WO2012102245A1

WO2012102245A1 - Toner supplying device and electrophotographic printing device

Info

Publication number: WO2012102245A1
Application number: PCT/JP2012/051369
Authority: WO
Inventors: 妹尾　慎一郎; 佐藤　稔; 国彦山室
Original assignee: 三菱重工印刷紙工機械株式会社
Priority date: 2011-01-26
Filing date: 2012-01-23
Publication date: 2012-08-02
Also published as: JPWO2012102245A1; EP2669748A1

Abstract

A toner supplying device and an electrophotographic printing device are provided with: a toner supply pan (61) that stores a liquid toner; an anilox roller (52) that has a portion immersed in the liquid toner stored in the toner supply pan (61) and that can supply the liquid toner by rotating; a smoothing roller (53) that can receive and carry the liquid toner by rotating in counter-contact with the anilox roller (52); and a toner cover (67) that is arranged close to the side upstream of the counter-contact section between the anilox roller (52) and the smoothing roller (53) in regard to the respective rotating directions of the rollers (52, 53). Thus, a liquid toner layer having an even thickness in the width direction of the rollers can be formed and supplied.

Description

Toner supply apparatus and electrophotographic printing apparatus

The present invention relates to a toner supply device that supplies stored toner and an electrophotographic printing apparatus to which the toner supply device is applied.

Conventionally, a liquid toner in which a toner composed of a thermoplastic resin and a pigment is dispersed in a carrier is developed into an electrostatic latent image formed on a photoconductor, and is primarily transferred to an intermediate transfer body. There has been proposed an electrophotographic printing apparatus that performs printing by transferring toner onto the surface of a printing material and fixing the toner in the transferred liquid toner onto the printing material.

In this electrophotographic printing apparatus, the liquid toner is supplied from the reservoir to the developing roller via the leveling roller by the anilox roller, and from the peripheral surface of the developing roller to the portion where the electrostatic latent image on the photosensitive drum is formed. Transcribed. In this case, the anilox roller has a groove or a recess formed on the peripheral surface. By rotating a part of the anilox roller immersed in the liquid toner, the groove or the recess is supported with the liquid toner, and the blade is The liquid toner filled in the grooves and the recesses is made uniform, and the liquid toner is supplied to a leveling roller that contacts the liquid toner.

As such a toner supply device, there is one described in Patent Document 1 below.

JP 2007-293177 A

In the conventional toner supply device described above, the anilox roller rotates while a part of the anilox roller is immersed in the reservoir (tank), and the outer peripheral surface contacts the blade, thereby adjusting the amount of liquid toner to be carried. In addition, the amount of liquid toner in the width direction is made uniform. However, since the liquid toner is supplied to the storage unit through the pipe, the flow of the liquid toner drifts in the storage unit, and the amount of liquid toner varies in the width direction of the anilox roller. In this case, the amount of liquid toner carried by the anilox roller is made uniform by the blade, but it is difficult to equalize the pressing force of the blade against the anilox roller in the width direction.

SUMMARY An advantage of some aspects of the invention is to provide a toner supply apparatus and an electrophotographic printing apparatus that can form and supply a liquid toner layer having a uniform film thickness in the width direction of a roller. .

In order to achieve the above object, a toner supply device of the present invention includes a toner supply pan that stores liquid toner, and a liquid toner that is partially immersed in the liquid toner stored in the toner supply pan and rotates. A toner supply roller that can be supplied, a toner conveyance roller that can receive and convey liquid toner by rotating in contact with the toner supply roller, and a contact portion between the toner supply roller and the toner conveyance roller. And a toner staying member disposed close to the upstream side in the rotation direction of the roller.

Accordingly, when the toner supply roller rotates while being immersed in the liquid toner in the toner supply pan, the toner supply roller rotates with the liquid toner attached to the outer peripheral surface, and the liquid toner is brought into contact with the toner conveying roller. Is supplied to the surface of the toner conveying roller. At this time, since the toner staying member is disposed close to the contact portion of each roller, the toner staying member retains an amount of liquid toner larger than the thickness that can pass through the contact portion. The liquid toner layer that has passed through the contact portion has a predetermined thickness, and the liquid toner can be appropriately supplied to the surface of the toner conveying roller. As a result, the toner conveying roller can form a liquid toner layer having a uniform thickness in the width direction on the surface thereof.

In the toner supply device of the present invention, the toner retention member has a first covering portion that covers the peripheral surface of the toner supply roller and a second covering portion that covers the peripheral surface of the toner transport roller. .

Therefore, the toner retaining member covers both peripheral surfaces at the contact portion between the toner supply roller and the toner transport roller, and a sufficient amount of the roller contact portion can pass through the contact portion. Liquid toner can be retained.

In the toner supply device according to the aspect of the invention, the toner staying member includes a surface covering portion that covers a peripheral surface side of each of the rollers facing the contact portion, and an end surface covering portion that covers an end surface side of each of the rollers. It is characterized by.

Accordingly, the toner retaining member covers not only the peripheral surfaces of the toner supply roller and the toner transport roller but also the end surfaces thereof, and a sufficient amount of liquid toner that can pass through the contact portion of each roller. Can be retained.

In the toner supply device of the present invention, the toner retention member is provided to extend from the toner supply pan.

Therefore, the toner retention member covers from the toner supply pan to the contact portion of the toner supply roller and the toner transport roller, and the liquid toner in the toner supply pan is appropriately retained to the contact portion of each roller, so that the toner transport An appropriate amount of liquid toner can be supplied to the surface of the roller.

In the toner supply device of the present invention, the toner supply pan includes a first pan located on the upstream side in the rotation direction of the toner supply roller and a second pan located on the downstream side in the rotation direction of the toner supply roller. The toner staying member is configured to be integrally joined, and is provided to extend from the second pan.

Therefore, by dividing the toner supply pan, the manufacturing and assembling can be facilitated to improve the manufacturability, and the toner retaining member can be easily extended by extending the toner retaining member from the second pan. Can be arranged.

In the toner supply device of the present invention, the toner supply pan is provided with a toner supply unit that supplies liquid toner to the first pan.

Accordingly, since the toner supply pan is provided with the toner supply portion on the first pan side and the toner retention member is provided on the second pan side, the liquid toner has a rotation direction of the toner supply roller in the toner supply pan. Similarly, the toner flows from the toner supply unit toward the toner retention member, so that the retention of the liquid toner in the toner supply pan can be suppressed, and the temperature rise of the liquid toner can be suppressed.

In the toner supply device of the present invention, the toner supply pan is provided with a bearing on each side wall portion in the width direction, and each end portion of the toner supply roller is rotatably supported by each bearing, and the toner retention member Is provided to extend from the side wall.

Therefore, by supporting the toner supply roller on each side wall portion of the toner supply pan via a bearing, the support structure of the toner supply roller can be simplified, and a toner retention member can be provided from each side wall portion. The configuration can be simplified.

The toner supply device of the present invention is characterized in that the toner retention member is provided as a separate member from the toner supply pan.

Therefore, by providing the toner retention member separately from the toner supply pan, each member can be designed separately, and the degree of design freedom can be improved.

In the toner supply device of the present invention, the toner staying member is a deformable film member or an elastic member, and a base end portion is fixed to an end portion of the toner supply pan, and a tip end portion is the toner supply roller. And the toner conveying roller.

Therefore, by using a deformable film member or elastic member as the toner retaining member, the toner retaining member can be appropriately deformed according to the retention amount of the liquid toner, and the structure can be simplified and the cost can be reduced. it can.

In the toner supply device of the present invention, the toner staying member is a rod-shaped member, and is disposed along a contact portion between the toner supply roller and the toner transport roller.

Therefore, by using a rod-like member as the toner retention member, the structure can be simplified and the cost can be reduced.

In addition, the electrophotographic printing apparatus of the present invention includes a paper feeding device that can supply the printed materials one by one, and liquid toner that forms an electrostatic latent image on the photosensitive member with respect to the printed material supplied from the paper feeding device. A printing device for transferring the transferred and developed toner image, a fixing device for heating and fixing the toner image transferred to the substrate, and discharging the substrate on which the toner image is fixed by the fixing device An electrophotographic printing apparatus comprising a paper discharge device, wherein the printing device is developed by transferring a liquid toner onto a photosensitive member on which an electrostatic latent image is formed, and developing the printing unit. A primary transfer member that transfers the liquid toner, and a secondary transfer member that forms a nip by contacting the primary transfer member and applies a bias voltage to transfer the liquid toner to the substrate. Have The printing unit includes a toner supply pan for storing liquid toner, a toner supply roller capable of supplying liquid toner by rotating partly immersed in the liquid toner stored in the toner supply pan, and the toner A toner transport roller that can receive and transport liquid toner by rotating in contact with the supply roller, and a liquid toner charged by rotating in contact with the toner transport roller can be received and transferred to the primary transfer member A photosensitive member, and a toner staying member disposed close to the upstream side in the rotation direction of each roller from a contact portion between the toner supply roller and the toner transport roller.

Accordingly, when the printing unit rotates in a state where the toner supply roller is immersed in the liquid toner in the toner supply pan, the toner supply roller rotates with the liquid toner attached to the outer peripheral surface, and is opposed to the toner transport roller. Liquid toner is supplied to the surface of the toner conveying roller at the contact portion. At this time, since the toner staying member is disposed close to the contact portion of each roller, the toner staying member retains an amount of liquid toner larger than the thickness that can pass through the contact portion. The liquid toner layer that has passed through the contact portion has a predetermined thickness, and the liquid toner can be appropriately supplied to the surface of the toner conveying roller. As a result, the toner conveying roller can form a liquid toner layer having a uniform thickness in the width direction on the surface thereof. Thereafter, the toner transport roller transfers the charged liquid toner onto the photosensitive member on which the electrostatic latent image is formed and develops, and the developed liquid toner is transferred to the primary transfer member and is transferred to the primary transfer member. When the substrate is conveyed between the secondary transfer member and the secondary transfer member, the liquid toner of the primary transfer member is transferred to the substrate and printing is performed. As a result, printing accuracy and printing quality can be improved.

According to the toner supply device and the electrophotographic printing apparatus of the present invention, the toner retention member is disposed close to the upstream side in the rotation direction of each roller from the contact portion between the toner supply roller and the toner transport roller. A liquid toner layer having a uniform film thickness can be formed and supplied.

FIG. 1 is a schematic diagram showing an electrophotographic printing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating the printing apparatus of this embodiment. FIG. 3 is a schematic diagram illustrating the printing unit of the present embodiment. FIG. 4 is a front view illustrating the toner supply device of this embodiment. FIG. 5 is a schematic diagram illustrating the flow of the liquid toner by the toner supply device of this embodiment. FIG. 6 is an exploded perspective view of the toner supply device. FIG. 7 is a cross-sectional view illustrating a support portion of the anilox roller in the toner supply device. FIG. 8 is a schematic diagram illustrating a modification of the toner supply device. FIG. 9 is a schematic diagram illustrating a modification of the toner supply device. FIG. 10 is a schematic diagram illustrating a modified example of the toner supply device.

Hereinafter, preferred embodiments of a toner supply device and an electrophotographic printing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

FIG. 1 is a schematic diagram illustrating an electrophotographic printing apparatus according to an embodiment of the present invention, FIG. 2 is a schematic diagram illustrating a printing apparatus according to the present embodiment, and FIG. 3 is a schematic diagram illustrating a printing unit according to the present embodiment. 4 is a front view showing the toner supply device of this embodiment, FIG. 5 is a schematic view showing the flow of liquid toner by the toner supply device of this embodiment, and FIG. 6 is an exploded perspective view of the toner supply device. FIG. 7 is a cross-sectional view illustrating a support portion of the anilox roller in the toner supply device.

In this embodiment, as shown in FIG. 1, the electrophotographic printing apparatus 10 is a liquid developing electrophotographic double-sided and single-sided printing machine, and includes a paper feeding device 11, a printing device 12, a fixing device 13, and a conveying device 14. , And a paper discharge device 15.

The sheet feeding device 11 has a pair of upper and lower

sheet feeding units

11a and 11b. Each of the

sheet feeding units

11a and 11b includes a sheet feeding table 21a and 21b and a

separator device

22a and 22b as a sheet feeding mechanism. And have. The

paper feed bases

21a and 21b are for stacking and placing print sheets (substrates) S up and down, and the

separator devices

22a and 22b are a large number of print sheets S stacked on the

paper feed bases

21a and 21b. Are picked up one by one in order from the top and sent forward. In this case, the

paper feed bases

21a and 21b can be moved up and down in response to the supply of the print sheet S so that the

separator devices

22a and 22b can maintain a substantially constant positional relationship with the print sheet S. ing.

The printing device 12 can perform process color printing of K (black), C (indigo), M (red), and Y (yellow). In this case, as shown in FIGS. 1 and 2, the printing device 12 transfers the toner developed by transferring the liquid toner to the electrostatic latent image on the photosensitive member with respect to the printing sheet S supplied from the paper feeding device 11. The image is transferred. That is, the printing apparatus 12 includes a backup roller (secondary transfer member) 31, an intermediate transfer member (primary transfer member) 32, and four

printing units

33, 34, 35, and 36 corresponding to the respective colors. ing.

The backup roller 31 and the intermediate transfer member 32 are rollers having the same outer diameter (peripheral length), and can be driven synchronously in the direction of the arrow in a contact state, and a predetermined pressure is set at the contact portion. The nip (transfer position) is set. The backup roller 31 is provided with grippers 31a on the outer peripheral portion at equal intervals in the circumferential direction. The gripper 31a can grip the leading end portion of the print sheet S supplied from the paper feeding device 11, and the gripped print sheet S can be guided to the nip portion by rotating the backup roller 31. On the other hand, the intermediate transfer body 32 is configured such that a blanket made of, for example, urethane conductive rubber is mounted on the outer peripheral surface, and a bias for voltage control or current control is applied.

