JP2006201320A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for solving the problem that toner is eventually stuck to a squeeze roller and a squeeze blade without providing constitution to entail complication and upsizing. <P>SOLUTION: The difference between the potential of an electrostatic latent image holder and the potential of a development electrode in a cleaning mode is made higher than the difference between the potential of the electrostatic holder and the potential of the development electrode in an image forming mode, and thereby, a developer of low toner density in the cleaning mode is supplied to the squeeze member and the squeeze cleaning member to flush the stuck toner. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus using a developer having toner and a liquid carrier.

  An electrophotographic recording apparatus using a developing solution can use extremely fine toner particles of submicron size, so that high image quality equivalent to that of offset printing can be realized, and a sufficient image density can be obtained with a small amount of toner, so that the copy cost can be obtained. In addition, there are advantages that cannot be realized with a dry electrophotographic recording apparatus, such as being able to reduce energy consumption and realizing energy saving because toner can be fixed on a recording sheet at a relatively low temperature, and its value is being reconsidered in recent years.

  One of characteristic features of an electrophotographic recording apparatus using a developer is a squeeze device. The squeeze device is composed of, for example, a metal roller and a blade brought into contact therewith. The solvent held by the toner image on the photoreceptor is removed by a metal roller, and is removed from the metal roller by a blade. As a result, the toner image is fixed on the photosensitive member, and the image is less likely to be disturbed thereafter.

  The solvent that the squeeze device collects from the photoreceptor includes toner. When the apparatus is stopped and the solvent containing the toner remains between the metal roller and the blade of the squeeze device for a long period of time, the solvent is not volatilized and therefore the toner remains between the metal roller and the blade. The remaining toner adheres to the blade and the metal roller, and further adheres both. When the apparatus is started again in this state, the toner mass fixed to the rotating metal roller hits the blade, or the toner fixed to the blade repeatedly adheres to and peels from the rotating metal roller, and vibration is applied to the photosensitive member. In some cases, so-called jitter occurs.

  Further, the toner adheres to the surface of the blade and the contact property with the metal roller is lowered, so that the solvent removal performance from the metal roller may be lowered.

  Furthermore, the contact surface of the blade with the metal roller may be damaged and the life may be shortened.

As a countermeasure against these problems, there has been proposed one having a movable structure for cleaning the metal roller and the blade before the apparatus is stopped for a long time (see, for example, Patent Document 1). Further, a method has been proposed in which a solvent is supplied to a metal roller from a tank for cleaning. (For example, refer to Patent Document 2).
JP-A-11-327312 JP 2000-10446 A

  However, if the above configuration is provided, the apparatus becomes complicated and large.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a means for solving the problem that toner adheres to a squeeze device without providing a configuration that increases complexity and size.

  In order to solve the above problems, the present invention provides an electrostatic latent image holder, a charger for charging the electrostatic latent image holder, and the charged electrostatic latent image holder. An exposure device for forming a latent image, a developing device having a developing electrode, and developing the electrostatic latent image with a developer having toner and a liquid carrier to form a toner image, and the toner image having been formed A squeeze member for removing a part of the developer adhering to the electrostatic latent image holding member, a squeeze cleaning member for removing the toner adhering to the squeeze member, and a potential control device for controlling the potential of the developing electrode; An image forming mode for forming an image, and a cleaning mode for removing the toner adhering to the squeeze member in the image forming mode, and the potential control device is in the cleaning mode. The difference between the potential of the electrostatic latent image holding member and the potential of the developing electrode is greater than or equal to the difference between the potential of the electrostatic holding member and the potential of the developing electrode in the image forming mode. Providing equipment.

  An electrostatic latent image holding member; a charger that charges the electrostatic latent image holding member; an exposure unit that exposes the charged electrostatic latent image holding member to form an electrostatic latent image; and a toner. And a developer that develops the electrostatic latent image with a developer having a liquid carrier to form a toner image, and a part of the developer that adheres to the electrostatic latent image holder on which the toner image is formed. An image forming mode for forming an image, comprising: a squeeze electrode to be removed; a squeeze cleaning member for removing the toner adhering to the squeeze electrode; and a potential control device for controlling the potential of the squeeze electrode; A cleaning mode for removing the toner adhering to the squeeze member, and the potential control device determines the potential of the squeeze electrode in the cleaning mode as the image. To provide an image forming apparatus characterized by higher than the potential of the squeeze electrode in adult mode.

  Also, an electrostatic latent image holding member, a charger for charging the electrostatic latent image holding member, an exposure unit for exposing the charged electrostatic latent image holding member to form an electrostatic latent image, and development A developer having an electrode and developing the electrostatic latent image with a developer having a toner and a liquid carrier to form a toner image; and the electrostatic latent image holding member on which the toner image is formed. An image forming mode for forming an image, comprising: a squeeze electrode for removing a part of the developer; a squeeze cleaning member for removing the toner adhering to the squeeze electrode; and a potential control device for controlling the potential of the developer electrode; A cleaning mode for removing the toner adhering to the squeeze member in the image forming mode, and the potential control device applies a potential to the squeeze electrode in the cleaning mode. To provide an image forming apparatus characterized by higher than potential of the developing electrode.

  In addition, the electrostatic latent image holding member is charged, the charged electrostatic latent image holding member is exposed to form an electrostatic latent image, and the electrostatic latent image held by the electrostatic latent image holding member is Then, a developing electrode having a first potential difference with respect to the potential of the electrostatic latent image holding member is developed with a developer having toner and a liquid carrier to form a toner image, and the static image on which the toner image is formed is formed. An image forming step of removing a part of the developer adhering to the electrostatic latent image holding member by a squeeze member; charging the electrostatic latent image holding member; and A developer is supplied to the electrostatic latent image holding body using the developing electrode having a second potential difference larger than the first potential difference, and the developer is attached to the electrostatic latent image holding body supplied with the developer. A part of the developer is removed by a squeeze member, and the squeeze electrode The deposited the toner, an image forming method characterized by having a cleaning step of removing by the squeeze cleaning member.

  In addition, the electrostatic latent image holding member is charged, the charged electrostatic latent image holding member is exposed to form an electrostatic latent image, and the electrostatic latent image held by the electrostatic latent image holding member is Then, a toner image is formed by developing with a developer having toner and a liquid carrier, and a part of the developer adhering to the electrostatic latent image holder on which the toner image is formed is held on the electrostatic latent image. An image forming step of removing the toner adhering to the squeeze electrode with a squeeze cleaning member, and charging the electrostatic latent image holding member; The developer is supplied to the charged electrostatic latent image holding member, and a part of the developer adhering to the electrostatic latent image holding member supplied with the developer is removed from the electrostatic latent image holding member. A second potential greater than the first potential difference with respect to the potential; Was removed by squeezing the electrodes having, the toner adhering to the squeeze electrode, to provide an image forming method characterized by comprising a cleaning step of removing by the squeeze cleaning member.

