JP2005315950A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus, having simple constitution to supply liquid developer to a development device, and capable of preventing air from being taken in the liquid developer, in supplying the liquid developer from a storage tank to the development device. <P>SOLUTION: The image forming apparatus is provided with the development device for visualizing an electrostatic latent image with the liquid developer and the tanks 51 to 54 and 57 for storing the liquid developer, with which the developing device is replenished. The tanks 51 to 54 and 57 are formed cylindrical in shape and are supported to rotate, centered about their axial lines. The tanks 51 to 54 and 57 are provided with supply ports 73 on the circumferential sides of their end walls. By rotating the tanks 51 to 54 and 57 by a driving motor, the positions of the supply ports 73 are changed, so that the liquid developer in the tanks 51 to 54 and 57 is supplied to the development device from the supply ports 73. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wet image forming apparatus employed in a copying machine, a facsimile machine, a printer, or the like.

  In general, in this type of image forming apparatus, an electrostatic latent image is formed by irradiating the surface of a photosensitive drum with light according to image information, and toner and carrier are formed on the electrostatic latent image. A liquid developer made of a liquid is attached by a developing roller, whereby a toner image is formed on the photosensitive drum. The liquid developer stored in the liquid developer storage container is stirred and mixed by a stirring screw, and applied to the outer peripheral surface of the developing roller by a supply roller and an application roller.

  Further, when the liquid developer stored in the liquid developer storage container becomes a predetermined amount or less due to the application of the liquid developer to the photosensitive drum as described above, the liquid developer replenishing device removes the liquid from the storage tank. A liquid developer is supplied to the developer storage container. At the same time, the carrier liquid is supplied from the carrier liquid tank to the liquid developer storage container by the carrier liquid supply device.

Thus, in order to replenish the liquid developer and the carrier liquid, for example, as disclosed in Patent Document 1 and Patent Document 2, a configuration in which a liquid developer supply pump and a carrier liquid supply pump are provided in the supply pipe line Has been proposed.
JP-A-10-177304 JP 2000-214687 A

  However, in these conventional configurations, there is a problem that the structure is complicated because the supply pump is provided in the supply line for the liquid developer and the carrier liquid. In these configurations, a supply port to the supply pipe is generally formed at one place in the lower part of the liquid developer or carrier liquid storage container, so that the liquid developer and carrier liquid are externally supplied from the supply port. When supplied, a vortex centering on the supply port is formed in these liquids, and air is easily taken into the liquids. As described above, when the liquid developer or the carrier liquid is supplied to the liquid developer storage container in a state of taking in air and the dispersion adjustment of the liquid developer is performed, fine bubbles are mixed in the liquid developer. There is also a problem that a defect occurs in image formation.

  The present invention has been made paying attention to such problems existing in the prior art. The purpose is to simplify the supply configuration of the liquid developer to the developing device and to prevent air from being taken into the liquid developer when the liquid developer is supplied from the storage tank to the developing device. An object is to provide an image forming apparatus.

  In order to achieve the above object, an invention according to claim 1 is provided to store a developer for visualizing an electrostatic latent image using a liquid developer and a replenishment liquid developer for the developer. In the image forming apparatus provided with the storage tank, the storage tank has a cylindrical shape as a whole, is supported rotatably about its axis, and has a developer supply port on the outer peripheral side of the end wall of the storage tank. It is characterized by providing.

The invention described in claim 2 is characterized in that, in the invention described in claim 1, changing means for changing the rotational position of the storage tank is provided.
According to a third aspect of the present invention, in the second aspect of the present invention, the operation of the changing unit is controlled so that the supply port maintains a predetermined relationship position with the liquid level of the liquid developer in the storage tank. The control means for providing is provided.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the supply port has a hose for supplying a liquid developer to the developing device at an end thereof. It is connected in a connecting tool, and the connecting tool is rotatable relative to the supply port.

  According to the first and second aspects of the present invention, when the liquid developer is supplied from the storage tank, the storage tank may be rotated. Accordingly, the supply pump is connected to the supply line from the storage tank to the developing device. The liquid developer supply configuration can be simplified. Also, when supplying the liquid developer from the storage tank to the developing device, the position of the supply port is changed by the rotation of the storage tank, and the liquid developer is taken out from the liquid level position, so air is taken into the liquid developer. Can be suppressed. Therefore, it is possible to prevent fine bubbles from being mixed in the liquid developer, and to prevent the possibility of problems in image formation. Furthermore, since the position of the supply port is changed by the rotation of the storage tank, the liquid developer stored in the storage tank can be supplied to a required location without leaving any excess.

