JPH02287481A - Multicolor image recording device - Google Patents

Abstract

PURPOSE:To improve the cleaning reliability and to prolong the life of a photosensitive body by providing a fur brush cleaning device in the downstream side in the moving direction of the photosensitive body of a blade cleaning device and selecting and using each cleaning device. CONSTITUTION:After a toner image is transferred, the residual toner on the photosensitive body 1 is scraped down by pressing a blade 13 on the photosensitive body 1 by a device for moving and separating such as a plunger and is recovered to a recovering part by a toner carrying roll 18. Then, the fur brush roll 14 is pressed on the photosensitive body 1 by the device for moving and separating such as a plunger. The fur brush roll 14 and a recovering roll 15 are rotated and slide over the surface of the photosensitive body 1 in order to remove the toner on the photosensitive body 1. Here, when the fur brush roll 14 comes into contact with the photosensitive body 1, the blade 13 is released. In this way, the cleaning of the photosensitive body 1 can be surely performed by selectively using the blade cleaning and/or the fur brush cleaning.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a multicolor image recording device using an electrophotographic method, more specifically, a multicolor image recording device that forms a multicolor image on an electrophotographic photoreceptor and then transfers it all at once to a transfer paper. The present invention relates to a multicolor image recording apparatus that cleans residual toner on a photoreceptor after transfer.

Conventional technology Traditionally, charging, exposure, and development are repeated multiple times to form multiple toner images of different colors on an electrophotographic photoreceptor (hereinafter referred to as photoreceptor), and then the toner images are transferred all at once to paper. Various color electrophotographic techniques for obtaining color images have been proposed.

For example, color electrophotography technology described in Japanese Patent Publication No. 0-95458 is one of them.

This configuration is shown in FIG. In Fig. 3, 1 is a photoconductor rotating in the direction of the arrow, 2 is a corona charger that charges the photoconductor 1, 3 is a laser beam scanner, and 4 to 7 are yellow (Y), magenta (M), and cyan ( C), black (B
8 is a recording paper; 9 is a transfer charger for transferring the toner image onto the recording paper; 10 is a remover for erasing the electrostatic latent image on the photoreceptor 1; 11 is a cleaning device for removing toner remaining on the photoreceptor 1 of the toner transfer device; 12 is a heat fixing device;

Next, the operation when forming a color image using this color electrophotographic apparatus will be explained. First, corona charger 2
After charging the photoreceptor 1, a laser beam scanner 3 scans and exposes a yellow image signal, and the image area is exposed to form an electrostatic latent image in which the surface potential of the photoreceptor 1 is attenuated. This electrostatic latent image is reversely developed with a toner carrier 4 containing Y toner to form a yellow toner image on the photoreceptor 1. At this time, the toner carrier 4 containing the Y toner
A developing bias is applied to , but the other toner carriers 5 to 7 are grounded and adjusted to prevent toner from flying away. After developing with the Y toner, the entire surface of the photoreceptor 1 is neutralized using a static eliminator 10. Next, in the same manner as the method used to form the Y toner image, the steps of charging, exposing, and developing the static electricity removal process are repeated to form M, C, and BK toner images on the photoreceptor 1 on top of the Y toner image. Form sequentially. After all toner images have been formed, a transfer charger 9 electrostatically transfers the toner images onto the recording paper 8. The toner image transferred to the recording paper 8 is fixed by a heat fixing device 12. After the transfer, the blade 13 of the cleaning device 11 is pressed against the photoreceptor 1 to remove the toner remaining on the photoreceptor 1, and then the blade 13 is separated from the photoreceptor 1 again and the photoreceptor 1 is used for the next image formation.

In such a multicolor image recording apparatus, the configuration of the cleaning device 11 is important.

That is, the cleaning device 11 is separated from the photoreceptor 1 from the first image formation until the last image is formed and transferred.
After the transfer, it is necessary to contact the photoreceptor 1 to reliably remove the toner.

Blade cleaning and fur brush cleaning are known as cleaning techniques.

In blade cleaning, the edge of an elastic blade 13 made of urethane rubber or the like is pressed against the photoreceptor 1 using a general cleaning technique as shown in FIG. 3 to remove toner remaining on the surface of the photoreceptor 1 after transfer. It is something.

In addition, fur brush cleaning can be done, for example, in JP-A-57
There is one shown in Japanese Patent No.-185488. Its configuration is shown in FIG. A fur brush roller 4 flocked with conductive fibers is brought into contact with the photoconductor 1, and a conductive collection roller 15 is brought into contact with this fur brush roller 14 and rotated in the counter direction at each contact portion. One end of a scraping plate 16 made of an elastic material is brought into contact with the fur brush roller 14 and the collection roller 15, and a voltage of opposite polarity to that of the toner is applied to each of the fur brush rollers 14 and collection rollers 15. This fur brush cleaning
After the transfer, the toner remaining on the photoconductor 1 is transferred to the fur brush 14 by a mechanical wiping action and an electric field, and further transferred to the collection roller 15 by the electric field, and the toner adhering to the collection roller 15 is scraped off by the scraping plate 16. It is collected by scraping it off.

Problems to be Solved by the Invention However, the multicolor image recording apparatus using such a leaning device has the following problems.

When color prints are continuously made using a color electrophotographic apparatus configured as shown in FIG. 3 using a blade cleaning device, the toner carriers 4 to 7 become contaminated with different types of toner in proportion to the number of prints, and the image quality gradually deteriorates. There was a problem that color purity decreased.

The cause of this is that the blade 13 is in pressure contact with the photoreceptor 1 and the photoreceptor 1
While the toner on the top is being cleaned and collected, a toner lump with a thickness of about 21 cm and a width of 5 cm is generated at the tip of the blade 13, and an image is formed every time the photoreceptor 1 rotates, resulting in a multicolor image. When recording a multicolor image to form on the photoreceptor 1, the blade 13
is separated from the photoconductor 1, but at this time, the toner lump at the tip of the blade remains in a linear shape on the photoconductor 1, and is carried to the toner carriers 4 to 7 by the rotation of the photoconductor 1, and is transferred to the toner carrier 1. 4 to 7, causing color turbidity.

Further, blade cleaning causes scratches on the surface of the photoreceptor 1 due to friction with the blade 13, which adversely affects the life of the photoreceptor 1 and images.

Further, in the fur brush cleaning device as shown in FIG. 4, there is a problem in that when the amount of toner remaining on the photoreceptor 1 increases, cleaning residue is generated.

For example, in a multicolor image recording device that uses many types of toner, the amount of toner that adheres to the photoreceptor 1 is larger than in a black and white monochrome image recording device, and the amount of toner that remains after transfer is also large. It was difficult to completely remove the particles using the roller 14.

In addition, especially when a paper jam or the like occurs and the image is not transferred to the recording paper 8, a large amount of untransferred toner remains on the photoreceptor 1 and the toner accumulates in the fur brush roller 14 in an oversaturated state, causing clogging. You may not be able to perform thorough cleaning,
On the other hand, under high humidity environmental conditions, the resistance of the fur brush decreases and the toner adsorption force decreases, causing toner to remain on the photoreceptor l, which adversely affects subsequent recording.

An object of the present invention is to provide a plurality of cleaning means and select one according to the recording conditions, thereby recording a stable image with no residual toner, without being affected by the amount of toner remaining on the photoreceptor. The object of the present invention is to provide a multicolor image recording device that is capable of recording images in multiple colors.

Means for Solving the Problems The technical means of the present invention for solving the above-mentioned problems is to use an elastic body that linearly contacts the surface of the photoconductor in the axial direction and removes toner remaining on the photoconductor after transfer. a first cleaning means consisting of a cleaning blade, and a second cleaning means consisting of an electrically conductive fur brush roller that contacts parallel to the axial direction of the photoconductor and rotates in the opposite direction on the downstream side of the cleaning blade.
a cleaning means, a first contact/separation means for bringing the cleaning blade into contact with and away from the photoreceptor, a second contact/separation means for bringing the fur brush roller into contact with and away from the photoreceptor, and a voltage application for applying voltage to the fur brush roller. and means for differentiating the operation timings of the first cleaning means and the second cleaning means, as well as means for identifying the mode of the toner image formed on the photoreceptor, and depending on the identification of the identifying means, the mode of the toner image formed on the photoconductor is determined. The cleaning means is selectively operated.

For production The effects of the present invention are as follows.

(1) The toner remaining on the photoreceptor is scraped off by the blade of the first cleaning means provided on the upstream side, and the linear toner/clumps remaining when the blade is separated is removed by the conductivity of the second cleaning means provided on the downstream side. By removing the toner with a fur brush roller, the cleaning characteristics of the toner remaining on the photoreceptor can be significantly improved.

(2) By distinguishing between the recording modes of single-color recording and multi-color recording, blade cleaning and fur brush cleaning are used together during multi-color recording, and fur brush cleaning is operated during single-color recording, thereby extending the life of the photoreceptor. , costs can be reduced.

Example The present invention will be explained below based on one embodiment.

The overall configuration of the multicolor image recording apparatus is the same as that shown in FIG. 3 in the conventional example, except for the cleaning device 11, and will not be described in this section.

Next, the detailed configuration of the cleaning device will be explained using FIG. 1. First, the first cleaning device will be explained. The configuration of this device is almost the same as the configuration shown in FIG. 13 is a blade made of elastic material such as rubber; 17
1 is a support for supporting the blade 13 in parallel with the photoreceptor 1;
Reference numeral 8 denotes toner conveying rollers that convey the toner written off by the blade 13 in the axial direction of the photoreceptor 1 to a collection section (not shown), and are supported by the unit main body 19, respectively. The blade support 17 is driven toward and away from the photoreceptor 1 by a well-known driving source such as a plunger so that the leading edge of the blade 13 is pressed against and separated from the photoreceptor 1. Next, the second cleaning device will be described.

This configuration is almost the same as the configuration of the conventional example shown in FIG. 14 is a conductive fur brush roller provided parallel to the axial direction of the photoreceptor 1, and is made of, for example, acrylic fiber in which carbon black is dispersed, conductive polymer compound, carbon fiber, metal fiber, etc., and has a specific resistance value of 107 to 14. 10120c
It is a cylindrical rotating body in which conductive fibers in the range of m are implanted around the outer periphery of a metal roller.

In this fur brush roller 14, the blade 13 is attached to the photoreceptor 1.
The photoreceptor is located downstream in the direction of movement of the photoreceptor from the position where it contacts the photoreceptor. 15 is a conductive collection roller made of metal or the like that is in contact with the fur brush roller 14 in parallel; 16
has one end in contact with the outer peripheral surface of the collection roller 15, and the collection roller 1
5 is a scraping plate made of an elastic material for scraping off toner adhering to the collection roller; 20 is a toner transport roller that transports the toner scraped off from the collection roller in the axial direction of the photoreceptor and guides it to a collection section (not shown); . The fur brush roller 14, collection roller 15, and toner transport roller 20 are each rotatably supported by a unit body 21. A DC bias voltage V having a polarity opposite to that of the charged polarity of the toner is applied to the fur brush roller 14, and a DC bias voltage V2 having the same polarity as that of the fur brush roller 14 is applied to the collection roller 15. For example, when the toner is of positive polarity, the bias voltage to be applied is a negative polarity voltage of N Vl>Va
It is set to have a potential difference of 200 to 500 V in the direction of .

The second cleaning unit main body 21 is driven toward and away from the photoreceptor 1 by a known drive source such as a plunger so as to press the fur brush roller 14 away from the photoreceptor 1 . The fur brush roller 14 and the collection roller 15 rotate in the same direction and in the opposite direction to the photoconductor 1, and the rotational speeds of the fur brush roller 14 and the collection roller 15 are the same as that of the photoconductor, the fur brush roller, and the collection roller. It is set so that

Next, the operation when recording an image with the image recording apparatus having such a configuration will be explained using FIG. 2.

When recording an image, the recording mode of multicolor or monochrome is set by input operation.

First, in the multicolor image recording mode, charging, exposure, and development are repeated n times for each rotation of the photoreceptor 1, and electrostatic latent images corresponding to each color are formed, and each toner carrier 4
to 7 to form a multicolor toner image on the photoreceptor 1. After the toner image has been transferred to the recording paper 8 by the transfer charger 9, the toner remaining on the photoconductor 1 is scraped off by the blade 13 being pressed against the photoconductor 1 by a separation drive source such as a plunger, and the toner is scraped off by the toner conveying roller. At 18, it is collected by the collection unit. When the cleaning operation of approximately one rotation of the photoreceptor 1 is completed, the fur brush roller 14 is pressed against the photoreceptor 1 by a separation driving source such as a plunger. Then, the fur brush roller 14 and collection roller 15 rotate to rub the surface of the photoreceptor 1, and the toner on the photoreceptor 1 is removed.

When the fur brush roller 14 comes into contact with the photoreceptor 1, the blade 13 is released. The toner deposited on the blade edge adheres to the photoreceptor 1 when the blade is separated, but is electrostatically attracted to the fur brush. The toner adsorbed by the fur brush is electrostatically adsorbed from the fur brush roller 14 to the collection roller 15, scraped off by the scraping plate 16, and collected by the toner transport roller 20 to the collection section.

After the fur brush roller 14 is separated, the photoreceptor 1 moves approximately 1
/2 rotations, the detachment drive source for fur brush cleaning is released, the entire unit moves away from the photoreceptor 1, the fur brush roller 14 separates from the photoreceptor 1, the cleaning is completed, and the photoreceptor 1 is ready for the next recording. .

Next, the monochrome image recording mode will be explained.

To record a monochrome image, the toner carriers 4 to 7 containing toner of the desired color are selected from among the plurality of toner carriers 4 to 7, and the image is recorded in a single process of charging, exposing, developing, and transferring. The image is transferred onto paper 8 and recorded via a fixing device. The toner remaining after the transfer is scraped off by the fur brush roller 14 pressed against the photoreceptor 1 by the operation of the second fur brush cleaning separation drive source. At this time, the first blade cleaning separation drive source is released,
The blade 13 is not in contact with the photoreceptor 1.

For example, if the recording paper 8 jams and toner is not transferred, when removing the recording paper and restarting the device, blade cleaning and fur brushing are necessary, regardless of the image recording mode at the time of paper jam. By using cleaning together, the photoreceptor 1 can be reliably cleaned.

Next, the specific process conditions of this example will be described for the case where an image is recorded by negative/positive reversal development using a Se-based photoreceptor.

First, as the image forming conditions, the photoreceptor 1 is an aluminum tube with a Se-based photosensitive layer deposited on the surface, the process speed (rotation speed of the photoreceptor) is 150 mm/sec,
It was charged with a corona charger 2 so that the surface potential was 600 to 1000V. The toner has positive charging characteristics, and is developed using general YMC and Bk toners with a charge amount of +3 μC/g and an average particle size of 10 μm, and at approximately the same potential as the surface potential of the photoreceptor 1. Developing device 4 to which bias voltage is applied
-7, respectively.

Next, the specifications of the cleaning device will be explained. 1st
The cleaning conditions for the blade cleaning device are as follows: The blade 13 is made of urethane rubber with a rubber hardness of 45 to 60 degrees, and the contact force to the photoreceptor 1 is 10 to 40 g/cm.
The axial direction of the photoreceptor 1 was constructed to be uniform over almost the entire width. The cleaning conditions of the second cleaning device are that the fur brush roller 14 has a metal shaft and a fur (specific resistance: IO"Qc) made of acrylic fibers with carbon dispersed therein.
m, length: 5 mm, 10 denier, density: 3600 pieces/
cm2) was used, and the diameter was 30 ma. Further, the fur brush roller 14 is configured such that the tip III+ of the fur comes into contact with the photoreceptor 1 when the fur brush roller 14 comes into contact with the photoreceptor 1. The collecting roller 15 is 1 m away from the fur brush roller 14.
m so that they touch each other. The fur brush roller 14 is rotated at a circumferential speed of 150 to 180 mm/sec, and the collection roller 1
5 was rotated at a circumferential speed 1 to 2 times that of the fur brush roller 14.

The bias voltage applied to the fur brush roller 14 is a DC voltage in the range of -100V to -300V since the toner is positively charged, and the bias voltage applied to the collection roller 15 is -100V to -300V lower than that of the fur brush roller 14. A DC voltage was applied.

When a color image was formed using four color toners under these configuration conditions and the residual toner was cleaned after transfer, toner remained in the overlapping color areas and solid image areas during fur brush cleaning, and the next Although it affected the image, I was able to clean the blade with almost no problems. Further, the streak-like residual toner generated when the blade 13 was separated could be easily removed by scraping it off with the fur brush roller 14. This is because the toner attached to the tip of the blade is not electrostatically attached.

In addition, the cleaning was performed without any transfer assuming that the paper jammed, and the cleaning was similarly successful without any change.

On the other hand, as a result of cleaning with only the fur brush roller 14 in monochrome image recording mode, there is no residual toner that will affect the next image, and the lifespan due to scratches on the photoreceptor 1 is twice that of blade cleaning (in the same mode). (ratio) became longer.

In addition, as a result of experiments by changing the environmental conditions, especially the environmental humidity,
There was almost no change in blade 13, but there was a tendency for a little more toner to remain in the fur brush cleaning. From this, it has been found that reliability can be further improved by detecting the environmental humidity in addition to the recording mode and using a combination of blade cleaning and fur brush cleaning when the humidity is higher than a predetermined humidity.

Effects of the Invention In the multicolor image recording apparatus of the present invention, a blade cleaning device and a fur brush cleaning device are used, and the fur brush cleaning device is provided on the downstream side of the blade cleaning device in the moving direction of the photoreceptor. By configuring the camera to select and use a cleaning device, fur brush cleaning, which causes less damage to the photoreceptor, can be selected and used in monochrome recording mode, which is used frequently and has a small amount of toner adhering to the photoreceptor. In multi-color image recording mode where multiple colors of toner are used and a large amount of toner adheres to the photoreceptor, reliability is improved by cleaning with blade cleaning and removing toner lumps generated when the blade separates with fur brush cleaning. is high, and the life of the photoreceptor can be extended.

Further, even if an untransferred image occurs due to a paper jam or the like, cleaning with a blade eliminates toner residue, and reliability can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of a multicolor image recording device according to an embodiment of the present invention, FIG. 2 is an operation flowchart of a cleaning device in the same embodiment, and FIG. 3 is a configuration of a conventional multicolor image recording device. 4 are configuration diagrams of a conventional fur brush cleaning device. DESCRIPTION OF SYMBOLS 1... Photoreceptor, 2... Corona charger, 3... Laser scanner, 4.5.6.7... Developing device (developer carrying means), 13... Blade, 14...・Fur brush roller, 15...Collection roller, 18.20...
Toner conveyance roller, name of agent: Patent attorney Shigetaka Awano (1 person) Figure 12

Claims (5)

[Claims] (1) An image forming means that forms a multicolor image on a photoreceptor using a plurality of developer carrying means and transfers it all at once to a recording paper to obtain a multicolor image; a first cleaning means having an elastic cleaning blade that contacts and removes toner remaining on the photoreceptor after transfer; and a conductive fur brush roller that contacts parallel to the axial direction of the photoreceptor downstream of the cleaning blade. a second cleaning means having: a first contact/separation means for moving the cleaning blade toward and away from the photoreceptor; a second contact/separation means for moving the fur brush roller toward and away from the photoreceptor; and applying a voltage to the fur brush roller. 1. A multicolor image recording device comprising: a voltage applying means for applying a voltage. (2) The multicolor image recording apparatus according to claim 1, wherein the fur brush is separated by the second separating means after a predetermined time after the first separating means performs the separating operation of the fur brush. . (3) The fur brush according to claim 1, characterized in that the action of bringing the fur brush into contact with the photoreceptor by the second contact/separation means is performed at the same time as the action of separating the blade from the photoreceptor by the first contact/separation means. Multicolor image recording device. (4) An image forming means that forms a multicolor image on a photoconductor using a plurality of developer carrying means and transfers the multicolored image to a recording paper all at once, and an image forming means that forms an image using a single developer carrying means. an identification means for identifying whether or not the toner image is an image; a first cleaning means comprising an elastic cleaning blade for removing toner remaining on the photoreceptor after the toner image has been transferred; a second cleaning means consisting of a conductive fur brush roller for removing residual toner; a first separating means for bringing the cleaning blade into contact with and separating from the photoreceptor; and a second separating means for bringing the fur brush roller into contact with and separating from the photoreceptor. What is claimed is: 1. A multicolor image recording apparatus, comprising: means for selecting the first or second cleaning means using the identification means. (5) When an image is formed by a single developer carrying means, the identification means operates the second cleaning means, and the first cleaning means operates.
5. The multicolor image recording apparatus according to claim 4, wherein said cleaning means is made inactive.