JPH04483A - Cleaning device for image forming device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

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 transfer process, such as an electrostatic copying machine or a printer, and particularly to a cleaning device for the same. be.

(Prior Art and Issues to be Solved) A process is performed in which a transferable toner image formed on the surface of a moving image carrier is superimposed on a transfer material such as paper, and the toner image is electrostatically transferred to the transfer material. In known image forming apparatuses, residual toner that is not transferred to the transfer material during transfer is removed.
It is necessary to sufficiently remove it from the image carrier each time.

Various methods have been proposed to remove residual toner, including one in which one edge of a cleaning blade made of an elastic material such as urethane rubber is brought into pressure contact with the surface of the image carrier to scrape off the residual toner. It is well known that devices that remove toner are widely used because they have a simple construction, are compact, and have an excellent toner removal function.

FIG. 4 shows an example of a typical configuration of such a leaning device, and the configuration and operation will be briefly described using this figure.

A cleaning device C is disposed close to and parallel to a cylindrical image carrier 1 that extends perpendicularly to the plane of the paper and rotates in the direction of the arrow in the figure.

The cleaning device C has an opening formed on the side facing the image carrier, and a support member 2 attached to the edge of the opening.
A cleaning blade 3 supported by is in pressure contact with the image carrier 1 .

Some of the toner that has not been transferred to the transfer material at a transfer site (not shown) reaches the edge portion of the cleaning blade 3 as the image carrier 1 rotates, and is scraped off from the image carrier by the cleaning blade 3 here. The toner is guided by the scooping sheet 5 and sequentially stored in the toner storage section in the casing 4.

In such a device, in order to prevent collected toner from accumulating near the scooping sheet 5, the toner storage space can be fully utilized by moving the toner to the back of the toner storage section using, for example, a rotating blade or the like. It has been previously proposed to do so.

However, a cartridge that has become widely used in recent years is a cartridge that integrates an image carrier and some components arranged around it, such as a wide charger, a developing device, and a cleaning device. Since this type of image forming apparatus is intended to be small and low-cost, it is common to have a configuration in which means such as the above-mentioned rotating blades are removed.

In such a case, to increase the collected toner capacity, the casing 4 of the cleaning device C should be extended downward or to the left in FIG.
Since there is a conveyance path in that part for conveying the transferred transfer material to the fixing site, it can be said that this is virtually impossible in a cartridge-type image forming apparatus where compactness is the top priority.

Furthermore, extending the casing 4 to the left will increase the smoothness, but if there is no means to send the collected toner deep into the casing, such as the aforementioned blade, the toner will be removed from the area near the blade. This causes the problem that even if the capacity of the casing is increased, it cannot be utilized.

This will be further explained with reference to FIG. 4 and subsequent figures.

As shown in FIG. 4, if the point at which the cleaning blade 3 comes into contact with the surface of the image carrier is i, then this point is at an angle greater than the horizontal line passing through the center g of the image carrier 1 when the image carrier is traveling. By configuring the blade 3 so that it is located on the downstream side when viewed in the direction of the blade, the permissible setting range for the direction of the blade 3 is increased, and the length of the casing, especially the vertical length of the image carrier side thereof, is reduced. It is normal to make sure that there are no problems.

However, with such a configuration, the toner scraped off from the surface of the image carrier is scraped off by subsequent toner.
Since the toner is subjected to a pressing action in the tangential direction at point i, it tends to solidify in this area, and as a result, the toner gradually grows in the vicinity of the inlet of the cleaning device, as shown by the arrow in FIG. , and finally reaches the top of the casing, as shown in FIG.

In this state, the toner continues to be subjected to the force in the direction of arrow C, so some of the toner falls in the direction of arrow d, but the other part tends to further assimilate, and from then on The toner scraped off by the blade cannot enter the cleaning device (and slips through the blade, resulting in poor cleaning).

Such a situation is extremely inconvenient in a cartridge-type image forming apparatus because the life of the cartridge is unduly shortened due to a malfunction of the cleaning device.

The present invention has been made in order to cope with such a situation, and it is possible to completely utilize the recovered toner storage section in a cleaning device using a cleaning blade without causing the above-mentioned inconveniences. like,
The present invention is intended to provide a cleaning device, and is particularly advantageous in the case of a cartridge type that does not have a separate waste toner container for guiding and storing waste toner.

(2) Structure of the invention (technical means for solving the problem and its operation) In order to achieve the above object, the present invention provides a cleaning apparatus equipped with a cleaning blade that comes into pressure contact with an image bearing member, in which a casing above the cleaning blade is It is characterized by forming a layer made of a material with good slipperiness on the wall surface.

With this configuration, it is possible to effectively utilize the space of the toner storage section without providing a special toner moving means in the toner storage section of the cleaning device, and to increase the toner storage capacity of the cleaning device. I can do it.

(Description of Embodiments) FIG. 1 is a side sectional view of a process cartridge showing an embodiment in which the present invention is applied to a cartridge-type image forming apparatus. An image carrier 1 having an axis in the vertical direction and rotating in the direction of arrow a, a charging device 7, a developing device 6, and a cleaning device C are arranged, and these can be attached to and removed from the main body of the image forming apparatus as a whole. It can be worn freely.

To explain the cleaning device C among the above,
One free edge of the cleaning blade 3, which is formed integrally with the support member 2 attached to the cleaning device, is in pressure contact with the surface of the image carrier.

The contact point i of the cleaning blade 3 on the image carrier is located at an angle h, 3° in the case of the illustrated apparatus, above (downstream side) from a horizontal line passing through the center g of the image carrier.

The support member 2 is bent into a substantially L-shape, and is located on the image carrier 1 side of the casing 4 and constitutes a part thereof. (one of which is shown) is attached to the side wall of the casing of the cleaning device.

It is assumed that the toner scraped off from the surface of the image carrier by the cleaning blade 3 is guided by the transparent sheet 5 and sequentially stored in the casing.

In such a configuration, the inner wall surface of the casing of the support member 2 is coated or formed in the form of a tape with a layer 9 made of a fluororesin with good slipperiness such as PTFE, PFA, FEP, silicone resin, or paraffin. It is formed by an appropriate means such as pasting something else.

Since such a layer 9 is formed, the toner gradually grows inside the casing, behind the cleaning blade 3 and the support member 2 (when the toner reaches the top of the casing, due to the presence of the layer 9 with good slipperiness, The toner is guided and stored toward the back of the casing along the arrow e without solidifying.

Therefore, it is possible to reliably avoid a situation where toner accumulates and solidifies near the cleaning blade and becomes impossible to collect even though there is sufficient space within the casing.

The image carrier 1 contacts the horizontal line passing through the center of the image carrier 1 at an angle to the upstream side in the rotation direction of the image carrier, and supports the support member 2, the blade 3, and the contact point i of the blade to the image carrier. When the angle j formed with the tangent to the body is 28°,
When the angle is up to 45 degrees, the collected toner is pushed up by the rotation of the image carrier rather than in the direction of gravity, and even after a certain amount of toner has been stored, the toner is collected one by one.

If the angle is greater than 45 degrees on the upstream side as viewed from the image carrier traveling direction, the toner will be stored in the container by gravity, so the above-mentioned layer with good slipperiness is not necessary.

Furthermore, when the blade is moved downstream in the running direction of the image carrier, by providing a slippery layer as described above up to an angle of 90 degrees, the toner can be transferred into the toner storage casing. It has been confirmed that the items can be stored efficiently and sequentially.

FIG. 2 shows another embodiment of the present invention, in which the inner surface of the opening on the image carrier side of the casing 4 of the cleaning device C on the side where the support member 2 of the cleaning blade 3 is located is It is formed into a curved surface 4a that is concave inward, and a layer 91 is formed from the curved surface to the top of the casing by applying or adhering a coating made of the same material as the slippery layer 9 of the above embodiment. be.

If the mold of the cleaning container covers the entire back surface (waste toner storage side) of the blade support member 2 in the longitudinal direction, it is usually made of PP01ABS or the like rather than directly contacting the waste toner on the back surface of the blade support member 2. If the inner surface of the mold of the cleaning container directly contacts the waste toner, the circulation of the toner will be better without forming a slipping layer.

FIG. 3 shows still another embodiment of the present invention,
The same reference numerals are given to the parts corresponding to those of the apparatus of each of the above-mentioned embodiments, and the explanation thereof will be omitted.

In this device, a blur 3 is held between two support members 2, and a toner guide plate 10 recessed inside the casing is attached above the cleaning blade 3 in the drawing. As in the case of the previous embodiment, a layer 92 made of PTEF or other slippery material is formed on the inner surface of the holder.

As the guide plate 10, it is preferable to use a plate made of, for example, 1 mm thick SuS with a radius of curvature of about 10 mmφ, but of course it is not limited to SuS.

With this configuration, the toner collected in the casing is smoothly conveyed along the guide plate 1o, and the space inside the casing can be effectively utilized.

The above configuration is advantageous because it can be easily applied to the casing of a known cleaning device without any major design changes.

(3) As described in detail, according to the present invention, there is no need to provide a means such as a blade in the toner storage space of the cleaning device to actively move the collected toner to the back side.
By effectively utilizing the space, the toner storage capacity can be substantially increased, and especially by applying it to a cleaning device for a cartridge-type image forming apparatus, it is possible to realize downsizing and cost reduction.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a cleaning device showing an embodiment of the present invention, FIGS. 2 and 3 are side sectional views of a cleaning device showing other embodiments of the present invention, and FIGS. 4 to 6 1 is a side sectional view for explaining the behavior of toner in a known cleaning device. DESCRIPTION OF SYMBOLS 1... Image carrier, 2... Supporting member, 3... Cleaning blade, 4... Casing, 5... Scooping sheet, 9.91.92... Slippery layer, 10.・・・
Guide plate. 3n

Claims (3)

[Claims] (1) A cleaning device including a cleaning blade that presses against an image carrier, in which a layer made of a material with good slipperiness is formed on the inner wall surface of a casing above the cleaning blade. (2) The inner wall surface of the casing, which forms a layer with good slipperiness,
Claim 1 formed by forming a concave inside the casing.
Cleaning device as described in section. (3) The inner wall surface of the casing, which forms a layer with good slipperiness,
2. The cleaning device according to claim 1, which is a plate body located above the cleaning blade inside the casing and having a curved surface formed concavely inside the casing.