JPH0721687B2 - Cleaning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image forming apparatus such as an electrophotographic copying machine.
The present invention relates to a cleaning device that cleans an image forming body.

(Background of the Invention) Recently, an image forming apparatus has been studied in which an image forming body is developed a plurality of times while being rotated a plurality of times to form one original image on a transfer material. There is a point.

For example, a color copying machine which is a color image forming apparatus will be described. In a color copying machine that has been generally adopted in the past, a latent image forming step, a developing step, and a transfer step are repeatedly performed as shown in FIG. 12A each time a drum-shaped or belt-shaped photosensitive member as an image forming member makes one revolution. Accordingly, a multicolor original image (hereinafter referred to as a multicolor image) corresponding to the original is formed on a transfer material such as a recording paper or an intermediate transfer body. Since the multicolor image is formed by sequentially synthesizing the monochromatic toner image formed by the monochromatic color toner every one rotation of the photoconductor on the transfer material,
There is a problem that it is difficult to transfer each single-color toner image without causing transfer deviation, and the combined multicolor image easily causes color deviation. Further, since it is necessary to repeatedly convey the transfer material to the transfer position a plurality of times in synchronization with the rotation of the photoconductor, there is a problem that the apparatus for conveying the transfer material is complicated.

In order to solve the above-mentioned problems, a multicolor toner image corresponding to an original is combined on a photoconductor, and the multicolor toner image is transferred onto a transfer material by one transfer to obtain a predetermined multicolor image. An image forming apparatus such as a color copying machine is being developed. For example, as shown in FIG. 12B, while the photoconductor rotates a plurality of times, the latent image formation and the development of the monochromatic toner image with the monochromatic color toner are repeated plural times to form a multicolor toner image corresponding to the original on the photoconductor. A color copying machine which is designed to form a predetermined multicolor image by transferring the multicolor toner image onto a transfer material by one-time transfer, or a photoconductor as shown in FIG. 12C. Latent image formation during one rotation of multiple times
After the rotation, the monochromatic toner images are developed with different monochromatic color toners one by one every rotation of the photoconductor, and a multicolor toner image corresponding to the original is synthesized to form one multicolor toner image.
It is a color copying machine or the like which is transferred onto a transfer material by a single transfer to form a predetermined multicolor image. In each of the color copying machines, a multicolor toner image corresponding to an original is formed on a photoconductor, and the multicolor toner image is transferred onto a transfer material by one transfer to form a multicolor image. Therefore, the multicolor image is well formed without causing color misregistration, and the device for conveying the transfer material is much simpler than the conventional device. However, toner that has not been used for transfer (hereinafter referred to as residual toner) adheres to the photoconductor after transfer, and it is necessary to remove the residual toner by the time of the next image formation. No suitable cleaning device has been developed. For example, a conventional image forming apparatus cleaning device applied to an image forming apparatus is one in which a cleaning member such as a blade, a brush, or a magnetic brush is provided so as to always contact the image forming body. However, when it is applied to the color image forming apparatus, it faces the cleaning apparatus without transferring a monochromatic toner image developed every one rotation of the photoconductor. Since the toner passes through the position, each single-color toner image comes into contact with the cleaning member and the image is disturbed, and there is a problem that a good multicolor image cannot be formed.

The color image forming apparatus which has been put into practical use as described above is
There is a problem that the transfer material conveying device is complicated and the formed original image is a blurred image due to transfer deviation, and a color image forming apparatus that can solve the above problems is As one of the causes, there is a problem that it cannot be put to practical use because a cleaning device capable of removing the attached residual toner and cleaning the image forming body satisfactorily has not been developed.

(Object of the Invention) The present invention has been developed in view of the above conventional circumstances, and an object of the present invention is to develop a plurality of toner images sequentially while the image forming body rotates a plurality of times. A cleaning device that cleans an image forming body that is applicable to an image forming apparatus that forms a document image by transferring the combined toner image onto a transfer material after the image is formed on the image forming body, that is, the cleaning device of the image forming apparatus. It is an object of the present invention to provide a cleaning device that can remove an residual toner and clean an image forming body satisfactorily without impairing the image forming function.

(Structure of the Invention) The present invention has been completed in order to achieve the above-mentioned object, and the structure is such that a plurality of margins are formed on the outer periphery while the image forming body is rotated a plurality of times so that a margin in which a non-image area is generated on the outer periphery. In an image forming apparatus that forms a toner image, synthesizes the toner image, and transfers the synthesized toner image to a transfer material, the operation is released while an image region having a toner image other than the last toner image among the plurality of toner images passes through. Then, the switching operation of the cleaning means, which operates during the passage of the image area onto which the synthetic toner image is transferred, between the operation and the release of the cleaning means is performed during the passage of the non-image area. And a cleaning device.

(Example) An example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory view schematically showing a color copying machine for explaining an embodiment of the present invention. In FIG. 1, reference numeral 1 is a drum-shaped photosensitive member which is an image forming member, and 2 is a charging device including a scorotron discharge electrode. 3 is a color developing device capable of developing three colors of blue, red and black.
Is a blue developing device, B is a red developing device, and C is a black developing device. Reference numeral 4 is a transfer device including a corotron discharge electrode, 5 is a separator including an AC corona discharge electrode, and 6 is a fixing device including a fixing roller. Reference numeral 7 denotes a first static eliminator including a static eliminator, a static eliminator lamp, etc., which is turned on during the cleaning operation to neutralize the photoconductor 1 and the residual toner after transfer. Reference numeral 8 denotes a cleaning device for cleaning the photoconductor 1, which is a sponge-like member such as a urethane 81, a chloroprene system, etc., which is disposed rotatably and is arranged upstream of the blade 81 in the rotation direction of the photoconductor 1. It has a first cleaning member 83 composed of a toner receiving member 82 composed of a roller. The blade 81 and the toner receiving member 82 are provided so as to be operated (contacted) and deactivated (contact released) with respect to the photoconductor 1, as will be described later with reference to FIGS. 5 and 6. Further, the toner receiving member 82 preferably has a scraper or the like for scraping off the toner attached to the sponge roller. Reference numeral 9 denotes a second static eliminator including a static eliminator, a static eliminator, and the like, which neutralizes the photoconductor 1 before the transfer and the toner forming the toner image after being activated. 10 is a paper feed cassette for accommodating a recording paper Pa as a transfer material, 11 is a paper feed roller for sending out the recording device Pa from the paper feed cassette 10, and 12 is a photoconductor for the recording paper Pa sent out by the paper feed roller 11. A registration roller that feeds the toner to the transfer device 4 in synchronism with the toner image formed on the transfer roller 4. L is an image exposure that illuminates the photoconductor 1 to form a latent image corresponding to the original 14, and the projection light from the original 14 optically scanned by the image exposure lamp 15 is blue for each optical scanning. Color-based filters that are exchanged in the order of red and black
16, an image processing unit which is introduced into an image pickup device 19 via a reflecting mirror 17 and a lens 18 and reads the optical information of a document 14 by photoelectrically converting the image pickup device 19 and then arithmetically processes the optical information. 20 and a laser optical system 13 operated via a storage unit 21 for storing image data from the image processing unit 20.
It is generated by.

2A and 2B are views for explaining the operating state of the cleaning device 8 which is the main part of FIG. 1, and FIG. 2A shows the blade 81.
And the toner receiving member 82 is shown in contact with the photoconductor 1, and FIG. 2B shows the state where the contact is released.

FIG. 5 is a time chart for explaining an example of the operating state of the color copying machine of FIG. 1, in which the number of revolutions of the photoconductor 1 is used as a reference when the photoconductor 1 passes the position where image exposure L is performed. Shows the operating state of the main part expressed as a time axis, blue,
The case where two original images of three primary colors, red and black, are continuously formed is shown.

FIG. 6 shows the operating state of each member operated according to the time chart shown in FIG. 5 such that the portion of the photosensitive member 1 that has reached the position facing the blade 81 of the first cleaning member 83 faces each member. Is a time chart expressed as a time point at which the toner image formed on the photoconductor 1 passes through a position where the toner image formed on the photoconductor 1 faces the blade 81 of the first cleaning member 83. It is represented as a reference time axis.

In FIG. 5 and FIG. 6, the photoconductor 1 is preliminarily rotated by three rotations until the start command number 2 is completed and formation of the document image is stopped, and the photoconductor 1 is formed by the three rotations for forming each document image. The rotation is controlled so that the rotation is performed at a constant speed of 9 rotations. The pre-rotation is controlled to be performed once before and after the image forming process and once during the process of forming the first original image and the process of forming the second original image, respectively. As shown in FIG. The control may be performed only before or after the formation process, or may be performed before or after the formation process of each original image or one of them. The charging device 2 has an earlier time than the time when the photoconductor 1 finishes the preliminary rotation, that is, a time corresponding to a time required for the photoconductor 1 to reach the position of the image exposure L from the position of the charger 2. The operation is controlled to be started, and after charging corresponding to two original images is performed, the operation is stopped. The image exposure L irradiates the photoconductor 1 with the projection light from the brie portion, the red portion, and the black portion of the original document every time the photoconductor 1 rotates once,
The latent images corresponding to the respective parts of the original 14 are controlled to be formed in the same image area. Reference characters a ₁ , b ₁ , c ₁ are latent images corresponding to the blue portion, the red portion, and the black portion of the original 14 in the process of forming the first original image. Similarly, a ₂ , b ₂ and c ₂ are latent images in the process of forming the second original image. In the developing device 3, the photosensitive member 1 is set to 1 in the process of forming each original image.
Each time it rotates, the blue developing device A, the red developing device B, and the black developing device C are actuated in order, and the blue latent images a ₁ , a ₂ and the red latent image are
b _1, b _2, wander latent image c _1, blue toner images A ₁ are sequentially developed c _2, A _2, Retsudotona image B _1, B _2, wander toner image C _1, C ₂
Are sequentially formed, and a three-color toner image is synthesized. Each developing device A, B, C starts its operation after the time required for the photosensitive member 1 to reach the operating position of each developing device from the position where the image exposure L is performed after the image exposure L is started. It is controlled to stop after the time corresponding to the length of the image, that is, the length of the image area has elapsed. The transfer device 4 starts its operation after the black developing device C starts its operation and immediately before the photoreceptor 1 reaches the position of the transfer device 4 from the position of the black developing device C, and the black toner images C ₁ , C It is controlled so that the operation is stopped after the trailing end of the image forming position where ₂ is formed has passed the position of the transfer unit 4. That is, after the black toner images C ₁ and C ₂ are formed and the three-color toner images start to be combined, the transfer device 4 starts to operate when the tip of the three-color toner image reaches the position of the transfer device 4. The operation is stopped after the rear end of the three-color toner image (the position on the photoconductor on which the three-color toner image is formed) has passed the position of the transfer unit 4. In addition, the operation start timing of the transfer device 4 is the same as that of the red toner image.
At any point in time after the trailing ends of B ₁ and B ₂ have passed the position of the transfer unit 4 and before the leading end of the combined three-color toner image reaches the position of the transfer unit 4. Good. The operation of the transfer device 4 is stopped at the time when the rear end of the three-color toner image (the position on the photoconductor on which the three-color toner image is formed) has passed, and in the process of forming the first original image, in the process of forming the next original image. Until the front end of the blue toner image A ₂ reaches the position of the transfer device 4 or in the process of forming the second document image, the process of forming the second document image is completed and the photoreceptor 1 is stopped. while,
It may be at any time, but it is preferable that it is immediately after the trailing edge of each three-color toner image has passed.

The timing when the toner image on the photoconductor passes (opposes) the cleaning blade is shown. 6, 7 and 9
As shown particularly in FIGS. 10 and 11, the blade 81 and the toner receiving member 82 are released immediately before the tip of the blue toner image comes to a position facing the toner receiving member 82. At the time when the contact operation is performed, immediately after the rear end of the toner image on which the red toner image is formed passes the position facing the blade 81, the tip of the image on which the black toner image is formed (residual toner image after transfer) is It may be any time until just before it comes to the position facing the blade 81. Further, the cleaning blade 81 and the toner receiving member 82, which are in contact with each other in the previous period and are in contact with each other, are released immediately after the trailing edge of the residual toner image has passed and the leading edge of the blue toner image for forming the next image. May be any time as long as the non-image area Y of the photoconductor 1 shown in FIG.

In the above, an example in which the blade 81 and the toner receiving member 82 are activated and deactivated at substantially the same time has been shown, but the present invention is not limited to this, and the point is that the front end of the first toner image passes just before the blade 81. The blade 81 does not come into contact with the toner receiving member 82 from the end of the first toner image until the rear end of the toner image immediately before the toner image formed last passes. It is only necessary that the toner receiving member 82 does not come into contact with the toner image immediately before passing through the receiving member 82 until the trailing edge of the toner image immediately before the toner image formed last passes.

The color copying machine shown in FIG. 1 is constructed as shown in the above respective drawings, and the blue toner image is made every one rotation of the photoconductor 1 in accordance with the time charts shown in FIGS. 5 and 6. , A red toner image and a black toner image are sequentially developed to synthesize a three-color toner image corresponding to the original 14 on the photoconductor 1, and then the three-color toner image is transferred to the recording paper Pa to form a three-color original image. After forming and transferring, the first cleaning member 83 is brought into contact with the photoconductor 1 to remove the residual toner adhering to the photoconductor 1 to clean the photoconductor 1. By making contact and contact release in the non-image area, it is possible to prevent the toner adhering to the photoconductor 1 from remaining in the image area at the time of contact release. In the following,
The operation of forming the original image and the cleaning operation of the photoconductor 1 will be described.

