JPH03141387A - Cleaning device for image forming device - Google Patents

Abstract

PURPOSE:To obtain a stable cleaning function that is hardly affected by temperature, humidity and environment by a comparatively simple structure by providing a heating means heating bristles of a brush roller. CONSTITUTION:After a toner image on a photosensitive body 5 is transferred onto a transfer material, toner T remaining on the photosensitive body 5 is scraped away by the bristles of the rotating brush roller 1, and electrically grasped by the bristles 11. During the cleaning operation, a temperature adjusting circuit 7 energizes a heater 6 which emits heat to heat and dry the bristles. Consequently, the comparatively simplified cleaning device can exhibit a stable cleaning function that is hardly affected by temperature, humidity and environment without requiring both a humidity sensor and a device controlling a voltage applied to the brush roller 1 according to information from the sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cleaning device for an image forming apparatus such as a copying machine or a printer.

[Conventional technology]

In electrophotographic image forming apparatuses such as copying machines and printers, an image carrier having a photoconductive photosensitive layer on the surface is used, and image information is exposed onto the surface of the image carrier to form an electrostatic latent image. This latent image is developed by a developing device to form a toner image, and this toner image is transferred to a transfer material and fixed. However, when a toner image is transferred from an image carrier to a transfer material, some toner remains on the image carrier. Therefore, in order to clean this residual toner from the image bearing member in preparation for the next image formation, a cleaning device for cleaning the residual toner is provided.

There are several types of this cleaning device.
Among them, there is a cleaning device using a brush roller.

For example, as shown in FIG. 14, this device applies a bias voltage to a brush roller 1 that rubs an image carrier (in the illustrated example, a photoreceptor drum) 5 to remove residual toner on the photoreceptor 5 from the brush 1. The toner is removed onto the cola 1 and a bias voltage is applied to the collection roller 2 in contact with the brush roller 1 to collect the toner from the brush roller onto the collection roller 2.

For example, when the residual toner T is charged to a positive polarity, the brush bristles 11 constituting the brush roller 1 are charged to a negative polarity, and the residual toner is removed from the image carrier 5 by the brush roller 1. As the brush bristles rub the surface of the image, the toner T is rubbed on the brush bristles 11.
It is scraped off and removed by being electrically attracted to it.

111! The particles captured by the recovery roller 2 are scraped off by the scraper 3, and recovered below the recovery roller (falling into the freeway 4, and rotating by means of a coil or suffrip provided there, etc.). The toner is collected by a conveying means into a toner collection bottle (not shown).

[Problem to be solved by the invention]

However, in a cleaning device using a brush roller, there is a problem in that the electric resistance of the solar cell changes depending on the ambient temperature and humidity, and the cleaning performance changes accordingly. As a means to solve such problems, Japanese Patent Laid-Open No. 63-249182 discloses a leaning device as follows.

That is, a temperature sensor is disposed (near the contact area between the brush roller and the image carrier), the sensor detects the ambient humidity, and the bias voltage value applied to the brush roller is switched in accordance with a preset humidity value. This is a cleaning device that allows you to

However, this cleaning device requires a humidity sensor and also requires a control device for switching the bias voltage 11^ applied to the brush roller according to information from the humidity sensor.

Therefore, the present invention eliminates the need for a humidity sensor and a device that uses information from the sensor to control the voltage applied to the brush roller, and has a relatively simple structure that is stable and not easily affected by temperature and humidity environments. An object of the present invention is to provide a cleaning device that can exhibit high cleaning performance.

(Means for Solving the Problems) In accordance with the above-mentioned object, the present invention applies a bias voltage to a brush roller that rubs an image bearing member to remove residual toner on the image bearing member to the brush roller F; In a cleaning device for an image forming apparatus that applies a bias voltage to a collection roller in contact with a brush roller and collects toner from the brush roller to the collection roller, a heat generating heating means is provided for heating the bristles of the brush roller. The present invention provides a cleaning device characterized by: -J.

The heat generation temperature of the brush bristles may be, for example, a temperature slightly higher than room temperature, for example, 35 to 50°C.

It is desirable to heat the brush bristles in advance during the warming amplifier before the image forming operation starts in the image forming apparatus.Also, in order to sufficiently heat the brush bristles to the desired temperature state, the brush bristles should be heated to a temperature smaller than that during cleaning. It is desirable to rotate at the number of revolutions and add while increasing the number of revolutions.

