JPS63163387A - Cleaning device for image forming device - Google Patents

Abstract

PURPOSE:To remove foreign matter sticking strongly on an image carrier by performing the rubbing of a cleaning roller against an image carrier stronger in preliminary rotation before the start of image forming operation than that after the start of the image forming operation. CONSTITUTION:The rubbing force of the elastic cleaning roller 7 is increased during the preliminary rotating operation of the image carrier 1 after a copy switch is turned on and before copying operation is started actually. The elastic cleaning roller 7 uses a roller in two-layered structure of, for example, silicone sponge as an internal layer 7a and silicon rubber as an external layer. Consequently, foreign matter sticking after the previous use of an image forming device is all removed before next operation is started and even when the device is left unused for a long time, invariably excellent cleaning operation is performed.

Description

Detailed Description of the Invention (1) Purpose of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus that utilizes an electrostatic recording process, such as an electrostatic copying machine and a printer, and particularly to a cleaning device therefor. It is.

(Prior Art and Issues to be Solved) Image forming apparatuses that repeat the process of electrostatically transferring a toner image electrostatically formed on an image carrier onto a sheet-like transfer material such as paper have been well known for some time. .

This type of image forming apparatus has various parts such as forming an electrostatic latent image, forming a toner image that visualizes the latent image, transferring this toner image to a transfer material, and separating the transfer material from the image carrier.
Because high-pressure components such as high-pressure corona discharge are installed, there are corona products generated due to the discharge, fine paper dust from using paper as a transfer material, rosin, talc, etc. that are deposited from this. Particularly when the apparatus is left unused for a long period of time, there is a tendency for the precipitates to adhere to the surface of the image carrier in the vicinity of these members.

On the other hand, in the image forming apparatus as described in 1i11, since images are repeatedly formed on the image bearing member, it is essential to thoroughly clean the surface of the image bearing member each time the image is transferred. A cleaning means such as a cleaning roller is provided, but these have a certain effect on removing toner that does not transfer to the transfer material and remains on the surface of the image carrier during transfer, but 1)
As mentioned in 11 above, this method is not necessarily effective in removing various foreign substances.

There is a risk that the foreign matter adhering to the image carrier becomes low in resistance in a high humidity environment and disturbs the electrostatic latent image, resulting in deterioration of image quality.

In order to avoid such drawbacks, a flexible cleaning roller made of urethane rubber, silicone rubber, fluororubber, polyethylene rubber, etc. having appropriate elasticity is brought into contact with the surface of the image carrier and rubbed against it. Some proposals have been made to remove foreign substances by abrasive removal.

As described above, by using a leaning roller, especially in combination with a cleaning blade, cleaning of the image carrier can be effectively performed, but on the other hand, the cleaning action of the cleaning roller is to grind the photosensitive layer on the surface of the image carrier. Because it is due to the fact that it is always 1 due to strong pressure?
If J is rubbed, the photosensitive layer may be damaged, resulting in deterioration of image quality and shortening of service life.

The present invention has been made to deal with such Js7ffi, and it is possible to remove all foreign matter from the surface of the image carrier before starting the actual copying process, and to use a thoroughly cleaned image carrier at all times. The object of the present invention is to provide a leaning device that can obtain high-quality images without image deletion.

(2) Structure of the invention (technical means for solving the problem, its operation) In order to achieve the above object, the present invention provides a preliminary rotation of the image carrier before the actual copying starts after the Kobisui Sochi is inserted. The cleaning roller is characterized by a structure in which the sliding force of the cleaning roller is sometimes strengthened.

With this configuration, all foreign matter that has adhered to the image forming apparatus after the previous use can be removed before starting the next operation, so even if the image forming apparatus has been left unused for a long time, it can always be A good leaning effect can be obtained.

(Description of Embodiments) FIG. 1 is a side view of essential parts of a copying machine equipped with a rotating cylindrical image bearing member (referred to as a photoreceptor) to which the present invention is applied.

In the image forming process, a transfer material (not shown) supplied from the conveyance path 3 is fed in synchronization with the toner image formed by the developing device IO on the surface of the photoreceptor 1 rotating in the direction of arrow A, and the transfer material is transferred. When the toner image reaches a transfer site equipped with a charger 4, the toner image is transferred to the transfer material by the action of the transfer charger, and then separated from the photoreceptor by the action of the separation charger 5 and transported to the next fixing part. shall be.

At the transfer site, toner that does not contribute to the transfer and remains on the photoconductor, and foreign matter such as those mentioned above that adhere to the photoconductor surface, are
Proceed as it is until you reach the cleaning device 2.

The toner and the like that have reached the cleaning device are made of a resilient material, and some of the toner and the aforementioned foreign matter are rubbed off by the cleaning roller 7, which rotates in the opposite direction to the photoreceptor, and passes through the roller. The cleaned toner is scraped off by the cleaning blade 6.

The toner etc. captured in this way is removed by the rotation of the roller 7.
The scraper 8 is conveyed along the surface.
The toner reaches the toner storage section in the cleaning device, and is further discharged by the conveying screw 9 if necessary.

A copying machine as described above was used, and an amorphous silicon photoreceptor was used as the photoreceptor, and the circumferential speed was 340 mm.
The cleaning roller used had a two-layer structure (hardness Asker C 40° load 400gr) with silicone sponge as the inner layer 7a and silicone rubber (hardness 30' JISA) as the outer layer 7b. The experiment was conducted in an environment of 35° and 85% RH (7).
After passing 1,000 sheets, the copying machine was turned on overnight, and the next morning, the main switch of the copying machine was turned on, and as soon as copying became possible, paper was passed and the presence or absence of flow in the charger path was determined.

