JPH11249448A - Transfer device - Google Patents

Abstract

(57) [Problem] To provide a transfer device capable of improving the quality of a transfer object. SOLUTION: An electrostatic printing plate 3 transfers a toner image formed on a surface thereof to a sheet 1 by an electric suction force of a transfer device. The pressure roller 2 includes a first roller 2c and a second roller 2d. No image is formed on both ends 1a and 1b of the sheet 1 along the sending direction. For this purpose, the first roller 2 c presses the end 1 a of the sheet 1 on which no image is formed with the electrostatic printing plate 3 under pressure.
Similarly, the second roller 2 d presses the end 1 a of the sheet 1 on which the image is not formed with the electrostatic printing plate 3 under pressure.
As a result, since the peripheral speed of the electrostatic printing plate 3 and the sending speed of the paper 1 substantially match, slippage between the electrostatic printing plate 3 and the paper 1 can be eliminated, and image unevenness can be prevented. it can.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device in a copying machine, a printer, or the like using an electrostatic printing system, an electrophotographic system, or the like.

[0002]

2. Description of the Related Art A conventional electrophotographic apparatus includes, for example, a cylindrical photosensitive drum, a charging device, an exposure device, a developing device, a transfer device, a cleaning device, and a fixing device arranged so as to surround the photosensitive drum. It is equipped with devices. The charging device charges the photoconductor drum, and the exposure device exposes an image and a non-image as necessary to form an electrostatic latent image having a potential difference on the surface of the photoconductor drum. Then, the developing device forms a toner image with the toner as the charged particles, and the transfer device transfers the toner image to a sheet or the like, and forms a toner image on the sheet. The fixing device fixes the toner image on paper by drying or heat melting,
Make the final print state.

In such an image forming apparatus, the speed of an image carrier such as a photosensitive drum or a dielectric drum or an electrostatic printing plate for forming an image to be printed, and a conveying roller for conveying a sheet are controlled at a predetermined speed. You need to control the speed precisely. For example, if there is a large variation in the rotation speed of the photosensitive drum, a speed difference occurs between the transfer device and the sheet to be transferred, and when the image formed on the photosensitive drum is transferred to the sheet, the image flows in the transport direction of the sheet. Image is produced. As described above, the unevenness of the rotation speed of the image bearing member such as the photosensitive drum, the dielectric drum, or the electrostatic printing plate which constitutes the image forming apparatus is caused by a striped pattern (so-called band) in a direction perpendicular to the printing direction. (Printing), which is a cause of deterioration in the quality of printed matter.

[0004] In order to reduce such unevenness of the rotation speed, for example, Japanese Patent Application Laid-Open No. 63-88579 discloses a method of improving rotation accuracy and the like by improving a motor drive system. . Further, a transfer device of a type for transferring an image to a sheet by using a charge transfer roller is known. In this transfer device, the paper is brought into pressure contact (nip) between the photosensitive drum and the charging transfer roller, so that the speed of the photosensitive drum and the paper is the same, and the speed difference between the photosensitive drum and the paper is reduced. Therefore, an effect of preventing image deletion during transfer can be expected.

[0005]

However, when one motor is used as a drive source, the rotational speed ratio of each roller becomes constant. For this reason, when printing continuous paper having different thicknesses, the peripheral speed ratio of the rollers provided on the paper feeding side and the pulling side cannot be adjusted. As a result, if thin paper is fed at the peripheral speed for thick paper, the tension may be too high and the paper may break.If the thick paper is fed with the peripheral speed difference for thin paper given, the paper may cause slack and wrinkles. Could be.

Further, since the image size in the flow direction of the image to be transferred is determined by the tension of the paper applied at the time of transfer, it is necessary to appropriately adjust the tension according to the type of paper. However, an image transferred with a strong tension is printed on a stretched sheet, so that when the tension is restored after printing, the image shrinks from its original size. As described above, even if an attempt is made to print the same image, if the elongation ratio of the paper is different, the image size in the paper flow direction is different. For this reason, it is necessary to increase the peripheral speed difference in order to apply an appropriate tension to thick paper, and to reduce the peripheral speed difference in order to apply an appropriate tension to thin paper, and transfer while maintaining an appropriate tension. There is.