[Function] According to the cleaning device of the present invention, the brush bristles can be heated by the heating means disposed in contact with or close to the tips of the brush bristles constituting the brush roller, thereby drying the brush bristles.

When the brush bristles are heated during the warming amplifier, the brush roller is rotated at a lower rotational speed than during cleaning to sufficiently heat and dry the bristles.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the invention.

This cleaning device is used in a copying machine, and includes a brush roller 1 having conductive brush bristles 11, a collection roller 2 that contacts the roller, and a brush roller 1 that contacts or approaches the tip of the brush bristles of the brush roller 1. A heater 6 consisting of an electric heater is provided.

The brush roller 1 and collection roller 2 are rotated by a brush roller rotation motor (not shown) in a direction opposite to the direction of the rotational force of the photosensitive drum 5 via a transmission device (not shown).

A bias voltage ■1 is applied to the brush roller 1 for capturing residual toner T on the photoreceptor 5 onto the brush bristles 11, and a bias voltage ■2 is applied to the collecting roller 2 for collecting the toner from the roller l. is applied.

The heater 6 is energized by a heater temperature control circuit 7 so as to generate heat to a predetermined temperature. In this example, the degree of heat generation is such that the full brush is heated to 35 to 50° C., which is slightly higher than room temperature.

This cleaning device also includes a scraper 3 that comes into contact with the collection roller 2, and a tree-collection 1 furthest path 4 that collects the toner scraped off by the scraper.

After the toner image on the photoreceptor 5 is transferred to the transfer material, the photoreceptor 5
The toner (positive polarity in the illustrated example) remaining on the plate is scraped off by the brush bristles 11 of the rotating brush roller l and is electrically captured by the plan 1:, 11. The toner on the brush roller 11- is collected by the collection roller 2, and the toner on the roller 2 is scraped off from the roller by the scraper 3 and falls to the toner collection 1 general path 4.
is collected into a collection bottle.

During this cleaning I, the temperature control circuit 7 is connected to the heater 6.
The heater 6 generates heat and the brush bristles are heated. The bristles are heated and dried, providing stable cleaning performance that is less affected by ambient temperature and humidity.

According to another embodiment of the present invention, in the cleaning device having the configuration shown in FIG. 1, the brush roller is heated while being rotated at a lower rotational speed than during cleaning during warming up of the image forming apparatus. If you operate like this,
The brush bristles can be sufficiently dried before the image forming operation, and the desired cleaning performance can be more reliably exhibited during the image forming operation.

In the second cycle, when the image forming apparatus is warming up, the heater 6 is energized while rotating the brush roller 1 at a lower rotational speed than during cleaning, and after warming up, the brush roller 1 is rotated at a rotational speed that allows the predetermined cleaning to be performed. The outline of the control means for switching is shown.

Figure 3 shows each part of the cleaning device. and the operation timing of parts related to these.

According to this control means, the motor for rotating the brush l-1 is connected to the brush roller l via a brush roller rotation switching clutch and (a low-speed rotation gear or a high-speed rotation gear).

The VJ clutch is an electric VJ clutch, and when it is not energized, it is on the high-speed rotation gear side, and when it is energized, it switches to the low-speed rotation gear at 1.

The fixing 2S temperature control circuit energizes the heater of the fixing 2 (not shown) for melting and fixing the toner image on the roll 1; This indicates that when the heater temperature reaches THHI3 and the temperature of the fixing device reaches 1 or higher, which is necessary for fixing the toner image, warming up is completed and 1p becomes possible.

As can be seen from FIGS. 2 and 3, when the main body power switch is turned on, the main body power is turned on, and the brush roller rotation motor is energized via a control circuit (not shown).
The brush roller rotation switching clutch, the heater temperature control circuit 7, and the fixing device temperature control circuit are respectively energized.

As a result, the brush roller rotation switching clutch enters the low speed rotation gear side, and the brush roller 1 and collection roller 2 begin to rotate at a lower speed than during cleaning. Further, the heater temperature control circuit 7 turns on the heater 6. Meanwhile, the fuser temperature control circuit also begins to operate.

Thus, the bristles 11 of the brush roller I are heated and dried prior to the image forming operation.

When the heater temperature reaches TH or higher and the fixing device temperature reaches 1.2 or higher, warming-up ends, and at the same time, the copy-ready indicator lamp lights up.

At the same time, the plan roller rotation switching clutch is switched to the high speed rotation gear side.

When the copy start switch is turned on after the copy ready indicator lamp lights up, the brush roller rotation motor starts rotating again, and the brushes 1 and 1-1 rotate at the required number of rotations for cleaning, and at the same time the cleaning power source (not shown) turns on. It is turned on in response to an instruction from the control circuit not to operate, and a bias voltage is applied to the brush row 1 and collection roller 2.

The copy ready indicator lamp goes out at the same time as the copy start switch is turned on. Note that the heater temperature control circuit may be stopped by turning on the 12-bee enable indicator lamp.

Next, the main points of other embodiments of the present invention will be explained.

In the embodiments shown in FIGS. 4 to 7, the brush shim is heated by heating 23 provided on the outside of the brush roller 1, respectively.

In the embodiments shown in FIGS. 8 to 13, the brush t is heated by a heater provided in the brush roller 1, respectively.

More specifically, in the one shown in FIG. 4, an electric heater 6a built into the photoreceptor 5 heats the brush bristles through the photoreceptor wall. In the one shown in FIG. 5, an electric heater 6b built into the collection roller 2 heats the brush bristles through the collection roller wall. In the one shown in Figure 6, the brush roller l
The brush bristles are heated by a heating lamp (for example, a tungsten lamp) 6C placed facing the brush. In the one shown in FIG. 7, heat from an electric heater 6dh placed in a duct D and facing the brush roller 1 is blown onto the brush bristles by a fan 6df.

In the one shown in FIG. 8, an electric heater 6e built into the cylindrical core shaft 12 of the brush roller l heats the brush bristles through the core shaft wall. In the one shown in Fig. 9, the brush roller l
An electric heater 6f disposed throughout the core shaft 12 heats the brush bristles through the core shaft wall.

In the one shown in FIG. 10, the cylindrical core shaft 12 of the brush roller 1 is
The brush bristles are heated by an electric heater 6g built into the brush and in contact with the inner circumferential wall of the core shaft.

In the one shown in FIG. 11, the cylindrical core shaft 12 of the brush roller 1 is
The brush bristles are heated through the core shaft wall by a heating lamp (for example, a tungsten lamp) 6h placed inside the brush.

In the one shown in FIG. 12, the cylindrical core shaft 12 of the brush roller 1 is
It uses itself as a heater 61, thereby heating the bristle. In the one shown in FIG. 13, the core shaft of the brush roller 1 is a solid cylindrical body 13, and the core shaft itself is connected to a heater 6.
Heat the brush bristles as j.

[Effects of the Invention] According to the present invention, a humidity sensor and a device for controlling the voltage applied to the brush roller Δ based on information from the sensor are not required, and the brush roller Δ can be controlled in a temperature and humidity environment with a relatively simple structure. It is possible to provide a cleaning device that exhibits stable cleaning performance in a state that is not easily affected.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing one embodiment of the present invention, FIG. 2 is a schematic block diagram of a control stage for preheating brush bristles during warming up of an image forming apparatus, and FIG. The system shown in the diagram? 4 to 13 are diagrams showing main points of other embodiments of the present invention, and FIG. 14 is an explanatory diagram of a conventional example. . 1...Brush roller 11...Brush bristles 2...Collection roller 5...Photoconductor 6...Heater Applicant Minolta Camera Co., Ltd. Main unit power switch On Copy start switch on Main unit power on Fuser unit Temperature control circuit operation Heater Temperature control circuit operation Brush roller rotation motor operation Brush roller rotation switching Clamber/edge Low speed side Brush roller rotation switching Clutch High speed side Copy possible indicator lamp lights Fuser temperature Heater temperature Main body Brush heater temperature is above TH Warming-up ends with 797- Figure 4 Figure 1 Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) Applying a bias voltage to a brush roller that rubs the image carrier to remove residual toner on the image carrier onto the brush roller, and applying a bias voltage to a collection roller in contact with the brush roller. A cleaning device for an image forming apparatus that collects toner from the brush roller onto the collection roller, characterized in that the cleaning device is provided with a heat generating means for heating the bristles of the brush roller. (2) The cleaning device according to claim 1, wherein during warming up of the image forming apparatus, the brush bristles are heated by the heat generating heating means while rotating the brush roller at a lower rotational speed than during cleaning.