JPH04172479A - Transfer device - Google Patents

Abstract

PURPOSE:To miniaturize a transfer device by sandwiching a transfer sheet between first and second sheets each having a conductive layer, and winding all of the sheets around a wind roller. CONSTITUTION:A transfer sheet 10 is conveyed to the space between first and second sheets 1, 6 being wound at predetermined timing by a timing roller 15, so that a toner image 5 on a dielectric layer 3 coincides with the transfer sheet 10. The transfer sheet 10 is then wound around a wind roller 9 in such a manner as being sandwiched between the first and second sheets 1, 6 and an electric field is formed by an electric field generating means 12 between conductive layers 3, 8 and then the toner image 5 carried on the dielectric layer 3 of the first sheet 1 is transferred onto the transfer sheet 10. The transfer sheet 10 is wound around the wind roller by more than two turns and the toner image 5 carried on the first sheet 1 can be transferred onto the transfer sheet 10. Therefore the diameter of the wind roller 9 can be reduced and the transfer device can be miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transfer device, and particularly to a transfer device used in an electrostatic copying type image forming device.

[Conventional technology]

As a conventional transfer device, for example, Japanese Patent Application Laid-Open No. 59-20856
The one described in Publication No. 7 is known.

This product includes a toner image carrying sheet that is made of a conductive layer and an insulating layer and is capable of carrying a toner image, and a roller that has a conductive layer and a dielectric layer formed on the conductive layer, and is made to carry a toner image. The transfer sheet and the toner image-bearing sheet are wound around a pick-up roll so that the transfer sheet is sandwiched between the toner image-bearing sheet and the roller, and between the conductive layer of the toner image-bearing sheet and the conductive layer of the pick-up roll. An electric field is created to transfer the toner image to the transfer sheet.

[Problem to be solved by the invention]

However, in such conventional transfer devices,
The transfer sheet and the toner image bearing sheet were wound around a pick-up roll to form an electric field between the conductive layer of the toner image bearing sheet and the conductive layer of the roll. Therefore, in order to apply an electric field to all the toner images, it is not possible to wrap the transfer sheet twice around the Tiquambro roll, and it is necessary to make the circumference of the roll longer than the length of the transfer sheet. Therefore, there was a problem that the diameter of the pick-up roll became large and the size of the transfer device became large.

[Purpose of the invention]

Therefore, the present invention can be applied by sandwiching a transfer sheet between first and second sheets each having a conductive layer and winding them up on a take-up roller, or by sandwiching a transfer sheet between first and second sheets each having a conductive layer, or The purpose of the present invention is to reduce the size of a transfer device by winding a first sheet having an insulating layer together with a transfer sheet onto a take-up roller so that the transfer sheet can be wound around the take-up roller in two or more layers. There is.

C Structure of the Invention] In order to achieve the above object, the transfer device according to the invention according to claim 1 includes: a first sheet having a conductive layer and carrying a toner image; a second sheet having a conductive layer; a winding roller that sandwiches the transfer sheet between a first sheet and a second sheet so that the toner image carried on the sheet comes into contact with the transfer sheet, and winds up the transfer sheet together with the first sheet and the second sheet; an electric field forming means for forming an electric field between the conductive layer of the first sheet and the conductive layer of the second sheet in a state where the first sheet, the second sheet and the transfer sheet are wound around a winding roller; The conductive layer of the first sheet and the second sheet
A transfer device according to the invention according to claim 2, characterized in that the toner image carried on the first sheet is transferred to the transfer sheet by an electric field formed between the conductive layers of the sheets. In order to achieve the above object, the method has a layer structure consisting of a first conductive layer, a second conductive layer, and an insulating layer sandwiched between the first conductive layer and the second conductive layer, and carries a toner image. a first sheet, a take-up roller that stacks the transfer sheet on the first sheet so that the toner image carried on the first sheet comes into contact with the transfer sheet, and winds up the transfer sheet together with the first sheet; and an electric field forming means for forming an electric field between the first conductive layer and the second conductive layer of the first sheet in a state where the transfer sheet is wound around a take-up roller. The toner image carried on the first sheet is transferred to the transfer sheet by an electric field formed between the first conductive layer and the second conductive layer.

Hereinafter, the present invention will be specifically explained based on Examples.

1 to 4 are diagrams showing an embodiment of the transfer device according to the invention as set forth in claim 1, and are examples in which the transfer device is applied to an electrostatic copying type image forming device.

First, the configuration will be explained.

In FIGS. 1 to 3, 1 is a first sheet, and the first sheet 1 is composed of a base layer 2, a conductive layer 3, and a dielectric layer 4. The dielectric layer 4 of the first sheet 1 carries a toner image 5 . 6 is a second sheet, and the second sheet 6 is composed of a protective layer 7 and a conductive layer 8. 9 is a rolled cola,
The take-up roller 9 moves the transfer sheet 10 so that the toner image 5 carried on the first sheet 1 comes into contact with the transfer sheet 10.
is sandwiched between the first sheet 1 and the second sheet 6, and the transfer sheet IO is wound up together with the first sheet 1 and the second sheet 6. Specifically, one end of each of the first sheet 1 and the second sheet is fixed to each other with tape (not shown) or the like so that the conductive layer 3.8 does not come into electrical contact. One end of the first sheet 1 and the second sheet 6, which are fixed to each other, is wound around a winding roller 9, and the first sheet l
The other end of the second sheet 6 is wound around the supply roller 20, and the other end of the second sheet 6 is wound around the auxiliary roller 11. Therefore, when the transfer sheet 10 is inserted into the contact portion of the first sheet 1 and the second sheet 6, the transfer sheet 10
0 is adapted to be wound up on a winding roller 9 together with the first sheet 1 and the second sheet 6. Reference numeral 12 denotes an electric field forming means, and the electric field forming means 12 is configured to apply the conductive layer 3 of the first sheet 1 and the conductive layer A voltage is applied to the conductive layers 8 of the two sheets 6, creating an electric field between the conductive layers 3.8. The toner image 5 carried on the first sheet 1 is transferred to the transfer sheet 10 by an electric field formed between the conductive layer 3 of the first sheet 1 and the conductive layer 8 of the second sheet 6. . 13 is a transfer sheet insertion opening for manually inserting the transfer sheet O; 14 is a conveyance guide that guides the inserted transfer sheet 10; and 15 is a conveyance guide for guiding the inserted transfer sheet 10 into the first sheet 1 and the inserted transfer sheet 10 at a predetermined timing. A timing roller for sending out between the second sheets 6, 1
A fixing device 6 fixes the toner image 5 on the transfer sheet 10.

In addition, 24 is a slot 7) for manually inserting the original, and 26
28 is an elastic foam roll, 29 is an exit document chute, 30 is an exposure lamp for exposing the dielectric layer 4 of the first sheet 1 in the exposure section 34, 32 is an illumination cavity, and 36 is a SELFOC a lens-like lens, 41 a cylindrical brush charging device for charging the dielectric layer 4;
0 is a developing section which includes a rotating roll 42 having a single component developer and develops the electrostatic latent image formed on the dielectric material 4 to form a toner image 5; 54 is a copy exit chute; and 55 is a dielectric layer 4.
This is a cleaning blade for cleaning residual toner.

The detailed structure and operation of these members and the above-mentioned supply roll 20 are described in Japanese Patent Laid-Open No. 59-208567, and therefore will be omitted in this embodiment.

Next, the effect will be explained.

First, when the transfer sheet O is guided by the conveyance guide 14 and is manually inserted from the transfer sheet insertion opening 13 until it reaches the vicinity of the contact point between the timing roller 15 and the take-up roller 9, the transfer sheet LO is The transfer sheet 10 is conveyed between the first sheet 1 and the second sheet 6 being wound up at a predetermined timing by a timing roller 15 so that the toner image 5 on the layer 3 and the transfer sheet 10 coincide with each other. Next, the transfer sheet 10 is transferred to the first sheet 1 and the second sheet 6.
It is wound up on the winding roller 9 so as to be sandwiched between the
When an electric field is formed between the conductive layers 3.8 by the electric field forming means 12, the toner image 5 carried on the dielectric layer 3 of the first seam 1 is transferred to the transfer seam 0. After the transfer is completed, when the auxiliary roller 11, supply roll 20, and take-up roller 9 rotate in the opposite direction in the unwinding direction of the take-up roller 9, as shown in FIG. 3 degrees, and then the second sheet 6 is separated from the second sheet 6 due to the sharp bend in the traveling direction of the auxiliary roller 11. Then, the second sheet 6 is separated from the first sheet 1 and the second sheet 6. The transferred transfer sheet 10 enters the fixing device 16, and the toner image 5 transferred to the transfer sheet IO is fixed on the transfer sheet 10, and is discharged to the outside of the device.

As described above, in this embodiment, the toner image 5 has the conductive layer 3.
A transfer sheet 10 is sandwiched between the first sheet 1 carrying the conductive layer 1 and the second sheet 6 having the conductive layer 8, and the transfer sheet 10 is wound together with the first sheet 1 and the second sheet 6 by a winding roller 9. Since an electric field is formed between the conductive layers 3.8, the transfer sheet 10 is wound around the take-up roller twice or more, and the toner image 5 carried on the first sheet 1 is transferred onto the transfer sheet 10. Can be transcribed. Therefore, the diameter of the winding roller 9 can be reduced, and the transfer device can be downsized.

In this example, the first sheet 1 is directly exposed and
Although the present invention is applied to an image forming apparatus that develops and forms a toner image on the first sheet 1, it may also be applied to an apparatus as shown in FIG. That is, in FIG. 4, the photosensitive drum 9
1, 92 and 93 are formed with toner images of mutually different colors and transferred to an intermediate transfer sheet 94, and this intermediate transfer sheet 94 is used as the above-mentioned first transfer sheet) 1 and is applied to the winding roller 9 in the same manner as above. I try to wind it up. Therefore, the first sheet l is not limited to a so-called bad light material, but may be any sheet as long as it carries a toner image. In addition, the resistance value of the transfer sheet 10 is arbitrary depending on the user and takes various values, and also varies greatly depending on the environment. Therefore, the resistance value of the transfer sheet NO. Although a protective layer 7 is provided on the second sheet 6 so that the electric field does not change much even if the dielectric constant changes, the protective layer 7 may be unnecessary depending on the conditions. Furthermore, the base 2 of the first sheet 1
is provided to improve mechanical strength, but it is not necessarily necessary depending on the conditions, or it may be provided on the second sheet 6.

5 to 7 are diagrams showing an embodiment of the transfer device according to the second aspect of the invention, and are examples in which the transfer device is applied to an electrostatic copying type image forming device. In FIG. 5, the same members as those shown in FIG. 1 are designated by the same reference numerals, and their explanations will be omitted.

First, the configuration will be explained.

5 to 7, 71 is a first sheet, and the first sheet 71 includes a protective layer 72, a first conductive layer 73, an insulating layer 74
, a second conductive layer 75 and a dielectric layer 76. An insulating layer 74 is sandwiched between a first conductive layer 73 and a second conductive layer 75 to prevent leakage between the two conductive layers, and a dielectric layer 76 of the first sheet 71 carries a toner image 77. 78 is a winding roller;
The transfer sheet 79 is stacked on the first sheet 71 so that the toner image 77 carried on the first sheet 71 comes into contact with the transfer sheet 79, and the transfer sheet 79 is placed together with the first sheet 71.
Wind up. Specifically, one end of the first sheet 71 is wound around a take-up roller 78, and the other end is wound around a supply roll 20.

When the transfer sheet 79 is inserted into the contact area between the first sheet 71 wound up by the take-up roller 78 and the first sheet 71 immediately before being wound up by the take-up roller 78, the transfer sheet 79
is wound up on a winding roller 78 together with the first sheet 71. 80 is an electric field forming means, and the electric field forming means 80 is arranged so that the first sheet 71 and the transfer sheet 79 are
The first conductive layer 73 of the first sheet 71 is
and applying a voltage to the second a conductive layer 75, the first conductive layer 7
3 and the second conductive layer 750. The first conductive layer 73 of the first sheet 71 and the second conductive layer 75 located at a position sandwiching the transfer sheet 79 from the first conductive layer 73
The toner image 77 carried on the first sheet 71 is transferred to the transfer sheet 79 by the electric field formed between the two sides. 81 is a separation roller that rapidly changes the traveling direction of the transfer sheet 79; 82 is a plurality of transfer sheets 79;
83 is a feed roller that separates the transfer sheets 79 in the paper feed section 82 one by one and sends them out between the first sheets 71 at a predetermined timing, and 84 is a conveyor that guides the transferred transfer sheets 79. A guide 85 is a fixing device that fixes the toner image 77 on the transfer sheet 79.

Next, the action will be explained.

First, the transfer sheet 79 of the paper feeding section 82 is placed between the first sheet 71 being wound up by the feed roller 83 at a predetermined timing so that the toner image 77 on the dielectric layer 76 and the transfer sheet 79 match. transported. Next, the transfer sheet 79 is sandwiched between the first sheet 71 and wound around the winding roller 78, and an electric field is formed between the first conductive layer 73 and the second conductive layer 75 by the electric field forming means 80. , the toner image 77 carried on the dielectric layer 76 of the first sheet 71 is transferred to the transfer sheet 79. After the transfer is completed, when the supply roll 20, take-up reroller 9, and separation roller 81 reversely rotate in the unwinding direction of the take-up roller 9, the transfer sheet 79 is first separated from the inner first sheet 71, and then the outer first sheet 71 is separated. As the traveling direction of the first sheet 71 is sharply bent by the separation roller 8I, the outer first sheet 71
separated from Next, the transfer sheet 79 separated from the first sheet 71 enters the fixing device 85, and the transfer sheet 79 is separated from the first sheet 71.
The toner image 77 transferred to the toner image 71 is fixed on the transfer sheet 79 and discharged to the outside of the apparatus.

As described above, in this embodiment, when the first sheet 71 having the first conductive layer 73 and the second conductive layer 75 that are electrically insulated from each other is wound around the winding roller 78, the first sheet B1
Since an electric field is formed between the first conductive layer 73 and the second conductive layer 75 with the transfer sheet 79 sandwiched between them, the transfer sheet 79
The toner image 77 carried on the first sheet 71 can be transferred to the transfer sheet 79 by winding the toner image 77 around the winding roller 78 twice or more, and the diameter of the winding roller 78 can be reduced. Therefore, the transfer device can be downsized, and the image forming device itself can also be downsized.

Further, since the first sheet 71 is configured as described above, the second sheet as described above can be made unnecessary, and the cost can be reduced and the transfer device can be further downsized.

In this embodiment, the first sheet 71 is directly exposed and developed to form a toner image on the first sheet 71, but as in the previous embodiment shown in FIG. It may be something like a sheet.

〔effect〕

According to the present invention, the transfer sheet is sandwiched between the first and second sheets each having a conductive layer, or the transfer sheet is sandwiched between the first sheets having the first and second conductive layers, and the transfer sheet is rolled. Since the transfer sheet is wound around the take-up roller, the transfer sheet can be wound around the take-up roller twice or more, and the diameter of the take-up roller can be reduced. Therefore, the transfer device can be downsized, and the image forming apparatus to which the transfer device is applied can also be downsized.

[Brief explanation of the drawing]

1 to 4 are diagrams showing an embodiment of the transfer device according to the invention as claimed in claim 1, FIG. 1 is a schematic sectional view of an image forming apparatus to which the transfer device is applied, and FIG. 2 is a diagram showing the transfer device. A diagram for explaining the principle of sheet separation; FIG. 3 is an enlarged sectional view showing state 3 in which the transfer sheet is wound up on a winding roller together with the first sheet and the second sheet; FIG. 4 is the transfer device. 5 to 7 are diagrams showing an embodiment of the transfer device according to the invention as claimed in claim 2, and FIG. A schematic cross-sectional view of the applied image forming apparatus, FIG. 6 is a diagram for explaining the separation principle of the transfer sheet, and FIG. 7 shows the transfer sheet wound together with the first sheet by a winding roller. It is an enlarged sectional view. l...first sheet, 3...-conductive layer, 5...toner image, 6...second sheet, 8...conductive layer , 9... Winding roller, lO... Transfer sheet, 12... Electric field forming means, 71... First sheet, 73...・First conductive layer, 74... Insulating layer, 75... Second conductive layer, 77... Toner image, 78... Winding roller, 79 ...Transfer sheet, 80...Electric field forming means. Figure 1 Figure 2 Figure 5 q

Claims (2)

[Claims] (1) A first sheet that has a conductive layer and carries a toner image, a second sheet that has a conductive layer, and a transfer sheet that is placed so that the toner image carried on the first sheet comes into contact with the transfer sheet. A take-up roller that is sandwiched between the first sheet and the second sheet and winds up the transfer sheet together with the first sheet and the second sheet; , an electric field forming means for forming an electric field between the conductive layer of the first sheet and the conductive layer of the second sheet, and an electric field formed between the conductive layer of the first sheet and the conductive layer of the second sheet. A transfer device characterized in that the toner image carried on the first sheet is transferred to the transfer sheet. (2) A first conductive layer, a second conductive layer, and a first conductive layer and a second conductive layer.
It has a layer structure consisting of an insulating layer sandwiched between a conductive layer,
A first sheet carrying a toner image, and a take-up roller that stacks the transfer sheet on the first sheet so that the toner image carried on the first sheet comes into contact with the transfer sheet, and winds up the transfer sheet together with the first sheet. With the first sheet and the transfer sheet being wound up by the take-up roller, the first sheet of the first sheet is
an electric field forming means for forming an electric field between the conductive layer and the second conductive layer, and the electric field formed between the first conductive layer and the second conductive layer of the first sheet causes the first sheet to be supported. A transfer device characterized in that a toner image is transferred onto a transfer sheet.