FIG. 7 is a side view schematically showing a general configuration of an electrostatic printing apparatus having a transfer device. FIG. 8 is a plan view schematically showing an electrostatic printing apparatus including the transfer device (Comparative Example 1). As shown in FIGS. 7 and 8, the electrostatic printing apparatus includes an electrostatic printing plate 300, a transfer device 400,
A drying device 500, a delivery roller 600, a pulling roller 700, nip rollers 800 and 900, a motor M, a plurality of pulleys p and a belt b, a speed reducer R,
It comprises a continuously variable transmission V and the like.

The feed roller 600 is a roller that continuously feeds the wound sheet 100 in the direction of the arrow in FIG. The feed roller 600 presses the paper 100 with the nip roller 800 to feed the paper 100 to the electrostatic printing plate 300 and the transfer device 400. The electrostatic printing plate 300 has its surface patterned with a dielectric material or the like corresponding to the image portion and the non-image portion of the image, and the image portion and the non-image portion are provided by a charging device (not shown) provided below. Is a cylindrical member on which a toner image is formed by a developing device by generating a potential difference. The transfer device 400 includes the electrostatic printing plate 3
00 is an apparatus for transferring the image on the sheet 100 to the paper 100. The transfer device 400 is, for example, a charging device for transfer using an electric attraction force. The drying device 500 is a device for drying the paper 100 and fixing an image on the paper 100. The drying device 500 fixes an image on the paper 100 by, for example, drying or heat melting.

The pulling roller 700 is a roller that continuously feeds the paper 100 in the direction of the arrow in FIG. The pulling roller 700 presses the sheet 100 with the nip roller 900. Paper 10 with fixed image
0 is rolled up. The nip roller 800 is a roller that presses the sheet 100 with the feed roller 600, and the nip roller 900 is a roller that presses the sheet 100 with the pulling roller 700.

The drive motor M is for rotating the electrostatic printing plate 300, the feed roller 600, and the pulling roller 700. The reduction gear R is a device for reducing the rotation speed by a reduction gear, a pulley, or the like. The continuously variable transmission V is a device that can continuously change the gear ratio. The continuously variable transmission V is provided between the motor M and the speed reducer R and the delivery roller 600.

As shown in FIGS. 7 and 8, the feed roller 600 and the nip roller 800 press the paper 100 before transferring an image to the paper 100, and
00 and the nip roller 900 press the paper 100 after transferring the image to the paper 100. In order to keep the tension of the paper 100 constant during transfer by one drive motor M, as shown in FIG.
It is necessary to provide a continuously variable transmission V on the 00 side.

FIG. 9 is a plan view schematically showing an electrostatic printing apparatus provided with a transfer device (Comparative Example 2). In the electrostatic printing apparatus shown in FIG. 9, a continuously variable transmission is provided on the pulling roller 900 and the electrostatic printing plate 300 side.

However, the peripheral speed adjusting means shown in FIGS. 8 and 9 requires a small speed change range of, for example, about ± 5%. Need to use a machine. Since the ring-cone type transmission uses a gear internally, the gear causes a slight speed fluctuation, and a speed difference occurs between the electrostatic printing plate 300 and the paper 100.

FIG. 10 is a diagram showing a state of an image transferred by an electrostatic printing apparatus having a transfer device (Comparative Example 1 and Comparative Example 2). FIG. 10 shows a state when an image having a halftone dot area ratio of 50% is transferred. As shown in FIG.
Image fluctuations occur due to speed fluctuations caused by gears in the transmission R.

FIG. 11 is a plan view schematically showing an electrostatic printing apparatus provided with a transfer device (Comparative Example 3). FIG.
FIG. 9 is a plan view schematically illustrating an electrostatic printing apparatus including a transfer device (Comparative Example 4). When the pulley p is used in a drive system in order to eliminate the speed unevenness, the slip ratio of each loaded pulley p cannot be made completely zero. For this,
In the electrostatic printing apparatus shown in FIG. 11, a continuously variable transmission V is provided on the electrostatic printing plate 300 side and on the delivery roller 600 side.
In the electrostatic printing apparatus shown in FIG. 2, it is preferable to provide a continuously variable transmission V on the pulling roller 700 side to adjust a small difference in peripheral speed. However, in order to make a minute shift, a ring-cone type transmission is required, and image unevenness occurs due to gears in the transmission.