The backup roller 31 is disposed so as to apply pressure to the intermediate transfer member 32 at a predetermined pressure, for example, about 1 to 13 kg / cm, at the nip portion described above. Therefore, when the print sheet S is conveyed by the backup roller 31, a predetermined nip pressure is applied when passing through the nip portion formed between the print sheet S and the intermediate transfer body 32. The backup roller 31 is applied with a transfer bias (in the case of voltage control) of about −1000 V, for example. Therefore, the difference between the bias voltage (about −1000 V) of the backup roller 31 and the bias voltage of the intermediate transfer body 32 gives a force for sucking liquid toner, which will be described later, toward the backup roller 31, and the intermediate transfer body 32 prints the print sheet. The electrostatic transfer of liquid toner to S can be promoted.

The

printing units

33, 34, 35, and 36 are arranged around the intermediate transfer body 32 along the rotation direction, and the configuration is the same except that the color of the liquid toner to be used is different. ing. Therefore, the printing unit 33 will be described in detail below.

As shown in FIGS. 2 and 3, the printing unit 33 forms an electrostatic latent image on the photosensitive drum 41 based on image data transmitted from a control device (not shown), and corresponds to the electrostatic latent image. The liquid toner is supplied to the position, and the liquid toner image formed on the photosensitive drum 41 is transferred to the intermediate transfer member 32.

Here, the liquid toner is a mixture of a particulate toner formed of a thermoplastic material resin and a pigment dispersed in a liquid carrier. Here, a petroleum solvent (as a carrier) For example, a non-polar, paraffinic solvent such as mineral oil) is used as the liquid toner in which about 10 to 40 percent by weight of particulate toner having an average particle size of about 1 to 2 μm is contained.

The printing unit 33 includes a photosensitive drum (photoconductor) 41, a cleaning unit 42, a static eliminator 43, a charging device 44, an exposure device 45, and a developing device 46. The photosensitive drum 41 has a photosensitive layer formed on its peripheral surface containing a photosensitive agent such as amorphous silicon (a-Si) or a photosensitive polymer (organic photosensitive member). The photosensitive drum 41 is in contact with the intermediate transfer body 32 with a nip portion so that the liquid toner on the photosensitive drum 41 can be transferred to the intermediate transfer body 32 side.

The photosensitive drum 41 has a cleaning unit 42, a static eliminator 43, a charging device 44, an exposure device 45, and a developing device 46 in order from the upstream side of the photosensitive drum 41 along the rotation direction of the photosensitive drum 41. The photosensitive layer is disposed to face the photosensitive layer.

The cleaning unit 42 includes a cleaning blade 42a, and can remove liquid toner remaining on the peripheral surface of the photosensitive drum 41 and discharge it to a toner collection path (not shown). In other words, the cleaning blade 42 a is a rectangular plate made of an elastic material, and is supported so that the tip portion is in contact with the peripheral surface of the photosensitive drum 41, and the liquid toner on the peripheral surface of the photosensitive drum 41 is removed. Can be scraped off.

The static eliminator 43 has a function of erasing charges remaining on the photosensitive layer of the photosensitive drum 41. The charging device 44 includes a plurality of non-contact discharge type chargers such as a corotron type or a scorotron type along the circumferential direction of the photosensitive drum 41, and the photosensitive layer of the photosensitive drum 41 is uniformly formed. For example, it has a function of charging to about 500V.

The exposure device 45 is composed of a light emitting device (LED array) in which light emitters (for example, LEDs) are arranged in a rod shape along the axial direction of the photosensitive drum 41, and is based on image data sent from a control device. Each LED is made to emit light. That is, the surface of the photosensitive layer of the photosensitive drum 41 that is uniformly charged by the charging device 44 is irradiated with light from the exposure device 45, so that the photosensitive layer is uncharged in the light irradiation portion, and the photosensitive layer An electrostatic latent image based on the image data can be formed. The light emitting device may be configured to form an electrostatic latent image by scanning a semiconductor laser or the like based on image data instead of the LED array.

The developing device 46 includes a toner storage unit 51, an anilox roller 52, a leveling roller 53, a developing roller 54, a toner charger 55, and

toner recovery units

56 and 57. The liquid toner can be transferred to the portion where the image is formed.

The toner storage unit 51 stores liquid toner, and the liquid toner can be supplied and discharged so that a part of the anilox roller 52 is immersed in the liquid toner. The anilox roller 52 is, for example, a metal roller, and a concave portion (cell) suitable for supplying liquid toner with a desired film thickness is formed on the entire surface of the anilox roller 52. The anilox roller 52 can be driven to rotate together with the photosensitive drum 41.

The leveling roller 53 is made of, for example, conductive rubber (urethane rubber), and is disposed between the anilox roller 52 and the developing roller 54, and the peripheral surface is in contact with the anilox roller 52 and the developing roller 54. Yes. Further, the leveling roller 53 is rotatable in such a direction that the peripheral surfaces thereof advance in the same direction at the contact point with the anilox roller 52.

The developing roller 54 is made of, for example, conductive rubber, and is disposed so as to form a nip portion in contact with the photosensitive drum 41, and the peripheral surface of the photosensitive drum 41 and the peripheral surface of the developing roller 54 are formed. It can be rotated in the same direction. Further, the developing roller 54 is set to have the same peripheral speed as that of the photosensitive drum 41. The toner charger 55 has a function of uniformly charging the liquid toner on the developing roller 54.

Accordingly, when the conductive developing roller 54 and the photosensitive drum 41 are in contact with each other at the nip portion, the liquid toner containing the toner charged from the peripheral surface of the developing roller 54 to the portion where the electrostatic latent image of the photosensitive drum 41 is formed. Is transferred and developed. Then, the developed liquid toner on the peripheral surface of the photosensitive drum 41 is transferred to the intermediate transfer body 32 at the nip portion, and the liquid toner layer (toner image) containing the toner image on the peripheral surface of the intermediate transfer body 32 is transferred. ) Can be formed.

The toner collecting unit 56 can remove and collect the liquid toner remaining on the peripheral surface of the developing roller 54. The toner collecting unit 57 can remove and collect the liquid toner remaining on the peripheral surface of the leveling roller 53. The

toner recovery units

56 and 57 have substantially the same configuration, and the residual toner peeled off from the surface of the leveling roller 53 and the developing roller 54 by a blade is conveyed to a predetermined position to be described later. To be collected.

Here, the toner supply device of this embodiment applied to the developing device 46 will be described. As shown in FIG. 4, the toner supply device of the developing device 46 includes a toner supply pan 61, an anilox roller (toner supply roller) 52, a leveling roller (toner transport roller) 53, and a toner retention member described later. .