  In addition, the electrostatic latent image holding member is charged, the charged electrostatic latent image holding member is exposed to form an electrostatic latent image, and the electrostatic latent image held by the electrostatic latent image holding member is A developing electrode is used to develop a toner image by developing with a developer having toner and a liquid carrier, and a part of the developer adhering to the electrostatic latent image holding body on which the toner image is formed is removed by a squeeze electrode. The image forming step to be removed, the electrostatic latent image holding member is charged, the developing electrode is used to supply the developer to the electrostatic latent image holding member, and the electrostatic latent image to which the developer is supplied A cleaning step of removing a part of the developer adhering to the holding body with a squeeze electrode, and removing the toner adhering to the squeeze electrode with the squeeze cleaning electrode having a higher potential than the development electrode. Specially To provide an image forming method according to.

  According to the present invention, in the cleaning mode, a developer having a low toner concentration can be supplied to the squeeze member and the squeeze cleaning member, and the adhered toner can be washed away. Therefore, it is possible to obtain a means for solving the problem that the toner is fixed to the squeeze roller and the squeeze blade without providing a configuration that causes an increase in complexity and size.

(First embodiment)
FIG. 1 is a configuration diagram of an image forming apparatus 1 according to the present embodiment.

  The image forming apparatus 1 includes a photosensitive member 10 as an electrostatic latent image holding member, a charging device 20 as a charger, an exposure device 30 as an exposure device, a developing device 40 as a developing device, a squeeze device 50, a drying device 60, An intermediate transfer member 70, a photosensitive member cleaning device 80, a charge eliminating device 90, and a transfer device 100 are provided.

  The photoconductor 10 is obtained by providing a photoconductive layer 103 on a curved surface of a photoconductive substrate 101 that is cylindrical and conductive.

  The charging device 20 uniformly charges the photosensitive layer 103.

  The exposure device 30 selectively exposes a laser to the photosensitive layer 103 uniformly charged by the charging device 20 to form an electrostatic latent image.

  The developing device 40 develops the electrostatic latent image formed by the exposure device 30 using a developer having a liquid carrier and toner, and forms a toner image on the photoreceptor 10.

  The squeeze device 50 squeezes the liquid carrier adhering to the photoconductor 10 on which the developing device 40 has formed a toner image.

  The drying device 60 applies air to the photoconductor 10 to further remove the liquid carrier that the squeeze device 50 could not squeeze out from the photoconductor 10.

  The intermediate transfer member 70 is pressed against the photosensitive member 10 in an image forming mode described later. In the cleaning mode, the photosensitive member 10 is separated. The toner image on the photoreceptor 10 is transferred to the intermediate transfer body 70 by the pressure at the contact portion between the intermediate transfer body 70 and the photoreceptor 10.

  The photoconductor cleaning device 80 removes toner remaining on the photoconductor 10 after the toner image is transferred to the intermediate transfer body 70.

  The neutralizing device 90 uniformly neutralizes the photosensitive layer 103 of the photosensitive member 10 from which the toner is removed by the photosensitive member cleaning device 80.

  The transfer device 100 is pressed against the intermediate transfer member 70 with a predetermined amount of force. The surface of the transfer device 100 becomes high temperature, and the toner image on the intermediate transfer member 70 is transferred and fixed onto the paper 1020 by the pressure at the contact portion between the surface and the intermediate transfer member 70.

  The potential control device 120 controls a potential of a wire 201 and a grid 202 (to be described later) of the charging device 20 and a developing roller 403 (to be described later) of the developing device 40.

  The developer is obtained by dispersing resin particles as a toner in an insulating solvent as a liquid carrier. The toner of the present embodiment is positively charged when dispersed in a liquid carrier.

  The main configuration will be described in more detail. First, the configuration of the charging device 20 will be described in detail.

  The charging device 20 is a scorotron charger having a wire 201 and a grid 202. By changing the voltage or current applied to the wire 201 and the grid 202 by the potential control device 120 according to an operation mode such as an image forming mode and a cleaning mode, which will be described later, the charging potential of the photoreceptor 10 charged by the charging device 20 changes.

  Next, the configuration of the developing device 40 will be described in detail.

  The developing device 40 includes a developer container 402, a developing roller 403 as a developing electrode, and a developing cleaning roller 404.

  The developer container 402 holds the developer.

  The developing roller 403 rotates in the direction (within the direction) in which the outer periphery of the developing roller 403 moves in the same direction as the direction in which the surface of the photosensitive layer 103 moves as the photosensitive member 10 rotates, and supplies the developer to the photosensitive member 10. There is a gap of about 100 μm between the developing roller 403 and the photoreceptor 10.

  The potential of the developing roller 403 is changed by changing the voltage applied to the developing roller 403 provided by the potential control device 120 in accordance with an operation mode such as an image forming mode or a cleaning mode described later.

  The development cleaning roller 404 removes toner adhering to the development roller 403. The developing cleaning roller 404 is made of conductive rubber and is electrically grounded.

  The configuration of the squeeze device 50 will be described in detail.

  The squeeze device 50 includes a squeeze roller 501 as a squeeze member or a squeeze electrode, a squeeze blade 502 as a squeeze cleaning member, a squeeze container 503, and a squeeze bias power source 504.

  The squeeze roller 501 rotates in the direction (against direction) in which the outer periphery of the squeeze roller 501 moves in the direction opposite to the direction in which the surface of the photosensitive layer 103 moves due to the rotation of the photosensitive member 10, and the developer attached to the surface of the photosensitive member 10. Squeeze out. There is a gap of about 50 μm between the squeeze roller 501 and the photoreceptor 10. A predetermined bias voltage is applied to the squeeze roller 501.

  The squeeze blade 502 contacts the squeeze roller 501 and removes the developer attached to the squeeze roller 501.

  The squeeze container 503 holds the developer removed by the squeeze blade 502.

  The squeeze bias power supply 504 applies a bias voltage to the squeeze roller 501.

  The operation of the image forming apparatus 1 of the present embodiment having the above-described configuration will be described below.

  The image forming apparatus 1 has an operation mode of an image forming mode and a cleaning mode.

  In the image forming mode, the image forming apparatus 1 performs image formation.

  In the cleaning mode, toner attached to the squeeze roller 501 and the squeeze blade 502 in the image forming mode is cleaned.

  FIG. 2 is a flowchart showing the relationship between the image forming mode and the cleaning mode.

  When the image forming apparatus 1 is turned on, it first enters a standby state (step 1).

  When an image formation instruction is received in the standby state, the image forming mode is entered and image formation is performed (step 2). When the image formation is completed, it returns to the standby state again.

  When a shutdown instruction is received in the standby state, the mode shifts to the cleaning mode and the toner adhering to the squeeze roller 501 and the squeeze blade 502 is washed away (step 3). After the operation in the cleaning mode is completed, the image forming apparatus 1 is turned off.

  First, the operation of the image forming apparatus 1 in the image forming mode will be described with reference to the flowchart of FIG.

  First, the charging device 20 uniformly charges the photosensitive layer 103 of the rotating photoconductor 10 that has been uniformly discharged by the discharging device 90 (step 101). In this embodiment, the potential control device 120 is applied with a voltage of about 6 kV on the wire 201 and about 800 V on the grid 202.