  According to the third aspect of the present invention, when the liquid developer is supplied from the storage tank to the developing device, the supply port can be maintained at a predetermined relationship position with the liquid surface of the liquid developer in the storage tank. Therefore, it is possible to reliably prevent the air from being taken in from the supply port, and it is possible to suppress the disturbance of the liquid surface of the liquid developer due to the air being taken in. As a result, it is possible to stably supply the liquid developer from which bubbles are not mixed from the storage tank to the developing device.

  According to the fourth aspect of the present invention, even if the position of the supply port is changed with the rotation of the storage tank, the connector at the end of the supply hose is rotated relative to the supply port, so that the storage tank The liquid developer inside can be smoothly supplied from the supply port to the developing device via the supply hose.

Hereinafter, an embodiment in which the present invention is embodied in a tandem color image forming apparatus (hereinafter simply referred to as a wet image forming apparatus) will be described with reference to the drawings.
As shown in FIG. 1, the wet image forming apparatus includes a paper feed mechanism 11, a vertical conveyance path 12, a registration roller pair 13, a belt conveyance mechanism 14, a first image formation mechanism 15, a second image formation mechanism 16, and a first image formation mechanism 16. 3 image forming mechanism 17, fourth image forming mechanism 18, secondary transfer mechanism 19, fixing mechanism 20, discharge conveyance path 21, discharge tray 22, intermediate transfer cleaning unit 23, and the like. The paper feed mechanism 11 includes a paper feed cassette 11a and a pickup roller 11b, and transports the paper P in the paper feed cassette 11a to the vertical transport path 12 by the pickup roller 11b. The vertical conveyance path 12 conveys the sheet P conveyed from the sheet feeding mechanism 11 to the secondary transfer mechanism 19 via the registration roller pair 13.

  The belt conveying mechanism 14 includes a driving roller 14a, a driven roller 14b, and an endless intermediate transfer belt 14c that is stretched between the rollers 14a and 14b. The intermediate transfer belt 14c is maintained in an appropriate tension state by a tension roller 14d. Then, the drive roller 14a is rotated by a drive motor (not shown), so that the intermediate transfer belt 14c has a peripheral speed equivalent to the peripheral speed of the photosensitive drum 25 of each of the image forming mechanisms 15 to 18 described later, as shown in FIG. It is driven in the direction of the arrow.

  The first to fourth image forming mechanisms 15 to 18 are arranged for black (BK), magenta (M), cyan (C), and yellow (Y) from the left side in FIG. It has become. Here, for convenience of explanation, the configuration of the first image forming mechanism 15 will be described in detail with the first image forming mechanism 15 as a representative of image formation. Note that, in the other image forming mechanisms 16 to 18, the same components as those of the first image forming mechanism 15 are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 2, the first image forming mechanism 15 includes a photosensitive drum 25 as an image carrier, a main charging device 26, an LPH (LED PRINT HEAD) 27, and a liquid developer as a developing device constituting a developing unit. The apparatus 28, a primary transfer mechanism 29, a cleaning mechanism 30, and a static elimination lamp 31 are configured. These portions 25 to 31 are assembled in a synthetic resin casing so as to constitute one unit, and are attached to a body frame (not shown) of the wet image forming apparatus.

  The photosensitive drum 25 is made of an amorphous silicon drum, and is charged by the main charging device 26 so that the dark potential at the developing position is about 300V. Then, the surface of the charged photosensitive drum 25 is irradiated with light according to image information from the LPH 27, whereby an electrostatic latent image is formed on the surface of the photosensitive drum 25.

  The liquid developing device 28 uses a liquid developer composed of toner and carrier liquid with stirring and mixing so as to have a predetermined concentration, and the liquid developer is irradiated with light on the photosensitive drum 25 by a developing roller. A toner image is formed (developed) on the photosensitive drum 25 by applying to the electrostatic latent image of the portion. For this purpose, the dark potential of the photosensitive drum 25 is set to 300V, the developing bias is 200V, and the post-exposure potential is 20V. That is, the dark potential corresponds to the white portion of the image and the post-exposure potential corresponds to the black portion of the image, and this difference is a so-called contrast potential.

  The toner image developed (developed) from the electrostatic latent image on the photosensitive drum 25 as described above is transferred to the intermediate transfer belt 14c of the belt transport mechanism 14 by the nip with the primary transfer mechanism 29. . The primary transfer mechanism 29 includes a transfer roller, and a voltage having a polarity opposite to the surface potential of the photosensitive drum 25 is applied at a predetermined set value within a range of −200 to −1300V. The potential for image formation is set to an optimum value according to the characteristics of the photosensitive drum 25, the performance of the liquid developer, the environment, and the like.

  On the other hand, the transfer residual liquid developer remaining without being transferred on the photosensitive drum 25 is scraped off by a cleaning blade 47 described later in the cleaning mechanism 30 of the next process. Further, the photosensitive drum 25 is neutralized by a neutralizing lamp 31 so as to make the residual potential on the surface uniform and is prepared for the next series of image forming steps. In this wet image forming apparatus, images corresponding to magenta, cyan, and yellow are exposed by the second to fourth image forming mechanisms 16 to 18 in the same manner as the first image forming mechanism 15 described above. Full-color image formation is performed by developing on the body drum 25 and sequentially and repeatedly transferring onto the intermediate transfer belt 14c without positional deviation.

  As shown in FIG. 1, the secondary transfer mechanism 19 is constituted by a secondary transfer roller in this embodiment, and is disposed at a secondary transfer position on the vertical conveyance path 12. The secondary transfer position refers to a position where the secondary transfer mechanism 19 faces the driving roller 14a of the belt transport mechanism 14 and presses against the intermediate transfer belt 14c. A secondary transfer bias is applied to the secondary transfer mechanism 19, and an intermediate transfer belt is applied to the sheet P conveyed by the secondary transfer mechanism 19 via the vertical conveyance path 12 and the registration roller pair 13. A full color image is secondarily transferred from 14c.

  Then, the paper P after the secondary transfer of the full color image is separated from the intermediate transfer belt 14 c and conveyed to the fixing mechanism 20. The fixing mechanism 20 includes a first fixing roller 20a and a second fixing roller 20b. Each of the fixing rollers 20a and 20b includes a fixing heater (not shown) for heating to a predetermined temperature necessary for fixing. As a result, when the paper P passes while being pressed between the fixing rollers 20a and 20b, a fixing process of a full-color image is performed. Thereafter, the paper P is discharged from the fixing mechanism 20 to the discharge tray 22 via the discharge conveyance path 21.

  As shown in FIG. 1, the intermediate transfer cleaning unit 23 is configured by accommodating an intermediate transfer cleaning roller 23b, an intermediate transfer cleaning blade 23c, and a conveying screw 23d in a cleaning case 23a. The intermediate transfer cleaning roller 23b is pressed against the intermediate transfer belt 14c of the belt transport mechanism 14, and is rotated in the same direction as the rotation direction of the intermediate transfer belt 14c by a drive motor (not shown). The intermediate transfer cleaning blade 23c is in counter contact with the intermediate transfer belt 14c at a position downstream of the intermediate transfer cleaning roller 23b in the moving direction of the intermediate transfer belt 14c, and the liquid transfer residue is transferred from the intermediate transfer belt 14c. The liquid developer is scraped off and removed. The transport screw 23d collects the transfer residual liquid developer scraped off by the intermediate transfer cleaning blade 23c at the lower part in the cleaning case 23a.

Next, a specific configuration of the liquid developing device 28 in the first image forming mechanism 15 will be described with reference to FIG.
The liquid developing device 28 of this embodiment includes a liquid developer storage container 36 that stores the liquid developer 35. Inside the liquid developer storage container 36, a developing roller 37 as a liquid developer carrying member, a coating roller 38, a pumping roller 39, a doctor blade 40, a developing cleaning blade 41, and a pair of stirring screws 42 as stirring members, 43 is provided. The developing roller 37, the application roller 38, the pumping roller 39, and both the agitating screws 42 and 43 are rotationally driven by a drive motor (not shown) via a drive transmission mechanism including a gear train and the like.

  The liquid developer 35 is adjusted so that the toner is dispersed at a high concentration in a carrier liquid made of a nonpolar insulating liquid such as silicon oil. The agitation screws 42 and 43 circulate and agitate the liquid developer 35 in the liquid developer storage container 36. The pump-up roller 39 is rotated in contact with the application roller 38 in a state where a part of the pump-up roller 39 is immersed in the liquid developer 35, and the liquid developer 35 is pumped up and applied to the application roller 38.

