JPH05210316A - Image forming device - Google Patents

Abstract

PURPOSE:To simply carry out maintenance work without damaging a transfer bias roll by providing a secondary transfer unit provided with both of a cleaning means and a recovery part of stuck material such as toner. CONSTITUTION:The paper transfer device 15 carrying out secondary transfer to a transfer paper is arranged in a position facing a drive pulley 10A3 with a transfer belt 10A in between them and the paper transfer device 15 is constituted from a unit which can be brought into contact with or separated from the transfer belt 10A. Then, a cleaning blade 15D is attached to a bracket 15C of the paper transfer device 15 and a state where the cleaning blade 15D is abutted to a periphery surface of the paper transfer bias roll 15A supported by a side plate 15B is set by having the bracket 15C restrained by a hinge to the side plate 15B1 of a unit 15B. Furthermore, the device is put into a state where the toner eliminated from a paper transfer bias roll 15A by the cleaning blade 15D can be recovered by having the recovery container 15E inserted from a window 15B3 of a side plate 15B1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus,
More specifically, it relates to a transfer structure for transferring from an intermediate transfer body to paper.

[0002]

2. Description of the Related Art A multicolor image forming apparatus capable of forming a full color image or two or more color images is one of image forming apparatuses for executing an image forming process by an electrophotographic system such as a copying machine, a printer or a fax machine. There is. In this apparatus, for example, a primary transfer process of temporarily transferring a visible image formed for each color on a photoconductor to an intermediate transfer body is performed to superimpose the image of each color on the intermediate transfer body, and then the intermediate image is transferred. Transfer the visible image carried on the transfer body to the transfer paper at once 2
The next transfer process is executed.

A belt having a length corresponding to the maximum size of an image that can be wound around a plurality of pulleys may be used as the intermediate transfer member. Is provided with a paper transfer bias roller facing the secondary transfer portion for the transfer paper and capable of coming into contact with and separating from the intermediate transfer belt. The paper transfer bias roller is transferred toward the intermediate transfer belt. The transfer bias is applied when the transfer paper is pressed against the intermediate transfer belt in accordance with the transfer timing onto the paper.

[0004]

By the way, the paper transfer bias roller which can be brought into contact with and separated from the intermediate transfer belt is designed to transfer the transfer paper when the front end of the transfer paper in the conveying direction reaches the secondary transfer position on the intermediate transfer belt. The intermediate transfer belt is designed to move in the direction of pressing the transfer belt. However, in terms of the actual contact timing, the transfer paper does not press the transfer paper after it reaches the secondary transfer position. In order to ensure the transfer of the image to the leading end position, the transfer paper comes into contact with the intermediate transfer belt immediately before reaching the secondary transfer position, and transfer of the residual toner from the intermediate transfer belt to the paper transfer bias roller. In order to prevent this, the transfer paper leaves the intermediate transfer belt immediately after passing through the secondary transfer position. However, at such a contact timing, the toner attached to the non-image portion on the intermediate transfer belt is easily transferred to the paper transfer bias roller, and in some cases, the toner image to be transferred is transferred. If a part of the toner image is transferred, or if the transfer paper is jammed during transportation, the entire toner image will be transferred to the paper transfer bias roller, and will be sent next. When it comes into contact with the back surface of the transfer paper, the back surface of the transfer paper is soiled. Therefore,
A structure in which a scraping member such as a blade is brought into contact with the paper transfer bias roller in order to remove the toner transferred to the paper transfer bias roller is also conceivable. However, since the blade itself is a consumable item, it becomes necessary to replace it when the toner removal efficiency deteriorates over time. For this reason, when this blade is pulled out of the apparatus by itself and is to be replaced, the blade is fixedly provided in the apparatus separately from other parts such as a paper transfer bias roller. In this case, it is troublesome to remove it while paying attention to the interference with other parts. There is a risk that the scratches may be rubbed against the surface to damage the uniformity of the bias surface. Further, the amount of the toner collected by the blade is limited to the accumulated amount due to the volume inside the apparatus, so it is necessary to discard the toner to the outside like the blade. At this time, if the structure is moved together with the blade, the above-mentioned problems occur.

Therefore, an object of the present invention is to prevent damage to the paper transfer bias roller in view of the problem in the above-mentioned conventional image forming apparatus, especially in the cleaning portion of the paper transfer bias roller in the secondary transfer portion. An object of the present invention is to obtain an image forming apparatus having a structure capable of easily performing maintenance work without coming.

[0006]

To achieve this object, the present invention electrostatically primary-transfers a toner image formed on an image bearing member such as a photoreceptor to an intermediate transfer member. After that, in the image forming apparatus in which the paper is inserted between the paper transfer bias rollers pressed against the intermediate transfer member to perform the secondary transfer, the paper transfer bias roller and the paper transfer bias roller are cleared. A secondary transfer unit is provided which includes a cleaning means for cleaning and a collecting portion for collecting the adhered matters including toners from the paper transfer bias roller removed by the cleaning means. It is characterized by that.

Further, the present invention is characterized in that the secondary transfer unit is detachably provided separately from the main body of the apparatus in addition to the other structural parts.

Further, the present invention is characterized in that the recovery part is provided so as to be detachable independently from other components in the secondary transfer unit.

[0009]

According to the present invention, the paper transfer bias roller arranged at the secondary transfer position, the cleaning means for removing the residue such as the toner adhering to the roller, and the cleaning means. A collecting section for collecting the deposits removed from the paper transfer bias roller by the steering means is provided in an integrated unit. Further, according to the present invention, the above-described unit can be pulled out to the outside independently of the other components in the image forming apparatus. Furthermore, according to the present invention, the recovery unit can be pulled out to the outside independently of the other components in the unit described above.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a layout diagram showing an overall configuration of a multicolor image forming apparatus which is one of the image forming apparatuses according to the embodiments of the present invention. In FIG. 1, the image forming apparatus 1 according to the present embodiment includes a document reading section 1A and an image recording section 1B. Each section will be described below.

The above-mentioned document reading section 1A is composed of a scanner for reading a document image placed on a document placing table by a photoelectric conversion element, and this scanner includes the document placing table 2, the illumination light source 3, and the optical path forming mirror. -4, an image forming lens 5 and a color sensor 6 including a photoelectric conversion element formed of a CCD or the like for receiving reflected light from the color-separated document. In the document reading section 1A, the reflected light from the document is color-separated in the order of, for example, blue, green and red, and then read by the color sensor 6 as color image information, and an image signal corresponding to this information Is output to an image processing unit (not shown). Further, in the image processing unit, color conversion processing is performed based on the signal relating to the intensity level of the image output from the color sensor 6, and then cyan, magenta, yellow and gradation improvement and monochrome are performed. Color image data about black at the time of an image is obtained and processed as a signal to the image recording unit 1B described later.

On the other hand, the image recording section 1B includes a writing section 7,
The photoconductor 8, the developing unit 9, and the transfer unit 10 are provided. The writing unit 7 converts the color image data from the color scanner 6 into an optical signal and performs optical writing according to the original image to form an electrostatic latent image on the photoconductor 8. A laser light source 7A, a polygon mirror 7B forming an optical scanning portion, an fθ lens 7C, and a reflection mirror are provided inside the portion.
7D is deployed. Further, in the case of this embodiment, the photoconductor 8 is composed of a drum rotatable in the direction of the arrow shown in the drawing, and the charging device 11 for executing the copying process along the rotation direction is provided around the drum. Optical path from writing unit 7, developing unit 9, transfer unit 10, cleaning device 12
And the static elimination lamp 13 is each arrange | positioned.

The developing unit 9 described above, as shown in FIG.
In addition to the black developing device 9A, cyan developing for supplying a developer having a color complementary to the color separated in the document reading section 1A or a color corresponding to color image data from the image processing section. A developing device 9B, a magenta developing device 9C, and a yellow developing device 9D are provided respectively, and a developing sleeve 9E capable of causing each developing device to make a spike of the developer and bring the spike into contact with the photoconductor. And a rotatable development paddle 9 for assembling and transporting the developer and stirring.
F and a density detection sensor 9G for detecting the density of the developer contained therein. And this developing unit 9
In the above, only the developing device containing the developer of the color corresponding to the color of the electrostatic latent image formed on the photosensitive drum 8 is operated, and when supplying the developer, A developer containing a developer of a color that is not related to the color of the electrostatic latent image on the photoconductor by making the developer stand on the developing sleeve to electrostatically adhere to the electrostatic latent image. Meanwhile, the container keeps the standby state without causing the developer to rise. Further, this developing unit supplies a latent image on the side of the photoconductor drum 8 when the developer is supplied to the photoconductor drum 8 so that only the developer of a necessary color is supplied to the photoconductor drum 8. Development sleeve 9E from the leading edge to the trailing edge of the area
The operating state is determined so that the ears can be brought into contact with each other, and is switched to the inactive state after the trailing edge of the latent image area has passed.

As shown in FIG. 2, the transfer portion 10 is composed of an intermediate transfer member which uses a belt-shaped transfer member to perform the primary transfer.
Is hung on a plurality of pulleys including a pulley 10A1 arranged at a position facing the photosensitive drum 8 and a tension pulley 10A2 arranged at a position facing the photosensitive drum 8, and is transferred to a transfer paper described later. The drive pulley 10A3 is arranged at a position corresponding to the secondary transfer position of (1) to move in the direction indicated by arrow B. Further, among the above-mentioned plurality of pulleys, the pulley 10A1 arranged at a position facing the photoconductor drum 8 is applied with a bias for transferring a visible image on the photoconductor drum 8. In addition, this pulley 10A1 and drive pulley 10A
A pulley 10A4 facing the belt cleaning device 14 is disposed between the pulley 10A4 and the belt cleaning device 3. The belt cleaning device 14 uses a contact / separation mechanism (not shown) to transfer, for example, the image transfer of the first color onto the transfer belt 10A and then the image transfer of the second and subsequent colors while the transfer belt 1 is being transferred.
It is arranged so as not to cause image loss by being separated from 0A.

On the other hand, at a position facing the drive pulley 10A3, there is arranged a paper transfer device 15 for performing a secondary transfer on the transfer paper with the transfer belt 10A interposed therebetween. Reference numeral 15 is a unit that can be brought into contact with and separated from the transfer belt 10A by a structure described later,
A paper transfer bias roller 15A to which a bias for image transfer is applied is provided at a position facing the drive pulley 10A3 in this unit.

That is, as shown in FIG. 3, the paper transfer device 15 is composed of a unit 15B having side plates 15B1 located at both ends of the paper transfer bias roller 15A in the axial direction. It is swingably supported by a support shaft 15B2 pivotally supported on the image forming apparatus main body side. Further, on the side plate 15B1, the above-mentioned paper transfer bias roller 15A is provided at a position facing the drive pulley 10A3 with the transfer belt 10A interposed therebetween.
Is rotatably supported and its roller 15A
The bracket 15C is screwed to the lower position of
A paper transfer bias roller 15 is attached to the bracket 15C.
A cleaning blade 15D which is in contact with A is attached. Further, the side plate 15B1 is formed with a window 15B3 below the cleaning blade 15D, and the window 15B3 is composed of a bottom plate for connecting the side plates to each other and a housing having an open upper part. A collecting container 15E is slidably provided, and a cleaning blade 15D is provided.
Thus, the toner removed from the peripheral surface of the paper transfer bias roller 15A is collected. This collection container 1
5E can be inserted and removed through the window 15B3,
In this case, the guide member 15F provided on the bottom plate
Will be guided by.

On the other hand, on the swinging end side of the bracket 15C attached to the unit 15B, there are provided overhanging pieces 15C1 made of bent pieces at both axial ends of the paper transfer bias roller 15A. A roller 15G is rotatably supported on the overhanging piece 15C1. An eccentric cam 15H, which is rotatably supported on the main body side of the multi-color image forming apparatus and is used to bring the unit 15B into and out of contact with the transfer belt 10A at the timing of feeding the transfer paper, comes into contact with the roller 15G. Touching.
The eccentric cam 15H causes the unit 15B to approach the transfer belt 10A side when the position of the maximum lift of the cam profile is opposed to the roller 15G, and
When the position of the minimum lift is made to face the roller 15G,
The unit 15B can be separated from the transfer belt 10A. Therefore, when the unit 15B is displaced to a position approaching the transfer belt 10A, the paper transfer bias roller 1
5A comes into contact with the transfer belt 10A, and the unit 15
When B is displaced in the direction away from the transfer belt 10A, the paper transfer bias roller 15A is separated from the transfer belt 10A. In FIG. 3, reference numeral 15J is a slide rail disposed below the bottom plate of the unit 15B in the main body of the multicolor image forming apparatus.
The unit 15B can mount the unit 15B when the unit 15B is displaced to a position separated from the transfer belt 10A, and the unit 15B can be mounted in the mounted state.
Can be inserted into and removed from the device body.

In the paper transfer device 15, an image on the transfer belt 10A is sandwiched and conveyed while the transfer paper fed from the paper feeding device 16 (see FIG. 1) is synchronized with the image leading end position. Is to be transcribed. In FIG. 2, reference numeral 17 indicates a conveyor belt, and in FIG. 1, reference numerals 18 and 19 indicate a fixing device and a paper ejection tray, respectively.

By the way, the above-mentioned transfer belt 10A is
By the drive setting of the drive pulley 10A3, the following movement control is performed. (1) Constant speed forward method This is a method of continuing the movement at a constant speed even after the image of the first color is transferred. In the case of this method, it is visible on the photosensitive drum 8 side. The image processing is performed with the timing set so that the leading edge of the image of the next color to be image-processed and the leading edge of the image on the transfer belt 10A match.

(2) Skip forward method In this method, after the image of the first color is transferred, the transfer belt 10A is separated from the photosensitive drum 8 and the image of the first color is transferred. This is a method in which the photosensitive drum 8 is moved to the same direction at a higher speed than the above, and when the predetermined amount is moved, the initial moving speed is switched again and the photosensitive drum 8 is again contacted. The image processing in 8 is performed with the timing set so that the positions of the first color image and the next color image match. Such a scheme
For example, it is executed when the length of the image to be transferred is shorter than the length of the transfer belt, and it is possible to prevent the image forming time cycle on the side of the photoconductor drum 8 from becoming long.

(3) Quick return method This is a method of separating the transfer belt 10A from the photosensitive drum 8 after the image of the first color is transferred, and transferring the transfer belt 10A in the reverse direction at a higher speed than before. Is moved to wait for the position of the previously transferred image to match the position of the image of the next color carried on the photoconductor drum 8, and then again contact the photoconductor drum 8 to bring the photoconductor drum 8 into contact. It is a method to start the movement in the same direction as the movement direction of, and to continue this operation until before the transfer of the visible image of the final color.
Similar to the method described above, the image processing on the photoconductor drum 8 is performed with the timing set so that the positions of the images of the first and next colors match. Such a scheme
The control when the image position on the transfer belt 10A side is aligned with the image position on the photoconductor drum 8 side is simple in that it is not necessary to secure a large movement amount of the transfer belt 10A.

Since this embodiment has the above-mentioned configuration,
The cleaning blade 15D is attached to the bracket 15C of the paper transfer device 15, and the bracket 15C is screwed to the side plate 15B1 of the unit 15B, whereby the circumference of the paper transfer bias roller 15A supported by the side plate 15B is secured. The state is set so that the cleaning blade 15D can come into contact with the surface. Also, the window 15B3 of the side plate 15B1
When the collecting container 15E is inserted from the cleaning container 15E, the cleaning blade 15D causes the paper transfer bias roller 15 to move.
The toner removed from A is ready to be collected. On the other hand, the roller 15G provided on the overhanging piece 15C1 of the bracket 15C is located at the maximum lift position of the eccentric cam 15H (in FIG. 3,
(State indicated by the solid line) when facing the side plate 15B.
The paper transfer bias roller 15A is brought into contact with the transfer belt 10A by pushing up the swinging end of the transfer belt. Therefore,
In this state, since the transfer paper can be pressed toward the transfer belt 10A, it is in a position just before the leading end of the transferred transfer paper reaches the secondary transfer position.

Then, the roller 15G is placed at the position of the minimum lift of the eccentric cam 15H described above (the state shown by the chain double-dashed line in FIG. 3).
, The side plate 15B swings downward to separate the paper transfer bias roller 15A from the transfer belt 10A. Therefore, in this state, since the unit 15B is placed on the slide rail 15J, the unit 1B is placed outside the apparatus.
5B can be pulled out, and further, the collection container 15E can be pulled out from the window 15B3 of the side plate 15B1. When the cleaning blade 15D is replaced, a new cleaning blade 15D can be mounted by removing it from the bracket 15C in a state where the unit 15B and the recovery container 15E can be pulled out. You can

[0024]

As described above, according to the present invention, the paper transfer bias roller in the paper transfer device, the cleaning means corresponding to the cleaning means of the paper transfer bias roller, and the cleaning means are removed. Since the means for collecting the adhered matter is arranged by one unit, by integrating the constituent parts of these paper transfer devices, the labor and management of the parts mounting in the device are simplified.

Further, according to the present invention, since each component arranged in the unit can be independently attached and detached, it is possible to perform the attaching and detaching operation without worrying about the order of the attaching and detaching operation and the maintenance work is simplified.

[Brief description of drawings]

FIG. 1 is a layout view showing an overall configuration of a multicolor image forming apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged layout view of a part of the apparatus shown in FIG.

FIG. 3 is a schematic layout diagram for explaining a partial configuration of a main part shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multicolor image forming apparatus 8 Photoconductor drum 9 Developing section 10 Transfer section 10A Transfer belt 15 which is an intermediate transfer body 15 Paper transfer apparatus forming a secondary transfer section 15A Paper transfer bias roller 15B Unit 15B1 forming an essential part of a transfer apparatus Unit side plate 15D Cleaning blade 15E Toner recovery container 15G Roller 15H Unit eccentric cam for contact and separation

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshiaki Motohashi 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. (72) Hideki Ueyama 1-3-6 Nakamagome, Ota-ku, Tokyo・ In Ricoh Co., Ltd. (72) Inventor Takashi Misasai 1-3-6 Nakamagome, Ota-ku, Tokyo ・ In Ricoh Co., Ltd.

Claims (3)

[Claims] 1. A toner formed on an image bearing member such as a photosensitive member.
In an image forming apparatus configured to perform secondary transfer by electrostatically primary-transferring an image to an intermediate transfer member and then inserting a paper between the paper transfer bias rollers pressed against the intermediate transfer member, The paper transfer bias roller, cleaning means for cleaning the paper transfer bias roller, and toner and other deposits removed from the paper transfer bias roller are collected by the cleaning means. An image forming apparatus comprising: a secondary transfer unit that collectively includes a recovery unit that performs 2. The image forming apparatus according to claim 1, wherein 2
The next transfer unit is an image forming apparatus that is separately provided from the main body of the apparatus separately from other structural parts. 3. The image forming apparatus according to claim 1, wherein the recovery unit is separately and separately provided separately from other components in the secondary transfer unit.