  Next, the exposure device 30 exposes the laser to the photosensitive layer 103 of the photoconductor 10 uniformly charged by the charging device 20 to form an electrostatic latent image (step 102).

  Next, the electrostatic latent image formed by the exposure device 30 on the photosensitive layer 103 of the photoconductor 10 is developed by the developing device 40 with a developing solution to form a toner image on the photoconductor 10 (step 103). In the present embodiment, the developing roller 403 rotates in the width direction with respect to the photoreceptor 10. Further, a voltage of about 550 V is applied to the developing roller 403 from the potential control device 120. The potential of the photosensitive layer 103 drops while moving to the position facing the developing device 40, the portion not exposed to the exposure device 30 is 700V, and the exposed portion is about 200V.

  Next, the squeeze device 50 squeezes the liquid carrier adhering to the toner image formed on the photoconductor 10 and the developer adhering to the portion other than the toner image of the photoconductor 10 formed (step 104). .

  In the present embodiment, the squeeze roller 501 rotates in the against direction with respect to the photoreceptor 10. The squeeze roller 501 is applied with a bias voltage of about 550 V from the squeeze bias power source 504 as in the developing roller 403. Note that the potential drop of the photosensitive layer 103 during the movement from the position facing the developing device 40 to the position facing the squeeze device 50 is negligible. A squeeze blade 502 that contacts the squeeze roller 501 removes the developer adhering to the squeeze roller 501.

  Next, the liquid carrier that could not be squeezed out by the squeeze device 50 is removed by the drying device 60, and the photoreceptor 10 and the toner image are dried. (Step 105).

  Next, the dried toner image on the photoconductor 10 is transferred to the intermediate transfer body 70 pressed against the photoconductor 10 (step 106).

  Next, the transfer device 100 transfers the toner image on the intermediate transfer member 70 to the paper 1020 that passes through the contact portion between the transfer device 100 and the intermediate transfer member 70 (step 107).

  Next, the photoconductor cleaning device 80 removes the toner remaining on the photoconductor 10 (step 108), and the operation in the image forming mode is completed.

  Here, the phenomenon in step 103 will be described with reference to FIG.

  In step 103, the potential of the exposed portion (exposed portion) of the photosensitive layer 103 that has moved to a position facing the developing device 40 is approximately 350V lower than the potential of the developing roller 403. Therefore, an electric field is generated in the direction from the developing roller 403 toward the photosensitive layer 103 in a gap of 100 μm between the exposed portion of the photosensitive layer 103 and the developing roller 403. Due to this electric field, in the developer supplied to the developing roller 403 and entering the gap, the positively charged toner moves toward the photosensitive layer 103, and the toner adheres to the photosensitive layer 103.

  Further, the potential of the unexposed portion (non-exposed portion) of the photosensitive layer 103 that has moved to a position facing the developing device 40 is approximately 150 V higher than the potential of the developing roller 403. For this reason, an electric field is generated in the direction from the photosensitive layer 103 toward the developing roller 403 in the gap between the exposed portion of the photosensitive layer 103 and the developing roller 403. Due to this electric field, the positively charged toner moves toward the developing roller 403 in the developer supplied to the developing roller 403 and entering the gap.

  Actually, the toner does not adhere to the unexposed portion of the photosensitive layer 103, but adheres slightly.

  The phenomenon in step 104 will be described with reference to FIG.

  In step 104, the potential of the exposed portion of the photosensitive layer 103 that has moved to the position facing the squeeze device 50 is about 350 V lower than the potential of the squeeze roller 501. Therefore, an electric field is generated in the direction from the squeeze roller 501 toward the photosensitive layer 103 in the gap between the exposed portion of the photosensitive layer 103 and the squeeze roller 501.

  Further, since the 50 μm gap between the photosensitive layer 103 and the squeeze roller 501 is smaller than the 100 μm gap between the photosensitive layer 103 and the developing roller 403, the generated electric field is stronger.

  The adhesion of the positively charged toner to the photosensitive layer 103 is further strengthened by this electric field.

  Further, the potential of the unexposed portion of the photosensitive layer 103 is about 150 V higher than the potential of the squeeze roller 501. Therefore, an electric field is generated in the direction from the photosensitive layer 103 toward the squeeze roller 501 in the gap between the unexposed portion of the photosensitive layer 103 and the squeeze roller 501. Due to this electric field, the positively charged toner moves toward the squeeze roller 501 in the developer entering the gap.

  As a result, a portion of the photosensitive layer 103 that has not been exposed, that is, a portion where the toner should not be placed, is removed by the squeeze roller 501.

  Next, the operation of the image forming apparatus 1 in the cleaning mode will be described with reference to the flowchart of FIG.

  First, the intermediate transfer member 70 is separated from the photoconductor 10, and the drying device 60 stops. (Step 201).

  Next, the photosensitive layer 103 of the photoconductor 10 on which the static eliminator 90 is rotating is uniformly neutralized (step 202).

  Next, the charging device 20 uniformly charges the photosensitive layer 103 of the photoreceptor 10 that has been uniformly discharged by the charge eliminating device 90 (step 203). In the present embodiment, the potential control device 120 is applied with a voltage of about 6.3 kV on the wire 201 and about 800 V on the grid 202.

  Next, the exposure device 30 does not expose the laser to the photosensitive layer 103 of the photoreceptor 10 uniformly charged by the charging device 20 (that is, does not form an electrostatic latent image), and the developing device 40 supplies the developer. Supply (step 204).

  However, even when the developer is supplied, no toner image is formed because an electrostatic latent image is not formed on the photosensitive layer 103. In the present embodiment, the developing roller 403 rotates in the width direction with respect to the photoreceptor 10. The developing roller 403 is applied with a voltage of about 450 V to the potential controller 120.

  Next, the squeeze device 50 squeezes the developer adhering to the photoreceptor 10 (step 205). In the present embodiment, the squeeze roller 501 rotates in the against direction with respect to the photoreceptor 10. The squeeze roller 501 is applied with a bias voltage of about 550 V by the squeeze bias power source 504 as in the image forming mode. A squeeze blade 502 that contacts the squeeze roller 501 removes the developer adhering to the squeeze roller 501.

  Next, the photoconductor cleaning device 80 removes the toner remaining on the photoconductor 10 (step 206).

  The above operation is repeated a predetermined number of times (that is, while the photoconductor 10 is rotated a predetermined number of times) to sufficiently remove the toner from the squeeze roller 501 and squeeze blade 502 (step 207), and then the operation ends.

  Here, the phenomenon in step 204 will be described with reference to FIG.

  In step 204, the photosensitive layer 103 that has moved to a position facing the developing device 40 is not exposed, and thus is approximately 350 V higher than the potential of the developing roller 403. For this reason, an electric field is generated in the gap between the photosensitive layer 103 and the developing roller 403 in the direction from the photosensitive layer 103 to the developing roller 403. Due to this electric field, the positively charged toner moves toward the developing roller 403 in the developer supplied to the developing roller 403 and entering the gap.

  The difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation of the cleaning mode is equal to or greater than the difference of the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation of the image forming mode. Since a strong electric field is generated, the movement of the toner toward the developing roller 403 becomes more remarkable.