  The application roller 38 applies a liquid developer 35 onto the development roller 37, thereby forming a thin layer of the liquid developer 35 on the development roller 37. In the developing area on the photosensitive drum 25, the latent image is developed by the liquid developer 35. Further, the liquid developer 35 remaining on the developing roller 37 after the development is removed from the developing roller 37 by the developing cleaning blade 41 and returned to the liquid developer storage container 36.

  As shown in FIG. 2, the cleaning mechanism 30 includes a cleaning case 45 that accommodates the collected transfer residual liquid developer. Inside the cleaning case 45, a cleaning roller 46, a cleaning blade 47, and a conveying screw 48 are provided. The cleaning roller 46 is in pressure contact with the photosensitive drum 25 and is driven to rotate in the same direction as the photosensitive drum 25 at a contact portion by a drive motor (not shown). The cleaning blade 47 counter-contacts the photoconductive drum 25 below the cleaning roller 46 to collect and remove the transfer residual liquid developer on the photoconductive drum 25, and the photoconductive drum 25 is subjected to the next image formation. Prepare for the process. The conveying screw 48 collects the transfer residual liquid developer scraped off by the cleaning blade 47 at the lower part in the cleaning case 45.

Next, a liquid developer supply path, a carrier liquid supply path, a transfer residual liquid developer reflux path, and a liquid developer disposal path in the wet image forming apparatus will be described with reference to FIG.
Here, the liquid developer supply path and the carrier liquid supply path are for supplying the liquid developer and the carrier liquid for supply to the liquid developing devices 28 of the first to fourth image forming mechanisms 15 to 18. . The recirculation path of the transfer residual liquid developer is for returning the transfer residual liquid developer collected by each cleaning mechanism 30 to the liquid developing device 28. Further, the liquid developer discard path is for collecting and discarding the transfer residual liquid developer of the intermediate transfer cleaning unit 23.

  Above the belt conveyance mechanism 14, first to fourth storage tanks 51, 52, 53, 54 are arranged. The first to fourth storage tanks 51 to 54 are for black, magenta, cyan, and yellow from the left side in FIGS. 1 and 3. Each of the storage tanks 51 to 54 stores a replenishing liquid developer concentrated more than the liquid developer 35.

  The liquid developer supply path of the first storage tank 51 is constituted by a conduit 55 such as a supply hose connected between the first storage tank 51 and the liquid developer storage container 36 of the liquid developing device 28. Has been. When the toner concentration in the liquid developer storage container 36 decreases, the replenishment liquid developer 35 in the storage tank 51 is changed to a pipeline by changing the rotational position of the first storage tank 51 as will be described later. The liquid developer storage container 36 is supplied with its own weight through 55.

  A carrier liquid tank 57 is detachably attached to a main body frame (not shown) of the wet image forming apparatus so as to be positioned above the belt conveyance mechanism 14 adjacent to the first storage tank 51. A carrier liquid supply path corresponding to the first storage tank 51 is connected to a main pipe 58 such as a supply hose connected to the carrier liquid tank 57 and the main pipe 58 and is connected to the liquid developer storage container 36. And a branch pipe 59 such as a supply hose. When the liquid developer 35 in the liquid developer storage container 36 is insufficient, the carrier liquid in the tank 57 is changed into the main pipe 58 and the branch pipe 59 by changing the rotational position of the carrier liquid tank 57 as will be described later. Is supplied to the liquid developer storage container 36 through its own weight.

  In this embodiment, the first storage tank 51, the pipeline 55, and the like constitute a replenishing liquid developer replenishing means. Further, the carrier liquid tank 57, the main pipe 58, the branch pipe 59 and the like constitute carrier liquid replenishing means.

  The liquid developer supply paths of the second to fourth storage tanks 52 to 54 and the corresponding carrier liquid supply paths are the same as the liquid developer supply path and the carrier liquid supply path of the first storage tank 51. Therefore, the same components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 3, a reflux pipe 61 as a reflux path is connected between the cleaning case 45 of each cleaning mechanism 30 and the liquid developer storage container 36 of each liquid developing device 28. Then, the recovered transfer residual liquid developer is refluxed to the liquid developer storage container 36 of the liquid developing device 28 via the reflux line 61 by driving the conveying screw 48 of the cleaning mechanism 30.

  A waste liquid tank 63 is connected to the cleaning case 23a of the intermediate transfer cleaning unit 23 via a waste liquid conduit 62 as a liquid developer disposal path. Then, the transfer residual liquid developer recovered by the transport screw 23 d of the intermediate transfer cleaning unit 23 is disposed of in the waste liquid tank 63 via the waste liquid conduit 62.

  A waste pipe 64 is branched and connected in the middle of each reflux pipe 61 so that the transfer residual liquid developer collected by each cleaning mechanism 30 is guided to the waste liquid tank 63. An electromagnetic switching valve 65 constituting switching means is disposed at a branch portion between the reflux pipe 61 and the waste pipe 64, and the collected transfer residual liquid developer is switched to the liquid developing device 28 or the waste liquid tank 63 and supplied. Like to do.

  As shown in FIGS. 1 to 3, the toner as a toner concentration detecting means for detecting the concentration of toner contained in the carrier liquid of the liquid developer 35 is stored in the liquid developer storage container 36 of the liquid developing device 28. A density sensor 66 is provided. The liquid developer storage container 36 is provided with a liquid level sensor 67 as liquid level detecting means for detecting the liquid level (liquid level height) of the liquid developer 35.

Next, a characteristic configuration of the present invention will be described with reference to FIGS.
As shown in FIGS. 4 to 6, the storage tanks 51 to 54 and the carrier liquid tank 57 are formed in a cylindrical shape as a whole, and are rotatably supported via a support shaft 71 on the central axis. Yes. A drive motor 72 as a changing means is connected to the support shaft 71, and the tanks 51 to 54, 57 are rotated by the drive motor 72 so that the rotation position thereof is changed.

  A projecting portion 56 is formed at one end of each of the tanks 51 to 54, 57 in the outer peripheral direction, and a supply port 73 is formed at an end wall of the projecting portion 56. The supply port 73 is located on the outer peripheral side of the tanks 51 to 54, 57 on the outer side in the radial direction around the center of the tanks 51 to 54, 57 rather than the outer periphery. It is located outside the peripheral wall. A connection tool 74 is fitted to the supply port 73 through a seal ring 75 so as to be relatively rotatable. A supply hose 76 constituting the pipe 55 or the main pipe 58 is connected to the connection tool 74. Then, the tanks 51 to 54 and 57 are rotated by the drive motor 72, and the position of the supply port 73 with respect to the liquid developer 35 or the liquid level L of the carrier liquid in the tanks 51 to 54 and 57 is changed. The liquid developer or carrier liquid is supplied from the supply port 73 to the liquid developer storage container 36 of the liquid developing device 28 via the pipe 55 or the main pipe 58.

  As shown in FIGS. 5, 6, and 8, a detection electrode 77 including a large number of detection terminals 77 a arranged in an annular shape is disposed on the inner end edge of the supply port 73. A detection sensor (not shown) is connected to. Then, as shown in FIG. 7, the position of the supply port 73 with respect to the liquid level of the liquid developer or carrier liquid is changed by the rotation of the tanks 51 to 54, 57, and as shown in FIG. And the supply port 73 are in a predetermined relationship position, that is, when the liquid level L is positioned above the outer periphery of the lower end of the supply port 73 by a predetermined amount, the current value flowing through the detection electrode 77 is Based on this, a detection signal is output from the detection sensor to a control device (not shown). Further, based on this detection signal, the drive motor 72 is rotationally controlled by the control device, and the supply port 73 is maintained at the predetermined relationship position with respect to the liquid level L during the supply of the liquid developer or the carrier liquid. It is like that.

In this embodiment, a control means is configured by the detection electrode 77, a detection sensor (not shown), and a control device.
Next, the operation of the liquid developer or carrier liquid supply configuration configured as described above will be described.

  In the normal state, as shown in FIGS. 4 and 5, the tanks 51 to 54 and 57 are pivoted to the original positions, and the supply port 73 is the liquid developer or carrier in the tanks 51 to 54 and 57. It is arranged above the liquid level L of the liquid. In this state, when the liquid developer or carrier liquid in the tanks 51 to 54 and 57 is supplied to the liquid developer storage container 36 of the liquid developing device 28, the tanks 51 to 54 and 57 are rotated by the drive motor 72. Thus, the position of the supply port 73 is changed.

  Then, as shown in FIGS. 7A, 7 </ b> B, 7 </ b> C, and 8, the liquid level of the liquid developer or the carrier liquid is positioned a predetermined amount above the outer periphery of the lower end of the supply port 73. When this happens, the state is detected by the detection electrode 77 and a detection sensor (not shown), and the rotation of the tanks 51 to 54 and 57 by the drive motor 72 is temporarily stopped. In this state, the liquid developer or carrier liquid in the tanks 51 to 54, 57 is slowly supplied from the supply port 73 to the liquid developer storage container 36 through the supply hose 76 by a predetermined amount.