As described above, the anilox roller 52 is a metal roller in which concave portions (cells) suitable for supplying liquid toner with a desired film thickness are formed on the entire surface of the anilox roller 52 in a predetermined direction (see FIG. 4 can be rotated in the clockwise direction.

The leveling roller 53 is in contact with the anilox roller 52 at the circumferential surface, and can be driven to rotate in a predetermined direction (counterclockwise direction in FIG. 4). For this reason, the leveling roller 53 is rotatable at a contact portion in contact with the anilox roller 52 such that the circumferential surfaces thereof advance in the same direction.

In this embodiment, the anilox roller 52 is described as a toner supply roller and the leveling roller 53 is described as a toner transport roller. However, the present invention is not limited to this configuration. For example, the leveling roller 53 may be eliminated, and the anilox roller 52 may be directly brought into contact with the developing roller 54. In this case, the developing roller 54 functions as a toner conveying roller. Further, not only the leveling roller 53 but also a plurality of rollers (toner conveying rollers) may be interposed between the anilox roller 52 and the direct developing roller 54.

The toner supply pan 61 stores liquid toner and is long along the axial direction of the anilox roller 52 and is bent (or curved) along the circumferential surface on the lower side of the anilox roller 52. And the shape rising from the end face in the axial direction of the anilox roller 52. The toner supply pan 61 is disposed with a predetermined gap from the peripheral surface and end surface of the anilox roller 52.

The toner supply pan 61 is configured by integrally joining a first pan 62 located upstream in the rotational direction of the anilox roller 52 and a second pan 63 located downstream in the rotational direction of the anilox roller 52. Yes. As shown in FIGS. 4 and 6, the first pan 62 includes a bottom portion 62 a that is bent along the peripheral surface of the anilox roller 52, and a peripheral surface of the anilox roller 52 from the bottom portion 62 a on each shaft end side of the anilox roller 52. Two first mounting portions 62b that rise along the bottom, a second mounting portion 62c that hangs down from the peripheral surface of the anilox roller 52 from the bottom portion 62a, and a flange portion 62d that is formed along the end surface of the anilox roller 52. And a mounting piece 62e formed to protrude from the bottom 62a to the side.

The second pan 63 includes a bottom portion 63 a that is bent along the peripheral surface of the anilox roller 52, a mounting portion 63 b that hangs from the bottom portion 63 a so as to be separated from the peripheral surface of the anilox roller 52, and an end surface of the anilox roller 52. And a flange portion 63c formed along the line. The toner supply pan 61 is configured to be integrally fixed by a plurality of bolts 61 a in a state where the second mounting portion 62 c of the first pan 62 and the mounting portion 63 b of the second pan 63 are in close contact with each other. The toner supply pan 61 has an attachment piece 62e fixed to a bracket 64 by a plurality of bolts 61b. The bracket 64 is connected to a toner collection pan 68 described later.

The toner supply pan 61 is provided with a toner supply unit 65 that supplies liquid toner to the first pan 62. The toner supply unit 65 supplies liquid toner in a toner storage tank (not shown) into the toner supply pan 61 by a supply pump. In the toner supply unit 65, the mounting plate 65a is in close contact with the first mounting portion 62b of the first pan 62 constituting the toner supply pan 61 from the inside, and is fixed by a plurality of bolts 65c in this state. In the toner supply part 65, three connecting

parts

65b and 65c are fixed to the mounting plate 65a along the axial direction of the anilox roller 52, and a supply pipe 65d is connected to the connecting part 65b in the central part. In addition, the connecting portion 65b in the central portion and the connecting portions 65c on both sides are connected by a connecting tube 65e, and the connecting tube 65f extends from the connecting portions 65c on both sides to the connecting portion 65b in the central portion, and each end The connecting pipe 65g is extended on the part side, and the connecting parts 65b and the connecting

pipes

65f, 65g on both sides penetrate the mounting plate 65a.

Accordingly, the liquid toner is supplied to the supply pipe 65d, reaches the connecting parts 65c on both sides via the connecting pipes 65e from the central connecting part 65b, and passes through the connecting parts 65b and the connecting

pipes

65f and 65g to the toner supply pan 61. To be supplied. In this case, the positions where the connecting portions 65 b and the connecting

pipes

65 f and 65 g communicate with the toner supply pan 61 are supplied to five locations equally divided in the width direction of the toner supply pan 61. Thus, the supply pressure of the liquid toner is set so as not to be biased.

In addition, the toner supply pan 61 is provided with a side wall portion having an arc shape on both sides in the width direction because the flange portion 62d of the first pan 62 and the flange portion 63c of the second pan 63 are continuous. A bearing 66 is fitted to the

flange portions

62d and 63c. As shown in detail in FIG. 7, the anilox roller 52 is rotatably supported so that each shaft portion 52 a passes through the bearing 66.

In the toner supply device of the present embodiment configured as described above, as shown in FIGS. 4 and 6, upstream from the contact portion between the anilox roller 52 and the leveling roller 53 in the rotational direction of the

rollers

52 and 53. On the side, a toner cover 67 as a toner retention member is disposed in the vicinity. In this case, the toner cover 67 is provided integrally with the toner supply pan 61 and is extended from the second pan 63 and provided integrally therewith.

That is, the toner supply pan 61 is paired with the leveling roller 53 so that the bottom 63a of the second pan 63 has a predetermined gap with the peripheral surface of the anilox roller 52 and forms a curved shape along the peripheral surface. It extends to the contact part. Further, the toner supply pan 61 is in contact with the leveling roller 53 so that the flange portion 63c of the second pan 63 has a predetermined gap with the end surface of the anilox roller 52 and forms a planar shape along the end surface. It is extended to the department.

In this case, a portion extending from the bottom 63a of the second pan 63 of the toner supply pan 61 to the contact portion between the anilox roller 52 and the leveling roller 53 and the flange portion 63c of the second pan 63 are the contact portion. The toner cover 67 is configured by the portion extended to the end. That is, the toner cover 67 includes a surface covering portion 67 a that covers the peripheral surface side of each

roller

52, 53 facing the contact portion of each

roller

52, 53, and an end surface covering portion that covers each end surface side of each

roller

52, 53. 67b.

Further, the toner cover 67 has a surface covering portion 67 a extending from the second pan 63 of the toner supply pan 61 along the peripheral surface of the anilox roller 52, and this leveling portion is in contact with the leveling roller 53. Bending along the circumferential surface of the roller 53. In this case, the toner cover 67 has a first covering portion 67c that covers the peripheral surface with a predetermined gap from the anilox roller 52, and a second covering portion 67d that covers the peripheral surface with a predetermined clearance from the leveling roller 53. is doing. The toner cover 67 is opened without the second covering portion 67d being in contact with the circumferential surface of the leveling roller 53 in the middle.