  For this reason, the developer adhering to the photosensitive layer 103 is only a liquid carrier and has a very low toner concentration.

  In step 205, the squeeze roller 501 removes the developer having a low toner density from the photosensitive member 10, so that the amount of toner adhering to the squeeze roller 501 and the squeeze blade 502 is extremely small. Further, the toner adhering before the start of the cleaning mode is also washed away by the developer having a low toner concentration.

  Accordingly, the amount of toner remaining between the squeeze roller 501 and the squeeze blade 502 is extremely small, and the problem of fixing due to toner can be avoided.

  Note that if the operation is performed with the potential difference between the photosensitive layer 103 and the developing roller 403 at a position facing the developing device 40 being 600 V or more, a large amount of toner adheres to the developing roller 403, and the developing roller 403 and the developing cleaning roller 404. A large force is applied to the battery, and a failure may occur. Furthermore, the toner may be negatively charged by charge injection and may adhere to the unexposed portion of the photosensitive layer 103. Accordingly, it is desirable that the potential difference between the photosensitive layer 103 and the developing roller 403 at a position facing the developing device 40 is 600 V or less.

  As described above, by setting the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the cleaning mode to be equal to or larger than the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the image forming mode. Since the developer removed from the photoreceptor 10 by the squeeze roller 501 is only a liquid carrier and has a low toner density, the amount of toner remaining between the squeeze roller 501 and the squeeze blade 502 is extremely small, and there is a problem of sticking by the toner. Can be avoided.

  Further, since the electric potential of the charging device 20 and the developing device 40 only needs to be controlled by the electric potential control device 120, it is only necessary to replace the conventional power supply device that applied the electric potential to the charging device 20 or the developing device 40, and a special movable The problem that the toner adheres to the squeeze roller and the squeeze blade can be solved without providing a configuration or a configuration that causes an increase in size or a tank.

(Second Embodiment)
In the above-described embodiment, the configuration for controlling the potential of the charging device 20 has been described. On the other hand, in the present embodiment, even if the potential of the charging device 20 is not controlled, the difference between the potential of the photosensitive layer 103 in the cleaning mode operation and the potential of the developing roller 403 is calculated as the photosensitive layer in the image forming mode operation. A configuration that can be greater than or equal to the difference between the potential of 103 and the potential of the developing roller 403 will be described.

  FIG. 8 is a configuration diagram of the image forming apparatus 1 according to the present embodiment. The description of the same configuration as in FIG. 1 is omitted.

  In the present embodiment, the potential control device 120 controls the potential of the developing device 40.

  The charging device 20 includes a charging power source 203. The charging power source 203 applies voltage or current to the wire 201 and the grid 202, respectively.

  The operation of the image forming apparatus 1 of the present embodiment having the above-described configuration will be described below.

  The image forming apparatus 1 has an operation mode of an image forming mode and a cleaning mode.

  In the image forming mode, the operation is the same as that of the image forming apparatus 1 of the first embodiment, except that the charging power source 203 supplies power to the charging device 20.

  Next, the operation of the image forming apparatus 1 in the cleaning mode will be described with reference to the flowchart of FIG.

  First, the intermediate transfer member 70 is separated from the photoreceptor 10, and the developing device 40 and the drying device 60 are stopped. (Step 301).

  Next, the photosensitive layer 103 of the photosensitive member 10 on which the static eliminator 90 is rotating is uniformly neutralized (step 302).

  Next, the charging device 20 uniformly charges the photosensitive layer 103 of the photoconductor 10 that has been uniformly discharged by the discharging device 90 (step 303). In this embodiment, since the charging power source 203 applies a voltage of about 6 kV to the wire 201 and about 750 V to the grid 202, the photosensitive layer 103 that has passed the charging position of the charging device 20 once is charged, and the developing device Attenuates to about 700 V while moving to a position facing 40.

  After the charging device 20 is uniformly charged, the photosensitive member 10 is rotated once and is uniformly charged again by the charging device 20, and further rotated and charged to the charging device 20 each time (step 304). Meanwhile, the exposure device 30 does not expose the laser to the photosensitive layer 103 uniformly charged by the charging device 20 (that is, does not form an electrostatic latent image).

Next, the developing device 40 supplies a developing solution to the photosensitive layer 103 of the photoreceptor 10 charged by the charging device 20 five times (step 305). However, a toner image is not formed even when the developer is supplied because an electrostatic latent image is not formed on the photosensitive layer 103. In the present embodiment, the developing roller 403 rotates in the width direction with respect to the photoreceptor 10. The developing roller 403 is applied with a voltage of about 450 V to the potential controller 120. The reason for charging the photosensitive layer 103 five times will be described later.
Next, the squeeze device 50 squeezes the developer adhering to the photoreceptor 10 (step 306). In this embodiment, the squeeze roller 501 rotates the photoconductor 10 in the against direction. The squeeze roller 501 is applied with a bias voltage of about 550 V by the squeeze bias power source 504 as in the image forming mode.

  Next, the photoconductor cleaning device 80 removes the toner remaining on the photoconductor 10 (step 307).

  The above operation is repeated a predetermined number of times (that is, while the photoconductor 10 is rotated a predetermined number of times) to sufficiently remove toner from the squeeze roller 501 and squeeze blade 502 (step 307). If Step 303 to Step 307 are repeated, the charging device 20 faces the photosensitive layer 103 that has not been neutralized, further charges the previously charged photosensitive layer 103, and further increases the potential of the photosensitive layer 103.

  When the above operation is completed, the operation of the developing device 40 is then stopped (step 309). Thereafter, the charging operation of the charging device 20 is stopped (step 310), and the operation ends.

Here, a phenomenon in the cleaning mode of the image forming apparatus 1 of the present embodiment will be described. FIG. 10 shows the potential of the photosensitive layer 103 at a position facing the developing device 40 in the cleaning mode. The photosensitive layer 103 that has been neutralized by the neutralization device 90 in the first rotation is charged by once facing the charging device 20, and attenuates to 700 V while moving to a position facing the developing device 40. If the neutralization operation of the neutralization device 90 is stopped and the charged photosensitive layer 103 again faces the charging device 20, it is further charged. The photosensitive layer 103 is charged by the charging device 20 at the fifth rotation of the photosensitive member 10 and attenuates to 800 V while moving to the position facing the developing device 40. Also, Step 305 after the charging device 20 is stopped. The phenomenon will be described again with reference to FIG.

  In step 304, since the photosensitive layer 103 was not exposed, the potential of the photosensitive layer 103 moved to a position facing the developing device 40 is higher than the potential of the developing roller 403 by about 350 V or more. For this reason, an electric field is generated in the gap between the photosensitive layer 103 and the developing roller 403 in the direction from the photosensitive layer 103 to the developing roller 403. Due to this electric field, the positively charged toner moves toward the developing roller 403 in the developer supplied to the developing roller 403 and entering the gap.

  The difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation of the cleaning mode is equal to or greater than the difference of the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation of the image forming mode. Since a strong electric field is generated, the movement of the toner toward the developing roller 403 becomes more remarkable.