  In this case, when the liquid level L gradually decreases as the liquid developer or the carrier liquid is supplied, the tanks 51 to 54 and 57 are moved by the drive motor 72 based on the detection by the detection electrode 77 and the detection sensor. The position of the supply port 73 is changed under rotation control. As a result, as shown in FIG. 8, the liquid level L is always maintained in a state positioned a predetermined amount above the outer periphery of the lower end of the supply port 73. In other words, the supply port 73 is maintained at the liquid level, and when the liquid developer or the carrier liquid flows into the supply port 73, air is taken in or the liquid level L is disturbed by the intake of the air. Can be suppressed. Accordingly, it is possible to prevent the possibility that fine bubbles are mixed into the liquid developer 35 in the liquid developer storage container 36 to cause a problem in image formation.

  When a predetermined amount of liquid developer or carrier liquid is replenished in the liquid developer storage container 36, the tanks 51 to 54, 57 are rotated back in the reverse direction to the above case by the drive motor 72, and FIG. As shown, the supply port 73 is disposed above the liquid level L. As a result, the supply of the liquid developer or carrier liquid to the liquid developer storage container 36 is stopped. As described above, since the liquid developer or the carrier liquid can be supplied to and stopped from the liquid developer storage container 36 by the rotation of the tanks 51 to 54, 57, the liquid developer pipe 55 and the carrier liquid can be supplied. It is not necessary to equip the branch pipe 59 or the like with a supply pump or an electromagnetic on-off valve, and the configuration can be simplified.

  Further, as shown in FIGS. 7A to 7C, when the liquid developer or the carrier liquid is supplied, the smaller the amount of the liquid developer or the carrier liquid stored in the tanks 51 to 54 and 57, the smaller the tank 51 to 51. 54 and 57 are rotated so that the position of the supply port 73 is further lowered. For this reason, the liquid developer or the carrier liquid stored in the tanks 51 to 54 and 57 can be supplied to the liquid developer storage container 36 without any excess.

1 is a schematic configuration diagram of a wet image forming apparatus according to an embodiment embodying the present invention. FIG. 2 is a schematic front view of a first image forming mechanism in the wet image forming apparatus of FIG. 1. 2 is a block circuit diagram showing a liquid developer supply path, a liquid developer discard path, a carrier liquid supply path, and the like of the wet image forming apparatus. FIG. 3 is a perspective view showing a main part of a configuration for supplying a liquid developer from a storage tank. FIG. 5 is a cross-sectional view of the liquid developer supply configuration of FIG. 4. The principal part sectional drawing which expands and shows the supply-portion part of the supply structure. (A) (b) (c) is sectional drawing which shows the operation state of the supply structure of FIG. FIG. 3 is an explanatory diagram illustrating a relationship between a supply port and a liquid level of a liquid developer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 15-18 ... Image forming mechanism, 28 ... Liquid developing device as a developing device, 35 ... Liquid developer, 36 ... Liquid developer storage container, 37 ... Developing roller, 51-54 ... Storage tank, 57 ... Carrier liquid tank, DESCRIPTION OF SYMBOLS 71 ... Support shaft, 72 ... Drive motor as a change means, 73 ... Supply port, 74 ... Connector, 76 ... Supply hose, 77 ... Detection electrode which comprises a control means, L ... Liquid level.

Claims (4)

In an image forming apparatus provided with a developing unit that visualizes an electrostatic latent image using a liquid developer and a storage tank for storing a replenishing liquid developer for the developing unit, the storage tank as a whole An image forming apparatus having a cylindrical shape and supported so as to be rotatable about its axis, and further provided with a developer supply port on the outer peripheral side of the end wall of the storage tank. The image forming apparatus according to claim 1, further comprising a changing unit that changes a rotation position of the storage tank. The image forming apparatus according to claim 2, further comprising a control unit configured to control the operation of the changing unit so that the supply port maintains a predetermined relation position with a liquid level of the liquid developer in the storage tank. The hose for supplying a liquid developer to the developing device is connected to the supply port at a connection tool at an end thereof, and the connection tool is rotatable relative to the supply port. The image forming apparatus according to claim 1.

Images