When a copy start switch (not shown) is turned on and a start command is issued, the photoconductor 1 starts rotating. The first rotation of the photoconductor 1 is preliminary rotation, and is cleaned by the first cleaning member 83 which is in contact with the photosensitive member 1 from the beginning.
Immediately before the photoconductor 1 finishes the preliminary rotation, the charger 2 starts to operate, and the cleaned photoconductor 1 is continuously and uniformly charged. When the photoconductor 1 finishes the preliminary rotation and enters the second rotation, the tip of the charged portion reaches the position where the image exposure L is performed, and the projection light from the document 14 is emitted by the laser optical system 13.
The photoconductor 1 is irradiated as image exposure L via the. The image exposure L is obtained by introducing the projection light into the image pickup device 19 through the color filter 16 which is controlled corresponding to the blue color of the original 14, and corresponds to the blue portion of the original 14. The photoreceptor 1 is irradiated as image exposure to form a blue latent image a ₁ . When the tip of the blue latent image a ₁ reaches the operating position of the blue developing device A, the blue developing device A starts to operate, the blue latent image a ₁ is developed, and the blue toner image A ₁ is formed. The second discharger 9 starts to operate when the tip of the blue toner image A ₁ reaches the operating position of the second discharging device 9, the photosensitive member 1, including the blue toner image A ₁ is neutralizing. Blue toner image A ₁
Of the blade 81 of the first cleaning member 83 after passing through the operating position of the transfer device 4 controlled in the non-operating state.
The first cleaning member 83 is released from contact immediately before reaching the position facing the toner receiving member 82, that is, when reaching the position substantially facing the toner receiving member 82. That is, in the first cleaning member 83, the rear end of the non-image area is substantially the toner receiving member.
Since the contact with the photoconductor 1 is released when it reaches the position opposed to 82, the blue toner image A ₁ is not rubbed by the first cleaning member 83 and is not disturbed. It passes through a position facing the member 83. Further, at that time, toner is accumulated between the edge portion of the blade 81 of the first cleaning member and the photoconductor 1, or the toner scraped off by the blade 81 is removed by the blade 81.
Even if the toner is adhered to the portion of the photoconductor 1 between the toner receiving member 82 and the toner receiving member 82, the toner is attached in the non-image area of the photoconductor 1 in the image forming process of the second original image. Fogging caused by the toners is prevented. Although the photosensitive member 1 is charged continuously at all times, after the blue toner image A ₁ has passed the position opposed to the first cleaning member 83 is charged, including the blue toner images A _1, blue toner images A ₁ 2 reaches the position where the tip of the
Enter the turning eye. When the photosensitive member 1 enters the third rotation, the image exposure L corresponding to the red portion of the original 14 is irradiated, and the red latent image b ₁ is formed in conformity with the image area of the blue toner image A ₁ . The red latent image b ₁ is developed by the red developing device B ₁ in the same manner as in the case of the blue latent image a ₁ to obtain the red toner image.
Formed on B ₁ . At this time, the red toner image B ₁ is combined with the blue toner image A ₁ previously formed, and a two-color toner image of blue and red is formed on the photoconductor 1.
Since the transfer device 4 is controlled to the non-operating state and the contact of the first cleaning member 83 is released, the two-color toner image sequentially passes through the position facing the transfer portion 4 and the first cleaning member 83. Then, as in the case of the blue toner image A ₁ , it is charged by the charging device 2, the tip of the two-color toner image reaches the position where the image exposure L is performed, and the photoconductor 1 enters the fourth rotation. When the photosensitive member 1 enters the fourth rotation, the image exposure L corresponding to the black portion of the original 14 is irradiated, and the black latent image c ₁ is formed in conformity with the image area of the two-color toner image. The black latent image c ₁ is developed by the black developing device C,
The black toner image C ₁ is formed. At that time, the black toner image is added to the blue and red two-color toner images previously formed.
C ₁ is synthesized, and a three-color toner image of blue, red, and black is formed on the photoconductor 1. The three-color toner image is discharged by the second discharging device 9 before being transferred, and then moved to a position facing the transfer device 4. The transfer device 4 starts its operation when the tip of the three-color toner image reaches the opposite position, and the recording paper Pa is fed by the registration roller 12 in synchronization with the three-color toner image. The color toner image is transferred onto the recording paper Pa. The recording paper Pa on which the multicolor original image is formed by transferring the three-color toner images is separated by the separator 5
After being separated from the photoconductor 1 by means of, the paper is fed to the fixing device 6 and fixed. On the other hand, the photoconductor 1 after the recording paper Pa is separated is further rotated, and is discharged by the first charge removing device 7 and then cleaned by the cleaning device 8.
The first cleaning member 83 of the cleaning device 8 is used when the front end of the transferred three-color toner image reaches the position facing the blade 81, that is, when the rear end of the non-image area reaches the position facing the blade 81. Alternatively, when the rear end of the two-color toner image, that is, the front end of the non-image area reaches the position facing the blade 81, the photoconductor 1 is contacted, but the upstream side of the first cleaning member 83 in the rotation direction of the photoconductor 1. The first static eliminator 7 provided in the above section starts its operation quickly to neutralize the photoconductor 1 and the transferred three-color toner image, and the blade 81 removes the residual toner forming the three-color toner image after the transfer. Then, the photoreceptor 1 is cleaned. The scraped off toner adheres to and is collected by the toner receiving member 82, which is a sponge-like roller that is rotated by being contacted with the photoconductor 1. The first cleaning member 83 performs a preliminary rotation for one rotation after the photosensitive member 1 has completed the fourth rotation, and enters the sixth rotation to enter the blue toner image A which is the first toner image in the process of forming the second original image. _{before second} leading edge reaches a position facing the blade 81, i.e. when the tip of the blue toner image a ₂ reaches the approximately opposite positions with a member 82 receives the toner,
Since it is in contact with the photoconductor up to at least 1
Since the rubbing is performed for more than the circumference, all the residual toner can be scraped off. While the first original image is formed and the photoconductor is cleaned as described above, the second original image is also formed in the same manner and the photoconductor 1 is similarly cleaned. That is, the red toner image B ₂ is formed when the photosensitive member 1 enters the 7th rotation, and the black toner C ₂ is formed when the photosensitive member 1 enters the 8th rotation, and the three-color toner image corresponding to the original 14 is synthesized. Then, the three-color toner image is transferred, and the second original image is formed on the recording paper Pa. On the other hand, when the front end of the three-color toner image after transfer or the rear end of the two-color toner image reaches the position facing the blade 81 of the first cleaning member 83, the first cleaning member 83 comes into contact with the photoconductor 1 and the photoconductor 1 The residual toner adhering to the portion of the three-color toner image of No. 1 is scraped off by the blade 81. The photosensitive member 1 enters the 9th rotation and completes one preliminary rotation and is stopped. During that time, the first cleaning member 83 is in contact with the photosensitive member 1, so that the photosensitive member 1 has at least one revolution. As described above, since the first cleaning member 83 is rubbed, all the residual toner is scraped off.

As described above, the color copying machine shown in FIG. 1 is controlled so as to operate in accordance with the time charts shown in FIGS. 5 and 6, and the three-color toner image corresponding to the original is formed on the photoconductor 1. And a three-color original image is formed by transferring them onto the recording paper Pa by one transfer,
The original image is formed as a clear image without color misregistration, and does not require a complicated transfer material conveying device. Further, in the applied cleaning device 8, the three-color toner image corresponding to the original is combined, and the first cleaning member 83 is released from contact with the photoconductor 1 until the three-color toner image is transferred. It is possible to remove the residual toner adhering to the photoconductor 1 after transfer without disturbing the image of each color toner image in the forming process. Further, since the first cleaning member 83 is released from contact in the non-image area, the first cleaning member 83 is released.
Toner is accumulated between the edge portion of the blade 81 of 83 and the photoreceptor 1, or the toner scraped off by the blade 81 is a portion of the photoreceptor 1 between the blade 81 and the toner receiving member 82. Even if they adhere to each other, the respective toners are adhered in the non-image area of the photoconductor 1, and the occurrence of fogging or the like due to the respective toners is prevented in the image forming process of the second original image.

In the color copying machine shown in FIG. 1, the cleaning device can achieve the object of the present invention as described above, but the charging device 2, the transfer device 4, the separator 5 and the like are contaminated by residual toner and the developing device. In order to suppress the deterioration of the performance of the peripheral device of the photoconductor 1 such as the color mixture due to the residual toner of the developing devices A, B and C of No. 3, the toner is not attached to the photoconductor 1 even in the non-image area. Preferably, the cleaning device is 3A
As shown in FIGS. 3B, a second cleaning member is provided on the downstream side of the first cleaning member 83 in the rotation direction of the photoconductor 1, and each cleaning member has, for example, FIGS. 3C and 7C.
It is preferable that it is operated as shown in the figure and is configured to remove the toner retained by the first cleaning member that passes when the contact of the first cleaning member is released.

The cleaning device will be described with reference to FIGS. 3A, 3B, 3C and 7. Figures 3A and 3B show
FIG. 3 is a diagram showing an operating state of the cleaning device corresponding to FIGS. 2A and 2B. FIG. 3C is a diagram for schematically explaining the process of the operation of the cleaning device. FIG. 3 (1) shows the state immediately before the contact of the first cleaning member 83 is released, and FIG.
A state immediately after the cleaning member 84 is contacted, (3) FIG. 3 is a state immediately after the second cleaning member 84 is released from the contact,
FIG. 4 (4) is a diagram for explaining a state immediately after contact with the first cleaning member 83 in order to remove residual toner adhering to the photoconductor 1 after transfer. FIG. 7 is a time chart showing the operating state of the cleaning device corresponding to FIG. In each drawing, the same reference numerals in FIGS. 2A, 2B and 6 indicate the same functional members. In FIGS. 3A and 3B, reference numeral 84 denotes a second cleaning member, which is arranged on the downstream side of the blade 81 of the first cleaning member 83 in the rotation direction of the photoconductor 1 and is rotationally driven in the direction opposite to the photoconductor 1. It is composed of a sponge roller such as urethane type or chlorobrene type. 85 is the second cleaning member
A scraper for scraping off the toner adhering to 84 and 86 is a toner guide member for guiding the toner scraped off by the scraper 85. The second cleaning member 84 is operated in association with the first cleaning member 83 as shown in FIGS. 3C and 7, and the first cleaning member 83 releases the contact with the completion of the process of the rear end R of the image portion. Further, the contact of the second cleaning member 84 is made before the surface of the photoconductor 1 which the blade 81 was in contact with at the time of the release reaches the position opposite to the second cleaning member 84 ((1) to (3) in FIG. 3C). 2)), and when the first cleaning member is released, the toner receiving member 82 faces the surface of the photoconductor 1 or the front end F of the image portion is the second.
It is controlled so that the contact of the second cleaning member 84 is released before the position of the cleaning member 84 is reached ((3) in FIG. 3C). In the figure, X indicates an image area where each toner image is formed. In FIG. 7, ~ indicates the time points corresponding to the states shown in the drawing numbers (1) to (4) of FIG. 3C. Since the cleaning device is configured as described above, it is operated as follows in the process of image formation according to the time chart shown in FIG. The photoconductor 1 starts to rotate, and the front end of the non-image area Y adjacent to the front end of the blue toner image A _{1 in} the process of forming the first original image faces the blade 81 as shown in FIG. 3C (1). The first cleaning member 83 is in contact with the second cleaning member 84 and the second cleaning member 84 is in contact with the second cleaning member 84 until the second cleaning member 84 is reached. Immediately after the tip of the non-image area Y reaches a position facing the blade 81, the first cleaning member 83 is released from contact, but
The cleaning member 84 is still in the contact released state.
Immediately before the portion reaching the position facing the blade 81 when the contact of the first cleaning member 83 is released reaches the position facing the second cleaning member 84, as shown in FIG. 3C (2), The two cleaning members 84 are contacted. Next, as shown in FIG. 3C (3), when the portion of the first cleaning member 83 that has reached the position facing the toner receiving member 82 when the contact is released, reaches the position that faces the second cleaning member 84. Second cleaning member 84
Is released from contact. The rear end of the non-image area Y, that is, the front end of the blue toner image A ₁ is located at the first cleaning member 83 and the second cleaning member 83.
When the cleaning members 84 and 84 reach the positions facing the respective cleaning members 84, the cleaning members 83 and 84 have been released from contact, and the red toner image B ₁ and the black toner image C _{1 on the} photoconductor 1 are released.
Are sequentially formed to synthesize a three-color toner image, and the front end of the non-image area Y adjacent to the rear end of the red toner image B ₁ is a blade of the first cleaning member 83 as shown in FIG. 3C (4).
The first cleaning member 83 is released from contact until it contacts again immediately after reaching the position facing 81. After the first cleaning member 83 is contacted again as shown in FIG. 3C (4), the three-color toner image forming position after transfer is opposed to the first cleaning member 83 while being rubbed against the first cleaning member 83. After the photoconductor 1 has passed through the position and has undergone one preliminary rotation, the process of forming the second original image is started, but the tip of the non-image area Y adjacent to the tip of the blue toner image A ₂ becomes the blade 81. Immediately after reaching the opposite position, the first
The cleaning member 83 is released from contact, and thereafter, the cleaning members 83 and 84 are brought into contact with each other and released from contact in the same manner as described above.

As described above, since the cleaning members 83 and 84 are released from contact when the toner image during the process of forming the original image passes through the positions facing the cleaning members, the image of the toner image is disturbed. In this case, the residual toner can be removed because the three-color toner image forming position after the transfer is in contact with the three-color toner image forming position after the transfer. Although the residual toner is removed by the first cleaning member 83, the toner or blade 81 accumulated between the edge portion of the blade 81 and the photoconductor 1 when the contact of the first cleaning member 83 is released.
Even if the toner adhered to the portion of the photoconductor 1 between the toner receiving member 82 and the toner receiving member 82 passes through the blade 81, it can be removed by the second cleaning member 84, so that the photoconductor 1 is sufficiently Can be cleaned. Also,
When the second cleaning member 84 is released from contact, the photoconductor 1
Although toner may adhere to the surface of the second cleaning member 84 in a very small amount, the second cleaning member 84 is released from contact with the non-image area, so that the formed original image hardly causes fogging or the like.

As a result of an experiment of the cleaning device shown in FIGS. 3A and 3B using an actual machine, the following good results were obtained.

<Specifications of the main part of the actual color copier> Photoconductor: OPC with a diameter of 140 mm, that is, about 440 mm in length First cleaning member: 2 mm thick urethane rubber blade and 14 mm diameter urethane sponge roller It is composed of a toner receiving member and the distance between them is set to 16 mm.

Second cleaning member: Urethane sponge roller with 14 mm diameter Original size: B4 plate <Experimental conditions and experimental results> The photoconductor is rotated at a peripheral speed of 60 mm / s, and three colors of blue, red and black toner are sequentially applied. It was developed to form a three color original image. At this time, the non-image area adjacent to the rear end of the three-color toner image forming position after the transfer is about 76 mm, and the first cleaning member is removed immediately after the front end reaches a position facing the blade of the first cleaning member. When the contact was released, toner adhered to the upstream side of the non-image area about 20 mm upstream over the length of about 25 mm in the rotation direction of the photoconductor. The second cleaning member is contacted with a contact load of 200 g when the tip of the non-image area reaches a position facing the second cleaning member, and is rotated at 40 rpm in the direction opposite to the photoconductor, and then released after 1.2 seconds. did. As a result, the toner adhering to the photoconductor was almost completely removed. In addition, when releasing the contact of the second cleaning member, subtle toner adhesion was recognized on the portion of the photoconductor that was in contact with the second cleaning member. However, the above-mentioned portion of the photoconductor is a non-image area portion, the original image obtained by the next copying operation is good, and no influence of the toner is recognized.

3A and 3B, the scraper 85 and the toner guide member 86 are preferably elastic members such as mylar and phosphor bronze plate. The second cleaning member 84 may be a fur brush having a scraper, a magnetic brush, or the like. Further, it may have a means for removing the residual toner without being brought into contact with the photoconductor 1, for example, a means for sucking the residual toner by a suction force. By performing the operation and the suction stop operation, the photoconductor 1 can be cleaned as described above.

In the color copying machine shown in FIG. 1, the toner receiving member 82 of the first cleaning member 83 is a sponge roller, and the toner scraped off by the blade 81 can be collected without damaging the photoconductor 1. Although it is possible, it may be a sheet-shaped toner receiving member which is always arranged in a non-contact state with the photoconductor 1. The first cleaning member may be a brush such as a fur brush 81 'having a scraper 87 as shown in FIGS. 4A and 4B, a magnetic brush or the like. When using these, the toner receiving member is omitted. Good. The means for generating the image exposure L may be a slit exposure optical system. Although the three-color toner image formed on the photoconductor 1 is directly transferred to the recording paper, it may be indirectly transferred by using an intermediate transfer material. In the image forming process, latent image formation and development are repeated as shown in FIG. 12B according to the time charts shown in FIGS. 5 and 6 to synthesize a three-color toner image on the photoconductor 1, Although it is controlled to transfer the three-color toner image to the transfer material, the latent image is formed once as shown in FIG. 12C, and thereafter, each time the photoconductor 1 makes one rotation, it is developed with a different color toner. In the same manner as described above, after the three-color toner image is synthesized on the photoconductor 1, the three-color toner image may be controlled to be transferred to the transfer material.

When two original images are continuously formed, the color copying machine shown in FIG. 1 continuously and without pre-rotating the photosensitive member 1 in the middle of the process of forming each original image as shown in FIG. Although it has been described that the image forming apparatus may be controlled so as to form an image, the operating state of the cleaning device at that time will be described with reference to FIGS. 8 to 10. FIGS. 8, 9 and 10 are views corresponding to FIGS. 5, 6 and 7, respectively.
The same reference numerals indicate the same functional members. The residual toner attached to the photoconductor 1 after the first original image is formed is
Cleaning member 83 and / or second cleaning member
It is removed by bringing 84 into contact with the photoreceptor 1, and its operation is as follows. The first cleaning member 83 and / or the second cleaning member 84 are arranged so that the blue toner image corresponding to the second original image is generated immediately after the trailing edge of the red toner image B ₁ corresponding to the first original image passes through the positions facing each other. It is controlled so that it is contacted before the tip of A ₂ reaches. That is, each cleaning member 83, 84
Means that the non-image areas adjacent to the trailing edge of the red toner image B ₁ corresponding to the first original image and the leading edge of the transferred three-color toner image corresponding to the first original image pass through the positions facing each other. So that the non-image areas adjacent to the trailing edge of the three-color toner image and the leading edge of the blue toner image A ₂ corresponding to the second original image are released while passing through the positions facing each other. Is set to. Therefore, the residual toner is scraped off by the first cleaning member 83, and the scraped toner after the contact of the first cleaning member 83 is released is the one that is still attached to the photoconductor 1. 2 removed by the cleaning member 84. The second cleaning member 84 may be controlled so as to be activated and deactivated for each non-image area, as shown in FIG.

