JP2000338786A - Wet image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a wet image-forming device which can reuse a recovered developer by arranging the component ratio of the developer recovered from a developer carrier and a latent image carrier without providing a special detecting means to detect the properties of the developer. SOLUTION: An optical write control board 104 which transmits write information to an optical write unit on the basis of image data is controlled to calculate the area of the image part of an electrostatic latent image formed on a photoreceptor drum, and on the basis of the calculated result, a CPU board 100 is controlled to decide an image forming material amount and a solvent amount to the replenished to a recovered developer from a developing belt and a photoreceptor drum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet image forming apparatus such as a copying machine, a facsimile or a printer using a developing solution, and more particularly, to a latent image carrier, a latent image forming means, and a developer carrier. Developing means having, a transfer means for transferring a visible image on the latent image carrier by contacting the recording body, a collecting means for collecting residual developing solution remaining on the latent image carrier and the developer carrier, The present invention relates to a wet image forming apparatus having a recovered developer recycling means for reusing the recovered developer after adjusting the component ratio of the recovered developer.

[0002]

2. Description of the Related Art An electrophotographic image forming apparatus forms an image by the following process, for example. That is, first, an electrostatic latent image is formed on a latent image carrier such as a photoconductor based on image data. Further, while rotating a developer carrying member such as a developing roller or a developing belt, the developer is carried on the surface thereof and is transported to a developing position which is a position facing the latent image carrying member. Then, at this developing position, a developer is adhered to the electrostatic latent image to develop (visualize) the electrostatic latent image.
Next, the visible image obtained by the development is transferred directly to a recording medium such as transfer paper or via an intermediate transfer member to form an image on the recording medium.

[0003] This type of image forming apparatus includes a dry type electrophotographic type using a non-liquid developer as a developer (hereinafter, referred to as a dry type image forming apparatus) and a wet type electrophotographic type using a developing solution ( Hereinafter, this is referred to as a wet image forming apparatus.)
The former has a configuration in which the developer remaining on the developing roller without being used for development is usually reused.

For example, in a dry image forming apparatus using a one-component developer consisting only of a toner as an image forming substance, the toner remaining on a developing roller is reused as follows. That is, the residual toner is re-conveyed to the developing position while remaining on the developing roller,
After being once dropped on a toner storage section or the like, it is again carried on the surface of the developing roller and transported again to the developing position.

For example, in a dry image forming apparatus using a two-component developer containing a magnetic carrier in addition to a toner, after adjusting the components of the two-component developer collected from the developing roller, the two-component developer after the component adjustment is adjusted. The developer is reused for development. In this type of image forming apparatus, the magnetic carrier is strongly attracted to the surface of the developing roller by the magnetic force, and usually only the toner in the two-component developer is consumed at the developing position. Shortage of toner density. Therefore, prior to reuse, the components of the recovered developer are adjusted. Specifically, the toner concentration of the collected developer is detected by a magnetic sensor or the like, and an appropriate amount of toner is replenished to the collected developer according to the detection result.

Further, in the dry image forming apparatus, not only the recovered developer from the developer carrier, but also the developer remaining on the latent image carrier without being transferred to a transfer paper or an intermediate transfer body is recovered. There are various proposals for reuse. For example, an image forming apparatus described in Japanese Patent Application Laid-Open No. 9-127841 is one of them, and this image forming apparatus includes a latent image forming means for forming a latent image on an image carrier, and a latent image forming means formed on the image carrier. Developing means for supplying a developer to the latent image to develop the latent image; transfer means for transferring the developer supplied to the image carrier by the developing means to a material to be transferred; and latent image forming means for the image carrier by the developing means A developer collection unit that collects, from the image carrier, untransferred developer remaining without transferring the developer supplied to the image onto the transfer target material by the transfer by the transfer unit; and collecting the developer by the developer collection unit. And recycling means for returning the developer other than the developer collected from the position corresponding to the specific area of the image carrier among the developer to the developing means. In a dry image forming apparatus using a two-component developer, usually, only toner is collected from a photoconductor or the like.

On the other hand, in a wet image forming apparatus, a developer containing a toner and a liquid carrier (solvent) is usually used, and the recovered developer recovered from a developer carrier or a latent image carrier is reused. To do so, it is necessary to readjust the components of the recovered developer as in the case of a dry image forming apparatus using a two-component developer. However, in order to readjust the components, a configuration for replenishing a liquid carrier is also required in addition to a configuration for replenishing the recovered developer with toner. In the wet image forming apparatus, the toner and the liquid carrier are attached to the latent image carrier, and only the liquid carrier is attached when the electrostatic latent image is not formed. This is because the concentration is made higher or lower than that before use.

By the way, in order to configure a wet image forming apparatus so as to reuse a developer recovered from a developer carrier or a latent image carrier, a dry image forming apparatus using a two-component developer is required. As in the case of the forming apparatus, it is necessary to provide a detecting means for detecting the toner concentration in the collected developer. However, at present, there is no simple detection means capable of detecting the toner concentration of the high-concentration and high-viscosity developer. Further, even if such a detecting means is provided, if the detecting means is incorporated, the size of the apparatus is increased and the cost is increased.

The present invention has been made in view of the above background, and an object of the present invention is to provide a developer carrier and a latent image carrier without providing a special detecting means for detecting the characteristics of a developer. It is an object of the present invention to provide a wet image forming apparatus capable of adjusting the component ratio of a collected developer from a body and reusing the collected developer.

[0009]

According to one aspect of the present invention, there is provided a latent image carrier, and a latent image forming device for forming a latent image on the latent image carrier based on image data. Means for forming a thin layer of a developer containing an image forming substance and a solvent on a developer carrier, and bringing the thin layer into contact with the latent image carrier to visualize the latent image Transfer means for transferring a visible image on the latent image carrier to a recording medium, first recovery means for recovering residual developer remaining on the developer carrier after visualization, and A second recovery means for recovering the residual developer remaining on the latent image carrier, and adjusting the ratio between the amount of the image forming substance and the amount of the solvent in the recovered developer to reuse the recovered developer. And a control means for controlling the recovered developer recycling means. Calculating means for calculating, based on the image data, an area of an image portion of the latent image formed on the latent image carrier and an area of a non-image portion in a developer adhering region of the latent image carrier. Determining means for determining the amount of the image forming substance and the amount of the solvent to be replenished to the recovered developer based on the calculation result of the calculating means; and a control means for controlling the recovered developer recycling means. The ratio is adjusted by the collected developer recycling means based on the result of the determination by the determining means.

