JPS63155080A - Cleaning device - Google Patents

Abstract

PURPOSE:To always attain a stable and satisfactory cleaning function by shaking a toner layer forming means so that a toner layer is not brought into contact with an image carrier periodically and preventing toner from overflowing from a cleaning device at the time of occurrence of jam. CONSTITUTION:A cleaning blade 3 and a magnetic roller of a toner layer forming member are arranged in the cleaning device, and the magnet roll 5 is supported freely shakably by a lever pivoted on a pin 9a, and control rollers 4 are attached to both end parts of the magnet roller, and a control blade 6 for controlling the toner layer thickness is arranged. The radius of the control roller 4 is equal on an arc B-A-D and is larger at a point C. The toner layer is brought into contact with a photosensitive body in case of delta>gamma where deltais the interval between the magnetic roller 5 and the control blade 6 and gammais the interval between the control roller and the photosensitive body 1, and the toner layer is not brought into contact with the photosensitive body in case of delta<gamma. Consequently, the non-contacting part is used to allow the toner to escape though a large quantity of toner infiltrates into the cleaning device.

Description

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

(Prior Art and Issues to be Solved) A well-known image forming apparatus that repeats the process of transferring a transferable toner image formed on a moving image carrier (hereinafter referred to as a photoconductor) onto a sheet-like transfer material such as paper. For each transfer, residual toner that is not transferred to the transfer material and remains on the photoreceptor must be sufficiently removed in preparation for the next step.

For this reason, cleaning means such as a cleaning blade or a cleaning web are disposed downstream of the transfer site when viewed in the traveling direction of the photoreceptor to remove residual toner, which are already in widespread use.

However, in reality, the image forming apparatus contains fine paper powder generated from the paper used as the transfer material, precipitates such as rosin and talc that are precipitated from the paper, and corona products due to the presence of high-pressure members within the apparatus. Various foreign substances exist, and these are mixed in the residual toner and adhere to the photoconductor. Moreover, these foreign substances are not only difficult to remove with the cleaning blade mentioned above, but also absorb moisture in a high humidity environment. However, when the resistance was lowered, the electrostatic latent image was disturbed.

In order to avoid such drawbacks, in image forming apparatuses that use magnetic toner, a magnetic roller is placed in the cleaning device close to the photoreceptor, thereby increasing the
This toner is used to rub the surface of the photoreceptor to abrade and remove foreign matter as described above, and the toner is also allowed to reach a cleaning blade disposed downstream of the magnetic roller. A lubricant has been proposed that acts as a lubricant between the photoconductor and the photoreceptor.

FIG. 7 shows an example of such:
A cleaning device 20 is disposed in parallel with and close to a cylindrical photoreceptor 10 that rotates in the direction of the arrow and extends perpendicular to the plane of the paper.
, a magnet roller 40 is arranged on the upstream side of the photoreceptor when viewed in the traveling direction of the photoreceptor.

Assuming that magnetic toner is used as the developer, residual toner that does not contribute to transfer and remains on the photoreceptor at a transfer site (not shown) reaches the cleaning device 20 as the photoreceptor rotates, and is transferred to the magnetic roller 40. The captured toner forms a toner layer around it, and by supplying a sufficient amount of toner, a portion of this toner reaches the position of the cleaning blade, where it acts to remove foreign matter and lubricate the blade. play.

Note that reference numeral 50 is a regulating blade that regulates the thickness of the toner layer.

An amorphous photoconductor was used as the photoconductor, and its circumferential speed was 440 mts/sec.The magnetic roller had a diameter of 18II1m, a surface magnetic force of 8 Gauss, and a number of poles, as described later.The circumferential speed was that of the photoconductor. 80%, and as shown in the figure, when the distance between the photoreceptor and the magnet roller is γ, and the distance between the magnet roller and the regulating blade is δ, γ
When formed at a ratio of δ=1.30 to δ=1.00, a good leaning function was obtained even in a high humidity environment (temperature 32.5° C., humidity 85% RH).

However, in such cases, over a long period of time,
In order to sufficiently supply and contact the toner with the photoreceptor, it is necessary to set the interval δ larger than the interval γ. Therefore, the toner is not transferred to the transfer material due to jams, etc., and is collected as is in the cleaning device. As a result, as schematically shown in FIG. 8, the toner overflows inside the cleaning device and may further scatter and leak to the outside.

The present invention has been made to deal with such a π state, and is intended to prevent toner from leaking out of the cleaning device even when a jam occurs in a cleaning device equipped with a toner layer forming member such as a magnetic roller. Without,
It is an object of the present invention to provide a leaning device that can always provide a stable and good leaning function.

(2) Structure of the invention (technical means for solving the problem and its operation) In order to achieve the above object, the present invention includes a magnetic toner layer forming means such as a magnet roller, and a magnetic toner layer forming means such as a magnetic roller in the cleaning device. The cleaning device is equipped with a thickness regulating means, characterized in that the toner layer forming means is swingably arranged, and the distance between the means and the photoreceptor is variable.

With this configuration, the thickness of the toner formed on the toner layer forming means can be locally thinned so that it does not come into contact with the photoreceptor, so even if a large amount of toner enters the cleaning device, this It is possible to release the toner that has entered the apparatus at any stage, and the cleaning function can be maintained in good condition at all times without overflowing the toner and impairing the cleaning function or contaminating various parts within the apparatus.

(Description of Embodiments) FIG. 1 is a side view of essential parts showing an embodiment in which the present invention is applied to a copying machine equipped with a rotating cylindrical photoreceptor.
A cleaning device 2 is disposed close to.

It goes without saying that a negative charger, an image signal applying means, a developing device, a transfer charger, and other members necessary for image formation are arranged around the photoreceptor, but these are not directly related to the present invention. Since there is no such thing, I have omitted everything.

Inside the cleaning device, a cleaning blade 3 is disposed, and on the upstream side of the blade when viewed from the direction in which the photoconductor travels, a magnet roller 5, which is a toner layer forming member, is disposed at both ends thereof, and a lever 9 ( (only one of which is shown in the figure).

In particular, as can be seen from FIG. 2, regulating rollers 4 (only one of which is shown in the figure) are further attached to both ends of the magnet roller, and the other end of the lever 9 is Unmoving inside the cleaning device.

One end of the spring 8 is fixed in a proper position, and the other end of the spring 8 is locked.
Furthermore, a regulating blade 6 is provided to control the toner layer thickness.

Therefore, as can be seen from FIG. 1, the regulating roller 4 forms an appropriate gap between the magnet roller 5 and the photoreceptor, and due to the action of the cleaning blade 3, the magnetic roller 5 forms an appropriate gap between the magnet roller 5 and the photoreceptor. It functions in substantially the same way, and exhibits a rubbing cleaning effect and a lubricating effect.

It goes without saying that the regulating roller 4 is arranged so as to be located outside the image area on the surface of the photoreceptor.

In one aspect of the present invention in the leaning device as described above, the regulating roller is configured to be eccentric as described below.

FIG. 4 is an end view of the regulating roller 4, showing the arc B-A-D
The diameter of this part (180") is the same, and the diameter of this part is 10.0".
0, the radius at point C was set to 10.70, and the radius increased proportionally between arcs B-C1 and D-C within the range of the numerical values listed in 1.

The broken line γ in FIG. 5 shows the change in radius of the regulating roller 4 in a developed manner.

Next, the distance δ between the magnet roller 5 and the regulating blade 6 is such that the radius of the regulating roller 4 is to and o.

When the part faces the photoreceptor 1, δ=1.30
Further, as shown in FIG. 3, the tip of the regulating blade was positioned so as to be perpendicular to the straight line connecting the center of the photoreceptor l and the center of the magnet roller.

The broken line indicated by δ in Fig. 5 indicates the position when the regulating roller 4 rotates and reaches the position facing the regulating roller in the order of A, D, C, B from point B in Fig. 4. It shows the change in the uII distance δ between the regulating roller and the magnet roller.

FIG. 6 shows the difference between the intervals γ and δ set as described above in correspondence with the rotation angle of the magnet roller.

As can be seen from this graph, it is possible to set the toner layer to be in contact with the photoreceptor when δ>γ and not to be in contact with the photoconductor when δ>γ, and the toner layer can be set so that it is not in contact with the photoreceptor over approximately 174 rotations of the magnetic roller. It turns out that it can be done.

Therefore, as described above, even if a large amount of toner enters the cleaning device, the toner can escape using the non-contact portion.

Under the following conditions, an experiment was conducted in which a solid black image was formed on the photoconductor and the image was collected directly into the cleaning device using the same photoconductor and magnet roller as shown in Fig. 7 above. Toner equivalent to 100 continuous sheets of solid black images was fed into the cleaning device, but no toner overflowed.

In addition, we conducted a paper feeding test using a normal image, but the A4
Even after passing 100,000 sheets of paper, there was no poor cleaning or filming, and as mentioned above, even though the toner may not come into contact with the photoconductor locally, it is completely removed after many rotations. Since the photoreceptor was rubbed almost uniformly, there was no deterioration in image quality such as image deletion even in a high humidity environment (temperature: 33° C., 82.5% RH).

In the above embodiments, the magnet roller was used as is, but a magnet roller coated with a non-magnetic sleeve may also be used. In this case, the magnet can be fixed, and there are no particular restrictions on the direction of rotation of the sleeve. Furthermore, the material of the photoconductor, the number of poles of the magnet, the magnetic flux density, etc. should be adjusted to a sufficient amount in relation to the characteristics of the toner. Of course, it is possible to freely modify the toner layer as long as the toner layer can be formed.

Although an embodiment in which the present invention is applied to a copying machine has been described above, it is easy to understand that the present invention is not limited to this and can be applied to other image forming apparatuses such as printers.

(3) Effects of the Invention As explained above, the present invention provides a cleaning device equipped with a cleaning blade and a toner layer forming member that rubs a photoreceptor, in which a toner layer is formed by swinging the toner layer forming member means. Since the space between the photoreceptor and the photoreceptor is increased intermittently so that there is no contact with the photoconductor, this type of cleaning device can maintain a good cleaning function even if a large amount of toner enters. This toner can be easily removed so that the toner does not salt out or scatter, resulting in poor cleaning or contaminating various parts within the apparatus.

[Brief explanation of the drawing]

FIG. 1 is a side view of a main part showing an embodiment in which a cleaning device according to the present invention is applied to a copying machine k, FIG. 2 is a front view of a part of the same, FIG. 3 is a side view showing the arrangement of a regulating blade, Figure 4 is a side view of the regulation roller, Figure 5 is a graph showing the distance between the regulation blade and the magnet roller, and the change in the distance between the magnet roller and the photoconductor due to the regulation roller. FIG. 7 is a side view showing a known cleaning device; FIG. 8 is a side view of essential parts schematically showing irregular operating conditions of the cleaning device. 1--photoconductor, 2--e cleaning device, 3-fist
Cleaning blade, 4...Regulation roller, 5.φ fist magnet roller, 6@-.Regulation blade, 8...Spring, 9.Fist/lever, γ...Distance between magnet roller and photoreceptor, δ. φ Distance between magnet roller and regulation blade. Figure 1 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] A cleaning blade that presses against a moving image carrier;
A cleaning device comprising a toner layer forming means disposed on the upstream side of the blade as viewed in the running direction of the image carrier, and a toner layer thickness regulating means disposed near the toner layer forming means, the toner layer forming means and The toner layer forming means is controlled so that the toner layer periodically comes out of contact with the image bearing member by changing the distance from the image bearing member and the distance between the toner layer forming means and the toner layer thickness regulating means. A cleaning device equipped with a means for swinging.