  For this reason, the developer adhering to the photosensitive layer 103 is only a liquid carrier and has a very low toner concentration.

  Here, the reason why the developing device supplies the developing solution after charging the photosensitive layer 103 five times will be described.

  In the present embodiment, the photosensitive layer 103 that has passed through the charging position of the charging device 20 once is charged to about 700 V. However, the photosensitive layer 103 that has passed through the charging position many times has a certain potential, and no more It will not rise. This potential is called a saturation potential. The saturation potential varies depending on the charging capability of the charging device 20 including the applied voltage, the characteristics of the photosensitive layer 103, and the like.

  In the present embodiment, when the charged position is passed through the photosensitive layer 103 by 5 degrees, the photosensitive layer 103 rises to +850 V and is saturated. The photosensitive layer 103 saturated at +850 V attenuates to +800 V while moving to a position facing the developing device 40, and this is observed as a saturated potential at a position facing the developing device 40.

  The phenomenon in step 305 after the charging device 20 is stopped as described above appears more remarkably and surely as the potential difference between the photosensitive layer 103 and the developing roller 403 increases. In order to maximize the potential difference between the potential of the photosensitive layer 103 and the developing roller 403, the photosensitive layer 103 is charged five times and raised to a saturated charged position.

  As described above, by setting the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the cleaning mode to be equal to or larger than the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the image forming mode. Since the developer removed from the photoreceptor 10 by the squeeze roller 501 is only a liquid carrier and has a low toner density, the amount of toner remaining between the squeeze roller 501 and the squeeze blade 502 is extremely small, and there is a problem of sticking by the toner. Can be avoided.

  Further, since the potential of the developing device 40 only needs to be controlled by the potential control device 120, it is only necessary to replace the conventional power supply device that has given the potential to the developing device 40, and a complicated structure such as providing a special movable configuration or a tank. In addition, it is possible to solve the problem that the toner adheres to the squeeze roller and the squeeze blade without providing a configuration that causes an increase in size.

  Furthermore, in this embodiment, the potential control device 120 only needs to control the potential of the developing device 40, so that the configuration is simplified and the device can be designed to be smaller.

  In the present embodiment, it has been described that the developing device 40 is stopped in step 301 and the developer is not supplied until the fourth rotation of the photoconductor 10, but the developer that adheres to the photosensitive layer 103 from the fifth rotation. Has a very low toner concentration, and the developer adhering to this time by the liquid carrier is caused to flow from the squeeze roller 501 or the squeeze blade 502. The developing device 40 may not be stopped.

(Third embodiment)
The configuration of the image forming apparatus 1 of the present embodiment is the same as that of the second embodiment.

  Similarly, the image forming mode and the cleaning mode have operation modes, and the image forming mode is the same as the operation of the image forming apparatus 1 of the second embodiment.

  The operation of the image forming apparatus 1 in the cleaning mode will be described with reference to the flowchart of FIG.

  First, the intermediate transfer member 70 is separated from the photoconductor 10, and the drying device 60 stops. (Step 401).

  Next, the photosensitive layer 103 of the photosensitive member 10 on which the static eliminator 90 is rotating is uniformly neutralized (step 402).

  Next, the charging device 20 uniformly charges the photosensitive layer 103 of the photoconductor 10 that has been uniformly discharged by the discharging device 90 (step 403). In this embodiment, the charging power source 203 applies a voltage of about 6 kV to the wire 201 and about 800 V to the grid 202.

  Here, the exposure device 30 does not expose the laser to the photosensitive layer 103 uniformly charged by the charging device 20 (that is, does not form an electrostatic latent image).

  Next, the developing device 40 supplies a developing solution to the photosensitive layer 103 of the photoconductor 10 uniformly charged by the charging device 20 (step 404). However, a toner image is not formed even when the developer is supplied because an electrostatic latent image is not formed on the photosensitive layer 103. In the present embodiment, the developing roller 403 rotates in the width direction with respect to the photoreceptor 10. The developing roller 403 is applied with a voltage of about 450 V to the potential controller 120.

  Next, the developer adhering to the photoreceptor 10 is squeezed out by the squeeze device 50 (step 405). In this embodiment, the squeeze roller 501 rotates the photoconductor 10 in the against direction. The squeeze roller 501 is applied with a bias voltage of about 550 V by the squeeze bias power source 504 as in the image forming mode.

  Next, the photoconductor cleaning device 80 removes the toner remaining on the photoconductor 10 (step 406).

  When the operation of the first rotation of the photosensitive member 10 is completed as described above, the discharging operation of the discharging device 90 is then stopped, and Steps 403 to 406 are repeated in the second and third rotations of the photosensitive member 10 ( Step 407). If Step 403 to Step 406 are repeated, the charging device 20 faces the photosensitive layer 103 that has not been neutralized, further charges the previously charged photosensitive layer 103, and further increases the potential of the photosensitive layer 103. In the present embodiment, the charging position of the charging device 20 is passed through the photosensitive layer 103 five times.

  When the second to fifth rotations of the photoconductor 10 are completed as described above, the charging operation of the charging device 20 is then stopped, and steps 404 to 406 are repeated after the sixth rotation (step 408). . The operation ends after the toner is sufficiently removed from the squeeze roller 501 and the squeeze blade 502 by the developer adhering to the photosensitive member 10 after the charging operation is stopped until it is rotated a predetermined number of times.

  Here, a phenomenon in the cleaning mode of the image forming apparatus 1 of the present embodiment will be described. FIG. 12 shows the potential of the photosensitive layer 103 at a position facing the developing device 40 in the cleaning mode.

  The photosensitive layer 103 that has been neutralized by the neutralization device 90 in the first rotation is charged by facing the charging device 20 once, and attenuates to 700 V while moving to the position facing the developing device 40. If the neutralization operation of the neutralization device 90 is stopped and the charged photosensitive layer 103 again faces the charging device 20, it is further charged.

  In the present embodiment, the photosensitive layer 103 is charged to a saturation potential and attenuates to about 800 V while moving to a position facing the developing device 40. It has been previously known by experiments and the like that the photosensitive layer 103 rises to the saturation potential when charged by passing the charging position of the charging device 20 five times. Therefore, the charging operation of the charging device 20 is continued until the fifth rotation. The charging operation is not performed after the sixth rotation after the potential of the photosensitive layer 103 reaches the saturation potential.

  Further, the phenomenon in step 404 after the charging device 20 is stopped will be described with reference to FIG. 7 again.

  In step 404, since the photosensitive layer 103 has not been exposed, the potential of the photosensitive layer 103 that has moved to a position facing the developing device 40 is about 350 V higher than the potential of the developing roller 403. For this reason, an electric field is generated in the gap between the photosensitive layer 103 and the developing roller 403 in the direction from the photosensitive layer 103 to the developing roller 403. Due to this electric field, the positively charged toner moves toward the developing roller 403 in the developer supplied to the developing roller 403 and entering the gap.

  The difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation of the cleaning mode is equal to or greater than the difference of the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation of the image forming mode. Since a strong electric field is generated, the movement of the toner toward the developing roller 403 becomes more remarkable.

  For this reason, the developer adhering to the photosensitive layer 103 is only a liquid carrier and has a very low toner concentration.