Similarly to the surface covering portion 67 a, the toner cover 67 has an end surface covering portion 67 b extending from the second pan 63 of the toner supply pan 61 along the end surface of the anilox roller 52, and is in contact with the leveling roller 53. This part faces the end face of the leveling roller 53. In other words, the toner cover 67 covers the end surface covering portion 67 b with a predetermined gap to the nip position between the anilox roller 52 and the leveling roller 53.

Further, as shown in FIG. 4, the toner recovery pan 68 is disposed below the toner supply pan 61 and receives liquid toner that has overflowed over the toner supply pan 61. Similar to the toner supply pan 61, the toner collection pan 68 is long along the axial direction of the anilox roller 52 and is slightly larger than the toner supply pan 61, and has a capacity to accommodate the toner supply pan 61. Yes. Therefore, it is possible to receive the liquid toner that has overflowed from the toner supply pan 61. The toner recovery pan 68 can discharge the liquid toner received from the toner supply pan 61 from a discharge port 68a formed at the bottom.

As shown in FIG. 1, the fixing device 13 heats the toner image transferred to the print sheet S and fixes the liquid toner layer (toner image) transferred to the upper surface of the print sheet S. The fixing device 13 includes a heating roller 71, a driving roller 72, a support roller 73, and an endless conveying belt 74. Accordingly, when the printing sheet S is conveyed between the heating roller 71 and the conveying belt 74 wound around the driving roller 72 and the support roller 73, the liquid toner layer (toner image) is heated by the heating roller 71. As a result, the toner image can be fixed on the print sheet S.

Incidentally, a first sheet conveyance path S1 for the print sheet S is provided between the paper feeding device 11 and the printing device 12 described above. The first sheet conveyance path S1 has a base end portion branched into two and connected to the

paper feeding units

11a and 11b, and a front end portion connected to a nip portion between the backup roller 31 and the intermediate transfer member 32. ing. In the first sheet transport path S1, a plurality of upper and lower driveable transport rollers 81 are provided at a predetermined interval between the paper feeding device 11 and the printing device 12. In this case, the intervals between the conveyance rollers 81 are shorter than the length of the print sheet S in the conveyance direction, and at least two sets of the conveyance rollers 81 can hold and convey the print sheet S.

Further, a second sheet conveyance path S2 for the print sheet S is provided between the fixing device 13 and the paper discharge apparatus 15, and a conveyance device 14 is provided in the second sheet conveyance path S2. The second sheet conveyance path S <b> 2 is connected to the fixing device 13 on the base end side and is connected to the paper discharge device 15 via the conveyance device 14 on the front end side. In the second sheet conveyance path S2, a plurality of drivable pair of upper and lower conveyance rollers 82 are provided at predetermined intervals between the fixing device 13 and the paper discharge device 15. In this case, the interval between the conveying rollers 82 is shorter than the length of the printing sheet S in the conveying direction, like the conveying rollers 81, and at least two sets of conveying rollers 82 can convey and hold the printing sheet S. It has become.

A reversing device 91 for reversing the front and back of the printing sheet S is provided between the first sheet transport path S1 and the front of the transport apparatus 14 in the second sheet transport path S2. The reversing device 91 includes a switch mechanism 92, a sheet switching path 93, a conveying roller 94, a sheet reversing path 95, a switchback roller 96, a sheet return path 97, and a conveying roller 98. The reversing device 91 is used for duplex printing.

The switch mechanism 92 switches and conveys the print sheet S conveyed on the first sheet conveyance path S <b> 1 to the conveyance device 14 or the sheet switching path 93, and the conveyance roller 94 supplies the print sheet S supplied to the sheet switching path 93. Can be supplied to the sheet reversing path 95. The sheet reversing path 95 is for reversing the printing sheet S, and the switchback roller 96 is capable of normal rotation and reverse rotation. The printing sheet S supplied to the sheet switching path 93 is guided to the sheet reversing path 95, Thereafter, the sheet can be supplied to the sheet return path 97. The printing sheet S supplied to the sheet return path 97 is returned to the first sheet conveyance path S1 by the conveyance roller 98 and is supplied to the printing apparatus 12 again.

The transport device 14 transports the printed print sheet S being transported through the second sheet transport path S2 to the paper discharge device 15, and supports the lower surface of the print sheet S by a belt member that can be circulated and transports horizontally. It is possible.

The paper discharge device 15 includes a paper discharge tray 101, front and rear direction

position adjusting members

102 and 103, and a left and right direction position adjusting member 104. That is, when the printed print sheet S is transported along the second sheet transport path S2, the transport device 14 releases the held print sheet S above the paper discharge device 15 and discharges it. At this time, the front position adjustment member 102 operates to position the front position of the print sheet S, and the rear position adjustment member 103 positions the rear position of the print sheet S. Further, the left-right position adjusting member 104 positions the left-right position of the print sheet S.

Hereinafter, the printing operation by the electrophotographic printing apparatus 10 of the present embodiment configured as described above will be described.

In the electrophotographic printing apparatus 10 of this embodiment, as shown in FIG. 1, in the paper feeding device 11, one of the two

paper feeding units

11a and 11b is operated to send out the printing sheets S one by one. The print sheet S sent out from the paper feeding device 11 is conveyed to the printing device 12 by a plurality of conveyance rollers 81 in the first sheet conveyance path S1. In the printing apparatus 12, the backup roller 31 receives the leading end portion of the printing sheet S with the gripper 31a open, holds the leading end portion of the printing sheet S by closing the gripper 31a, and holds it by rotating. The print sheet S is conveyed.

On the other hand, in the intermediate transfer body 32, K corresponding to the peripheral surface of the photosensitive drum 41 on which the electrostatic image to be transferred to the first surface of the print sheet S is formed by the

printing units

33, 34, 35, and 36. (Black), C (blue), M (red), and Y (yellow) liquid toners are transferred, the image is developed on the photosensitive drum 41, and the liquid toner transferred to the peripheral surface of the photosensitive drum 41 Is transferred to the intermediate transfer member 32.

Specifically, as shown in FIG. 5, when liquid toner is supplied from the toner supply unit 65 into the toner supply pan 61, the liquid toner is separated from the peripheral surface of the anilox roller 52 and the toner supply pan 61. As the anilox roller 52 rotates, it flows along the circumferential direction of the anilox roller 52 along the rotation direction, and also flows in the axial direction of the anilox roller 52 as the anilox roller 52 rotates. Part of the liquid toner supplied from the toner supply unit 65 to the toner supply pan 61 flows in a direction opposite to the rotation direction of the anilox roller 52, overflows from the toner supply pan 61, and flows down to the toner recovery pan 68. .

