JPH01170976A - Cleaning device for multicolor image recording device - Google Patents

Abstract

PURPOSE:To improve cleaning ability by using two fur brushes and rotating those two fur brushes in the opposite direction from a photosensitive body on the movement-directional upstream side of the photosensitive body and in the same direction on the downstream side. CONSTITUTION:The two fur brush rollers 14 and 15 which are parallel to the photosensitive body 1 and rotates in the mutually opposite direction are used as a cleaning means which sweeps residual toner on the photosensitive body 1, and the fur brush roller 15 on the downstream side in the moving direction of the photosensitive body 1 between those two fur rollers 14 and 15 is rotated in the same direction with the photosensitive body. Consequently, scattered toner is confined to the gap between the two fur brushes to reduce the toner scattering, thereby maintaining excellent cleaning performance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a multicolor image recording device using an electrophotographic method, and more specifically, to a multicolor image recording device that uses an electrophotographic method to form superimposed images of different colors on an electrophotographic photoreceptor and then transfer the images. The toner is transferred to paper and then sent to a cleaning device of a multicolor image recording apparatus that cleans residual toner on the 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 to transfer paper. Various image recording apparatuses have been proposed that obtain color images by batch transfer.

For example, the technique disclosed in Japanese Unexamined Patent Publication No. 130763/1986 is one of them. This method is illustrated in FIG.

In Fig. 3, 1 is a photoreceptor for electrophotography that rotates in the direction of the arrow and has a photosensitive layer on its surface, 2 is a corona charger that uniformly charges the photoreceptor l, and 3 is a laser beam or the like that charges the photoreceptor as desired. 4 to 6 are developer units containing toners of yellow (Y), magenta (M), and cyan (C), respectively; Recording paper, 8
9 is a transfer charger for electrostatically transferring the toner image onto the recording paper 7; 9 is a static eliminator for erasing the residual charge on the photoreceptor L;
Reference numeral 10 denotes a cleaning device comprising a fur brush or the like for removing toner remaining on the photoreceptor 1 after transfer.

During the first rotation of the photoreceptor 1, the photoreceptor 1 is uniformly charged by the corona charger 2, and is exposed to a signal corresponding to a yellow (Y) image by the exposure unit 3 to form a negative electrostatic latent image (image line). A portion of the surface of the photoreceptor 10 is exposed to light to form an attenuated electrostatic latent image.

Then, negative/positive reversal development (
A developing method in which toner is attached to areas whose potential has decreased due to exposure) is used to form a Y toner image on the photoreceptor 1. At this time, the magenta (M) and cyan (C) developing units 5 and 6 are retracted and their functions are stopped so as not to affect the Y toner image. Further, the transfer charger 8 and the static eliminator 9 also stop their respective functions, and the fur brush of the cleaning device 10 is separated from the photoreceptor I as shown by the solid line. Therefore, the Y toner image is returned to the charger 2 without being disturbed.
position and complete the first rotation. Subsequently, in the second rotation, a magenta image is formed superimposed on the seven images in the same manner as the Y image formation. Furthermore, in the third rotation, a cyan image is formed in the same manner. When the cyan image is formed, the recording paper 7 is conveyed from the paper feed section 11 in synchronization with the leading edge of the image.
A toner image is transferred onto recording paper 7 by transfer charger 8 . The recording paper 7 on which the image has been transferred is peeled off from the photoreceptor 1, conveyed to the fixing section 12, and discharged after being fixed. On the other hand, after the transfer, the photoreceptor l is neutralized by a static eliminator 9, and the fur brush of the cleaning device 10 comes into contact with it to remove the remaining toner and prepare for the next recording.

Problems to be Solved by the Invention In such an image recording apparatus, the cleaning device 1
The configuration of 0 is important.

That is, the cleaning device 10 is separated from the photoreceptor l from the first image formation until the last image is formed and transferred.
After transfer, it is necessary to uniformly contact the photoreceptor 1 to reliably remove the toner. The blade cleaning method and the fur brush cleaning method are generally known as cleaning methods. In the blade cleaning method, when the blade leaves the photoreceptor, toner accumulated at the contact area remains in a streak on the photoreceptor, and the next step is to remove the toner. It has been difficult to use this type of multicolor image recording apparatus because of the problem of adversely affecting images. As a fur brush cleaning method, for example, the technique disclosed in Japanese Patent Application Laid-Open No. 185468/1982 is one of the techniques, and the configuration thereof is shown in FIG. 4. When it comes into contact with the photoreceptor l rotating in the direction of the arrow (a), the arrow (b)
It has a fur brush roller 13 that rotates in the direction of the arrow, and a conductive roller 16 that contacts the fur brush roller 13 and rotates in the direction of the arrow. A voltage of the same polarity as the charge of the electrostatic latent image, that is, the opposite polarity to that of the toner, is applied to the conductive roller 16, and a voltage of the same polarity that is approximately equal to or higher than the voltage applied to the fur brush roller 16 by a bias power source is applied to the conductive roller 16. Voltage is applied. The fur brush roller 13 is
It is constructed by flocking conductive fibers onto a conductive core. This cleaning device uses the electrostatic force of a fur brush roller 13 to transfer the toner remaining on the photoreceptor 1 without being transferred to the recording paper, and then transfers the toner adhering to the fur brush roller 13 to a conductive roller 16. The toner adhered to the conductive roller 16 is scraped off by a scraping plate 17 and collected.

However, in such a fur brush cleaning device, a lot of toner scatters due to the restoring force due to the elasticity of the fur at the contact portion between the photoconductor 1 and the fur brush roller 13, especially on the upstream side in the direction of movement of the photoconductor 1, and cleaning There was a problem that the air could blow out from the gap between the main body of the apparatus and the photoreceptor 1, contaminating the interior of the apparatus.

In addition, if a paper jam occurs and the toner image is not transferred to the recording paper, the amount of toner may be large due to the multicolor image, and 1
Toner may not be completely removed during the first cleaning and cleaning residue may occur, or toner may accumulate in the fur brush to an oversaturated level, reducing cleaning performance and leaving toner residue, which may adversely affect the next recording. There was a problem.

An object of the present invention is to provide a multicolor image recording apparatus having a stable cleaning device that does not cause toner scattering or residual toner.

Means for solving the problems and technical means of the present invention for solving the above problems are as follows:
Cleaning means for sweeping residual toner on the photoreceptor.
Two fur brush rollers that are parallel to the photoreceptor and rotate in opposite directions, a toric body that is loosely inserted at both ends of one of the fur brush rollers and has a smaller diameter than the fur brush roller, and a conductive roller that is in contact with the fur brush roller. A cleaning unit consisting of a collection roller, a toner scraping plate made of an elastic material with one end in contact with the surface of the collection roller, and a fur brush roller in which the cleaning unit is rotatably supported around a support shaft parallel to the fur brush roller. and a voltage applying means for applying voltages to the fur brush roller and the collection roller, respectively.
Among the fur brush rollers of the book, the fur brush roller on the downstream side in the direction of movement of the photoreceptor is configured to rotate in the same direction as the photoreceptor, and to use conductive fur.

action The effects of the present invention are as follows.

By using two fur brush rollers, the cleaning performance is significantly improved, and the upstream fur brush roller rotates in the opposite direction to the photoreceptor, and the downstream fur brush roller rotates in the same direction as the photoreceptor. As a result, scattered toner can be trapped between the two fur brushes, and toner scattering can be significantly reduced. Furthermore, toner scattering is significantly reduced by electrostatic adsorption using a conductive fur brush. Furthermore, by transmitting the rotation of the fur brush from the photoreceptor through the rotating shaft of the detachment mechanism, even if the cleaning means is separated from the photoreceptor, the fur brush and collection roller continue to rotate while remaining in contact with each other. This makes it possible to remove toner adhering to the fur brush even when not cleaning, that is, during image formation. This means that the time interval between cleaning and non-cleaning is long compared to when the fur brush is closed during use, so toner can be removed from the fur brush sufficiently, and cleaning ability can be maintained over a long period of time. Further, by keeping the distance between the fur brush and the photoreceptor constant using a toric body, the contact state is stable and good, and leaning performance can be maintained.

Example Hereinafter, the present invention will be explained based on examples.

The overall configuration of the multicolor image recording apparatus is the same as that shown in FIG. 3 for the conventional example, except for the cleaner 10, and will not be described in this section.

Next, the detailed configuration of the cleaner 10 will be explained using FIG. 1 and FIG. 2.

14φ15 is a pair of conductive fur brush rollers installed parallel to the axial direction of the photoreceptor l. For example, acrylic fibers with carbon black dispersed therein, conductive polymer compounds, carbon fibers, metal fibers, etc., each having a specific resistance value of 104 ~1012
It is a cylindrical rotating body whose outer periphery is flocked with conductive fibers having an ΩcI of 11.

16 is a conductive collection roller made of metal or the like that is in contact with the two fur brush rollers 14 and 15, respectively; 17 is a collection roller with one end in contact with the outer peripheral surface of the collection roller 16 and the other end fixed to the cleaning unit main body 18; a scraping plate made of an elastic material for scraping off toner adhering to the roller 16;
A screw 19 conveys the removed toner in the axial direction.

The fur brush rollers 14 and 15, the collection row 16, and the screw 19 are each rotatably supported by the cleaning unit main body 18.The fur brush rollers 14 and 15 and the collection roller 16 are supplied with toner from a DC power source 20. Direct current bias voltage with opposite polarity to charging polarity■1.
V2 and v3 are applied so that V + = V 2 <v3.

21 is a plunger that presses the fur brush rollers 14 and 15 in the direction of the central axis of the photoreceptor 1; 22 is a cleaner device)
18 and the plunger 21; 23 is a spring that biases the fur brush rollers 14, 15 and the photoreceptor 1 in a direction to separate them; 24 is a spring having a smaller diameter than the fur brush roller 15 and is coaxially inserted loosely into both ends of the fur brush roller 15; The spacer ring 25 is coaxial with the screw 19 and connects the fur brush rollers 14 and 15.
This is a support that rotatably supports the cleaner unit 18 parallel to the . Numerals 26 and 27 are gear trains that transmit rotation from a drive source (not shown) such as a motor to the cleaner device.The gear train transmits the rotation from the screw 19, which is the axis of rotation, to the fur brush rollers 14, 15, The rotation is transmitted to the collection rollers 16, respectively. The respective rotation directions are the fur brush roller 15, collection roller 16, and screw 1.
9 is in the same direction as the photoreceptor l, and the fur brush roller 14 is in the opposite direction. The rotation speed is the fur brush roller 14.1
5 is preferably the same speed as the photoreceptor 1 or faster.

During cleaning after transferring a color image, the plunger 21 is energized to press the cleaner unit 18 to a position where the spacer ring 24 contacts the photoreceptor l. Since the spacer ring 24 has a smaller diameter than the fur brush roller 15, the tip of the fur contacts the photoreceptor l. At this time, the amount of contact between the fur brush roller 14 and the photoreceptor 1 is set to be approximately 1/2 of the amount of contact between the fur brush roller 15 and the photoreceptor 1. Then, the surface of the photoreceptor 1 is rubbed by rotation from the drive source. The toner adhering to the photoreceptor 1 is first scraped off by a fur brush roller 14, and then electrostatically attracted to the fur to which a voltage of opposite polarity to the charged polarity of the toner is applied.

Furthermore, the remaining toner is scraped off again by the fur brush roller 15, electrostatically attracted to the fur of the fur brush roller 15, and completely removed. The toner attracted to each fur is electrostatically attracted to the collection roller 16 to which a voltage higher than that of the fur brush rollers 14 and 15 is applied at the contact portion with the collection roller 16. The toner adsorbed by the collection roller 16 is scraped off by a scraping plate 17, conveyed in the X direction by a screw 19, and collected in a collection box (not shown). When cleaning is completed, the plunger 21 is de-energized, the spring 23 rotates the cleaning unit 18 in a direction away from the photoreceptor 1, and the fur brush rollers 14 and 15 are separated from the photoreceptor 1. At this time, even if the fur brush rollers 14 and 15 are separated from the photoconductor l, the rotation is transmitted through the rotation shaft, and by continuing to apply the bias voltage, the toner attached to the fur brush rollers 14 and 15 is removed. The fur is always kept in its initial clean state.

Next, specific conditions of this example will be explained.

First, as the image forming conditions, the process speed (rotation speed of the photoreceptor) is 150 mm/see, the photoreceptor l is made of aluminum bamboo material with a Se-based photosensitive layer deposited on its surface, and the surface is charged with a charger 2. It was charged to a potential of 1600 to 1000V. The toner is a general Y-M type with positive polarity and band-like property, charge amount +3μC/g, and average particle size 10μ.
-C color toner was used, and development was carried out using developing units 4 to 6 to which a developing bias voltage having approximately the same potential as the surface potential of the photoreceptor 1 was applied, respectively.

Next, as for the cleaning conditions, the fur brush rollers 14 and 15 are made of fur made of acrylic fibers with carbon dispersed in the metal shaft (specific resistance = 109Ω, length: 5m%)
10 denier, density: 3600 strands/cm2) was used, and the diameter was 30 denier.

Also, the diameter of the spacer ring 23 loosely inserted into the fur brush roller 15 is 1IllI in radius from the fur brush roller.
11 smaller, the tip of the fur 1III+ is the photoreceptor l
I made contact with. Further, the fur brush roller 14 was provided at a position such that the amount of contact with the photoreceptor was 0.5 vw. The collection roller 15 is attached to the fur brush 14, respectively.
I tried to make contact. The fur brush roller 14 is rotated at a peripheral speed of 150 to 180 mn+/see, the fur brush roller 15 is rotated at a peripheral speed of 150 to 200 mm/sec, and the collection roller 15 is rotated at a peripheral speed of 1 to 2 times that of the fur brush roller 14. Rotated at circumferential speed. The faster the rotation speed is, the better the cleaning properties will be, but the above range is preferable in view of toner scattering and fur life.

The bias voltage applied to the fur brush roller 14 is a negative voltage in the range of 100 to 500 V since the toner is positively charged. ■A negative polarity voltage with a large absolute value was applied. For example, if a negative voltage of -300V is applied to the fur brush 14, the collection roller 1
6, a negative voltage of -400 to -800v is applied. Note that the bias voltage applied to the fur brush roller is desirably changed depending on the resistivity of the fur and environmental conditions, particularly environmental humidity.

Effects of the Invention In the image recording apparatus of the present invention, by using two fur brushes, the cleaning performance is significantly improved even in multicolor image recording, and the amount of contact with the photoreceptor is set to be smaller on the upstream side. Therefore, the cleaning capacity can be divided into two, and as a result, the life of the fur on the fur brush roller can be improved. Furthermore, by keeping the contact state between the photoreceptor and the fur brush constant with a spacer ring, stable cleaning can be performed at all times and reliability can be improved. In addition, by setting the rotation directions of the two fur brushes so that the upstream side in the direction of movement of the photoreceptor is opposite to that of the photoreceptor, and the downstream side is set in the same direction, it is possible to significantly reduce toner scattering into the machine. Also, even when the fur brush is separated from the photoconductor, voltage is applied to the fur brush and collection roller to continue rotation, thereby removing toner accumulated on the fur brush and restoring the cleaning ability of the fur brush. However, it is possible to obtain a color image recording device that does not affect the next recording. As a result, it is possible to obtain a multicolor image recording apparatus using a cleaner that has high cleaning performance and whose performance does not deteriorate over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a basic configuration diagram of a cleaning device for a multicolor image recording apparatus in an embodiment of the present invention, FIG. 2 is a perspective view of the cleaner section shown in FIG. 1, and FIG. 3 is a multicolor image recording device. FIG. 4 is a block diagram of a conventional fur brush cleaning device. l...Photoreceptor, 2...Corona charger, 3...Exposure section, 4.5.6...Developer, 10...Cleaner, 1
4.15... Fur brush, 16... Collection roller,
17--Scraping plate, 18--Cleaning unit, 20--DC power supply, 21--Driving plunger, 22--Spring. Name of agent Patent attorney Toshio Nakao Haka 1 name - Ichiura Mitsui; Ki ζ /7-xt+=, treated as a failed zo-Nao/X power source 25-ichi Bunshogu

Claims (4)

[Claims] (1) Each time the photoreceptor rotates, charging, exposure, and development are repeated to form a plurality of toner images of different colors in a superimposed manner on the photoreceptor, which is then transferred to a recording paper, and after the transfer, a cleaning device is used to place the toner image on the photoreceptor. This is a multicolor image recording device that sweeps residual toner.The cleaning means includes two fur brush rollers that are parallel to the photoconductor and rotate in opposite directions. A pair of toric bodies with a small diameter, a conductive collection roller that contacts the two fur brush rollers in the axial direction and parallel to each other, and a toner scraping plate made of an elastic material with one end in contact with the surface of the collection roller. a cleaning unit, a support means for rotatably supporting the cleaning unit about a support shaft parallel to the fur brush roller, and a separating means for pushing and pulling the cleaning unit to move the fur brush roller toward and away from the photoreceptor; A cleaning device for a multicolor image recording device, comprising voltage application means for applying voltages to a fur brush roller and a collection roller, respectively. (2) Of the two fur brush rollers, the contact amount at the contact area between the upstream fur brush roller and the photoconductor in the direction of photoconductor movement is δ_1, and the contact amount at the contact area between the downstream fur brush roller and the photoconductor. When the quantity is δ_2, δ_
A cleaning device for a multicolor image recording device according to claim 1, configured such that 1<δ_2. (3) Among the two fur brush rollers, the rotation direction of the downstream fur brush roller (A) in the moving direction of the photoreceptor is the same direction as the photoreceptor.
A cleaning device for a multicolor image recording device according to paragraph 1. (4) Cleaning of the multicolor image recording device according to claim 1, 2, or 3, wherein at least the fur brush roller (A) on the downstream side in the moving direction of the photoreceptor is made of conductive fur. Device. (4) The multicolor image recording device according to claim 1, wherein the toric body is configured to be loosely inserted into the fur brush roller on the side farther from the pivot axis of the two fur brush rollers. cleaning equipment.