  Actually, since the photosensitive layer 103 is once charged to the saturation potential and is not charged, the toner concentration of the developer squeezed by the squeeze device 50 each time the photosensitive member 10 is followed by the attenuation of the potential of the photosensitive layer 103. Will rise. However, since the surface area of the photosensitive layer 103 is large when the photosensitive member 10 is large, the amount of the developer that the squeeze device 50 squeezes out while the photosensitive member 10 makes one round is large. This embodiment is used when the toner remaining in the squeeze roller 501 and the squeeze blade 502 can be sufficiently reduced with a developer having a very low toner concentration that can be squeezed out by one or two revolutions of the photoreceptor 10. The configuration of the form is effective.

  As described above, by setting the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the cleaning mode to be equal to or larger than the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the image forming mode. Since the developer removed from the photoreceptor 10 by the squeeze roller 501 is only a liquid carrier and has a low toner density, the amount of toner remaining between the squeeze roller 501 and the squeeze blade 502 is extremely small, and there is a problem of sticking by the toner. Can be avoided.

  Further, since the potential of the developing device 40 only needs to be controlled by the potential control device 120, it is only necessary to replace the conventional power supply device that has given the potential to the developing device 40, and a complicated structure such as providing a special movable configuration or a tank. In addition, it is possible to solve the problem that the toner adheres to the squeeze roller and the squeeze blade without providing a configuration that causes an increase in size.

  Furthermore, in this embodiment, the potential control device 120 only needs to control the potential of the developing device 40, so that the configuration is simplified and the device can be designed to be smaller.

(Fourth embodiment)
The configuration of the image forming apparatus 1 of the present embodiment is the same as that of the second embodiment.

  Similarly, the image forming mode and the cleaning mode have operation modes, and the image forming mode is the same as the operation of the image forming apparatus 1 of the second embodiment.

  The operation of the image forming apparatus 1 in the cleaning mode will be described with reference to the flowchart of FIG.

  Steps 501 to 507 are the same as steps 401 to 407 in FIG. 11, but in the present embodiment, at the sixth and seventh rotations of the photoconductor 10 after the charging device 20 is stopped. In order to raise the lowered potential of the photosensitive layer 103 to the saturation potential again, when the seventh rotation of the photoconductor 10 is completed, the charging operation of the charging device 20 is started again (step 508). When the eleventh rotation of the photoconductor 10 accompanied by the charging operation is completed, the charging operation of the charging device 20 is stopped again (step 509).

  After the charging operation is stopped, the toner is sufficiently removed from the squeeze roller 501 and the squeeze blade 502 by the developer adhering to the photoconductor 10 within three rotations (step 510), and then the operation ends.

  Here, a phenomenon in the cleaning mode of the image forming apparatus 1 of the present embodiment will be described. FIG. 14 shows the potential of the photosensitive layer 103 at a position facing the developing device 40 in the cleaning mode.

  The photosensitive layer 103 that has been neutralized by the neutralization device 90 in the first rotation is charged by once facing the charging device 20, and attenuates to 700 V while moving to a position facing the developing device 40. If the neutralization operation of the neutralization device 90 is stopped and the charged photosensitive layer 103 again faces the charging device 20, it is further charged. In this embodiment, the potential of the photosensitive layer 103 is increased to saturation. It has been previously known through experiments and the like that if the charging position of the charging device 20 is passed five times and charged, the potential of the photosensitive layer 103 becomes a saturated potential, so the charging operation of the charging device 20 is continued until the fifth rotation. . The charging operation is not performed at the sixth and seventh rotations after the potential of the photosensitive layer 103 becomes the saturation potential.

  However, the potential of the photosensitive layer 103 is attenuated, and the toner concentration of the developer that the squeeze device 50 squeezes out from the photoreceptor 10 increases. In order to avoid this, the charging operation of the charging device 20 is started again at the eighth rotation to charge the photosensitive layer 103.

  When the photosensitive member 10 is small, the amount of developer squeezed by the squeeze device 50 during one rotation of the photosensitive member 10 is small, and the developing solution has an extremely low toner concentration that can be squeezed by one or two revolutions of the photosensitive member 10. Therefore, the toner remaining between the squeeze roller 501 and the squeeze blade 502 cannot be reduced sufficiently. In such a case, if the potential of the attenuated photosensitive layer 103 is increased again, the developer having a very low toner concentration can be squeezed out by the squeeze device 50 for any number of rotations of the photosensitive member 10, and the squeeze roller 501 is sufficiently obtained. And the toner remaining between the squeeze blade 502 can be reduced.

  As described above, by setting the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the cleaning mode to be equal to or larger than the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the image forming mode. Since the developer removed from the photoreceptor 10 by the squeeze roller 501 is only a liquid carrier and has a low toner density, the amount of toner remaining between the squeeze roller 501 and the squeeze blade 502 is extremely small, and there is a problem of sticking by the toner. Can be avoided.

  Further, since the potential of the developing device 40 only needs to be controlled by the potential control device 120, it is only necessary to replace the conventional power supply device that has given the potential to the developing device 40, and a complicated structure such as providing a special movable configuration or a tank. In addition, it is possible to solve the problem that the toner adheres to the squeeze roller and the squeeze blade without providing a configuration that causes an increase in size.

  Furthermore, in this embodiment, the potential control device 120 only needs to control the potential of the developing device 40, so that the configuration is simplified and the device can be designed to be smaller.

(Fifth embodiment)
FIG. 15 is a configuration diagram of the image forming apparatus 1 according to the present embodiment. The description of the same configuration as in FIG. 8 is omitted.

  The image forming apparatus 1 according to the present embodiment includes a potential sensor 130.

  The potential sensor 130 sensitizes the potential of the photosensitive layer 103 immediately after the developer is supplied by the developing device 40 between the position facing the developing device 40 and the position facing the squeeze device 50 on the photoreceptor 10. Measured every rotation of the body 10.

  The operation of the image forming apparatus 1 of the present embodiment having the above-described configuration will be described below.

  The image forming apparatus 1 has an operation mode of an image forming mode and a cleaning mode.

  In the image forming mode, the operation is the same as that of the image forming apparatus 1 according to the second embodiment.

  Next, the operation of the image forming apparatus 1 in the cleaning mode will be described with reference to the flowchart of FIG.

  Steps 601 to 606 are the same as steps 401 to 406 in the cleaning mode of the third embodiment. However, in this embodiment, it is determined whether the photoconductor 10 has completed 14 rotations, and 14 If the rotation has not been completed, the next determination is made based on the detection result of the potential sensor 130 (step 607).

  When the potential sensor 130 detects the photosensitive layer 103 having a potential of 750 V or less, the charging device 20 starts the charging operation again after waiting for the detected portion of the photosensitive layer 103 to move to the charging position of the charging device 20. Steps 603 to 608 are repeated. Further, from this state, when the potential sensor 130 does not detect the photosensitive layer 103 having a potential of 750 V or less, the charging device 20 waits until the detected portion of the photosensitive layer 103 moves to the charging position of the charging device 20. The charging operation is stopped and Steps 604 to 608 are repeated. (Step 608).

  Here, a phenomenon in the cleaning mode of the image forming apparatus 1 of the present embodiment will be described. FIG. 17 shows the potential of the photosensitive layer 103 at a position facing the developing device 40 in the cleaning mode.

  The photosensitive layer 103 neutralized by the neutralization device 90 in the first rotation is charged by facing the charging device 20 once, and attenuates to 700 V while moving to the position facing the developing device 40. If the neutralization operation of the neutralization device 90 is stopped and the charged photosensitive layer 103 again faces the charging device 20, it is further charged.

  The potential of the photosensitive layer 103 that has passed the charging position of the charging device 20 two to three times is attenuated to 750 V or less when facing the developing device 40 at the end of the fourth rotation unless further charged. Therefore, the charging operation of the charging device 20 is continued even at the fourth rotation.

  The potential of the photosensitive layer 103 that has passed through the charging position of the charging device 20 four times maintains a potential of 750 V or more at the time of facing the developing device 40 at the end of the fifth rotation, without further charging. Therefore, the charging operation of the charging device 20 is stopped at the fifth rotation.

  The potential of the photosensitive layer 103 which has not been charged in the fifth rotation and passed the charging position of the charging device 20 five times is attenuated to 750 V or less at the time of facing the developing device 40 at the end of the sixth rotation unless further charged. End up. Therefore, the charging operation of the charging device 20 is performed at the sixth rotation.

  As described above, by setting the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the cleaning mode to be equal to or larger than the difference between the potential of the photosensitive layer 103 and the potential of the developing roller 403 in the operation in the image forming mode. Since the developer removed from the photoreceptor 10 by the squeeze roller 501 is only a liquid carrier and has a low toner density, the amount of toner remaining between the squeeze roller 501 and the squeeze blade 502 is extremely small, and there is a problem of sticking by the toner. Can be avoided.

  Further, since the potential of the developing device 40 only needs to be controlled by the potential control device 120, it is only necessary to replace the charging device 20 or the conventional potential applying device that applied the potential to the developing device 40. The problem that the toner adheres to the squeeze roller and the squeeze blade can be solved without providing a configuration that increases complexity and size.

  Furthermore, in this embodiment, since the potential sensor 130 monitors the charging of the photosensitive layer 103 to confirm that the photosensitive layer 103 has a predetermined potential, the temperature, humidity, and the degree of contamination of the surface of the photosensitive layer 103 are confirmed. Even if the charging property is changed due to damage or the like, the operation can be surely performed.

(Sixth embodiment)
FIG. 18 is a configuration diagram of the image forming apparatus 1 according to the present embodiment. The description of the same configuration as in FIG. 1 is omitted.

  In the present embodiment, the potential control device 120 controls the potential of the squeeze roller 501.

  The developing device 40 includes a developing power source 406. The developing power source 406 sets the developing roller 403 to a predetermined potential.

  The operation of the image forming apparatus 1 of the present embodiment having the above-described configuration will be described below.

  The image forming apparatus 1 has an operation mode of an image forming mode and a cleaning mode.

  In the image forming mode, the developing power source 406 supplies power to the charging device 40 and the potential control device 120 controls the potential to the squeeze roller 501. The image forming apparatus 1 according to the first embodiment has the following configuration. Same as operation.

  In the cleaning mode of the image forming apparatus 1, the squeeze roller 501 is different from the operation of the image forming apparatus 1 according to the first embodiment in that a bias voltage of about 650 V is applied by the potential control device 120.

  Here, the phenomenon in the photoconductor 10 and the squeeze roller 501 will be described.

  A 650 V voltage is applied to the squeeze roller 501 to which a voltage of 550 V has been applied in the image forming mode, and the potential difference with the photosensitive layer 103 is about 100 V smaller than in the image forming mode. Therefore, toner movement in the direction from the photosensitive layer 103 toward the squeeze roller 501 through a gap between the photosensitive layer 103 and the squeeze roller 501 is less likely to occur than in the image forming mode.

  For this reason, the developer squeezed from the photosensitive layer 103 by the squeeze roller 501 further has a very low toner concentration only with the liquid carrier.

Also,
As described above, by setting the difference between the potential of the photosensitive layer 103 and the potential of the squeeze roller 501 in the operation in the cleaning mode to be equal to or less than the difference between the potential of the photosensitive layer 103 and the potential of the squeeze roller 501 in the operation in the image forming mode. Since the developer removed from the photoreceptor 10 by the squeeze roller 501 is further only a liquid carrier and the toner concentration is low, the toner remaining between the squeeze roller 501 and the squeeze blade 502 is further reduced. The problem of sticking with toner can be avoided.

  Further, since the potential of the squeeze roller 501 only needs to be controlled by the potential control device 120, it is only necessary to replace the conventional power supply device that applied the potential to the squeeze roller 501. In addition, it is possible to solve the problem that the toner adheres to the squeeze roller and the squeeze blade without providing a configuration that causes an increase in size.

  Further, in the present embodiment, the toner concentration of the developer entering the squeeze device 50 becomes extremely small, so that the toner removing device can be simplified even when the toner is removed from the developer and reused as a liquid carrier. be able to.

(Seventh embodiment)
In the present embodiment, a description will be given of a modification of how the operations in various image forming modes including the first to fifth embodiments and the operations in the cleaning mode are performed.

  FIG. 19 is a flowchart showing the relationship between the image forming mode and the cleaning mode. The description of the same steps as those in FIG. 2 is omitted.

  The image forming apparatus 1 according to the present embodiment includes a timer (not shown). When the standby state has elapsed for a predetermined time, the timer shifts to the cleaning mode (step 3).

  As described above, the squeeze device 50 is removed from the photoconductor 10 during the standby state in an environment where the liquid carrier easily evaporates, such as a high temperature environment, by designing to shift to the cleaning mode when the standby state has passed for a predetermined time. It is possible to prevent toner sticking between the squeeze roller 501 and the squeeze 502 due to evaporation of the liquid carrier from the developer.

  In the present embodiment, the charging device 20 has been described as the scorotron type, but various types such as a corotron type without a grid, a solid ion generation type without a wire, and a frictional charging type can be applied.

  Further, although the potential of the photosensitive layer 103 is set to a predetermined value at the charging position of the charging device 20, the charging position of the photosensitive layer 103 is moved from the position facing the charging device 20 to the position facing the developing device 40. The photosensitive layer 103 may be charged to a slightly higher potential at a position facing the charging device 20 in anticipation of the potential of the drop.

  Further, although the drying device 60 has been described as applying air, various types including those that absorb the liquid carrier attached to the photoreceptor 10 using a porous elastic roller, for example, can be applied.

1 is a configuration diagram of an image forming apparatus 1 according to a first embodiment. 6 is a flowchart showing a relationship between an image forming mode and a cleaning mode. 10 is a flowchart of operations in the image forming mode of the image forming apparatus and the second embodiment. FIG. 4 is a diagram showing the relationship between the photosensitive layer and the developing roller potential in step 103 of the flowchart of FIG. 3. The figure which shows the relationship between the photosensitive layer in step 104 of the flowchart of FIG. 3, and the electric potential of a squeeze roller. 6 is a flowchart of the operation in the cleaning mode of the image forming apparatus according to the first embodiment. FIG. 7 is a diagram showing the relationship between the potential of the photosensitive layer and the developing roller in step 204 in the flowchart of FIG. 6. FIG. 3 is a configuration diagram of an image forming apparatus according to a second embodiment. 10 is a flowchart of an operation in a cleaning mode of the image forming apparatus according to the second embodiment. FIG. 10 is a diagram showing the relationship between the rotation of the photoreceptor and the potential of the photosensitive layer in the flowchart of FIG. 9. 10 is a flowchart of the operation in the cleaning mode of the image forming apparatus according to the third embodiment. FIG. 12 is a diagram illustrating a relationship between the rotation of the photosensitive member and the potential of the photosensitive layer in the flowchart of FIG. 11. 10 is a flowchart of an operation in a cleaning mode of an image forming apparatus according to a fourth embodiment. FIG. 14 is a diagram showing the relationship between the rotation of the photoreceptor and the potential of the photosensitive layer in the flowchart of FIG. 13. FIG. 10 is a configuration diagram of an image forming apparatus according to a fifth embodiment. 10 is a flowchart of an operation in a cleaning mode of an image forming apparatus according to a fifth embodiment. FIG. 17 is a diagram showing the relationship between the rotation of the photoreceptor and the potential of the photosensitive layer in the flowchart of FIG. 16. 10 is a flowchart of operations in a cleaning mode of an image forming apparatus according to a sixth embodiment. 9 is a flowchart illustrating a modification example of the relationship between the image forming mode and the cleaning mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 10 ... Photoconductor 20 ... Charging apparatus 30 ... Exposure apparatus 40 ... Developing apparatus 50 ... Squeeze apparatus 60 ... Drying apparatus 70 ... Intermediate transfer body DESCRIPTION OF SYMBOLS 80 ... Cleaning apparatus 90 ... Static elimination apparatus 100 ... Transfer apparatus 403 ... Developing roller 501 ... Squeeze roller 502 ... Squeeze blade

Claims (6)

An electrostatic latent image carrier;
A charger for charging the electrostatic latent image holding member;
An exposure device that exposes the charged electrostatic latent image holding member to form an electrostatic latent image; and
A developing device having a developing electrode and developing the electrostatic latent image with a developer having toner and a liquid carrier to form a toner image;
A squeeze member for removing a part of the developer adhering to the electrostatic latent image holding member on which the toner image is formed;
A squeeze cleaning member for removing the toner adhering to the squeeze member;
A potential control device for controlling the potential of the developing electrode;
An image forming mode for forming an image, and a cleaning mode for removing the toner adhering to the squeeze member in the image forming mode;
The potential control device is configured such that a difference between the potential of the electrostatic latent image holding member and the potential of the developing electrode in the cleaning mode is equal to or greater than a difference between the potential of the electrostatic holding member and the potential of the developing electrode in the image forming mode. An image forming apparatus. An electrostatic latent image carrier;
A charger for charging the electrostatic latent image holding member;
An exposure device that exposes the charged electrostatic latent image holding member to form an electrostatic latent image; and
A developer for developing the electrostatic latent image with a developer having toner and a liquid carrier to form a toner image;
A squeeze electrode for removing a part of the developer adhering to the electrostatic latent image holding body on which the toner image is formed;
A squeeze cleaning member for removing the toner adhering to the squeeze electrode;
A potential control device for controlling the potential of the squeeze electrode;
An image forming mode for forming an image, and a cleaning mode for removing the toner adhering to the squeeze member in the image forming mode;
The image forming apparatus, wherein the potential control device makes the potential of the squeeze electrode in the cleaning mode higher than the potential of the squeeze electrode in the image forming mode. An electrostatic latent image carrier;
A charger for charging the electrostatic latent image holding member;
An exposure device that exposes the charged electrostatic latent image holding member to form an electrostatic latent image; and
A developing device having a developing electrode and developing the electrostatic latent image with a developer having toner and a liquid carrier to form a toner image;
A squeeze electrode for removing a part of the developer adhering to the electrostatic latent image holding body on which the toner image is formed;
A squeeze cleaning member for removing the toner adhering to the squeeze electrode;
An image forming mode for forming an image, and a cleaning mode for removing the toner adhering to the squeeze member in the image forming mode; and a potential control device that controls the potential of the developing electrode.
The image forming apparatus, wherein the potential control device makes the potential of the squeeze electrode higher than the potential of the developing electrode in the cleaning mode. Charge the electrostatic latent image carrier,
An electrostatic latent image is formed by exposing the charged electrostatic latent image holding member,
The electrostatic latent image held by the electrostatic latent image holding member is developed with a developer having toner and a liquid carrier by a developing electrode having a first potential difference with respect to the potential of the electrostatic latent image holding member. To form a toner image,
An image forming step of removing a part of the developer adhering to the electrostatic latent image holding body on which the toner image is formed by a squeeze member;
Charging the electrostatic latent image carrier,
Supplying the developer to the electrostatic latent image holding body using the developing electrode having a second potential difference larger than the first potential difference with respect to the potential of the electrostatic latent image holding body;
A part of the developer adhering to the electrostatic latent image holding body supplied with the developer is removed by a squeeze member,
A cleaning step of removing the toner adhering to the squeeze electrode by the squeeze cleaning member;
An image forming method comprising: Charge the electrostatic latent image carrier,
An electrostatic latent image is formed by exposing the charged electrostatic latent image holding member,
The electrostatic latent image held by the electrostatic latent image holder is developed with a developer having toner and a liquid carrier to form a toner image,
A part of the developer adhering to the electrostatic latent image holding member on which the toner image is formed is removed by a squeeze electrode having a first potential difference with respect to the potential of the electrostatic latent image holding member;
An image forming step of removing the toner adhering to the squeeze electrode by a squeeze cleaning member;
Charging the electrostatic latent image carrier,
Supplying the developer to the charged electrostatic latent image carrier,
A part of the developer adhering to the electrostatic latent image holding body supplied with the developer has a second potential difference larger than the first potential difference with respect to the potential of the electrostatic latent image holding body. Remove by squeeze electrode with
A cleaning step of removing the toner adhering to the squeeze electrode by the squeeze cleaning member;
An image forming method comprising: Charge the electrostatic latent image carrier,
An electrostatic latent image is formed by exposing the charged electrostatic latent image holding member,
The electrostatic latent image held by the electrostatic latent image holding member is developed with a developing electrode using a developer having toner and a liquid carrier to form a toner image,
An image forming step of removing a part of the developer adhering to the electrostatic latent image holding body on which the toner image is formed by a squeeze electrode;
Charging the electrostatic latent image carrier,
Supplying the developer to the electrostatic latent image holding member using the developing electrode;
A portion of the developer adhering to the electrostatic latent image holding body supplied with the developer is removed by a squeeze electrode;
A cleaning step of removing the toner adhering to the squeeze electrode by the squeeze cleaning electrode having a higher potential than the developing electrode;
An image forming method comprising:

Images