjustment liquid tank,
The first and second temperature adjusting units adjust the temperature of the liquid developer stored in the concentration adjusting tank and the concentration adjusting liquid stored in the concentration adjusting liquid tank to a desired temperature. The wet image forming apparatus according to claim 1. A density adjusting tank for storing a liquid developer for density adjustment;
A concentration adjusting liquid tank containing at least two kinds of concentration adjusting liquids for concentration adjustment;
Toner for measuring the toner concentration of the liquid developer contained in the concentration adjustment tank and supplying the concentration adjustment liquid from the concentration liquid adjustment tank to the concentration adjustment tank in order to adjust to a desired toner concentration Density adjustment means,
The toner density adjusting means includes
Adjusting liquid temperature measuring means for measuring the temperature of the concentration adjusting liquid stored in the concentration adjusting liquid tank;
Supply means for supplying the concentration adjustment liquid from the concentration adjustment liquid tank to the concentration adjustment tank;
The supply means removes the concentration adjustment liquid from the concentration adjustment liquid tank based on the temperature of the concentration adjustment liquid stored in the concentration adjustment liquid measured by the adjustment liquid temperature measurement means when adjusting the toner concentration. A wet-type image forming apparatus that controls a supply amount to be supplied. A memory for storing an adjustment table for adjusting a supply amount of the concentration adjusting liquid provided in advance in association with the temperature of the concentration adjusting liquid;
The wet image forming apparatus according to claim 7, wherein the supply unit controls a supply amount for supplying the concentration adjusting liquid with reference to the adjustment table of the memory.

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