JPH03167580A - Image forming device - Google Patents

Abstract

PURPOSE:To form images of originals which are in nearby positions on both sides of a transfer material in one process by providing a transfer belt whose length of detour path is changeable. CONSTITUTION:The transfer belt 11 is provided so that an approximate abutting position of an image carrier 5 and the transfer belt 11 is one edge, the other edge is made to go through the detour path coming to a carrying path of the transfer material 20, and so that the length of the detour path is changeable. When images which are in nearby space of the both side pages of the opened book of the original 30, etc., are formed, a first visual image formed on the image carrier 5 is transferred to the transfer belt 11 at the approximate abutting position of the transfer belt 11 and the image carrier 5 and traveled on the detour path, next a second visual image formed on the image carrier is transferred to the transfer material 20, and each are traveled to a position where the carrying path and the detour path of the transfer material 20 are joined together. Thus, the images of the original 30, etc., which are positioned closely in space or in time are formed on both sides of the transfer material 20 in one process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an image forming apparatus, and more particularly, the present invention relates to an image forming apparatus that transfers images to a transfer material in one step based on originals or image information located close to each other in space or time. The present invention relates to an image forming apparatus capable of forming images on both sides of the image, or a combination thereof.

(Prior art) Conventionally, a photoconductor that develops an electrostatic latent image to form a developed image, and a transfer belt capable of transferring the developed images on the photoconductor are provided, and a plurality of developed images are transferred onto the transfer belt. Image forming apparatuses are known in which a combined image is formed by overlapping transfer, and the image is retransferred onto a transfer material.

In addition, the transport path of the transfer paper is arranged so as to pass through a transfer section between the photoreceptor and the transfer belt, and the first image is transferred to the transfer belt, and the first image is transferred onto the photoreceptor in synchronization with the image on the transfer belt. There is also a system that forms a second image and sends the transfer material to the transfer section in synchronization with these images, so that images can be simultaneously formed on both sides of the transfer material by passing the transfer material through the conveyance path once. Are known.

(Problem to be Solved by the Invention) However, in any of the above image forming apparatuses, the first
The transfer belt must rotate one revolution between the image of When supplied, there is a problem in that it is not possible to form a combined image as is or to form images on both sides simultaneously, and it is necessary to form images separately on each side.

For example, when using a copying machine to copy both pages of an open book onto both sides of a sheet of paper, the original is scanned one page at a time, the first scanned image is transferred to the transfer belt, and the second scanned image is transferred to the transfer belt. It is possible to make double-sided copies by feeding the transfer material in synchronization with the first scanned image, but it is not possible to scan both pages in one go with the book open and copy on both sides of the transfer material in one step. , there was a problem that copying required time and effort. A similar problem also occurs when image information for two pages is printed on both sides of a sheet of paper.

Also, when forming a merged image using a copying machine, the first document containing the image to be merged is scanned and the image is transferred to the transfer belt, and then the second document is scanned and the image is transferred to the transfer belt. It is necessary to transfer the above image onto a transfer belt and retransfer it to a transfer material, and to form a composite image in one scan by arranging both originals to be combined in parallel. Since it is not possible to do this, there is a problem that it requires time and effort, and the same problem occurs when printing by combining image information as described above.

In view of the above-mentioned conventional problems, the present invention forms images on both sides of a transfer material in one step based on originals or image information located close to each other in space or time, or forms a combined image of these images on both sides of a transfer material in one step. The purpose of the present invention is to provide an image forming apparatus capable of forming images.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the image forming apparatus of the present invention has an image carrier that forms an electrostatic latent image and carries a developed image of the electrostatic latent image. and at least l on this image carrier.
A transfer belt is arranged so as to be able to come into contact with a portion of the image carrier and can transfer the developed image on the image carrier, and a transfer belt is configured to pass between the image carrier and the transfer belt while substantially contacting a part of the image carrier. The conveyance path of the transfer material arranged and the transfer belt are arranged so that the transfer belt passes through a detour path where one end is at the approximate contact position of the image carrier and the transfer belt and the other end is aligned with the conveyance path of the transfer material, and the detour path is The present invention is characterized by comprising means for supporting the transfer belt so that its length can be changed.

Further, an image carrier having an electrostatic latent image formed thereon and carrying a developed image obtained by developing the electrostatic latent image; The length of the detour route is changed so that the transfer belt passes through a detour route between a transfer belt capable of transferring a visible image on the body and at least two approximate contact positions between the transfer belt and the image carrier. means for supporting the transfer belt, and conveyance of a transfer material arranged so as to be substantially in contact with the transfer belt at a position downstream in the direction of movement of the transfer belt from at least two substantially contact positions between the image carrier and the transfer belt. It is characterized by having a route.

(Function) According to the above feature of the present invention, first and second manuscripts that are spatially close to each other, such as manuscripts on both sides of an open book or two consecutive manuscripts, or first and second manuscripts that are temporally close to each other, When forming an image based on the second image information, the first developed image formed on the image carrier is transferred to the transfer belt at a position where the transfer belt and the image carrier substantially contact each other, and the transfer belt A second developed image formed on the image carrier in close proximity to the first developed image is a transfer material that is conveyed in synchronization with the conveyance path. or, while being carried on the image carrier as it is, move it toward a position where the conveyance path and detour path of the transfer material merge, or a second approximate contact position between the image carrier and the transfer belt. By this, and these first
The length of the detour route of the transfer belt is set to the length of the first developing image and the first approximately contacting position so that the first developing image and the second developing image reach the merging position or the second approximately abutting position in synchronization with each other. By setting the length equal to the sum of the distance from the contact position to the merging position or the second approximate contact position, when these double-headed images are transferred to both sides of the transfer material, double-sided images are obtained, and the transfer belt A composite image can be obtained by superimposing the two images on each other, and even if a plurality of images are formed in series on the image carrier, a composite image or a double-sided image can be obtained.

(Example) Hereinafter, each example of the present invention will be described with reference to FIGS. 1 to 23.

In the first embodiment shown in FIGS. 1 to 8, 2 is a document table glass on which a document is placed. 2 is a light source that illuminates the original, and 3 is a movable optical system that projects an image of the original onto the photosensitive drum 5. Reference numeral 4 denotes a prism interposed in the optical system 3, which switches the image of the document between a normal image and a mirror image by moving between a position where it is interposed in the optical path and a retracted position.

Around the photoreceptor drum 5, a developing device 6, a transfer charger 10,
A photoreceptor cleaner 7, an eraser 8, a charger 9, etc. are provided. An endless transfer belt 11 is disposed between the developer 6 and the photoreceptor cleaner 7 so as to face the photoreceptor drum 5 at two positions on both sides of the transfer charger 10. ing. The portion of the transfer belt 11 facing the photoreceptor drum 5 is configured to be movable between a position in which it is substantially in contact with the photoreceptor drum 5 and a position in which it is separated from the photoreceptor drum 5. Further, a passage path is arranged between the transfer belt 11 and the photosensitive drum 5.

As shown in FIG. 2, the transfer belt 11 has a 50 μm thick polybutylene layer (electrical A dielectric type belt is formed with a dielectric layer 13 having a resistance of 101ΩcII+ or more.

The transfer belt 11 includes rollers 21, 22, 23, 24.
, 25, 26, and each roller is preferably electrically conductive and grounded. Rollers 21 and 22 on both sides of the transfer charger 10 are configured to be able to approach and separate from the photoreceptor drum 5, and a roller 23 located between these rollers 21 and 22 is configured to move the length of the transfer paper or toner image. The length of the transfer belt 11 between these rollers 2122 can be changed depending on the situation. Furthermore, the roller 25 is also moved in order to prevent the transfer bell I-11 from loosening due to the movement of the roller 23. The roller 23 supports the side edge of the transfer belt 11 so as not to come into contact with the toner image on the transfer belt 11.

Around the transfer belt 11, a belt electrification charger 14 is arranged near the roller 26 and opposite the transfer belt 11, and a belt transfer charger 15 and a belt cleaner 16 are arranged near the roller 24 and opposite the transfer belt 1. ing.

Further, a register roller 17 for feeding the transfer roller 20 with a predetermined timing is disposed on the paper feeding side of the feeding path between the photoconductor drum 5 and the transfer belt 110, and a register roller 17 is provided on the ejecting side across the paper feeding path. An upper fixing roller 18a and a lower fixing roller 18b each having a built-in heater lamp 19 are arranged.

A specific example of the support mechanism for the transfer belt 11 by the roller 23 is shown in FIG.
A supporting material 11a having holes 1lb regularly formed on both sides of the roller 23 is fixed, and as shown in FIG. The locking protrusion 23b protruding from the outer periphery of the hole 1lb
This prevents the transfer belt 11 from loosening in the width direction.

Further, to show a concrete example of the moving mechanism of this roller 23, as shown in FIGS. The bearing member 33 is movably supported by the formed guide groove 35, and is driven by a feed screw 37 driven by a stevening motor 36.

Further, as another example of a specific structure of the support mechanism for the transfer belt l1 by the roller 23, as shown in FIG. The thick support portion 11c may be wound around and supported by tapered roller portions 23d formed at both ends of the roller 23, and as shown in FIG.
Instead of forming the thick support portions 11c on both sides of the support member lid, a support member lid having a triangular cross section may be attached.

Next, the operation will be explained. On the manuscript table glass 1, there is a manuscript 30, which is a so-called book object, which looks like an open book.
The movable optical system 3 moves from the right to the left in the figure with respect to the document 30, and the charger 9 charges the document 30 with -600
First, a normal image of the side A portion of the original document 30 is projected onto the charged photoreceptor drum 5 to form an electrostatic latent image. At this time, the prism 4 is located in the optical path. next,
When the optical system 3 reaches the B side of the original 30, the prism 4
is withdrawn from the optical path, and a mirror image of the B-side portion is projected onto the photosensitive drum 5, forming an electrostatic latent image. Each latent image on the photosensitive drum 5 is developed with toner by a developing device 6 with a developing bias of -150V.

On the other hand, between the positions where the rollers 21 and 22 substantially contact the photosensitive drum 5, the difference between the distance on the transfer belt 11 and the distance on the photosensitive drum 5 is exactly equal to the length of the transfer belt 20. The position of the roller 23 is adjusted in advance, and the transfer belt 11 is set to -100 by the belt charger 14.
It is charged to 0V.

Next, the transfer operation of the toner image on the photosensitive drum 5 will be explained based on FIG. 8. First, as shown in FIG. 8(a), the charged transfer belt 11 is brought into approximate contact with the photoreceptor drum 5 by the roller 21, and the normal image of side A of the original 30 is transferred onto the transfer belt 11. . At this time, the roller 22 is spaced apart from the photosensitive drum 5 so that the transfer belt 11 is not soiled.

Next, when the tip of the mirror image of side B of the document 30 comes to the roller 21, the roller 21 will move as shown in FIG. 8(b).
is separated from the photoreceptor drum 5, the roller 22 is brought into approximate contact with the photoreceptor drum 5, and the transfer ring 20 is moved by the register roller 17 so that the tip of the transfer ring 20 coincides with the tip of the mirror image of the B side portion. Paper is fed. Thereafter, as shown in FIG. 8(C), the transfer plate 20 is charged with an electric charge of opposite polarity to the toner by the transfer charger 10 from the back side, and the toner image on the B side on the photoreceptor drum 5 is transferred to the transfer plate 20. transferred onto the surface of 20. Next, when the leading edge of the transfer paper 20 reaches the roller 22, the leading edge of the toner image on side A on the transfer belt 11 also reaches the roller 22. Further, when the leading edge of the transfer paper 20 and the leading edge of the toner image on side A on the transfer bell 11 reach the belt transfer charger 15, the belt transfer charger 15 (-5kV) causes the transfer ring 20 to remove the toner from the surface. It is charged with a charge of opposite polarity,
The toner image on the A side portion is transferred to the back side of the transfer paper 20.

In this way, the toner image of the B side portion is formed on the surface of the transfer plate 20.
The toner image on side A is transferred to the back side.

The transfer belt 20, onto which the toner image has been transferred, separates from the transfer belt 11 at the roller 24 and moves to the fixing rollers 18a, 18b.
The toner is fixed and discharged.

In the above description, the toner image on the tip of the transfer sleeve 20 and the A side portion is synchronized, but by adjusting the movement of the roller 23, it is also possible to create a margin on the side of the transfer sleeve 20.

Further, in this embodiment, an example was shown in which a dielectric type transfer belt 1l was used in which a dielectric layer 13 was provided on a conductive layer 12, but a photoconductive transfer belt 1l in which a photoconductor layer was provided in place of the dielectric layer was used. A body type transfer belt can also be used.

Next, a second embodiment of the present invention will be described based on FIGS. 9 and 10. It should be noted that structural elements that are the same as those explained in the first embodiment above are given the same reference numerals, and explanations including their operations are omitted, and this second embodiment is different from the first embodiment. I will only explain what I am doing.

In the second embodiment, a pre-transfer eraser 31 is disposed between the developing device 6 and the roller 21 to facilitate the transfer of the toner image on the photosensitive drum 5, and the transfer charger 10 is eliminated. Further, a belt cleaner l6 is disposed near the roller 26, and the rollers 2l and 22 are fixedly disposed at positions substantially in contact with the photoreceptor drum 5.

Next, the transfer operation of the toner image on the photosensitive drum 5 in this embodiment will be explained based on FIG. 10. First, the first
As shown in FIG. 0(a), the normal image of the side A portion of the original 30 is transferred to the charged transfer belt 11, as in the first embodiment. Next, when the tip of the mirror image of side B of the original 30 comes to the roller 2l, as shown in FIG. A transfer ring 20 is fed so as to match the leading edge, and is placed on the transfer belt 11 which is charged with the opposite polarity to the toner. A mirror image of the B-side portion is transferred onto it. At this time, the negative charge on the photoreceptor drum 5 is transferred to the pre-transfer eraser 3.
Since the toner is erased at 1, the electrostatic attraction force between the toner and the photosensitive drum 5 is weakened, and the toner is easily transferred. Next, as shown in FIG. 10(C), when the leading edge of the transfer belt 20 reaches the roller 22, the leading edge of the toner image on the side A on the transfer belt 11 reaches the roller 22. After that, during belt transfer charging 15, the toner image on side A is transferred to 20
is transferred to the back side of

In this second embodiment as well, the dielectric type transfer bell l-
Instead of 11, a photoconductor type transfer belt can be used.

Next, third to fifth embodiments of the present invention will be described based on FIGS. 11 to 14. Note that the same structural elements as those described in each of the above embodiments are given the same reference numerals, and a description thereof including their operations will be omitted. Moreover, this also applies to the following examples.

The first and second embodiments described above are examples in which the transfer belt 11 is a dielectric type belt shown in FIG. This is an example in which a type of belt is used.

In FIG. 11, the transfer belt 41 is coated on the surface of a semiconductor support layer 42 made of a 600 μm thick urethane rubber base material (electrical resistance 109 to 101 Ωcm) and 20 μm thick polytetrafluoroethylene (electrical resistance 10'° to 1012 Ωcm).
It is provided with a semiconductor type belt on which a semiconductor layer 43 consisting of 4 cm) is formed.

The third embodiment shown in FIG. 12 has a basic structure corresponding to the first embodiment, and has a semiconductor type transfer belt 4.
Some parts of the structure have been changed in response to the change to 1. In FIG. 12, the belt transfer charger 14 is omitted, and instead the roller 21 is replaced by a conductive brush roller or a conductive rubber roller, which is connected to a transfer bias power source 44.

The operation of the third embodiment is such that when the toner image on side A of the document 30 comes to the roller 21, a transfer bias is applied to the roller 21 and the toner image is transferred to the transfer belt 41. Except for this, it is the same as the first embodiment.

The fourth embodiment shown in FIG. 13 corresponds to the second embodiment in terms of basic purchase, and similarly to the third embodiment, the belt transfer belt 41 is changed to a semiconductor type transfer belt 41. The roller 21 is connected to the transfer bias power source 44 instead of the charger 14, and the difference in operation from the second embodiment is also the same as the third embodiment.

The fifth embodiment shown in FIG. 14 is a modified embodiment of the fourth embodiment shown in FIG. A transfer charger 28 is arranged between rollers 21 and 27. In this case, the rollers 21, 27 do not necessarily need to be electrically conductive. The transfer operation in this example is as follows:
The second embodiment and the fourth embodiment are the same except that the transfer charger 28 transfers the toner image from the photosensitive drum 5 to the transfer belt 41 and to the transfer sleeve 20.

In the third to fifth embodiments described above, an example was shown in which a certain transfer belt 41 made of a semiconductor was used, but the transfer belt 41
Alternatively, a transfer belt made of dielectric material may be used.

Next, a sixth embodiment of the present invention will be described based on FIGS. 15 to 17. Each of the above embodiments is an example in which a dielectric type belt shown in FIG. 2 or a semiconductor type belt shown in FIG.
This is an example in which a photoconductive type of helmet as shown in FIGS. 5 and 16 is used.

In FIG. 15, the transfer belt 51 is connected to the conductive support 5.
A layer of photoconductor 53 is formed on top of the photoconductor 2. Further, instead of the single layer photoconductor 53, as shown in FIG. 16, a charge generation layer 54 on a conductive support 52 and a charge transport layer 55 formed thereon may be used. .

The sixth embodiment shown in FIG. 17 has a base structure corresponding to the second embodiment, and is a photoconductive type transfer bell.
51, a belt easer 56 is disposed between the rollers 21 and 22.

Further, in this embodiment, the roller 21 is arranged at a position substantially in contact with the photoreceptor drum 5, but the roller 22 is arranged at a position away from the photoreceptor drum 5 so as to face the paper passing path. A temporary guide 57 is provided between these rollers 21 and 22 to form a passing path.

The operation of this sixth embodiment is similar to that of the second embodiment, but the toner image on the side A is transferred onto the transfer belt 51 by the roller 21, and the toner image on the side B is transferred onto the transfer belt 51. 2
transferred to the surface of 0. While the toner image on the A side reaches the roller 22, the charge on the surface of the transfer belt 51 is erased by the belt eraser 56. When the toner image is transferred to the back surface of the transfer plate 20, it is easily transferred.

In the first to fifth embodiments described above, the roller 22 can be arranged at a position separated from the photosensitive drum 5 and at a position facing the passage path, similarly to the sixth embodiment. For example, when applied to the fourth embodiment shown in FIG.
A groove is formed as in the seventh embodiment shown in FIG. The transfer belt 11 in this seventh embodiment is a dielectric type belt in which a dielectric layer 13 made of a 30 μm thick polybutylene layer is formed on a conductive layer 12 of 600 μm'P7-.

Next, an eighth embodiment of the present invention will be described based on FIGS. 19 and 20.

In the first to seventh embodiments described above, an example was shown in which images are formed on both sides of the transfer plate 20 from the book manuscript 30 in one step.
This eighth embodiment is an embodiment in which a composite image of two originals arranged in parallel is formed on transfer paper.

In FIG. 19, in contrast to the structure of the first embodiment, originals 60a and 60b are placed in parallel on the original platen glass l.
Since only the normal image of is projected onto the photoreceptor drum 5, one mirror is added to the optical system 3 and the prism 4 is not disposed. Further, there is no communication path between the photosensitive drum 5 and the rollers 21 and 22, and the communication path of the transfer device 20 is provided close to the roller 24 portion, and the communication path between the rollers 21 and 22 is provided. The transfer charger 10 is eliminated and the belt transfer charger l5 is replaced with a roller 2 across the communication path.
A belt transfer charger 29 is disposed so as to face the belt transfer charger 4 . Further, among the rollers 21 and 22, at least the roller 21 on the upper side in the rotational direction of the transfer belt 11 is configured to be able to approach and separate from the photosensitive drum 5, and the belt cleaner 16 is arranged near the roller 26. There is.

Next, the transfer operation in this embodiment will be explained based on FIG. 20. First, as shown in FIG. 20(a), the toner image A of the original 60a is transferred to the transfer belt 11 charged by the belt charger 14 at the roller 2l. Next, the leading edge of the toner image B of the document 60b is placed on the roller 21.
20(b), the roller 21 separates from the photoreceptor drum 5, and then the photoreceptor drum l
, 5 and the leading edge of the toner image A on the transfer belt ll reach the roller 22 portion at the same time, as shown in FIG. 20(C).
As shown in the figure, toner image B is transferred onto transfer belt 11, and both toner images A and B are superimposed and combined on transfer belt 11, and then these combined toner images are transferred to the belt at roller 24. Transfer paper 2 with transfer charger 29
0, and a combined image is formed on the transfer paper 20.

Also in this embodiment, a photoconductor type transfer belt can be used instead of the dielectric type transfer belt 11.

Next, the ninth and tenth embodiments are modified embodiments of the eighth embodiment.
An embodiment will be described based on FIG. 21 and FIG. 22.

The ninth embodiment shown in FIG. 21 uses a semiconductor type transfer belt 4 as the transfer belt, similar to the third to fifth embodiments.
In this example, in place of the belt charger 14, a transfer bias power source 44 is connected to each of the rollers 21 and 22 in order to transfer the toner image on the photosensitive drum 5 onto the transfer belt 41. The transfer operation in this embodiment is similar to that in the eighth embodiment. In this embodiment as well, a transfer belt made of a dielectric material may be used instead of the transfer belt 41 made of a semiconductor.

In the tenth embodiment shown in FIG. 22, a photoconductive type transfer belt 51 is used as the transfer belt in the same way as in the sixth embodiment.
In this example, a belt eraser 56 is disposed at an upper position in the rotational direction of the transfer plate 51 of the roller 24. In this embodiment, before the belt transfer charger 29 transfers the toner image on the transfer belt 51 onto the transfer plate 20, the belt eraser 56 erases the surface charge of the transfer belt 5l. Transfer to the transfer plate 20 is easily performed.

Incidentally, in the case of image combination in the eighth to tenth embodiments, the developing device 6
It goes without saying that multicolor combination may be performed by arranging a plurality of colors and making the two originals have different colors.

Furthermore, if the transfer belt is supported so that the transfer belt contacts the photoreceptor at three locations, it is possible to combine three images.

Next, the paper passing paths shown in the first to seventh embodiments and the eighth to first embodiments are explained below.
By providing both of the paper passing paths shown in Example 0 and selecting one of the passing paths, it is possible to arbitrarily select and form a double-sided image and a double-sided image. The eleventh embodiment will be described based on FIG. 23.

This 11th embodiment is an embodiment in which a semiconductor type transfer belt 41 is used, and is constructed based on the 9th embodiment shown in FIG. 21. In FIG. 23, roller 21
, 22 are connected to a transfer bias power source 44, the roller 24 is arranged diagonally below the roller 22, and a paper feed path 70 for forming an image is connected to the upper side in the direction of movement of the transfer bell 41. has been done. Further, 7l is a paper feed cassette for double-sided image formation, 72 is a feed roller thereof, 73 is a paper feed cassette for composite image formation, 74 is a feed roller thereof, 75 is a conveyance roller, and 76 is a registration roller. The operation in this embodiment is the same as that in the above embodiment, except that it is possible to switch between a double-sided image and a composite image.

It is also possible to form a single image on one side of the transfer rack 20 by feeding paper from the paper feeding cassette 71 for double-sided image formation or the paper feeding cassette 73 for forming a combined image. When feeding paper from the cassette 71, the transfer paper 2
An image can be formed on either the front or back side of 0.
You can cast υ1 transcription gi 20 in either face-up or face-down state.

In the embodiment shown in FIG. 23, a semiconductor type transfer belt 4 is used.
Although an example using No. 1 has been shown, it goes without saying that the invention can be similarly applied to dielectric type or photoconductive type transfer belts.

In addition, in each of the above embodiments, when the humidity is high, the transfer
Since the resistance value of the transfer belt becomes low and the transfer efficiency deteriorates, a hygrometer is installed near the transfer belts 11, 41, and 51, and based on the detection signal, when the humidity is high, the transfer charger 10, belt charger l4, and belt transfer charger 15,
On the 2nd day of the transfer charger, the belt transfer charger 29, the transfer bias voltage 'fA44, etc.
It is preferable to prevent transfer defects at high humidity by increasing the charging potential of the transfer roller 1, 51 and the transfer roller 20.

In the above embodiment, only the case of original copying was explained, but image forming devices such as printers can also print temporally adjacent or continuous image information on both sides of transfer paper in one process, or combine images. You can also print it out.

Further, in the above embodiment, an example is shown in which a photosensitive drum is used as an image carrier, but a dielectric drum may also be used.

(Effects of the Invention) As is clear from the above explanation, according to the image format recognition device of the present invention, first and second documents that are spatially close to each other, such as true manuscripts on both sides of an open tree or two consecutive manuscripts, etc. When forming an image based on a document or first and second image information that are close in time, the first image formed on the image carrier is transferred to the transfer belt and the image carrier. A second developed image is transferred to the transfer belt at the contact position, carried by the transfer belt and moved along a detour path of the transfer belt, and then formed on the image carrier in close proximity to the first developed image.
The developed image is transferred to a transfer material sent in synchronization with the conveyance path, or left to be carried on the image carrier as it is, and placed at a position where the conveyance path and detour path of the transfer material meet, or with the image carrier. By moving the transfer belt toward the second substantially abutting position, these two developed images are transferred to both sides of the transfer material to obtain a double-sided image, and when superimposed on the transfer belt, a combined image is obtained. In this way, it is possible to obtain a combined image or a double-sided image in one step based on originals or image information located close to each other in space or time, which is a great effect.

[Brief explanation of the drawing]

1 to 8 show a first embodiment of the present invention, FIG. 1 is a general schematic diagram, FIG. 2 is a sectional view of a dielectric type transfer belt, and FIG. 3 is a movable roller. FIG. 4 is a plan view of the same, FIG. 5 is a side view of the roller moving mechanism, and FIG. 6 is another support structure of the transfer belt using a movable roller. FIG. 7 is a sectional view of a transfer belt in a modification of the support configuration example of FIG. 6, FIGS. 8(a) to (C) are explanatory diagrams of transfer operation,
FIG. 9 and FIG. 10 show a second embodiment of the present invention, and FIG.
10(a) to 10(C) are explanatory diagrams of the transfer operation, FIG. 11 is a sectional view of a semiconductor type transfer belt, and FIGS. 12 to 14 are diagrams of the present invention. 15 and 16 are sectional views of a photoconductive type transfer belt, and FIG. 17 is a schematic view of the main parts of the third to fifth embodiments, and FIG.
FIG. 18 is a schematic diagram of the main parts of the embodiment, FIG. 18 is an overall schematic diagram of the seventh embodiment of the present invention, FIGS. 19 and 20 are the eighth embodiment of the present invention, and FIG. Overall schematic structure diagram, 2nd
0(a) to (C) are explanatory diagrams of the transfer operation, FIGS. 21 and 22 are schematic configuration diagrams of the main parts of the ninth and 10th embodiments of the present invention, and FIG. FIG. 11 is a schematic diagram of the overall configuration of an eleventh embodiment.・1...1 photosensitive drum ・1 transfer charger...Dielectric type transfer belt -Belt charging charger Belt transfer charger Transfer paper Loaf transfer charger Belt transfer charger Semiconductor type transfer belt...1 transfer Bias power supply for -・1・1 Photoconductive type transfer heater 5・1 0・−・−・−・1 l・・・・・・1 4−・−・・−・1・1 5-・----・1--------・1・・20-・
−・１・・・・・−・・ 2 1～26・・１・・ 2 8−−１・１・・・−−１１・ 2 9 −−−−−−−−１・・・・1・−・−4 1
−・− ・・・・１・ ４ ４−・１・・・・・・・－－－・５ １・１・ ト

Claims (2)

[Claims] (1) An image carrier on which an electrostatic latent image is formed and which carries a developed image obtained by developing this electrostatic latent image; an image carrier disposed so as to be able to come into approximate contact with the photoreceptor at at least one position; a transfer belt capable of transferring the developed image above; a transport path for a transfer material disposed to pass between the image carrier and the transfer belt in substantially contact with a part of the image carrier; and a transfer belt capable of transferring the image. means for supporting the transfer belt so that the transfer belt passes through a detour path in which one end is located at a position where the carrier and the transfer belt substantially contact each other and the other end faces the conveyance path of the transfer material, and the length of the detour path can be changed; An image forming apparatus comprising: (2) An image carrier on which an electrostatic latent image is formed and which carries a developed image obtained by developing this electrostatic latent image; an image carrier disposed so as to be able to substantially abut on the image carrier at least at two positions; The transfer belt is capable of transferring a visible image on the body, and the length of the detour route is changed so that the transfer belt passes through a detour route between at least two approximate contact positions between the transfer belt and the image carrier. a means for supporting the transfer belt in a manner possible to support the transfer belt; and a means for transporting a transfer material disposed so as to be substantially in contact with the transfer belt at a position downstream in the direction of movement of the transfer belt from at least two substantially contact positions between the image carrier and the transfer belt. An image forming apparatus comprising a path.