The liquid toner in the toner supply pan 61 flows from the inner wall surface of the toner supply pan 61 to the contact portion with the leveling roller 53 along the inner wall surface of the toner cover 67 as the anilox roller 52 rotates. Here, the liquid toner stays in the contact portion (nip portion) between the anilox roller 52 and the leveling roller 53 by the toner cover 67. In this case, the thickness of the liquid toner layer that can pass through the nip portion between the anilox roller 52 and the leveling roller 53 is determined by the nip width and the nip pressure between the anilox roller 52 and the leveling roller 53. Therefore, the liquid toner layer having a thickness that can pass through the nip portion is retained in the contact portion between the anilox roller 52 and the leveling roller 53 by the toner cover 67, so that the contact portion (nip portion). The liquid toner layer that has passed through is made constant at a predetermined thickness, and a liquid toner layer having a uniform thickness in the width direction can be formed on the surface of the leveling roller 53.

Specifically, when the radius r of the anilox roller 52 and the leveling roller 53 is set, from the line connecting the center of the anilox roller 52 and the center of the leveling roller 53 to the upstream side in the rotation direction of the

rollers

52 and 53. It is preferable to retain liquid toner in the direction perpendicular to (1/2) r or more. In this case, the anilox roller 52 and the leveling roller 53 have the same diameter (radius r), but when they have different diameters, a small diameter roller is a target.

The liquid toner that has flowed from the toner supply pan 61 to the contact portions of the

rollers

52 and 53 by the toner cover 67 is supplied to the leveling roller 53 after the necessary amount, and then excess liquid toner is supplied to the second covering portion 67d. Overflows from the toner and flows down to the toner collecting pan 68.

Most of the liquid toner supplied to the toner supply pan 61 flows in the toner supply pan 61 in the same direction as the rotation direction of the anilox roller 52 and overflows without staying. The heat exchange efficiency is improved by expanding the contact area with the liquid toner, and the liquid toner whose temperature has risen is efficiently cooled by the anilox roller 52.

The liquid toner supplied from the anilox roller 52 to the leveling roller 53 is conveyed to the developing roller 54 by the leveling roller 53, and the liquid toner on the developing roller 54 is transferred by the toner charger 55 as shown in FIG. When the developing roller 54 is charged and comes into contact with the photosensitive drum 41, the liquid toner containing the charged toner is transferred from the peripheral surface of the developing roller 54 to the portion of the photosensitive drum 41 where the electrostatic latent image is formed, and development is performed. Done. The developed liquid toner on the peripheral surface of the photosensitive drum 41 is transferred to the intermediate transfer member 32, and a liquid toner layer (toner image) including an image of the toner is formed on the peripheral surface of the intermediate transfer member 32. be able to.

Thereafter, when the printing sheet S held by the backup roller 31 reaches the nip portion with the intermediate transfer body 33, the surface of the printing sheet S on the side in contact with the intermediate transfer body 32 from the peripheral surface of the intermediate transfer body 32 is here. Liquid toner (toner image) is transferred to (first surface).

Then, the print sheet S having the liquid toner transferred to the first surface is conveyed to the fixing device 13, and the upper surface (first surface) of the print sheet S is heated to be transferred to the first surface. The liquid toner layer (toner image) is fixed.

The printing sheet S with the liquid toner fixed on the first surface is conveyed by a plurality of conveying rollers 82 in the second sheet conveying path S2. Then, the front and back are reversed by the reversing device 91 and conveyed again to the printing device 12 via the first sheet conveying path S1.

Again, the printing sheet S conveyed to the printing apparatus 12 is gripped at the leading end by the gripper 31 a of the backup roller 31 and conveyed by the backup roller 31 as described above. In the intermediate transfer body 32, K (black) corresponding to the peripheral surface of the photosensitive drum 41 on which the electrostatic image to be transferred to the second surface of the print sheet S is formed by the

printing units

33, 34, 35, and 36. ), C (Indigo), M (Red), and Y (Yellow) liquid toners are transferred, an image is developed on the photosensitive drum 41, and the liquid toner transferred to the peripheral surface of the photosensitive drum 41 is intermediate. Transferred to the transfer body 32. When the printing sheet S held by the backup roller 31 reaches the nip portion with the intermediate transfer body 32, the surface of the printing sheet S on the side in contact with the intermediate transfer body 32 (from the peripheral surface of the intermediate transfer body 32 ( Liquid toner (toner image) is transferred to the second surface.

Then, the printing sheet S having the liquid toner transferred to the second surface is conveyed to the fixing device 13, and the upper surface (second surface) of the printing sheet S is heated to be transferred to the second surface. The liquid toner layer (toner image) is fixed.

The print sheet S having the liquid toner fixed on the first surface and the second surface is transported to the transport device 14 by a plurality of transport rollers 82 in the second sheet transport path S2, and the paper discharge device 15 is transported by the transport device 14. And is discharged by the paper discharge device 15.

In the above description of the embodiment, the toner staying member is the toner cover 67 and is provided integrally with the toner supply pan 61. However, the present invention is not limited to this configuration. For example, a toner cover as a toner retention member may be formed as a separate member (separate member) from the toner supply pan, and the toner cover may be integrally joined to the second pan 63 of the toner supply pan by welding, bolts, or the like. . In this case, the toner cover and the toner supply pan may be overlapped and joined, or the end portions may be contacted and joined. Further, the toner cover may be formed as a separate member (separate body) from the toner supply pan, and the toner cover may be disposed apart from the toner supply pan (second pan). In this case, the toner cover may be supported on the toner supply pan by a bracket or the like, or may be supported on another peripheral member.

8 to 10 are schematic views showing modified examples of the toner supply device.

As shown in FIG. 8, a toner cover 111 as a toner retention member is disposed close to the upstream side in the rotation direction of each of the

rollers

52 and 53 from the contact portion between the anilox roller 52 and the leveling roller 53. In this case, the toner cover 111 is a separate member and is provided separately from the toner supply pan 61, and is supported by, for example, the toner supply pan 61 and the toner collection pan 68.

That is, the toner cover 111 includes a surface covering portion 111a that covers the peripheral surface side of each of the

rollers

52 and 53 facing the contact portion of each of the

rollers

52 and 53, and an end surface covering portion that covers each end surface side of each of the

rollers

52 and 53. 111b. The toner cover 111 includes a first covering portion 111 c whose surface covering portion 111 a covers the peripheral surface with a predetermined gap from the anilox roller 52, and a second covering portion 111 d that covers the peripheral surface with a predetermined clearance from the leveling roller 53. have. The toner cover 111 is opened without the second covering portion 111d being in contact with the peripheral surface of the leveling roller 53 in the middle.

Further, as shown in FIG. 9, a toner cover 121 as a toner retention member is disposed close to the upstream side in the rotation direction of each of the

rollers

52 and 53 from the contact portion between the anilox roller 52 and the leveling roller 53. . In this case, the toner cover 121 is a resin-made deformable film, the base end portion is fixed to the end portion of the toner supply pan 61 by a fixing screw 122, and the front end portions are an anilox roller 52 and a leveling roller 53. It is extended toward the facing part. In this case, the front end portion of the toner cover 121 is folded back inward or outward to form a cylindrical portion (or thick cylindrical portion), so that the front end portion of the toner cover 121 approaches the peripheral surface of each of the

rollers

52 and 53. You may make it make it. The toner cover 121 may be an elastically deformable elastic member made of rubber instead of a resin deformable film.

Therefore, the liquid toner in the toner supply pan 61 flows from the toner supply pan 61 to the contact portion with the leveling roller 53 along the toner cover 121 as the anilox roller 52 rotates. Here, the liquid toner stays at the contact portion between the anilox roller 52 and the leveling roller 53 by the toner cover 121, and supplies a sufficient amount of liquid toner to the surface of the leveling roller 53. Then, the excess liquid toner at the contact portion overflows from the front end portion of the toner cover 121 and flows down to the toner collection pan 68.

Further, as shown in FIG. 10, a toner rod (rod-like member) 131 as a toner staying member is close to the upstream side in the rotation direction of each of the

rollers

52 and 53 from the contact portion between the anilox roller 52 and the leveling roller 53. Has been placed. In this case, the toner rod 131 is supported by, for example, the toner supply pan 61 and the toner collection pan 68.

As described above, the toner retaining member is not limited to the toner cover 67, and may be the toner covers 111 and 121 and the toner rod 131, or may be a wire or the like, and the anilox at the contact portion between the anilox roller 52 and the leveling roller 53. Any member can be used as long as it can temporarily retain the liquid toner scraped up by the rotation of the roller 52.

Further, the toner cover 67 as the toner retaining member described above is provided from the toner supply pan 61 to the contact portion between the anilox roller 52 and the leveling roller 53, and the toner covers 67, 111, 121 and the toner rod 131 are provided with the anilox. The toner collecting unit 57 is provided only at the contact portion between the roller 52 and the leveling roller 53 because the toner collecting unit 57 is disposed in the vicinity of the leveling roller 53. When the toner staying member is disposed at another location, the toner retaining member may be extended to both upper sides of the leveling roller 53.

As described above, in the toner supply device according to the present exemplary embodiment, the toner supply pan 61 that stores the liquid toner and the liquid toner that is partially immersed in the liquid toner stored in the toner supply pan 61 and rotates. An anilox roller 52 capable of supplying the liquid, a leveling roller 53 capable of receiving and transporting liquid toner by rotating in contact with the anilox roller 52, and a contact portion between the anilox roller 52 and the leveling roller 53. A toner cover 67 disposed close to the upstream side in the rotation direction of the

rollers

52 and 53 is provided.

Accordingly, when the anilox roller 52 rotates while being immersed in the liquid toner of the toner supply pan 61, the anilox roller 52 rotates with the liquid toner attached to the outer peripheral surface, and is in contact with the leveling roller 53. Liquid toner is supplied to the surface of the leveling roller 53. At this time, since the toner cover 67 is disposed close to the contact portion (nip portion) of each of the

rollers

52 and 53, the amount of liquid toner that is thicker than the toner cover 67 can pass through the contact portion. The liquid toner layer that has passed through the contact portion has a predetermined thickness, and the liquid toner can be appropriately supplied to the leveling roller 53. As a result, the leveling roller 53 can form a liquid toner layer having a uniform thickness in the width direction on the surface thereof.

In the toner supply device of the present embodiment, the toner cover 67 includes a first covering portion 67 c that covers the peripheral surface of the anilox roller 52 and a second covering portion 67 d that covers the peripheral surface of the leveling roller 53. Yes. Therefore, the toner cover 67 covers the peripheral surfaces of both the

rollers

52 and 53 at the contact portion between the anilox roller 52 and the leveling roller 53, and the contact portion of each

roller

52 and 53 is in contact with the contact portion. A sufficient amount of liquid toner that can pass through the portion can be retained.

In the toner supply device of the present embodiment, the toner cover 67 includes a surface covering portion 67 a that covers the peripheral surface side of each of the

rollers

52 and 53 facing the contact portion of each of the

rollers

52 and 53, and each of the

rollers

52 and 53. And an end face covering portion 67b covering the end face side of the. Therefore, the toner cover 67 covers not only the peripheral surfaces of the anilox roller 52 and the leveling roller 53 but also the end surfaces thereof, so that the contact portions of the

rollers

52 and 53 can pass through the contact portions. An amount of liquid toner can be retained.

Further, in the toner supply device of this embodiment, the toner cover 67 is provided so as to extend from the toner supply pan 61. Accordingly, the toner cover 67 covers from the toner supply pan 61 to the contact portions of the anilox roller 52 and the leveling roller 53, and the liquid toner in the toner supply pan 61 is properly retained to the contact portions of the

rollers

52 and 53. Accordingly, an appropriate amount of liquid toner can be supplied to the surface of the leveling roller 53.

In the toner supply device of this embodiment, the toner supply pan 61 includes a first pan 62 located upstream in the rotational direction of the anilox roller 52 and a second pan located downstream in the rotational direction of the anilox roller 52. The toner cover 67 is provided so as to extend from the second pan 63. Therefore, the toner supply pan 61 can be divided and configured so that the manufacture and assembly can be facilitated and the manufacturability can be improved, and the toner cover 67 can be extended from the second pan 63 so that the toner cover 67 can be manufactured. Can be easily arranged.

In the toner supply device of this embodiment, a toner supply unit 65 that supplies liquid toner to the first pan 62 of the toner supply pan 61 is provided. Accordingly, since the toner supply pan 61 is provided with the toner supply unit 65 on the first pan 62 side and the toner cover 67 is provided on the second pan 63 side, the liquid toner is transferred to the anilox roller in the toner supply pan 61. In the same manner as in the rotation direction of 52, the toner flows from the toner supply unit 65 toward the toner cover 67, thereby suppressing the retention of liquid toner in the toner supply pan 61 and increasing the contact efficiency between the liquid toner and the anilox roller 52. This temperature rise of the liquid toner can be suppressed. As a result, cooling of the liquid toner is promoted, melting of the toner particles is suppressed, and a liquid toner layer having a uniform film thickness can be formed in the width direction of the anilox roller 52.

In the toner supply device of the present embodiment, the toner supply pan 61 is provided with bearings 66 on the respective side wall portions (

flange portions

62d and 63c) in the width direction, and the shaft portions 52a of the anilox roller 52 are provided with the respective bearings 66. The toner cover 67 is provided so as to extend from the side wall portion. Accordingly, by supporting the anilox roller 52 on each side wall portion of the toner supply pan 61 via the bearing 66, the support structure of the anilox roller 52 can be simplified, and a toner cover 67 is provided from each side wall portion. Thus, the configuration can be simplified.

In the electrophotographic printing apparatus of the present invention, the paper feeding device 11, the printing device 12, the fixing device 13, the conveying device 14 for conveying the print sheet S on which the toner image is fixed, and the paper discharging device. 15, and the printing apparatus 12 includes

printing units

33, 34, 35, and 36, an intermediate transfer member 32, and a backup roller 31, and the

printing units

33, 34, 35, and 36 are liquids A toner supply pan 61 for storing toner, an anilox roller 52 capable of supplying liquid toner by rotating partly immersed in the liquid toner stored in the toner supply pan 61, and rotating in contact with the anilox roller 52 The leveling roller 53 that can receive and transport the liquid toner, and the current roller that can receive and transport the liquid toner by rotating in contact with the leveling roller 53. The roller 54 and the developing roller 54 rotate in contact with the photosensitive drum 41 that can receive liquid toner and transfer it to the intermediate transfer member 32, and the upstream side of the contact portion between the anilox roller 52 and the leveling roller 53. A toner cover 67 disposed in the vicinity is provided.

Accordingly, when the anilox roller 52 rotates in the

printing unit

33, 34, 35, 36 while being immersed in the liquid toner of the toner supply pan 61, the anilox roller 52 rotates with the liquid toner attached to the outer peripheral surface. Then, the liquid toner is supplied to the surface of the leveling roller 53 at the contact portion with the leveling roller 53. Since the toner cover 67 is disposed close to the contact portion (nip portion) of each of the

rollers

52 and 53, the toner cover 67 retains an amount of liquid toner having a thickness that can pass through the contact portion. Thus, the liquid toner layer that has passed through the contact portion is made to have a predetermined thickness, and the liquid toner can be appropriately supplied to the leveling roller 53. As a result, the leveling roller 53 can form a liquid toner layer having a uniform thickness in the width direction on the surface thereof. Thereafter, the leveling roller 53 transfers the liquid toner onto the photosensitive drum 41 on which the electrostatic latent image is formed via the developing roller 54 to perform development, and the developed liquid toner is transferred to the intermediate transfer body 32. When the printing sheet S is conveyed between the intermediate transfer body 32 and the backup roller 31, the liquid toner on the intermediate transfer body 32 is transferred to the printing sheet S and printing is performed. As a result, printing accuracy and printing quality can be improved.

In the above-described embodiment, the toner cover 67 as the toner staying member of the present invention is provided with the first covering portion 67 c that covers the peripheral surface of the anilox roller 52 and the second covering portion 67 d that covers the peripheral surface of the leveling roller 53. However, the present invention is not limited to this configuration. The toner retention member of the present invention is disposed closer to the upstream side in the rotation direction of each roller than the contact portion between the toner supply roller and the toner transport roller, and is bent from the first covering portion 67c to be the second covering portion. Instead of providing 67d, the toner staying member (first covering portion) may extend upward as it is to cover the contact portion between the toner supply roller and the toner transport roller.

DESCRIPTION OF SYMBOLS 10 Electrophotographic printing apparatus 11 Paper feeder 12 Printing apparatus 13 Fixing apparatus 14 Conveyance apparatus 15 Paper discharge apparatus 31 Backup roller (secondary transfer body)
32 Intermediate transfer member (primary transfer member)
33, 34, 35, 36 Printing unit 41 Photosensitive drum (photoconductor)
46 Developing Device 51 Toner Storage Unit 52 Anilox Roller (Toner Supply Roller)
53 Leveling roller (toner transport roller)
54 Development roller (toner transport roller)
55

Toner charger

56, 57 Toner collection unit 61 Toner supply pan 62 First pan 63 Second pan 65 Toner supply portion 66

Bearing portion

67, 111, 121 Toner cover (toner retention member)
67a Surface covering portion 67b End surface covering portion 67c First covering portion 67d Second covering portion 68 Toner recovery pan 131 Toner rod (toner retention member)

Claims

A toner supply pan for storing liquid toner;
A toner supply roller capable of supplying liquid toner by being partially immersed in the liquid toner stored in the toner supply pan and rotating;
A toner transport roller capable of receiving and transporting liquid toner by rotating in contact with the toner supply roller;
A toner retention member that is disposed closer to the upstream side in the rotation direction of each roller than a contact portion between the toner supply roller and the toner transport roller;
A toner supply device comprising:
2. The toner supply according to claim 1, wherein the toner staying member includes a first covering portion that covers a peripheral surface of the toner supply roller and a second covering portion that covers a peripheral surface of the toner transport roller. apparatus.
The toner retention member includes a surface covering portion that covers a peripheral surface side of each of the rollers facing the contact portion, and an end surface covering portion that covers an end surface side of each of the rollers. The toner supply device according to 2.
4. The toner supply device according to claim 1, wherein the toner retention member is provided so as to extend from the toner supply pan.
The toner supply pan is configured by integrally joining a first pan located upstream in the rotation direction of the toner supply roller and a second pan located downstream in the rotation direction of the toner supply roller, The toner supply device according to claim 4, wherein the toner retention member is provided to extend from the second pan.
6. The toner supply device according to claim 5, wherein the toner supply pan is provided with a toner supply unit that supplies liquid toner to the first pan.
The toner supply pan is provided with a bearing on each side wall portion in the width direction, each end portion of the toner supply roller is rotatably supported by each bearing, and the toner retention member extends from the side wall portion. The toner supply device according to claim 1, wherein the toner supply device is provided.
4. The toner supply device according to claim 1, wherein the toner retention member is provided as a separate member from the toner supply pan.
The toner retention member is a deformable film member or elastic member, and a base end portion is fixed to an end portion of the toner supply pan, and a tip end portion is a pair of the toner supply roller and the toner transport roller. The toner supply device according to claim 1, wherein the toner supply device extends to the contact portion.
3. The toner supply device according to claim 1, wherein the toner retention member is a rod-shaped member and is disposed along a contact portion between the toner supply roller and the toner transport roller.
A paper feeding device capable of supplying one substrate at a time;
A printing apparatus for transferring a developed toner image by transferring a liquid toner to an electrostatic latent image on a photoreceptor on the substrate supplied from the paper feeding apparatus;
A fixing device for heating and fixing the toner image transferred to the substrate;
A paper discharge device for discharging the printed material on which the toner image is fixed by the fixing device;
In an electrophotographic printing apparatus comprising:
The printing apparatus includes:
A printing unit that performs development by transferring liquid toner onto a photoreceptor on which an electrostatic latent image is formed; and
A primary transfer member for transferring the liquid toner developed by the printing unit;
A secondary transfer body for applying a bias voltage to form a nip portion by contacting the primary transfer body and transferring the liquid toner to the substrate;
Have
The printing unit includes:
A toner supply pan for storing liquid toner;
A toner supply roller capable of supplying liquid toner by being partially immersed in the liquid toner stored in the toner supply pan and rotating;
A toner transport roller capable of receiving and transporting liquid toner by rotating in contact with the toner supply roller;
A photoreceptor capable of receiving and transferring the charged liquid toner to the primary transfer member by rotating in contact with the toner transport roller;
A toner retention member that is disposed closer to the upstream side in the rotation direction of each roller than a contact portion between the toner supply roller and the toner transport roller;
An electrophotographic printing apparatus comprising: