JPH0324576A - Image forming device - Google Patents

Abstract

PURPOSE:To easily take out a transferring material in which a jam occurs by performing a changeover so that a part which is of an intermediate transfer ring body and is positioned in the vicinity of a second transferring means is moved to a position separated from the second transferring means. CONSTITUTION:The subject device is constituted so that a retransferring roller 19 attached to the leading edge part of a rocking arm 24 rotatable around the shaft core of a supporting shaft 23 is positioned in the vicinity of a second transferring charger 13 and can be moved in a space between a first position at which a retransferring operation to transferring paper from an intermediate transferring belt 10 is possible and a second position upwardly separated from the second transferring charger 13 in such a way that the retransferring roller 19 is lifted up by tension given to the intermediate transferring belt 10 by a tension roller 18. When, transferring paper clogging (a jam) occurs, the retransfer ring roller 19 is some what depressed and a locking claw 5 is rotated to a non-engaging position. Thus between the intermediate transferring body 10 and the second transferring means 13, a space which a hand enters is formed and the clogged transferring paper can be taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an image forming apparatus, and particularly to an image forming apparatus that transfers an image from a photoreceptor onto an intermediate transfer member once or multiple times, and transfers an image onto the intermediate transfer member thus formed. The present invention relates to an image forming device for retransferring an image to a transfer material.

(Prior Art) Conventionally, an image forming apparatus that transfers an image formed on a photoconductor to an intermediate transfer member and then retransfers it to a transfer material has been disclosed, for example, in Japanese Patent Application Laid-open No. 50-155232 and Japanese Patent Application Laid-Open No. 155232. Showa 5
It is known from Publication No. 6-147166 and the like.

On the other hand, in a normal image forming apparatus that directly transfers an image on a photoreceptor to a transfer material, the image is transferred on the transfer material transport path. In order to easily remove the transfer material in the event of a so-called jam, in which the transfer material becomes clogged and cannot be transferred, the image forming device is usually divided into upper and lower halves at the transfer material transport path, and the upper section is separated. It is constructed so that it can be lifted towards the side.

Furthermore, there is also known a device in which the transfer means is moved downward and retracted with respect to the photoreceptor, thereby separating the photoreceptor and the transfer means so that it is possible to insert one's hand into the transfer material transport path.

(Problem H to be solved by the invention) However, in an image forming apparatus equipped with the above-mentioned intermediate transfer body, in order to easily take out the transfer material when a jam occurs in the retransfer section, the transfer material transport path is If you try to divide the section into two parts, upper and lower, the optical system, the image forming system with a photoreceptor, and the intermediate transfer system with an intermediate transfer body will be placed in the upper part, which will increase the weight of the upper part, making it difficult to maintain sufficient structural rigidity. In particular, those that form full-color images require a large number of developing units, which causes the problem that the upper part becomes even larger and heavier. Also, a configuration in which the transfer means in the retransfer section is moved downward and retracted may be considered, but a large retraction space is required to ensure space for hands to enter the transfer material transfer path, which is a factor that increases the size of the device. There is a problem that In view of the above conventional problems, the present invention provides an image forming apparatus that can maintain the rigidity of the apparatus and easily take out the transfer material when a jam occurs without increasing the size of the apparatus. Purpose. (Means for Solving the Problems) In order to achieve the above object, the image forming apparatus of the present invention develops an electrostatic latent image formed on a photoreceptor and develops a developed image into a flexible endless In an image forming apparatus, the developed image on the intermediate transfer member is transferred from the intermediate transfer member to a transfer material by the second transfer member after the image is transferred from the intermediate transfer member by the first transfer member to the transfer material by the second transfer member. an intermediate transfer member such that at least a portion of the intermediate transfer member located near the second transfer member moves between a first position where retransfer is possible and a second position located a distance M from the second transfer member; The invention is characterized in that it is provided with a switching means for switching the rotation path of the.

(Function) According to the above structure of the present invention, when a jam occurs during paper passing, the switching means separates the portion of the intermediate transfer member located near the second transfer means from the second transfer means. The second
By moving it to the position, a space can be created between the intermediate transfer body and the second transfer means, and the jammed transfer material can be taken out. Therefore, since there is no need to divide the device into two, the rigidity of the device can be easily ensured, and since the rotation path of the endless belt is changed to create a space, it is possible to move the second transfer means. Since there is no need to do this, the apparatus does not become large-sized, and a large space can be formed over a wide range of the transfer material transport path.

(Example) Hereinafter, an example in which the present invention is applied to a color copying apparatus will be described with reference to FIGS. 1 to 4.

In FIG. 1, reference numeral l denotes an original platen glass on which an original is placed. Below the original platen glass 1, there are an exposure lamp 2, first to fifth mirrors 3a to 3e, a lens 4, and a color separation filter unit 5. A powerful optical system is installed. As shown in FIG. 4, in the color separation filter unit 5, a blue filter plate 5B, a green finoleta plate 5G, and a red finoleta plate 5R are supported in parallel by a frame 5l, and a drive motor 52 and a red finoleta plate 5R are supported in parallel. Position sensor 53a, 5
3b, one of the filter plates 5B, 5G, and 5R can be selectively positioned in the exposure optical path.

6 is a photosensitive drum, around which are an erase lamp 7, a charger 8, a developing section 9, and an intermediate transfer belt 10.
, a drum cleaner 11 are provided. The developing section 9
A yellow developer 9Y, a magenta developer 9M, and a cyan developer 9C are installed. Further, each developing device is equipped with a developing sleeve, a grain cutting shutter, a toner concentration detector, a toner replenishing device, and the like.

The intermediate transfer bell l-10 is made of a flexible semiconductor with good environmental resistance, for example, a volume resistivity of IXI O to IXIO".
It is made of polyurethane rubber, etc. and has a thickness of about 1 cm.
It is released by an endless belt of about 6 on+.

Around the intermediate transfer belt 10, there are a first transfer charger 12 that transfers the image from the photosensitive drum to the intermediate transfer belt 10, and a second transfer charger that transfers the image from the intermediate transfer bells 1 and 10 to the transfer paper. 13, Static elimination charger l4
, belt cleaner 15, etc. are provided.

Further, as shown in detail in FIG. 2, the intermediate transfer belt 10 is connected to pressure rollers l on both sides of the first transfer charger 12.
6, 17, tension roller 18, and retransfer roller 1
9 and a belt cleaner roller 20. The tension roller 18 is disposed approximately midway between the pressure roller I6 and the retransfer roller 19, is pivotally supported around the axis of the pressure roller I6, and is supported by a tension spring 22 to rotate the intermediate transfer belt lOO times. It is attached to the tip of the tension arm 21 which is biased toward the outside of the dynamic path.

The retransfer roller 19 is attached to the tip of a swinging arm 24 that is rotatable around the axis of a support shaft 23 disposed above and on the side of the retransfer roller 19.
A first position is located close to the transfer charger 13 of the intermediate transfer belt IO and can be retransferred from the intermediate transfer belt IO to the transfer paper, and a second position is raised by the tension applied to the intermediate transfer belt 10 by the tension roller 18. transfer charger
3 and a second position spaced above it.

Also, the shaft end 19 of this retransfer roller l9. A locking pawl 25 that engages with the retransfer roller 19 and holds the retransfer roller 19 at the first position is rotatably arranged between a locking position and a disengaging position. Further, an operating lever 26 for rotating the swinging arm 24 is provided.

Reference numeral 27 denotes a solenoid that presses the belt cleaner 15 into contact with and separates from the intermediate transfer belt 10.

In FIG. 1, 2 is a paper feed cassette, 29 is a registration roller, 30 is a transfer paper conveyance belt, and 31 is a fixing device having a fixing roller with a built-in heater.

Next, the operation will be explained. The original placed on the original table glass 1 is sequentially scanned in the horizontal direction, and the reflected light is
~Third mirrors 3a to 3c, color separation filter unit 5,
An image is formed on the photosensitive surface of the photosensitive drum 6 via the lens 4 and the fourth and fifth lenses 3d and 3e. Photosensitive drum 6
After being exposed and neutralized by the erase lamp 7, it is charged to, for example, a constant negative potential by the charger 8, and is rotated and exposed in synchronization with the scanning.

When the photosensitive surface is irradiated with reflected light from the original, the surface potential changes depending on the intensity of the light, and an electrostatic latent image is formed.

This electrostatic latent image is formed by the yellow developing device 9Y of the developing section 9,
The toners are developed using the respective color toners in either the magenta developer 9M or the cyan developer 9C. for example,
Color separation filter unit 5, blue filter + M5B
is located in the optical path, the yellow developing device 9Y, which is a complementary color to blue, is selected, and in the other developing devices 9M and 9C, the developer on the developing sleeve is scraped off by the ear-cutting shutter at the rear of each developing sleeve. After that, the yellow developing device 9Y is driven, and the electrostatic latent image is developed with yellow toner and made visible. Note that the toner is charged to, for example, a positive potential, which is opposite to that of the photoreceptor drum 6.

The intermediate transfer belt IO is driven in synchronization with the photoreceptor drum 6 at the same speed as the photoreceptor drum 6, and the toner image of the positive potential on the photoreceptor drum 6 is transferred by the first transfer charger 12 to which a negative potential is applied. is this intermediate transfer belt 10
transcribed into. Thereafter, the photosensitive surface of the photosensitive drum 6 is cleaned by a drum cleaner 11, and the exposure, development, and transfer steps are completed.

In the case of full-color copying, when the first exposure, development, and transfer steps for yellow are completed, the green filter plate 5G is selected in the color separation filter unit 5 and positioned on the optical path, and the image passes through the green filter plate 5G. The photosensitive surface of the photosensitive drum 6 is exposed to the light reflected from the original, forming an electrostatic latent image, which is visualized by the magenta developer 9M, which is a complementary color to green, and is superimposed on the yellow toner image on the intermediate transfer belt 10. The magenta toner image is transferred.

When the above-mentioned second exposure, development, and transfer steps are completed, the red filter plate 5R is selected and positioned on the optical path in the color separation filter unit 5 for the third time, and the reflected light of the original that has passed through this filter plate 5R is applied to the photoreceptor drum. The photosensitive surface of 6 is exposed to light to form an electrostatic latent image, and a cyan developer 9, which is the complementary color of Lett, is developed.
C, a cyan toner image is transferred onto the intermediate transfer belt 10 overlapping the yellow and magenta toner images, and a full-color toner image of yellow, magenta, and cyan is formed.

During this transfer process, the belt cleaner 15 of the intermediate transfer belt IO is turned off by the solenoid 27.
It is separated from 0.

On the other hand, at a predetermined timing based on a signal from a position detection device (not shown) of the intermediate transfer belt 10, the transfer paper is fed out from the paper feed cassette 2nd by the paper feed roller 28a and sent to the registration roller 29. The transfer paper is sent out toward the second transfer charger 13 at a predetermined timing, and the full-color toner image with a positive potential on the intermediate transfer bell 10 is electrostatically transferred to the second transfer charger l3 to which a negative potential is applied. is absorbed and transferred to transfer paper.

The transfer paper on which the toner image has been transferred is charged with an AC potential applied by the charger 14, and then transferred to the intermediate transfer belt 10.
The paper is separated, transported by suction by a transfer paper transport belt 30, sent to a heated fixing device 31, fixed, and discharged.

On the other hand, the intermediate transfer belt 1O that has completed the retransfer is cleaned by turning on the solenoid 27 and being pressed by the belt cleaner 15, and is ready for the next process.

In this retransfer process to the transfer paper, the transfer paper is sent out from the registration roller 29, the toner image is transferred from the intermediate transfer belt 10 by the second transfer charger 13, and separated from the intermediate transfer belt 10 by the static elimination charger 14. In the transfer process, if the transfer paper is not fed correctly and jams occur due to poor separation, etc.
In the illustrated example, the operating lever 26 is pulled up a little, and the retransfer roller 19 is slightly pushed down to loosen the engagement between the shaft end 19a and the locking pawl 25, and the locking pawl 25 is moved from the state shown in FIG. 3(a). Rotate it to the uncoupled position as shown in Figure 3 (1)). Then, the tension arm 21 releases the tension spring 22.
1 and 2, the tension roller 18 moves laterally as shown by the arrow, and the rotation path of the intermediate transfer belt 10 changes. The retransfer roller 19, which changes into a flat shape and is attached to the tip of the swinging arm 24, retracts upward, and a wide space is formed above the second transfer charger 13, and you can insert your hand into this space to remove any jammed objects. Transfer paper can be easily removed.

After removing the transfer paper, by rotating the operating lever 26 in the opposite direction of the arrow against the biasing force of the tension spring 22, the retransfer roller l9 is pushed down and positioned at a predetermined position where retransfer is possible. In this state, the locking pawl 25 is engaged with the shaft end 19a and locked.

In the above explanation, an example was given in which transfer is performed three times to the intermediate transfer belt 10 to form a full-color toner image, and then it is transferred again to the transfer paper. However, it is also possible to provide a mode in which a monochrome color image is formed and transferred Needless to say, it's a good thing.

Further, in the above embodiment, a corotron charger is used, but instead of this, another roller may be brought into pressure contact with the retransfer roller, and a transfer paper may be passed between them for pressure transfer, or a high-ass voltage may be applied to that roller. It is also possible to adopt a configuration in which bias transfer is performed or thermal transfer is performed by applying heat.

(Effects of the Invention) As is clear from the above description, according to the image forming device of the present invention, when a jam occurs, the switching means switches the intermediate transfer member to the portion located near the second transfer means. This second
By moving the intermediate transfer body to a second position spaced apart from the transfer means, a space can be created between the intermediate transfer body and the second transfer means, and the jammed transfer material can be easily taken out, thus making it possible to remove the jammed transfer material. Since there is no need to divide the belt into two, its rigidity can be easily ensured, and since the rotation path of the endless belt is changed to form a space, there is no need to move the second transfer means. Therefore, the device does not become large-sized, and a large space can be formed over a wide range of the transfer material transfer path.

[Brief explanation of drawings]

1 to 4 show an embodiment in which the present invention is applied to a full-color copying apparatus, in which FIG. 1 is a general schematic diagram, FIG. 2 is a perspective view of the intermediate transfer belt, and FIG. 3(a). , (b) are schematic front views of the same operating state, and FIG. 4 is a perspective view of the color separation filter unit.・Photosensitive drum --- Intermediate transfer belt 1--1---111-1 1st transfer charger---1111-1 2nd transfer charger tension roller re Transfer roller tension arm・1・・・・1 tension spring・I pull arm・・・・・1・・・1・1−1 Locking claw 6 10 l2 l3 18 19 2 1 −−−−−− 112 2---・11---・2 4.1251111・

Claims (1)

[Claims] (1) A developed image obtained by developing an electrostatic latent image formed on a photoreceptor is transferred to a first intermediate transfer member consisting of a flexible endless belt.
In the image forming apparatus, the developed image on the intermediate transfer member is transferred to the transfer material by the second transfer member after being transferred by the transfer member, wherein at least a portion of the intermediate transfer member near the second transfer member is provided. A switching means is provided for switching the rotation path of the intermediate transfer member so that the portion located at the intermediate transfer member moves between a first position where retransfer is possible and a second position separated from the second transfer means. An image forming apparatus characterized by: