KR920007716B1 - Color electrographic apparatus - Google Patents

Abstract

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Description

Color electronic photo equipment

1 is a schematic diagram illustrating a conventional color electrophotographic apparatus.

2 is a principle diagram of a color electrophotographic printer shown to explain the principle of a multicolor image recording apparatus according to an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

21: photosensitive member 22: main electric

23: light emitting diode 24: road lens array

25, 26, 27: developing machine 30: transfer machine

32: fur brush 34: power

35: solenoid 36: auxiliary electric

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a color electrophotographic apparatus which can be used for a color hard copying apparatus such as a color copying machine or a color printer, and obtains vivid color images without contamination due to poor cleaning.

Background Art Conventionally, a plurality of toner images having different colors are formed on an electrophotographic photosensitive member (hereinafter, referred to as a photosensitive member) repeatedly for charging, exposure, and development, and then color transfer is performed by transferring the toner images onto paper collectively to obtain a color image. Various photographic methods have been proposed.

1 is a schematic diagram of a color electrophotographic apparatus using a conventional process described in Japanese Patent Laid-Open No. 60-212927. (1) is a selenium (Se-Te) photosensitive member rotating in the direction of the arrow, (2) a corona charger for charging the photosensitive member, (3) a light emitting diode array, (4) a rod lens array, and (5) ) To (7) are each a developer containing yellow (Y), magenta (M) and cyan (C) developer, (8) copy paper, (9) antistatic lamp, (10) corona charger, Denoted at 11 is a peeling discharger, at 12 is a fur brush cleaner, and 13 is an antistatic lamp for initializing the surface potential of the photoconductor after transfer. A method of forming a color image using this apparatus will be described. After electrostatic charging of the photosensitive member 1 with the corona electrostatic charge 2, the yellow image signal is exposed with the light emitting diodes 3, and the electrostatic latent image of the um (electrostatic latent image whose surface potential of the photosensitive member is attenuated by the wire portion is exposed). ). Then, the electrostatic latent image is negatively and positively developed by the developing device 5 containing the (Y) rower, thereby forming a yellow toner image on the photosensitive member 1. At this time, only the developer 5 containing the toner (Y) is connected to the power source, but the other developers 6 and 7 are adjusted to a non-developable state. (Y) After developing with the toner, the photosensitive member 1 is irradiated with the antistatic lamp 13 in its entirety to erase the yellow electrostatic latent image.

Next, the charging, exposure, developing and photostatic processes were repeated by the same method as the method of forming the yellow toner image, and the toner images of (M) and (C) were placed on the photoconductor (1). Formed sequentially on the toner phase. After the formation of all the toner phases is finished, the electrostatic latent image is photoelectrically charged by the antistatic lamp 9, and the toner image is electrostatically transferred onto the copy paper 8 by the corona discharger 10. After electrostatic transfer, the fur brush cleaner 12 is pressed against the photoconductor, the toner remaining on the photoconductor is removed, the cleaner 12 is separated from the photoconductor, and the photoconductor 1 is again provided for the next image formation. .

When a color print is created using the conventional color electrophotographic apparatus described in FIG. 1, unevenness may appear in an image when humidity is high. The reason for this is that, when the humidity is high, the transfer efficiency of the toner to be transferred to the copy paper decreases, resulting in poor cleaning.

At this time, when the polarity of the toner remaining on the photoconductor was irradiated, the toner on the photoconductor was charged by the negative electrode corona of the transfer through the paper where the moisture was sucked out and the resistance was lowered. Therefore, it was found that in the fur brush applied with a voltage to suck the toner, the negative toner cannot be removed. In order to prevent this deterioration of the cleaning ability, it is possible to consider a method of using air suction together with the fur brush, but this method has a large noise and is not practical.

An object of the present invention is to provide a color electrophotographic apparatus which obtains a vivid color image without contamination due to poor cleaning.

The present invention relates to a main charging unit for charging electric charges to a photoconductor, an exposure apparatus, a plurality of developing devices each having a different color of a toner, a transfer unit for transferring a toner image formed on a photoconductor to a constant solution, and the counter electrode of the main charging unit. In a color electrophotographic apparatus composed of an auxiliary electric charge that charges a charge of the same polarity to a photosensitive member, a conductive fur brush, and a power source for applying a voltage to the fur brush, the fur brush contacts the photosensitive member when cleaning, A cleaning device having a separating contact mechanism that separates the photosensitive member when not being cleaned, and also surrounds the photosensitive member in the order of the main battery, the exposure apparatus, the plurality of developing devices, the transfer device, the auxiliary battery, and the fur brush. The present invention relates to a color electrophotographic apparatus disposed in the.

Since the toner remaining on the surface of the photosensitive member is not transferred from the photosensitive member to the transfer paper, the polarity of the toner remaining on the surface of the photosensitive member becomes opposite to the original polarity under the influence of the transfer corona and the charger, and thus cannot be removed as it is. Therefore, before cleaning with the cleaning apparatus, the reverse polarity of the toner is once returned to the original polarity in the corona charger, and then adsorbed by the electrostatic induction phenomenon with the conductive fur brush applied with the voltage. Therefore, even when the humidity with poor transfer efficiency is high, it does not cause a cleaning failure.

Hereinafter, embodiments of the present invention will be described.

The material of the fur of the fur brush used in the present invention is preferably conductive, and for example, any material can be used as long as it is conductive fiber such as acrylic fiber, carbon polymer, carbon fiber and metal fiber in which carbon black is dispersed. In particular, the specific resistance thereof is particularly preferably in the range of 10 ⁴ to 10 ¹² Pacm.

Next, the structure of the cleaning apparatus of this invention is demonstrated using FIG. As for the fur brush 32, the above-mentioned conductive fur is assembled on the conductive roller surface. The fur brush 32 may wind the fabric in which the fur is implanted in a roller or may be formed directly on the roller by an electrostatic induction phenomenon. The fur brush 32 is connected to a DC high-voltage power supply 34 for applying a DC voltage, and the fur brush 32 is press-contacted to the photosensitive member 21 during cleaning, and after cleaning, the photosensitive member 21 is cleaned. A detachable contact driving solenoid 35 is detached from the unit. At the time of cleaning, the micro fur brush 32 was pressed against the photosensitive member 21, and the peripheral speed of the photosensitive member was rotated 1.5 to 3 times in the direction opposite to the traveling direction of the photosensitive member.

When the fur brush 32 is subjected to the opposite electrode and reverse polarity DC voltage of the toner, the toner is adsorbed to the fur brush 32 due to the electrostatic induction phenomenon, so that the cleaning ability is preferably improved. For example, it is preferable to apply -100V to -600V for the toner of the hospitality.

Hereinafter, specific embodiments of the present invention will be described in more detail.

A fur brush was brushed with a stainless steel roller (diameter: 10 mm) and conductive fur (resistance: 10 ⁵ Ω㎝, length: 4 mm, thickness: 10 denier, density: 3600 pieces / cm2) in which carbon was dispersed in acrylic fiber. (32) was configured.

In the developing devices 25, 26 and 27, an aluminum roller was used to form a toner foil layer on the surface by a blade (not shown), which was opposed to the photosensitive member 21 at an interval. The toner of (Y) (M) (C) used the normal nonmagnetic toner which disperse | distributed the pigment to the vertical binder. The configuration and developing conditions of this developing machine and the specifications of the toner are as follows.

Developing condition and developing condition

Diameter: 16mm

Peripheral speed: 150mm / s

Toner layer thickness on toner carrier: 30㎛

Peripheral movement direction: same direction as the photosensitive member 21

Spacing with photoreceptor: 150㎛ for development, 700㎛ for no development

Developing bias: + 600V during developing, OV without developing

Toner Specification

Toner Charge: + 3μc / g

Average particle diameter: 10㎛

First, the amorphous Se-Te photosensitive drum 21 having a diameter of 100 mm was rotated at an ambient speed of 150 mm / s, and charged at a surface potential of +500 V with the auxiliary electric 36 (corona voltage: +5 V).

Next, the fur brush 32 was pressed against the photosensitive member using the solenoid 35.

Cleaning condition of fur brush (32)

Applicable voltage: -300V

Peripheral speed: 225mm / s

Peripheral movement direction: opposite to the photosensitive member 21

Since the conductive fur brush 32 was in contact with the photoconductor 21, the surface potential of the photoconductor 21 decreased to almost OV. Next, the photosensitive member 21 was charged to the surface potential of + 700V by the main battery 22 (Scolotron battery, corona voltage: + 7KV, grid voltage: + 850V). A light emitting diode 23 having an output of 7 kW and a wavelength of 670 nm was emitted, and a yellow signal was exposed on the photosensitive member 21 through the rod lens array 24 to form an electrostatic latent image.

Next, the electrostatic latent image was developed with a yellow developer 25 in a developing state. Thereafter, the photosensitive member 21 was passed through the magenta developer 26 and the cyan developer 27 in an undeveloped state. Next, (Y) the photoconductor 21 carrying the toner image was charged to + 750V with the auxiliary electric machine 36, passed through a cleaning device separated from the photoconductor, and again charged with the main battery 22 to obtain a surface potential. It set to + 800V. Next, the photosensitive member 21 was exposed to signal light corresponding to magenta by the light emitting diodes 23. The photosensitive member 21 carrying the electrostatic latent image of magenta passes through the yellow developer 25 in an undeveloped state, passes through the magenta developer 26 in a developed state, and is developed as a magenta toner, It passes through the cyan developer 27. The photoconductor 21 developed by the magenta toner is again charged to + 850V with the auxiliary unit 36, and then passed through a cleaning device separated from the photoconductor, and again charged to the surface potential + 800V with the main battery 22. It was.

Next, the light emitting diodes 23 exposed signal light corresponding to cyan. Thereafter, the photosensitive member 21 passed through the yellow developer 25 and the magenta developer 26 in an undeveloped state, passed through the cyan developer 27 in a developed state, and was developed by a cyan toner.

In this way, the color toner image of (Y) (M) (C) obtained on the photoconductor 21 was transferred to the paper 28 by the transfer charger 30, and was enthusiastically attached. At this time, the transfer efficiency was about 80%. On the photoreceptor 21, the untransferred toner which negatively charged initial counterelectrode and reverse polarity remained.

This was changed to positive by the auxiliary electric machine 36 and charged, followed by cleaning with a fur brush 32.

The cleaning conditions are as follows.

Applicable voltage: -300V

Peripheral speed: 225mm / s

Peripheral movement direction: opposite to the photosensitive member 21

As a result, the residual toner on the photoconductor 21 was completely absorbed by the fur brush 32 and recovered. After the cleaning, the driving solenoid 35 was again operated to separate the fur brush 32 from the photosensitive member 21, and to move to the next print cycle.

In this way, since the auxiliary unit 36 is newly installed in front of the cleaning apparatus, the cleaning ability does not decrease even during the next printing, and the cleaning failure occurs even at a high humidity of 80% relative humidity. Did not do it.

The present invention is particularly suitable for obtaining a negative / positive phone image when the counter electrode of the toner and the counter electrode of the photosensitive member 21 are the same.

In addition, as described in the embodiment, the auxiliary unit 36 not only functions to make the polarity of the toner remaining on the photoconductor 21 the same as that of the counter electrode of the photoconductor 21, but also the function of the photoconductor by the main battery 22. Since it has a function of assisting the charging, it is preferable to operate the auxiliary battery 36 with or without the cleaning device.

When the charging potential of the photoconductor by the auxiliary electric 36 becomes higher than a predetermined surface potential, it is difficult to lower the surface potential by the main charging unit 22. Therefore, it is important to set the electric potential of the photosensitive member 21 by the auxiliary electric charge 36 to the predetermined surface potential by the main battery 22 after making it lower than the predetermined surface potential applied to the photosensitive member 21.

In addition, in order to obtain a good image stably, it is necessary to make the surface potential of the photosensitive member constant. Therefore, the main charge 22 is preferably a scolotron charger that can easily control the surface potential.

The color image thus obtained was of high quality with a highest density of 1.7 and no color flow. Although the above process was repeated 30,000 times, the cleaning capacity did not decrease and no flow occurred. In addition, by using the auxiliary electric power 36, sufficient surface potential is used even when a photosensitive member having an easy optical memory or a photosensitive member having a low charging function, for example, a photosensitive member such as arsenic selenide (As ₂ Se ₃ ) is used at a high speed process. Could get

According to the present invention, it is possible to obtain a color electrophotographic apparatus which obtains a vivid color image without staining caused by poor cleaning. In addition, a color electrophotographic apparatus having a small cleaning apparatus with high cleaning ability and low noise can be obtained.

Claims (5)

The main battery 22 which charges the photoreceptor 21, the exposure apparatuses 23 and 24, and the plurality of developing devices 25, 26 and 27 in which the toner colors are different, respectively, A transfer device 30 for transferring the toner image formed thereon to a constant solution, an auxiliary battery 36 for charging a photosensitive member with electric charges having the same polarity as the counter electrode of the main battery, a conductive fur brush 32, and a fur In a color electrophotographic apparatus composed of a power supply 24 for applying a voltage to a brush, the fur brush 32 is in contact with the photosensitive member 21 when cleaning, and the photosensitive member 21 when not cleaning. And a cleaning device having a separating contact mechanism (35) which is separated from the main body, and arranged around the photoconductor in the order of the main battery, the exposure apparatus, the plurality of developing devices, the transfer machine, the auxiliary battery, and the fur brush. Color electrophotographic apparatus characterized by. The color electrophotographic apparatus according to claim 1, wherein said auxiliary unit (36) is operating irrespective of the operation of the separating contact of the cleaning apparatus. 2. The color electrophotographic apparatus according to claim 1, wherein said auxiliary unit (36) is charged such that the surface potential of the photoconductor charged to the secondary unit is lower than the surface potential of the photoconductor charged to the main charging unit. 2. The color electrophotographic apparatus according to claim 1, wherein the main charger (22) is a scolotron-type corona charger having a grid electrode. 2. A color electrophotographic apparatus according to claim 1, wherein the plurality of developing devices (25, 26, 27) are developed with negative-positive inversion.