FIG. 13 is a plan view schematically showing an electrostatic printing apparatus provided with a transfer device (Comparative Example 5). The drive motor M usually has a high rotation speed of about 3000 rpm, and thus the pulling roller 700 and the electrostatic printing plate 300 are used.
It is necessary to reduce the speed to about 10 rpm without using gears. For this purpose, as shown in FIG. 13, it is necessary to reduce the rotation speed of the drive motor M by a plurality of pulleys p or to combine a very large pulley and a small pulley, which requires a large space. .

FIG. 14 is a plan view schematically showing an electrostatic printing apparatus provided with a transfer device (Comparative Example 6). In the electrostatic printing apparatus shown in FIG. 14, the drive system is divided into three, and the rotation speed of each drive motor M is controlled (drive command) by one synchronization control device C to reduce the peripheral speed. I am adjusting. However, in order to control the rotation speeds of the respective drive motors M to be precisely synchronized, an expensive synchronization control device C is required, which increases the machine cost.

FIG. 15 is a side view schematically showing an electrostatic printing apparatus provided with a transfer device (Comparative Example 7). FIG.
FIG. 14 is a diagram illustrating a state of an image transferred by an electrostatic printing device including a transfer device (Comparative Example 7). The electrostatic printing apparatus shown in FIG. 15 differs from the electrostatic printing apparatuses shown in FIGS. 7 to 14 in that an image on the electrostatic printing plate 300 is formed on the paper 100 by using a transfer roller 401 instead of the transfer apparatus 400. Transcribed.
However, in this electrostatic printing apparatus, since the paper 100 is brought into pressure contact between the transfer roller 401 and the electrostatic printing plate 300, as shown in FIG. It is crushed by the action, causing cracks and thickening of the image. Such cracks and thickening of the image are remarkably generated when developing or transferring with a liquid toner onto a substrate such as a film that does not absorb liquid. The image formed on the electrostatic printing plate 300 by the liquid toner is not completely dried. As a result, the toner that forms the image has fluidity and is crushed by the pressing action.

Further, a trace amount of the solvent remains in the non-image area. For this reason, the electrostatic printing plate 300 and the transfer roller 401 push back the solvent that could not be absorbed by the base material before the area where they come into pressure contact (nip entrance). As a result, the solvent component stays in the vicinity of this area, the fluidity of the toner image formed on the electrostatic printing plate 300 increases, and the image is crushed or blurred.

It is an object of the present invention to provide a transfer device capable of improving the quality of a transfer object.

[0021]

The present invention solves the above-mentioned problems by the following means. In addition, in order to make it easy to understand, description is given with reference numerals corresponding to the embodiment of the present invention, but the present invention is not limited to this. That is, the invention of claim 1 provides an image forming unit (3) including an image carrier (30) on which an image is formed with toner, a transfer unit (4) for transferring the image to a transfer target, and the image forming unit. A transfer device including a non-slip means (2a, 2b; 20a, 20b) for preventing slip between a carrier and the transfer target.

According to a second aspect of the present invention, in the transfer device according to the first aspect, the non-slip means presses a portion of the transfer target on which the image is not formed with the image carrier. Is a transfer device.

According to a third aspect of the present invention, there is provided the first or second aspect.
Wherein the non-slip means presses the image carrier against both ends (1a, 1b) of the transfer object along the conveying direction of the transfer object.
2b).

According to a fourth aspect of the present invention, in the transfer device according to the third aspect, the pressure roller is a first pressure roller that presses one end (1a) of the transfer object along a conveying direction. (2a), and a second pressure roller (2b) that presses the other end (1b) of the transfer object along the transport direction, wherein the first and / or second pressure roller is A transfer device that is movable in a width direction of the transfer target.

The invention of claim 5 is the invention of claim 3 or claim 4.
Wherein the peripheral speed of the pressure roller is substantially the same as the transport speed of the transfer target.

The invention of claim 6 is the invention of claim 1 or claim 2.
Wherein the non-slip means presses against the image carrier to press both ends (1a, 1b) of the transfer object in the conveying direction.
0a, 20b).

According to a seventh aspect of the present invention, in the transfer device according to the sixth aspect, the pressing belt presses the one end (1a) of the transfer object in the transport direction of the transfer object outward. A pressure belt (20a); and a second pressure belt (20b) that presses the other end (1b) of the transfer object along the transport direction on the outside. The transfer unit includes the first and second transfer belts. A transfer device is provided inside the second pressure belt and in the width direction of the transfer target.

[0028] The invention of claim 8 is the invention of claim 6 or 7.
In the transfer device according to the speed of the pressure belt,
A transfer device, wherein the transfer speed of the transfer object is substantially the same.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Hereinafter, a first embodiment of the present invention will be described in more detail with reference to the drawings. Hereinafter, an example in which the transfer device according to the first embodiment of the present invention is applied to an electrostatic printing device will be described. FIG. 1 is a plan view schematically showing an electrostatic printing apparatus including a transfer device according to the first embodiment of the present invention. FIG. 2 is a side view schematically showing an electrostatic printing plate and a pressure roller in the transfer device according to the first embodiment of the present invention. FIG. 3 is a front view schematically showing an electrostatic printing plate and a pressure roller in the transfer device according to the first embodiment of the present invention. In the following, members that are the same as the members illustrated in FIGS. 7 to 16 will be described with the corresponding reference numerals, and detailed description of those members will be omitted.

As shown in FIGS. 1 and 2, the electrostatic printing apparatus includes an image forming apparatus 3 including an electrostatic printing plate 30, a charging device 31, a developing device 32, a transfer device 4, a drying device 5, and the like. , A feed roller 6, a pulling roller 7, nip rollers 8, 9, a motor M, a plurality of pulleys p and a belt b, a speed reducer R, a continuously variable transmission V, and the like. The paper 1 is fed in a direction indicated by an arrow in the drawing while being kept at a predetermined tension by a pulling roller 6 and a feeding roller 7. After the image is transferred, the paper 1 is dried and fixed by the fixing device 5 and wound up. .

The electrostatic printing plate 30 is a cylindrical member whose surface is patterned with a dielectric material or the like corresponding to an image portion and a non-image portion of an image. The charging device 31 is a device that charges the surface of the electrostatic printing plate 30. Charging device 31
Causes a potential difference between the image portion and the non-image portion of the electrostatic printing plate 30. The developing device 32 is a device that forms a toner image on the electrostatic printing plate 30. Charging device 31 and developing device 3
2 is disposed below the electrostatic printing plate 30.

The pressure roller 2 is, as shown in FIG.
Roller 2a, second roller 2b, air cylinder 2c,
2d or the like. The pressure roller 2 has a structure that does not press the central portion of the sheet 1 in the feeding direction. When the paper 1 is pressed by the first roller 2a and the second roller 2b and the electrostatic printing plate 30 and the electrostatic printing plate 30 is in contact with the paper 1, the transfer device 4 The image on the printing plate 30 is transferred to the sheet 1.

The first roller 2a is a roller for pressing the end 1a of the sheet 1 in the feeding direction, and the second roller 2b is for pressing the end 1b of the sheet 1 in the feeding direction. Of the roller. The air cylinders 2c and 2d are members that press the first roller 2a and the second roller 2b toward the electrostatic printing plate 30, respectively. Air cylinder 2c
Indicates a margin (edge) 1 of the sheet 1 on which no image is formed.
a between the first roller 2a and the electrostatic printing plate 30 under pressure, and the air cylinder 2d presses the margin (end) 1b between the second roller 2b and the electrostatic printing plate 30. Press contact.

FIG. 4 is a diagram showing a state of an image transferred by an electrostatic printing apparatus having the transfer device according to the first embodiment of the present invention. FIG. 4 shows a thickness of 30 (μm) and a width of 200 μm.
(Mm) substrate (OPP film) at a printing speed of 10
FIG. 4 is a diagram illustrating a state of an image transferred to the base material when the image is sent at (m / min). The first roller 2a and the second roller 2b are made of NBR rubber (rubber hardness: 80 °) in a material that comes into contact with the electrostatic printing plate 30 and the paper 1;
The pressing pressure by the air cylinders 2c and 2d is about 30
(Kgf). The first roller 2a and the second roller 2b press the ends 1a and 1b of the sheet 1 with a width of 5 (mm) in a direction perpendicular to the feeding direction of the sheet 1, respectively. The part that directly contacts 30 is 5
(Mm).

In this case, without pressing the paper 1 between the first roller 2 a and the second roller 2 b and the electrostatic printing plate 30,
When the image was transferred to the sheet 1, image unevenness as shown in FIG. 10 occurred. However, the first roller 2a and the second roller 2
When the both ends 1a and 1b along the feeding direction of the sheet 1 are brought into pressure contact between the printing plate 30 and the electrostatic printing plate 30, the image is prevented from flowing as shown in FIG. Could be obtained.

As described above, the transfer device according to the first embodiment of the present invention has the following effects. (1) In the first embodiment of the present invention, the paper 1 is pressed between the first roller 2a and the second roller 2b and the electrostatic printing plate 30, and the pressure between the electrostatic printing plate 30 and the paper 1 is increased. Prevents slippage. For this reason, even if components such as gears which cause speed unevenness are used in the drive system to adjust the tension of the sheet 1 during printing, image unevenness is affected by minute speed fluctuations caused by gears and the like. Does not occur. Also,
Even if a continuously variable transmission that causes speed unevenness is used, an image can be transferred to various types of paper having different thicknesses and materials under optimum transport conditions so that image unevenness does not occur. Furthermore, the air cylinders 2c and 2d are
Since the sheet 1 is brought into close contact with the sheet 1, the peripheral speed of the electrostatic printing plate 30 and the sending speed of the sheet 1 substantially match, and image unevenness can be prevented.

(2) According to the first embodiment of the present invention, both ends 1 along the sending direction of the paper 1 which is cut off after the transfer.
a, 1 b are pressed between the first roller 2 a and the second roller 2 b and the electrostatic printing plate 30. As a result, it is possible to prevent the image from becoming fat, bleeding, crushing, cracking, etc., because the blank portion on which no image is formed is pressed. A charging device 31 is provided around the electrostatic printing plate 30.
And the developing device 32 are arranged, and the winding angle between the electrostatic printing plate 30 and the sheet 1 cannot be structurally increased. However, the first embodiment of the present invention uses the first roller 2a and the second roller 2b and the electrostatic printing plate 3 in a limited space.
0 can be reliably applied to the sheet 1.

(Second Embodiment) FIG. 5 is a front view schematically showing an electrostatic printing plate and a pressure roller in a transfer device according to a second embodiment of the present invention. In the following, FIG.
The same members as those shown in FIG. 3 to FIG. 3 are described with the same reference numerals, and detailed description of the members will be omitted.

The transfer device according to the second embodiment of the present invention comprises:
Unlike the first embodiment, this is another embodiment in which the first roller 2a and the second roller 2b can move in the width direction of the sheet 1. The first roller 2a is a roller that can move integrally with the air cylinder 2c, and the second roller 2b
Is a roller that can move integrally with the air cylinder 2d.

The transfer device according to the second embodiment of the present invention comprises:
The following effects are provided in addition to the effects of the first embodiment. In the second embodiment of the present invention, the first roller 2a
And the second roller 2b can move in the width direction of the sheet 1 to change the distance between them, so that both ends 1a and 1b of various sheets having different widths are connected to the electrostatic printing plate 30. Pressurization can be surely performed between them.

(Third Embodiment) FIG. 6 is a perspective view schematically showing an electrostatic printing plate and a pressure belt in a transfer device according to a third embodiment of the present invention. In the following, FIG.
The same members as those shown in FIG. 3 to FIG. 3 are described with the same reference numerals, and detailed description of the members will be omitted.

The transfer device according to the third embodiment of the present invention comprises:
Unlike the first and second embodiments, the belt 20
This is another embodiment in which the sheet 1 is pressurized between the a and 20b and the electrostatic printing plate 30.

The outer peripheral surface of the first belt 20a is in pressure contact with the outer peripheral surface of the electrostatic printing plate 30 at a predetermined wrapping angle, and the end 1a of the first belt 20a along the feeding direction of the paper 1 is electrostatically printed. Edition 3
This is a belt for applying a pressure between zero and zero. The outer peripheral surface of the second belt 20b is in pressure contact with the outer peripheral surface of the electrostatic printing plate 30 at a predetermined wrapping angle, and the end 1b along the feeding direction of the paper 1 is electrostatically printed. This is a belt for applying a pressure between the belt 30. The first belt 20a is an electrostatic printing plate 3
It is wound around a pair of belt wheels 21a and 21b having a rotation axis substantially coincident with the rotation axis 0. Also, the second
The belt 20b is wound around a pair of belt wheels 21c and 21d having a rotation axis substantially coincident with the rotation axis of the electrostatic printing plate 30. First belt 20a and second belt 2
The speed of 0b is substantially the same as the sending speed of the sheet 1.

The transfer device 4 moves the belt 20 between the belt wheels 21a and 21c and the belt wheels 21b and 21d.
a and 20b are arranged in the width direction of the sheet 1 so as to go under the inner peripheral portions.

The transfer device according to the third embodiment of the present invention comprises:
The following effects are provided in addition to the effects of the first embodiment and the second embodiment. (1) The third embodiment of the present invention includes the belts 20a, 20a
b, the transfer device 4 is arranged in the width direction of the paper 1, so that the paper 1 is in pressure contact between the belts 20 a, 20 b and the electrostatic printing plate 30. And an image without unevenness can be transferred.

(2) In the third embodiment of the present invention, since the outer peripheral surfaces of the first belts 20a and 20b are in pressure contact with the outer peripheral surface of the electrostatic printing plate 30 at a predetermined winding angle, The air cylinders 2c and 2d can be omitted.

(Other Embodiments) The present invention is not limited to the above-described embodiments, and various modifications or changes can be made as described below. Within range. (1) The embodiment of the present invention has been described by taking as an example a case where a transfer device is applied to an electrostatic printing device, but the present invention is also applied to an electrophotographic device or the like whose structure is similar to that of the electrostatic printing device. You can also. Further, the present invention is not limited to the electrostatic printing plate 30, and can be applied to a dielectric drum, a photosensitive drum, and the like. In this case, for example, the electrostatic printing plate 3
Instead of 0, an exposure device that exposes the photosensitive drum by attaching a photosensitive drum and a cleaning device that removes toner remaining after transfer may be added.

(2) In the embodiment of the present invention, the transfer device 4 is arranged on the upstream side of the pressure roller 2, but the transfer device 4 may be arranged on the downstream side of the pressure roller 2. . Further, the pressure roller 2 may be installed on both the upstream side and the downstream side of the transfer device 4.

(3) In the embodiment of the present invention, the case where the paper 1 is pressed between the pressure roller 2 and the electrostatic printing plate 30 has been described as an example. The means for preventing the slip between them is not limited to the pressure roller 2. For example, when the paper 1 is a continuous form having equally spaced holes at both ends, if a projection is provided on the outer peripheral portion of the photoreceptor 1 so as to fit into the holes, the gap between the electrostatic printing plate 30 and the paper 1 can be increased. Can be prevented from slipping. Further, by providing a suction port on the outer peripheral surface of the electrostatic printing plate 30, the paper 1
To prevent slippage between the electrostatic printing plate 30 and the paper 1.

(4) In the embodiment of the present invention, an image is directly formed on the electrostatic printing plate 30 by a developing device or the like. The present invention can also be applied to an intermediate transfer medium such as an intermediate transfer belt or an intermediate transfer roller that re-transfers to an intermediate transfer belt.

(5) In the embodiment of the present invention, the case where the first roller 2a and the second roller 2b are movable has been described as an example. However, either one of the first roller 2a and the second roller 2b may be driven. The belt 20a and / or the second belt 20b may have a movable structure. Further, the present invention can be applied not only to continuous paper but also to sheet paper. Furthermore, although the embodiments of the present invention have been described with respect to application to a single-color printing mechanism, the present invention can be applied to a multi-color printing machine having a plurality of printing units.

[0052]

As described above in detail, according to the present invention, since the anti-slip means for preventing the slip between the image forming means and the transfer means is provided, a stable high-quality image can be obtained. it can.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an electrostatic printing apparatus including a transfer device according to a first embodiment of the present invention.

FIG. 2 is a side view schematically showing an electrostatic printing plate and a pressure roller in the transfer device according to the first embodiment of the present invention.

FIG. 3 is a front view schematically showing an electrostatic printing plate and a pressure roller in the transfer device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a state of an image transferred by an electrostatic printing device including the transfer device according to the first embodiment of the present invention.

FIG. 5 is a front view schematically showing an electrostatic printing plate and a pressure roller in a transfer device according to a second embodiment of the present invention.

FIG. 6 is a perspective view schematically showing an electrostatic printing plate and a pressure belt in a transfer device according to a third embodiment of the present invention.

FIG. 7 is a side view schematically illustrating a general configuration of an electrostatic printing apparatus including a transfer device.

FIG. 8 is a plan view schematically showing an electrostatic printing apparatus including a transfer device (Comparative Example 1).

FIG. 9 is a plan view schematically showing an electrostatic printing apparatus including a transfer device (Comparative Example 2).

FIG. 10 is a diagram illustrating a state of an image transferred by an electrostatic printing apparatus including the transfer device (Comparative Example 1 and Comparative Example 2).

FIG. 11 is an electrostatic printing apparatus including a transfer device (Comparative Example 3).
It is a top view which shows roughly.

FIG. 12 is an electrostatic printing apparatus including a transfer device (Comparative Example 4).
It is a top view which shows roughly.

FIG. 13 is an electrostatic printing apparatus including a transfer device (Comparative Example 5).
It is a top view which shows roughly.

FIG. 14 is an electrostatic printing apparatus including a transfer device (Comparative Example 6).
It is a top view which shows roughly.

FIG. 15 is an electrostatic printing apparatus including a transfer device (Comparative Example 7).
It is a side view which shows schematically.

FIG. 16 is an electrostatic printing apparatus including a transfer device (Comparative Example 7).
FIG. 6 is a diagram showing a state of an image transferred by the method shown in FIG.

[Explanation of symbols]

 1,100 paper 1a, 1b end 2 pressure roller 2a first roller 2b second roller 2c, 2d air cylinder 3 image forming device 30, 300 electrostatic printing plate 31 charging device 32 developing device 4,400 transfer device 20a 1 belt 20b 2nd belt

Claims (8)

[Claims] An image forming unit including an image carrier on which an image is formed by toner; a transfer unit configured to transfer the image to a transfer target; and a slip between the image carrier and the transfer target. And a non-slip means for preventing the transfer. 2. The transfer device according to claim 1, wherein the non-slip unit presses a portion of the transfer target where the image is not formed between the transfer target and the image carrier. Transfer device. 3. The transfer device according to claim 1, wherein the non-slip unit presses both ends of the image carrier along a conveying direction of the transfer target. A transfer device, which is a roller. 4. The transfer device according to claim 3, wherein the pressure roller includes a first pressure roller that presses one end of the transfer target along a transfer direction, and a transfer of the transfer target. A second pressure roller for pressing the other end along the direction, wherein the first and / or second pressure roller is movable in a width direction of the transfer target. Transfer device. 5. The transfer device according to claim 3, wherein a peripheral speed of the pressure roller is substantially equal to a transport speed of the transfer target. 6. The transfer device according to claim 1, wherein the non-slip unit presses against both ends of the transfer object in a conveying direction by pressing against the image carrier. A transfer belt. 7. The transfer device according to claim 6, wherein the pressure belt is a first pressure belt that presses one end of the transfer object along a transport direction to the outside, and the transfer object. A second pressure belt that presses the other end of the transfer object along the transport direction of the transfer object, wherein the transfer unit is located inside the first and second pressure belts, and A transfer device arranged in the width direction. 8. The transfer device according to claim 6, wherein a speed of the pressure belt is substantially the same as a conveyance speed of the transfer target.