In the present invention, the "non-image portion" is a portion of a latent image carrier which makes it difficult for an image forming substance to adhere thereto. For example, when an exposed portion of the latent image carrier becomes a latent image, The non-exposed part of the body becomes the non-image part.

If the consumption characteristics of the developer in the wet image forming apparatus are grasped in advance, it is possible to predict what kind of image is formed and how much amount of the image forming substance and the solvent are consumed. If the apparatus is configured to replenish an appropriate amount of the image forming substance or solvent to the recovered developer based on the prediction result, it is not necessary to provide a special detecting unit for detecting the characteristics of the recovered developer in the apparatus. Also, the ratio between the amount of the image forming substance and the amount of the solvent in the recovered developer can be adjusted. However, in the wet image forming apparatus, the liquid solvent is also attached to the non-image portion of the latent image carrier. Also,
In some cases, a very small amount of an image forming substance that cannot be seen is attached to the non-image portion of the latent image carrier. Thus, without considering the amount of the solvent or the image forming substance attached to the non-image portion, simply
Even if the apparatus is configured to replenish the collected developer with the image forming substance and the solvent based on the amount of the solvent and the image forming substance adhered to the image area, the above ratio of the replenished collected developer is not properly adjusted. There is a risk. Then, Claims 1, 2,
In the wet image forming apparatuses of 3, 4, 5 and 6, the area of the image portion formed of the latent image formed on the latent image carrier and the area of the non-image portion in the developing solution adhering area of the latent image carrier Is calculated by the calculation means. When the area of the non-image portion is calculated in this manner, for example, in addition to the amount of the image forming substance and the solvent consumed from the developer carrier to the recording body via the image portion of the latent image carrier, The amount of the image forming substance and the solvent to be replenished to the recovered developer, taking into account the amount of the image forming substance and the solvent consumed from the developer carrier to the recording medium via the non-image portion of the latent image carrier. Can be determined. Thus, even without providing the special detecting means as described above, an appropriate amount of the image forming substance or the solvent is replenished to the collected developer, and the ratio of the amount of the image forming substance to the amount of the solvent in the collected developer is adjusted. Can be adjusted appropriately, and the recovered developer can be reused.

According to a second aspect of the present invention, in the wet image forming apparatus of the first aspect, the area of the area corresponding to the recording paper and the area of the area not corresponding to the recording paper are calculated separately from the area of the non-image portion. Thus, the calculation means is configured as described above.

In the transfer process of a wet image forming apparatus, usually,
The latent image carrier and the recording medium are brought into close contact with each other, and the visible image on the latent image carrier is transferred onto the recording medium. At the time of this transfer, the solvent (and a very small amount of the image forming substance) attached to the non-image portion on the latent image carrier is also transferred onto the recording medium. In the transfer step, the recording medium is usually pressed against the latent image carrier by a pressing member such as a transfer roller. In such a transfer process,
When the size of the recording medium is changed from A4 transfer paper to B5 transfer paper, for example, the contact area of the latent image carrier with the recording medium is changed. When the contact area is changed in this manner, in the non-image portion of the developer adhering area of the latent image carrier, the area ratio of the area to be brought into contact with the recording medium and the area not to be brought into contact is changed. For the area contacted with the recording medium, the developer can be moved onto the recording medium, but for the area not contacted with the recording medium, the developing solution is not moved onto the recording medium, Cleaning may be performed after the transfer member is moved to a pressing member such as a transfer roller. Generally, the transfer rate of the developer from the latent image carrier to the recording medium is different from the transfer rate of the developer from the latent image carrier to the pressing member.
For this reason, if the area ratio between the area that is brought into contact with the recording medium and the area that is not brought into contact is changed, even when a visible image having the same shape and the same size is transferred, the non-image area of the latent image carrier is transferred. Changes the amount of transfer of the solvent (and a very small amount of the image forming substance) from the recording medium to the recording medium. The change in the transfer amount causes an error between the predicted value of the amount of the solvent (and the trace amount of the image forming substance) consumed from the non-image portion of the latent image carrier to the recording medium and the actual consumption amount. Will happen. Therefore,
In the wet image forming apparatus according to the second aspect, of the non-image portions formed in the developer adhering area of the latent image carrier, the area of the area corresponding to the recording medium and the area of the area not corresponding to the recording medium are calculated separately. The arithmetic means is configured as described above. With this configuration, even when the size of the recording medium to be used is changed, the amount of the solvent and the amount of the image forming substance transferred from the non-image portion of the latent image carrier to the recording medium, and the amount of the latent image It is possible to replenish the recovered developer with an amount of the solvent or the image forming substance closer to the amount of the solvent and the amount of the image forming substance transferred from the non-image portion of the body to the pressing member.

According to a third aspect of the present invention, there is provided the wet image forming apparatus according to the first or second aspect, wherein the recovered developer recycling means includes a recovered developer by the first recovery means and a recovered developer by the second recovery means. The ratio is adjusted by replenishing the mixed recovery developer mixed with the developer with the same amount of the image forming substance and the solvent as determined by the determination unit.

In this wet image forming apparatus, the recovered developer from the developer carrier and the recovered developer from the latent image carrier are mixed to form a mixed recovered developer. Replenish the same amount of imaging substance and solvent as consumed. When the image forming substance and the solvent are replenished in this manner, the amount of the developer in the developer circulation system in the image forming apparatus can be kept constant. And, by this, for example, the image quality is degraded due to the increase or decrease of the liquid amount, such that the image quality is deteriorated due to the increase or decrease of the developer carrying amount of the developer carrier. Can be avoided.

According to a fourth aspect of the present invention, there is provided the wet image forming apparatus according to the first or second aspect, wherein the recovered developer recycling means includes a recovered developer recovered by the first recovery means and a recovered developer recovered by the second recovery means. Adjusting the ratio by replenishing only the one of the image forming substance and the solvent that has been consumed more than the above ratio in the initial state of the developer with respect to the mixed recovery developer mixed with the developer. It is a feature.

Also in this wet image forming apparatus, the recovered developer from the developer carrier and the recovered developer from the latent image carrier are mixed to form a mixed recovered developer. It is configured to replenish the image forming substance and the solvent. However, instead of replenishing the same amount of the image forming substance and the solvent as the consumed amount, it is consumed by the movement from the developer carrier to the latent image carrier or from the latent image carrier to the recording body. Of the image forming substance and the solvent, only the component having the higher consumption rate is configured to be replenished to the recovered developer. With this configuration, when the consumption rates of the image forming substance and the solvent are significantly different, only the replenishment of only one of the image forming substance and the solvent is performed, and the above-described ratio of the mixed recovery developer is adjusted. Can be made equivalent to that of the developer in the initial state.

According to a fifth aspect of the present invention, there is provided the wet image forming apparatus of the first, second, third or fourth aspect, wherein the developer accommodating portion for accommodating the developer and the amount of the developer in the developer accommodating portion are maximum. A liquid amount upper limit detection sensor for detecting whether or not the allowable storage amount has been reached, and the liquid amount upper limit detection sensor has detected that the developer amount in the developer storage portion has reached the maximum allowable storage amount. And a ratio adjustment operation amount correction control means for correcting the operation amount of the ratio adjustment operation of the recovered developer recycling means at a point in time.

In this wet image forming apparatus, the liquid amount upper limit detection sensor detects whether or not the amount of the developer stored in the developer storage portion has reached the maximum allowable storage amount. When the state of reaching the maximum allowable storage amount is detected, the ratio adjustment operation amount of the collected developer recycling unit is corrected by the control of the ratio adjustment operation amount correction control unit. In such a control, for some reason, the replenishment amount of the image forming substance and the replenishment amount of the solvent with respect to the recovered developer exceed the amount of the consumed image forming substance and the amount of the solvent, and the amount of the developer contained in the developer container gradually decreases. However, before the developer overflows from the developer container, the ratio adjustment operation amount is corrected. By this correction, the replenishing amount of the image forming substance and the replenishing amount of the solvent with respect to the recovered developer approach the consumed amount of the image forming substance and the amount of the solvent, and the overflow of the developing solution from the developing solution container is avoided.

According to a sixth aspect of the present invention, there is provided the wet image forming apparatus according to the first, second, third or fourth aspect, wherein the developer accommodating portion for accommodating the developer and the amount of the developer in the developer accommodating portion are reduced. A liquid amount lower limit detection sensor for detecting whether or not the minimum allowable storage amount has been reached, and the liquid amount lower limit detection sensor detects that the developer amount in the developer storage unit has reached the minimum allowable storage amount. And a developer replenishing means for replenishing the developer accommodating portion with a new developer in which the above ratio is appropriately adjusted.

In this wet image forming apparatus, the liquid amount lower limit detection sensor detects whether or not the amount of the developer stored in the developer storage portion has reached the minimum allowable storage amount.
Then, when a state where the minimum allowable storage amount is reached is detected, a new developer in which the solvent component and the image forming substance component are appropriately adjusted is replenished by the developer replenisher. In such a configuration, for some reason, the replenishment amount of the image forming substance and the replenishment amount of the solvent with respect to the recovered developer are lower than the amount of the consumed image forming substance and the amount of the solvent, and the storage amount of the developer in the developer storage part gradually decreases. Even if it decreases to
New developer is replenished to the developer container. When the new developer is replenished in this manner, a shortage of the developer storage amount that may occur in the developer storage unit is avoided.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a wet electrophotographic printer (hereinafter simply referred to as a printer) as a wet image forming apparatus will be described below. First, a schematic configuration of a printer according to the present embodiment will be described with reference to FIG. Around a photosensitive drum 1 as a latent image carrier of the printer, a charger 2 as a charging unit, an optical writing unit 3 as an image data writing unit, a developing unit 4 as a developing unit, and a supply of transfer paper 11 are provided. Paper feed unit 5 as paper means, transfer roller 6 as transfer means, fixing unit 7 as fixing means, transfer paper 1
A paper discharging unit 8 as a paper discharging unit, a photoreceptor cleaning unit 9b as a second collecting unit and a part of a collected developer recycling unit, a discharging lamp (quenching lamp) 10 as a discharging unit, and the like are arranged. Has been established.

In FIG. 1, when image data is sent from a host computer (not shown) or the like, the photosensitive drum 1
Is rotated at a constant speed in a direction indicated by an arrow (clockwise) in the figure by a driving means such as a motor (not shown). With the rotation, first, the surface of the photosensitive drum 1 is uniformly charged by the charger 2 in the dark. Next, based on the image data, writing light is irradiated and imaged from the optical writing unit 3 on the surface of the photosensitive drum 1, and an electrostatic latent image corresponding to the image data is formed on the surface by the irradiation image. You.

The image data is written by the writing control board connected to the optical writing unit 3 upon receiving an exposure start command from a CPU board (to be described in detail later) which controls the operation of the printer body. Sent from the write control board.

The electrostatic latent image formed on the surface of the photosensitive drum 1 is visualized by the adhesion of toner, which is an image forming substance, in the developing solution 12 supplied from the developing unit 4. A toner image corresponding to the image data is formed.

On the other hand, in parallel with such an image forming process, the transfer paper 11 as a recording medium stacked and housed in the paper feed cassette 51 of the paper feed unit 5 is moved by the paper feed roller 52 and the separation roller 53 to one sheet. The sheets are separated and fed, and are held in a state of being held between a pair of registration rollers 54. Then, the leading end of the toner image visualized on the surface of the photosensitive drum 1 and the transfer paper 11 held between the registration rollers 54
At a timing such that the leading end of the image forming area of FIG.
The transfer paper 11 is conveyed toward the nip by the registration rollers 54. By this conveyance, the transfer paper 11 passes through the nip between the photosensitive drum 1 and the transfer roller 6, and the toner image visualized on the surface of the photosensitive drum 1 is transferred onto the transfer paper 11 at the nip.

The transfer paper 11 onto which the toner image has been transferred in this manner is subjected to a fixing process of the toner image by a fixing unit 7 having a heating roller 7a and a pressure roller 7b. The paper is discharged onto a paper discharge tray 82 by a paper discharge roller 81.

The residual potential is removed from the surface of the photosensitive drum 1 through the toner image transfer step by the charge removing lamp 10. The residual developer remaining on the surface of the photosensitive drum 1 from which the residual potential has been removed is mechanically scraped and removed by the cleaning blade 9b-1 of the photosensitive member cleaning unit 9b, and is transferred to the recovery liquid container 9b-2. It falls and becomes the second recovered developer.

Next, the developing unit 4 of the printer will be described. The developing unit 4 includes a developing belt 41 as a developer carrier, a developer tank 45 as a developer container, a developing solution layer applying roller 42, a liquid layer thickness regulating roller 43, a corona charger 44, a bias roller 46, and the like. Have. Further, a developing belt cleaning unit 9a which is a first collecting unit and a part of the collected developer recycling unit is provided. Note that, in the developing unit 4, the developing belt 41 is used as a developer carrier, but the developer carrier is not limited to the developing belt 41, and may be, for example, a developing roller.

In FIG. 1, the developing belt 41 is rotatably stretched by a plurality of rollers including a bias roller 46, and is driven to rotate in a direction indicated by an arrow (counterclockwise) in FIG. The developing belt 41 is stretched such that the surface thereof is in contact with the surface of the photosensitive drum 1 at a portion stretched by the bias roller 46.

A predetermined amount of the developer 1 is stored in the developer tank 45.
2 are accommodated. The developer 12 accommodated in this manner is a high-concentration and high-viscosity developer in which the amount of a solvent component such as a carrier liquid and the amount of a toner component as an image forming substance are adjusted at an appropriate ratio. .

The developing solution layer applying roller 42 is rotated so that the lower portion of the peripheral surface is immersed in the developing solution 12 stored in the developing solution tank 45 and the upper portion of the peripheral surface is in contact with the surface of the developing belt 41. It is freely disposed, and is rotationally driven in the direction of the arrow by a driving unit (not shown). When the developing solution layer applying roller 42 rotates, the developing solution 12 stored in the developing solution tank 45 adheres to the peripheral surface of the developing solution layer applying roller 42 and is pumped up. The developer 12 thus pumped is thinned to a predetermined uniform layer thickness by regulating the liquid amount by the liquid layer thickness regulating roller 43, and the developer thin layer having the uniform layer thickness is formed. It is applied to the surface of the developing belt 41 as it is.

The developer thin layer uniformly coated on the surface of the developing belt 41 in this manner has its charge amount increased by the action of the corona charger 44, and is formed on the component layer made of toner and on the component layer. To a certain extent by the solvent layer. By forming the component layer in this manner, physical adsorption of the toner to the non-image portion of the electrostatic latent image formed on the surface of the photosensitive drum 1 is avoided, and the image transferred to the transfer paper 11 is prevented. It is possible to prevent background contamination.

The thin developer layer charged by the corona charger 44 is applied to the bias roller 4 of the developing belt 41.
6 and contacts the surface of the photosensitive drum 1. Then, the toner inside is attracted to the electrostatic latent image formed on the surface of the photosensitive drum 1 by the developing bias applied to the bias roller 46, and a toner image is formed on the surface. At this time, the toner on the developing belt 41 undergoes electrophoresis under the influence of the developing bias, so that the toner traverses a solvent layer made of almost only a solvent and adheres to the image area.
On the other hand, in the non-image area on the photosensitive drum, the component layer is separated by the corona charger 44 as described above,
Only the component layer made of the solvent comes into contact, and physical adsorption of the toner to the non-image portion is avoided.

In this way, the toner is prevented from adhering to the image area on the photosensitive drum 1. Both the toner and the solvent adhere to the image area, and only the solvent is applied to the non-image area. Alternatively, a very small amount of toner adheres to the solvent. For this reason, the residual developer remaining on the surface of the developing belt 41 that has passed between the bias roller 46 and the photosensitive drum 1 without contributing to the development of the electrostatic latent image is a ratio of the solvent amount to the toner amount. Is different from that of the developer 12 before use. The residual developing solution is mechanically scraped off from the surface of the developing belt 41 by the cleaning blade 9a-1 of the developing belt cleaning unit 9a, and then falls into the collecting solution container 9b-2, where the first collected developing solution is removed. Becomes

Also, the ratio of the solvent amount to the toner amount of the second recovered developer recovered from the surface of the photosensitive drum 1 after the transfer process by the above-described photoconductor cleaning unit 9b is changed to the developer before use. It is different from the one of 12.

As described above, in the wet electrophotographic type image forming apparatus, the first recovered developer from the developer carrier and the second recovered developer from the latent image carrier depend on the amount of the solvent and the image formation. The ratio with the substance amount differs from the component ratio of the developer before use. Therefore, when the collected developer is returned to the developer tank 45 as it is and reused as the developer 12 for development, the ratio between the solvent amount and the toner amount of the developer 12 in the developer tank 45 is changed to the initial state. , The quality of the toner image formed on the photosensitive drum 1 is degraded.

Therefore, the first recovered developer recovered from the surface of the developing belt 41 after the development process and the second recovered developer recovered from the surface of the photosensitive drum 1 after the transfer process can be used without causing such a problem. In order to recycle and use, it is necessary to appropriately adjust the ratio between the solvent amount and the toner amount of the recovered developer.

Hereinafter, a configuration for adjusting the ratio between the amount of the solvent of the collected developer and the amount of the toner in the printer of the present embodiment will be described. FIG. 2 shows a mixed recovered developer obtained by mixing the first recovered developer from the developing belt 41 and the second recovered developer from the photosensitive drum 1. An example of the component ratio adjusting means for adjusting the ratio is shown. The component ratio adjusting means is also a part of the recovered developer recycling means.

In FIG. 2, the first recovered developer collected from the developing belt 41 (not shown) by the developing belt cleaning unit 9a and the photosensitive member cleaning unit 9
The second recovered developer recovered from the photosensitive drum (not shown) by b is transported to the recovered liquid tank 9c-3 of the component adjustment unit 9c via the dedicated recovery pipe. Then, the mixture is stirred and mixed by a stirring member 9c-4 provided inside the collection liquid tank 9c-3 to form a mixed collection developer. A toner replenishing pipe 9c-1 and a solvent replenishing pipe 9c-2 are connected to the recovery liquid tank 9c-3, and the toner replenishing pipe 9c-1 is connected to a toner replenishing means (not shown). Further, the solvent replenishing pipe 9c-2 is connected to a solvent replenishing means (not shown). Recovery liquid tank 9c-
The mixed and recovered developer in 3 is replenished as necessary with one or both of the toner and the solvent by the toner replenishing means and the solvent replenishing means. The ratio with the amount is adjusted.

At the lower end of the side surface of the recovery liquid tank 9c-3, a three-way automatic valve 9 which opens and closes by being driven by an electromagnet or a motor is provided.
c-5 is provided. Of the three flow paths of the three-way automatic valve 9c-5, the remaining two flow paths respectively include a pipe 9c-6 opening to the atmosphere and a developing solution of the developing unit 4 via a negative pressure pump 9c-8. Pipe 9c leading to tank 45
7 is connected.

The three-way automatic valve 9c-5 is provided with a flow path from the pipe 9c-6 to the pipe 9c-7 and a recovery liquid tank 9c-3.
Can be switched from the flow path to the pipe 9c-6, and the latter flow path is selected except when transporting the mixed and collected developer in the recovery liquid tank 9c-3 to the developer tank 45. ing. When a certain amount or more of the mixed recovery developer is accumulated in the recovery liquid tank 9c-3 and a predetermined amount of toner or solvent is replenished, and the components of the mixed recovery developer are adjusted, the former is completed. Is selected. After the selection, when the negative pressure pump 9c-8 operates, the mixed and collected developer solution whose components have been adjusted in the recovery solution tank 9c-3 is transported through the pipe 9c-7 toward the developer solution tank 45, and the developer Is recycled as the developing solution 12.

FIG. 3 is a block diagram showing an example of a control system of the printer according to this embodiment. In FIG. 3, the printer main body is controlled by a CPU board 100 which is a main control board. Various control parts such as a sensor 101, a clutch 102, and a motor 103 for controlling the operation of each unit described above are connected to the CPU board 100, which is also a control unit of the collected developer recycling unit. The operation of the printer is realized by controlling the components according to a predetermined image forming program.

A write control board 104 is connected to the CPU board 100.
Thus, the data processing and writing control of the image data described above are performed. Since the optical writing process for the photosensitive drum 1 has a lot of processing contents, the writing control board 104 is often configured separately from the main CPU board 100 as described above. Then, upon receiving a write start command signal from the CPU board 100, predetermined image data is sent to the optical writing unit 3, and the optical writing operation on the photosensitive drum 1 is performed while controlling the timing.

A host computer 105 is connected to the write control board 104, and the host computer 105 transmits the image data to the write control board 10.
4 and stored in a memory in the write control board 104 or an external memory controlled by the write control board 104. The write control board 104 transmits the image data stored in this manner to the optical writing unit 3 in accordance with a write start command from the CPU board 100.

The optical writing unit 3 forms an image portion composed of an electrostatic latent image on the photosensitive drum 1 on the basis of the image data transmitted as described above. The product of the area of the image portion and the image density is formed. Has a certain relationship with the amounts of the toner and the solvent of the developer 12 consumed for developing the image area.
In addition, the area of the non-image portion has the same relationship. That is, the consumption characteristics of the developer from the developing belt 41 to the photosensitive drum 1 and the consumption characteristics of the developer from the photosensitive drum 1 to the transfer paper 11 are related to the area of the image area and the area of the non-image area of the photosensitive drum 1. There is. Therefore, in the above-described developing step, at what rate the toner and the solvent in the developer thin layer formed on the developing belt 41 are transferred to the image area and the non-image area formed on the photosensitive drum 1. It is possible to predict the amounts of toner and solvent that are actually consumed in the developing process for developing the image portion formed of the electrostatic latent image formed on the photosensitive drum 1 by checking whether the toner is moved. It becomes possible. Also,
In the transfer step, it is necessary to check in advance how much the toner and the solvent attached to the image portion and the non-image portion on the photosensitive drum 1 are transferred to the transfer paper 11 and the transfer roller 6. For example, it is possible to predict the amounts of toner and solvent actually consumed in the transfer step. Then, based on these prediction results, if the apparatus is configured to adjust the ratio of the amount of the solvent and the amount of the toner of the mixed recovery developer to be recycled and used, it is possible to provide no special detecting means.
It is possible to keep the ratio after adjustment within a certain allowable range.

Therefore, in the present printer, the consumption characteristics of the developing solution from the developing belt 41 to the transfer paper 11 via the image portion of the photosensitive drum 1 are investigated by a preliminary experiment, and are converted into a database or a relational expression. The database or the relational expression is stored in a data storage device such as a ROM, a RAM, and a hard disk (not shown). Also,
The consumption characteristics of the developing solution from the developing belt 41 to the transfer paper 11 and the transfer roller 6 via the non-image portion of the photosensitive drum 1 are investigated, and a database or a relational expression is prepared.
This database or relational expression is also stored in the data storage device. Then, at the time of the printing operation, the image area of the photosensitive drum 1 is calculated based on the image data. Based on the calculation result and the database or the like regarding the image area, the developing belt 41 is used to calculate the area of the photosensitive drum 1. The amount of toner and solvent consumed through the image area to the area corresponding to the image area of the transfer paper 11 is predicted. Further, the non-image area of the photosensitive drum 1 is calculated, and the transfer paper 11 is transferred from the developing belt 41 to the non-image area of the photosensitive drum 1 via the non-image area of the photosensitive drum 1 based on the calculation result and the above-mentioned database and the like. And the amount of toner and solvent consumed to the transfer roller 6 is predicted. Then, based on these prediction results, the amount of the toner or the solvent to be replenished to the mixed and collected developer is determined, and the amount of the toner or the solvent is replenished to the mixed and collected developer.

The component ratio (the ratio between the amount of toner and the amount of solvent) in the first recovered developer from the developing belt 41 and the second recovered developer from the photosensitive drum 1 is adjusted individually. You may comprise. In the case of such a configuration, the amounts of the toner and the solvent to be replenished to the first recovered developer may be determined as follows. That is, through preliminary experiments, the consumption characteristics of the developer due to the movement of the photosensitive belt 1 from the developing belt 41 to the image area and the consumption characteristics of the developer due to the movement of the photosensitive drum 1 from the development belt 41 to the non-image area are investigated. Into a database or a relational expression.
Then, based on the calculation results of the image area and the non-image area and these databases and the like, the amounts of toner and solvent consumed from the developing belt 41 to the image area of the photosensitive drum 1, The amount of the toner and the solvent consumed to the image portion of the drum 1 is predicted. Furthermore, based on these prediction results, the amounts of toner and solvent to be replenished to the first recovered developer recovered from the developing belt 41 may be determined. In addition, the photosensitive drum 1
The characteristics of the consumption of the developer due to the transfer from the image portion to the transfer paper 11 and the transfer roller 6 and the characteristics of the consumption of the developer due to the transfer from the non-image portion of the photosensitive drum 1 to the transfer paper 11 and the transfer roller 6 were investigated. If you make a database or a relational formula,
Similarly, the amount of the toner or the solvent to be replenished to the second recovered developer can be determined.

When the amount of toner consumed from the non-image portion of the photosensitive drum 1 to the transfer paper 11 or the transfer roller 6 is negligible, the calculation of the amount of toner is omitted. You may comprise.

When adjusting the component ratio of the mixed and collected developer as in the present printer, the developer is consumed from the developing belt 41 via the image portion of the photosensitive drum 1 to the image portion corresponding area of the transfer paper 11. Transfer toner 1 from the developing belt 41 via the non-image portion of the photosensitive drum 1
1 and the amount of toner and solvent consumed to the transfer roller 6 without predicting the consumption amount, based on the calculation result of the area of the image portion and the non-image portion and the database, etc. The replenishing solvent amount may be directly determined.

As for the area of the non-image portion of the photosensitive drum 1, the area of the non-image portion of the developing solution adhering region (the contact region with the developing belt 41) of the photosensitive drum is calculated.
Further, regarding the area of the non-image portion, the transfer paper 1
It is desirable that the apparatus be configured to individually calculate the area of the region corresponding to the size of 1 and the area of the region not corresponding to the size. As described above, by calculating the area of the non-image portion separately, even if the size of the transfer paper 11 to be used is changed from the A4 size to the B5 size, for example, the photosensitive drum 1 comes into contact with the transfer paper 11 so as to contact the photosensitive drum. 1 and the amount of solvent (and a very small amount of toner) consumed from the non-image area to the transfer paper 11 and from the non-image area to the transfer roller 6 due to the contact between the photosensitive drum 1 and the transfer roller 6. It is possible to accurately predict the amount of the solvent (and a very small amount of toner).

In the preliminary experiment, the consumption characteristics of the developer when the image density of the image portion on the photosensitive drum 1 was changed were also investigated as the consumption characteristics of the developer. It is desirable to store a database and a relational expression for the above in the data storage means. Then, at the time of the printing operation, the average image density of the image portion on the photosensitive drum 1 is also calculated based on the image data, and the consumed toner amount is predicted based on a database or the like regarding the average image density. It is desirable to configure. With this configuration, the ratio between the amount of toner and the amount of solvent in the mixed recovery developer can be more accurately adjusted.

The timing of replenishment of the mixed recovery developer with the toner and the solvent is determined by the developing belt cleaning unit 9a.
The transfer timing of the first recovered developer from the cleaning unit 9b to the recovery liquid tank 9c-3 and the transfer timing of the second recovered developer from the photoconductor cleaning unit 9b to the recovery liquid tank 9c-3 vary.

For example, in a case where the collected developer is constantly conveyed from the cleaning units (9a and 9b) to the collected liquid tank 9c-3, every time the developing belt 41 is moved by a predetermined amount, Replenishment timings such as each time the photosensitive drum 1 is rotated by a predetermined angle, each time a printing operation on a predetermined number of transfer sheets is completed, and the like are possible.

For example, when a certain amount of collected developer is stored in each cleaning unit and each collected developer is transported to the collected liquid tank 9c-3 at a predetermined timing, the following method is used. It can be considered that the toner and the solvent are replenished in this way. That is,
First, each time the developing belt 41 is moved by a predetermined amount, each time the photosensitive drum 1 is rotated by a predetermined angle, or each time the printing operation on a predetermined number of transfer sheets is completed,
The amount of the toner or the solvent that needs to be newly replenished for each collected developer is calculated. Then, the calculation result is cumulatively added to the previous calculation result, and the cumulative amount of the toner and the solvent to be replenished to each collected developer in each cleaning unit is calculated. Next, at the time when each collected developer is transported from each cleaning unit to the collected liquid tank 9c-3, the toner and the solvent corresponding to these accumulated amounts are replenished to the mixed collected developer and the accumulated amounts are reset to zero. It is conceivable to configure so that the

The image density, the image area, and the non-image area are determined by the CPU board 100 and the writing control board 1.
04 or another calculation means, but the printer according to the present embodiment is configured to cause the writing control board 104 to calculate. Further, regarding the amount of toner and the amount of solvent to be replenished,
The PU board 100 or another determining means may be used for the determination, but in the printer of the present embodiment, the CPU board 100 is configured to determine the data, and the CPU board is provided with the data storage means. Connected. That is, in the printer of the present embodiment, the writing control board 104 functions as a calculation unit for the image area and the non-image area, and the CPU board 100 functions as a determination unit.

The writing control board 104 receives light at predetermined timing, such as every time the developing belt 41 moves by a predetermined amount, every time the photosensitive drum 1 rotates by a predetermined angle, or every time a printing operation on a predetermined number of transfer papers 11 is completed. The respective areas of the image portion and the non-image portion newly formed on the drum 1 and the image density of the image portion are calculated and transmitted to the CPU 100 as image density data, image area data and non-image portion area data. The CPU 100 includes a write control board 104
The consumption of toner and solvent is estimated based on the data transmitted from the above and the above-mentioned beta base stored in the data storage means. Then, based on the prediction result, the amounts of the toner and the solvent to be replenished to the mixed and collected developer are determined, and the amount of the mixed and collected toner is controlled while controlling the driving amount of the toner replenishing unit 9c-14 and the solvent replenishing unit 9c-15. The developer is replenished with the determined amount of toner and solvent. By this replenishment, the component ratio of the mixed and recovered developer can be adjusted to a value equivalent to the component ratio of the developer in the initial state.

As described above, in the present printer, the CPU board 100 controls the driving amount of the toner replenishing means 9c-14 and the solvent replenishing means 9c-15, thereby adjusting the component ratio of the mixed and recovered developer. The component ratio can be controlled in any manner by changing the driving amount. The purpose of the present invention is to obtain the control information of the driving amount based on the image data and the database.

Here, the toner replenishing amount from the toner replenishing means 9c-14 to the mixed and recovered developer and the solvent replenishing means 9c
From −15, it is desirable that the replenishment amount of the solvent to the mixed recovery developer is set to the same amount as the toner consumption amount and the solvent consumption amount, respectively. Specifically, the toner and the solvent consumed from the developing belt 41 to the transfer paper 11 via the image portion of the photosensitive drum 1, and the transfer paper from the developing belt 41 via the non-image portion of the photosensitive drum 1 The CPU 100 controls the driving amount of the toner replenishing unit 9c-14 and the solvent replenishing unit 9c-15 so that the same amount of toner and solvent as the toner and solvent consumed to the transfer roller 11 and the transfer roller 6 are replenished. Is desirable. By such control, the same amount of toner and solvent as the consumed toner and solvent are replenished to the mixed recovery developer as it is, and the components of the mixed recovery developer are adjusted. And by this,
The component ratio and liquid amount of the developer 12 in the developer circulation system of the present printer are kept constant. As a result, it is possible to form a stable quality image without developing defects due to an abnormality in the component ratio of the developer 12 or a change in the amount of the developer.

As another method of adjusting the component ratio of the mixed and recovered developer, the developer 12
Only the one that has been consumed more than the component ratio in the initial state may be replenished to the mixed recovery developer.
For example, when the ratio between the amount of toner and the amount of solvent in the developer 12 in the initial state is 9: 1, when the developer 12 is consumed at a ratio of 8: 2, the developer 12 is consumed at a higher ratio. You may make it replenish only a solvent. However, replenishment is performed so that the component ratio of the mixed recovery developer is maintained in the same manner as in the initial state. With such a replenishment of the toner and the solvent, the component ratio of the mixed and recovered developer is substantially the same as that of the developer 12 in the initial state only by replenishing the minimum amount of the toner or the solvent to the mixed and recovered developer. Can be adjusted. Therefore, in such an adjustment method, for example, even when the estimated consumption amount of the developer 12 is slightly different from the actual consumption amount, for example, the collection liquid tank 9c-3.
It is unlikely that the excess developer is transported from the developer tank 45 to the developer tank 45 and the developer 12 in the developer tank 45 overflows. When the consumption rates of the toner and the solvent are significantly different, only one of the toner and the solvent may be required as a component to be replenished to the mixed recovery developer. Specifically, if the excessively consumed component is fixed to one component in any image, only one component needs to be prepared as a supplemental component. In this case, simplification and downsizing of the printer can be promoted.

However, for some reason, the amount of components replenished to the mixed and recovered developer for adjusting the component ratio of the mixed and recovered developer becomes larger than the actual consumption, and The stored developer 12 may overflow. Therefore, in the printer according to the present embodiment, as shown in FIG.
Is provided in the developer tank 45 to detect whether or not the maximum allowable storage amount has been reached.

The liquid amount upper limit detection sensor 9c-16 is connected to the CPU board 100 as shown in FIG. When the liquid amount upper limit detection sensor 9c-16 detects that the developer storage amount in the developer tank 45 has reached the maximum allowable storage amount, this detection information signal is transmitted to the CPU board 100. Upon receiving this detection information signal, the CPU board 100 corrects the operation amount of the collected developer recycling means. Specifically, the toner replenishing means 9c-
14 toner replenishment operation amount and solvent replenishment means 9c-15
Is corrected. With this, even if the toner replenishment amount or the solvent replenishment amount for the mixed recovery developer exceeds the consumed toner amount or the solvent amount due to an unexpected situation, and even if the storage amount of the developer in the developer tank 45 gradually increases, The operation amount of the collected developer recycling means is corrected.
By this correction, the toner replenishment amount and the solvent replenishment amount for the recovered developer approach the consumed toner amount and the solvent amount, and the overflow of the mixed recovery developer from the developer tank 45 is avoided.

As the liquid amount upper limit detection sensor 9c-16,
When the viscosity of the developer 12 contained in the developer tank 45 is relatively low, an optical sensor for measuring the transmitted light intensity of the developer 12, a float for detecting the vertical movement of the float floating on the liquid surface A switch, an electrode sensor for detecting an electrical conduction state between the electrodes provided at various height levels in the developer tank 45, and the like can be used.
The developer 12 stored in the developer tank 45
If the reliability of the detection accuracy of the optical sensor, the float switch, the electrode sensor, and the like is impaired due to the relatively high viscosity of the developer, the weight of the developer tank 45 itself is measured. Based on the developer tank 45
Alternatively, it may be determined whether or not the developer storage amount in the printer has reached the maximum allowable storage amount.

On the other hand, if the replenishment amounts of the toner and the solvent determined by the CPU 100 are different from the actual consumption amounts for some reason, the mixed and collected toner is adjusted to adjust the toner component and the solvent component of the mixed and collected developer. In some cases, the amount of the component replenished in the developer becomes smaller than the actual consumption, and the amount of the developer stored in the developer tank 45 becomes insufficient. In particular, of the toner and the solvent, only the one consumed more than the component ratio in the initial state of the developer 12 is
When the configuration is such that the mixed recovery developer is replenished, the capacity of the developer 12 in the developer tank 45 gradually decreases.

As described above, when the storage amount of the developer 12 stored in the developer tank 45 becomes smaller than a certain value, for example, the developer 12
Since the supply amount of the developer 12 to the developer layer applying roller 42 for applying the developer is reduced, the developing ability of the developer thin layer applied on the developing belt 41 is reduced, and as a result, the image quality is deteriorated. This causes a problem. In a severe case, the image is not printed at all.

Therefore, in this printer, as shown in FIG. 4, a liquid amount lower limit detecting sensor 9c-17 for detecting whether or not the amount of developing solution in the developing solution tank 45 has reached the minimum allowable amount is provided. , The developer tank 45. Further, a start agent storage tank 9c-13 containing a start agent 12a made of a developer adjusted to an appropriate component ratio.
And the start agent storage tank 9c-13 and the developer tank 45 are connected by a transport pipe 9c-10. Further, in the middle of the transport pipe 9c-10, a three-way automatic valve 9c-
12 and a negative pressure pump 9c-9.

As shown in FIG. 3, the liquid level lower limit detection sensor 9c-17 is also connected to the CPU board 100. The developer tank 45 is detected by the liquid amount lower limit detection sensor 9c-17.
When it is detected that the developer storage amount in the printer has reached the minimum allowable storage amount, this detection information signal is sent to the CPU board 10.
Sent to 0. When the CPU board 100 receives the detection information signal, the CPU board 100 drives the three-way automatic valve 9c-12 so as to make the connection between the negative pressure pump 9c-9 and the starting agent storage tank 9c-13, and at the same time, the negative pressure pump 9c -9 is controlled to operate. By this control, the start agent 12a stored in the start agent storage tank 9c-13 passes through the transport pipe 9c-10 and the developer tank 4a.
5 transported. Therefore, even if a factor that causes a shortage of the developer storage amount in the developer tank 45 occurs as described above, it is possible to prevent the adverse effect caused by the shortage of the developer storage amount. This also allows normal printing of images to be continued.

As the lower limit detection sensor 9c-17,
Similarly to the liquid amount upper limit detection sensor 9c-16, an optical sensor, a float switch, an electrode sensor, or the like can be used. When the reliability of the detection accuracy of the optical sensor, the float switch, and the electrode sensor is impaired, the amount of the developer contained in the developer tank 45 is reduced based on the measurement result of the weight of the developer tank 45 itself. You may make it determine whether it has reached the minimum permissible storage capacity.

[0069]

According to the first, second, third, fourth, fifth and sixth aspects of the present invention, the amount of the image forming substance in the recovered developer can be reduced without providing any special detecting means for detecting the characteristics of the developer. There is an excellent effect that the recovered developer can be reused by appropriately adjusting the ratio between the solvent and the amount of the solvent.

In particular, according to the second aspect of the present invention, even if the size of the recording medium to be used is changed, the amount of the solvent or the amount of the image forming substance transferred from the non-image portion of the latent image carrier to the recording medium is changed. The amount of the solvent and the amount of the image forming substance transferred from the non-image portion of the latent image carrier to the pressing member and the amount of the solvent and the amount of the image forming substance which are closer to the collecting developer can be replenished to the collecting developer. There is an excellent effect that the ratio between the amount of the image forming substance and the amount of the solvent in the developer can be more accurately adjusted.

In particular, according to the third aspect of the present invention, a decrease in image quality caused by an increase or decrease in the amount of the developer in the developer circulation system is avoided, so that a stable quality image can be formed. There is an excellent effect that can be.

According to the fourth aspect of the present invention, only the component having a higher consumption rate among the consumed image forming substance and the solvent is replenished to the mixed recovery developer, so that the minimum amount of There is an excellent effect that the above ratio of the mixed and collected developer can be adjusted only by replenishing the mixed and collected developer with the image forming substance or the solvent. Further, when the consumption rates of the image forming substance and the solvent are remarkably different, only the replenishment of only one of the image forming substance and the solvent is performed, and the ratio of the mixed recovery developer is set to the initial state. Since it can be made equivalent to that of the developer, in such a case, there is an excellent effect that the apparatus can be simplified and downsized.

In particular, according to the invention of claim 5, since the replenishing amount of the image forming substance and the replenishing amount of the solvent with respect to the collected developer are brought close to the consumed amount of the image forming substance and the amount of the solvent, the developing amount from the developing solution storage portion There is an excellent effect that the overflow of the solution can be avoided and the ratio of the recovered developer can be adjusted more accurately.

In particular, according to the sixth aspect of the present invention, the shortage of the developing solution which can occur in the developing solution storage portion is avoided, and thus the image quality caused by the shortage of the developing solution, for example, due to the deterioration of the developing capacity. There is an excellent effect that an adverse effect such as deterioration of the device can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a printer according to an embodiment.

FIG. 2 is a schematic configuration diagram illustrating an example of a component ratio adjusting unit in the printer.

FIG. 3 is a block diagram showing an example of a control system of the printer.

FIG. 4 is a schematic configuration diagram showing a more specific example of the component ratio adjusting means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charger 3 Optical writing unit 4 Developing unit 5 Paper feed unit 6 Transfer roller 7 Fixing unit 8 Discharge unit 9 Recovered developer recycling means 10 Static elimination lamp 11 Transfer paper 12 Developing solution 41 Developing belt 42 Developing solution layer Coating roller 43 Liquid layer thickness regulating roller 44 Corona charger 45 Developer tank 46 Bias roller 100 CPU board 104 Writing control board 105 Host computer

Claims (6)

[Claims] 1. A latent image carrier, a latent image forming means for forming a latent image on the latent image carrier based on image data, and a thin layer of a developer containing an image forming substance and a solvent are developed. Developing means for forming the latent image on the developer carrier and bringing the thin layer into contact with the latent image carrier to develop the latent image, and transfer means for transferring the latent image on the latent image carrier to a recording medium A first recovery unit that recovers a residual developer remaining on the developer carrier after visualization, a second recovery unit that recovers a residual developer remaining on the latent image carrier after transfer, Adjusting the ratio between the amount of the image forming substance and the amount of the solvent in the collected developer collected, and recycling the collected developer to reuse the collected developer, and a controller for controlling the collected developer recycling. The latent image formed on the latent image carrier based on the image data. Calculating means for calculating the area of the image area and the area of the non-image area in the developer adhering area of the latent image carrier; and forming an image to be replenished to the recovered developer based on the calculation result of the calculating means. Determining means for determining the substance amount and the solvent amount; and control means for controlling the recovered developer recycling means, wherein the recovered developer recycling means adjusts the ratio based on the determination result of the determining means. 1. A wet image forming apparatus, comprising: 2. The wet image forming apparatus according to claim 1, wherein, in the area of the non-image area, the area of the area corresponding to the recording paper and the area of the area not corresponding to the recording paper are calculated separately. A wet-type image forming apparatus characterized by comprising means. 3. The wet image forming apparatus according to claim 1, wherein said collected developer recycling means mixes the collected developer with said first collecting means and the collected developer with said second collecting means. A wet image forming apparatus comprising: replenishing the mixed and recovered developer with the same amount of an image forming substance and a solvent as the result of the determination by the determining means, and adjusting the ratio. 4. The wet image forming apparatus according to claim 1, wherein said collected developer recycling means mixes the collected developer with said first collecting means and the collected developer with said second collecting means. The wet mixed image, wherein the ratio is adjusted by replenishing only the portion of the image forming substance and the solvent that has been consumed more than the ratio in the initial state of the developer with respect to the mixed recovery developer. Forming equipment. 5. A wet image forming apparatus according to claim 1, wherein the developer accommodating portion for accommodating the developer and the amount of the developer in the developer accommodating portion reach a maximum allowable amount. A liquid amount upper limit detection sensor for detecting whether or not the developer amount in the developer container has reached the maximum allowable storage amount by the liquid amount upper limit detection sensor. A wet image forming apparatus comprising: a ratio adjustment operation amount correction control unit that corrects an operation amount of a ratio adjustment operation of a liquid recycling unit. 6. The wet image forming apparatus according to claim 1, wherein the developer storage section for storing the developer and an amount of the developer in the developer storage section are set to a minimum allowable storage amount. A liquid amount lower limit detection sensor for detecting whether or not the developer amount has reached the liquid amount lower limit detection sensor, and the liquid amount lower limit detection sensor detects that the developer amount in the developer container has reached the minimum allowable storage amount. A developing solution replenishing means for replenishing the developing solution container with a new developing solution whose ratio is appropriately adjusted.