As described above, the embodiment of the present invention has been described with respect to the color copying machine for forming a three-color original image. However, even in the case of two or more colors or a single color, the development can be performed plural times while the image forming body is rotated plural times. It goes without saying that the cleaning device can also be applied to the image forming apparatus.

(Effect of the Invention) As described in the embodiment, the cleaning device of the present invention is deactivated for the image forming body until the toner image corresponding to the original is synthesized and the toner image is transferred. By so controlling, the image of each toner image in the image forming process is not disturbed, and the residual toner adhering to the image forming body after the transfer can be removed. Image formation in which a toner image is formed on an image forming body by sequentially developing a plurality of toner images during a plurality of rotations, and then the combined toner image is transferred to a transfer material to form a document image. It can be applied to a device. Further, in the cleaning device, since the cleaning member is deactivated in the non-image area of the image forming body, toner adheres to the portion of the image forming body where the cleaning member is operating when the cleaning member is deactivated. In that case, the portion of the image forming body is the portion of the non-image area, which does not cause any trouble in image formation.

[Brief description of drawings]

FIG. 1 is an explanatory view of a color copying machine for explaining an embodiment of the present invention, FIGS. 2A and 2B are views for explaining the operation of a cleaning device which is a main part of FIG. 1, FIG. 3A and Third B
FIG. 4 is a diagram for explaining another example corresponding to FIGS. 2A and 2B, FIG. 3C is an explanatory diagram of the operating process of the cleaning device shown in FIGS. 3A and 3B, and FIGS. 4A and 4B. FIGS. 5A and 5B are diagrams for explaining still another example corresponding to FIGS. 2A and 2B, FIG. 5 is a time chart for explaining the operating state of the color copying machine shown in FIG. 1, and FIG. 6 is for FIG. A time chart showing the main part on another reference time axis, Fig. 7 is Fig. 3A,
A time chart corresponding to FIG. 6 when the cleaning device shown in FIGS. 3B and 3C is used, and FIGS. 8 to 10 are views for explaining another operating state of the color copying machine shown in FIG. Time chart corresponding to FIGS. 7 to 7, FIG. 11 is a time chart showing a modification of that shown in FIG. 9, and FIG.
12A to 12C are flow charts for explaining the image forming process of the conventional color copying machine. 1 ... photoreceptor, 2 ... charging device, 3 ... developing device, 4 ... transfer device, 8 ... cleaning device, 81 ... blade, 82 ... toner receiving member, 83 ... first cleaning member, a ₁ , a ₂ ...... Blue latent image, b ₁ , b ₂ ...... Red latent image, c ₁ , c ₂ ...... Black latent image, A ₁ , A ₂ ...... Blue toner image, B ₁ , B ₂ … ... Red toner image, C ₁ , C ₂ ... Black toner image, X ... image area, Y ... non-image area.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shinobu Soma 2970 Ishikawa-cho, Hachioji City, Tokyo Satoshi Hirai (56) References, Satoshi Hirai (56) Japanese Patent Laid-Open No. 60-156084 (JP, A)

Claims (3)

[Claims] 1. An image in which a plurality of toner images are formed and combined on the outer periphery while an image forming body having a margin for producing a non-image area on the outer periphery is rotated a plurality of times, and the composite toner image is transferred to a transfer material. In the forming apparatus, a cleaning unit that is deactivated while an image area having a toner image other than the last toner image among the plurality of toner images passes and is activated while an image area to which the composite toner image is transferred passes. The cleaning device is characterized in that the switching operation between the operation of the image forming body and the operation release thereof is performed during the passage of the non-image area. 2. The image which the cleaning means comprises a first cleaning member on the upstream side in the rotational direction of the image forming body and a second cleaning member on the downstream side, and the image was in contact when the first cleaning member was deactivated. The position of the forming body surface is second
The cleaning according to claim 1, wherein the second cleaning member is switched from the deactivated state to the activated state before reaching the position of the cleaning member, and is returned to the deactivated state after the position of the image forming body surface has passed. apparatus. 3. The first cleaning member comprises a cleaning blade, and the second cleaning member comprises a sponge-like roller which is driven in contact with the surface of the image forming body to rotate in the opposite direction. The cleaning device according to the second section.