In this case, in order to change the sliding force of the cleaning roller during the preliminary rotation before the start of the image forming process from that during the image forming process, the pressing force of the roller against the photoreceptor is changed during the preliminary rotation. 80 gr/cs during the image forming process, and 40 gr/am during the image forming process (in both cases, the peripheral speed of the cleaning roller is 250 trrrs/sec
), and the peripheral speed of the cleaning roller is 400 tata/sea during preliminary rotation and 250/sec during one image forming process (in both cases, the pressure contact force of the cleaning roller against the photoreceptor is 40gr/cm)
I experimented with.

FIGS. 2 and 3 are graphs showing the former and latter cases, respectively.

As a result of the above experiments, it was possible to obtain high-quality images with no image blurring until the end.

4 and 5 show other cases in which experiments were conducted under the same conditions as the above case. In FIG. 4, the temperature and humidity of the environment were detected by the temperature sensor 19 and the humidity sensor 20. 1. Figure 5 shows the range in which the sliding force should be increased during pre-rotation, indicated by a hatched area, in order to respond to changes in both conditions. Only humidity is detected.

This allows the sliding force to be controlled.

Signals from the temperature sensor 19, humidity sensor 20, or
A signal from the humidity sensor 20 is transmitted to a microcomputer 21 storing a control program, and this microcomputer controls the rotation of the motor 15 within the range shown in FIGS. 4 and 5.

6 and 7 show means for changing the sliding force of the cleaning roller 7 against the photoreceptor 1. FIG.

The sixth method is to provide the cleaning roller 7 with an abutting habit by a spring 13 on an arm 11 driven around a shaft 12, and to determine the position of the arm with a cam 14 controlled by a motor 15. The pressure contact force of the cleaning roller is changed. The motor 15 may be controlled in the same manner as in FIG. 1 above.

FIG. 7 shows how the voltage changer 1 controls the rotation of the motor that drives the cleaning roller 7 by adjusting the voltage applied to the motor from the power source 18.
7 to change the photoreceptor l of the cleaning roller.
This shows an example in which the sliding force is changed by changing the relative speed with respect to the sliding force.

In this way, more suitable results can be obtained by controlling the sliding force by taking into account the above-mentioned environmental conditions in addition to the conditions of the above-mentioned experiment.

In addition, as means for controlling the rubbing action, the cleaning roller may be brought into pressure contact only during the preliminary rotation and then not in contact with it, or a speed difference may be created between the cleaning roller and the photoreceptor only during the preliminary rotation, and then the It is also possible to configure it to rotate at a circumferential speed.

Further, as the photoreceptor, appropriate materials such as selenium, cadmium sulfide, and organic semiconductors can be used.

Although the present invention has been described above for a case where it is applied to a copying machine, it goes without saying that the present invention is not limited to this and can be applied to other image forming apparatuses.

(3) Effects of the Invention As explained above, the present invention is configured to increase the sliding force of the cleaning roller against the image carrier during preliminary rotation of the image carrier before the image forming operation. By doing this, various foreign substances that have firmly adhered to the image carrier while it has been left unused for a long time after the previous work are thoroughly removed, so when starting the next work, it is necessary to Not only can a high-quality image be obtained from the cleaning roller, but also after that, foreign matter can be removed well by the original action of this type of cleaning roller, so there is an effect that a high-quality image can be stably obtained.

[Brief explanation of the drawing]

FIG. 1 is a side view of the main parts of a copying machine to which the present invention can be applied, FIG. 2 is a diagram showing the implementation state of the present invention when the pressure contact force of the cleaning roller is changed, and FIG. 3 is a diagram showing the cleaning roller. Fig. 4 is a graph showing the range in which the pressure contact force should be increased when environmental temperature and humidity are taken into account, and Fig. 5 is a graph showing only the humidity. FIGS. 6 and 7 are schematic side views of essential parts of an embodiment showing means for changing the sliding force of the cleaning roller. l-...Photoreceptor, 2...Cleaning device, 6.e.
Cleaning blade, 7... elastic cleaning roller, 8φφ fist scraper. Figure 1 @ Figure 2 Figure 7 Figure 3 Figure 4 Sky, J\L ['C] Figure 5 During pre-rotation. Sliding stirring 7) Up area λ eye relationship ['101 Figure 6 Figure 7

Claims (5)

[Claims] (1) In a cleaning device for an image forming apparatus equipped with an elastic cleaning roller that rubs against the surface of an image bearing member, the cleaning roller is applied to the image bearing member during preliminary rotation of the image forming apparatus before starting an image forming operation. A cleaning device characterized by comprising means for controlling the rubbing action to be stronger than after the start of the image forming operation. (2) The cleaning device according to claim 1, wherein the means for controlling the sliding action is means for detecting the contact pressure of the cleaning roller against the image carrier. (3) The cleaning device according to claim 1, wherein the means for controlling the sliding action is speed detection means for the circumferential speed of the opposing image carrier of the cleaning roller. (4) The cleaning device according to any one of claims 1 to 3, wherein the means for controlling the rubbing action is an environmental humidity detection means. (5) The cleaning device according to any one of claims 1 to 3, wherein the means for controlling the rubbing action is environmental temperature and humidity sensing means.