JPH01235985A - Device for cleaning 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 therefor. be.

(Prior art and problem to be solved B) In a well-known image forming apparatus that repeats the process of transferring a toner image electrostatically formed on an image carrier to a sheet-like transfer material mainly made of paper, Since the entire amount of toner forming the toner image is not transferred to the transfer material each time the toner image is transferred, it is essential to sufficiently remove the residual toner remaining on the surface of the image carrier each time the image is transferred.

As a cleaning means for this purpose, a conventional cleaning blade made of an elastic material such as rubber is used, and one edge of the cleaning blade is pressed against the surface of the image carrier to scrape off the toner that reaches this area. It is well known that the toner has a simple structure, low cost, and excellent toner removal function, so it is widely used.

FIG. 5 schematically shows an example of a typical cleaning device of such a cleaning device. 2 are arranged close to each other, and one edge of the free edge of the cleaning blade 3 attached to the cleaning blade 3 is in pressure contact with the surface of the image carrier 1, and does not contribute to the transfer at a transfer site (not shown). When the toner remaining on the surface of the image carrier reaches the pressure contact edge of the blade 3 as the image carrier rotates, it is scraped off by this.

At this time, it is effective and often adopted to press the free edge of the cleaning blade against the image carrier in the direction shown (counter direction), but on the other hand, There are drawbacks as mentioned.

That is, in order for the contact edge of the cleaning blade to perform a stable cleaning function, it is necessary to press the surface of the image carrier with uniform pressure over its entire length, but the surface of the image carrier is coated with toner due to use. Unavoidable fusion occurs, or corona products due to the presence of high-pressure members in the device, paper dust, and future deposits adhere to the image carrier, resulting in unevenness. The friction between the blade and the surface of the image carrier becomes extremely large, and the end of the blade sometimes curls up and loses its cleaning function, as shown by reference numeral 3b in the figure. In particular, in the case where the photosensitive layer on the surface of the image carrier is formed of an organic semiconductor, the friction with the cleaning blade is large and peeling is likely to occur. In the case of non-magnetic developers, which are becoming more popular, it has been found that poor cleaning and blade curling tend to occur from both ends of the blade.

In order to avoid such drawbacks, for example,
As seen in Japanese Patent No. 212881, it has been proposed to cut off both end portions of the blade that comes into contact with the image carrier, but with such means, toner that has run sideways to both ends is removed from the end portions. This resulted in defects that could scatter and contaminate the transfer material and other parts of the device.

The present invention has been devised to deal with such a situation, and is a cleaning device that uses a cleaning blade, which has an extremely simple configuration and can perform stable cleaning at all times without causing the blade to turn over. The object of the present invention is to provide a leaning device.

(2) Structure of the invention (technical means for solving the problem, its effect) In order to achieve the above object, the present invention brings an elastic cleaning blade integrally formed with a supporting member into pressure contact with the surface of a traveling image carrier. This cleaning device is characterized by having means disposed near both ends of the cleaning blade to release stress from the cleaning blade.

With this configuration, it is possible to prevent blade curling and cleaning defects, and to perform stable cleaning over a long period of time.

FIG. 2 is a front view of a cleaning blade to which the present invention is applied, which can be used in a cleaning device. The blade is attached to the casing so that the free edge of the blade is pressed against the surface of the image carrier.

In such a blade, both ends of the support member 5 are cut off as shown by the reference numeral 5a, so that the part on which the elasticity of the blade acts is substantially more at the ends than at the center of the blade. It is designed to be large.

With this configuration, the stress accumulated at the end of the blade can be released, the entire length of the blade can contribute to the toner removal action, and the blade can be prevented from turning over, allowing stable cleaning and cleaning action to be performed at all times. can.

Next, experimental examples of the present invention will be explained.

(Experimental Example) The blade configured as described above was used, and the image carrier to which the blade came into pressure contact was an aluminum cylinder with a diameter of 80 mm and a photosensitive layer configured as shown below was formed on the surface.

Ammonia aqueous solution of casein (casein 11.2 gr, 28% ammonia water 1 gr, water 2
22m1) was applied using the coating method and dried to a coating amount of 1.
．． A subbing layer of 0 gr/m'' was formed.

Next, 1.0 parts by weight of a charge generating substance represented by the formula below, 1 part by weight of butyral resin (S-LEC BM-2: manufactured by Sekisui Chemical) and 30 parts by weight of isoprobil anecol were dispersed for 4 hours using a ball mill disperser. This dispersion was applied onto the undercoat layer by a dip coating method and dried to form a charge generation layer. The film thickness at this time was 0.3 l.

Next, 1 part by weight of a charge transport substance represented by the following formula, 1 part by weight of polycarbonate resin (manufactured by Iupilon II, manufactured by Mitsubishi Chemical), and 6 parts by weight of dichloromethane were mixed and dissolved by stirring with a stirrer. This liquid was applied onto the charge generation layer by dip coating and dried to form a charge transport layer. The film thickness at this time was 17g.
Met.

Using the image carrier configured in this way, we conducted a paper feeding test of 100,000 sheets using non-magnetic toner, and no blade curling or poor cleaning occurred, and in the end, an image similar to the initial image was obtained. I was able to do that.

(Comparative Experimental Example) When a paper feeding test was carried out under the same conditions as in the experimental example above, except that both ends of the blade support member were not cut off, the blade curled up from the front end of the blade after 500 sheets. The device stopped. In addition, marks remained on the surface of the image carrier and appeared as sushi on the image.

FIG. 2 shows a blade according to another embodiment of the present invention, in which the blade supporting member is embedded in the cleaning blade to integrate the two, and the width of the supporting member near both ends is set to the width of the central part. It has a narrower configuration.

An image forming apparatus using this blade and a laser printer using non-magnetic toner can produce 20,000 images.
When a sheet feeding test was conducted, no blade curling or cleaning failure occurred.Furthermore, by using the above blade and using an amorphous silicon photoreceptor as the photosensitive layer of the image carrier, as an image forming apparatus, When a 25,000 sheet feeding test was conducted with the charging polarity reversed from the above case, no blade curling or poor cleaning occurred.

On the other hand, when similar tests were conducted using only the known configuration of the blade support member, in the former test, blade curling occurred from the back end of the blade after 250 blades, and in the latter test, In some cases, the blade turned over from the back side after 160 sheets, and the device stopped in both cases.

3A, 3B, 4A, and 4B show still other embodiments, and the front two figures show the support member 5.
The cleaning blade is glued to the 2nd figure.
The cleaning blade is integrally formed with the support member 5 by molding.

In this way, each of the illustrated cleaning blades has one or several recesses 3 near both ends of the cleaning blade.
a or 3c, and this portion is formed into a substantially thin wall portion.

Using the blades shown in Figures 3A and 3B, and using the same image carrier as in the above-mentioned experimental example, we conducted a 1cm paper passing test using non-magnetic toner. This did not occur at all, and the leaning was stable and good throughout.

In addition, we conducted a 20,000-sheet feeding test using the blade shown in Figures 4A and 4B and non-magnetic toner using an image forming apparatus equipped with a laser beam printer. Until the end, there were no blade curls or cleaning failures.

Comparative paper passing was carried out using the same image forming apparatus as above using a blade that did not form a recess as described above, but in the case of the blade shown in the first two figures, 300 sheets were passed, and the second two
In the case of the blade shown in the figure, blade curling occurred from the back side of the blade after passing 180 sheets, and the apparatus also stopped.

Furthermore, a 300 QO sheet feeding test was carried out using the image forming apparatus shown in FIGS. 4A and 4B using an amorphous silicon photoreceptor and with the charge polarity reversed from the above case. There were no problems in this case either, and the leaning was good from start to finish.

The embodiments of the present invention are generally as follows.

■ The stress relief means near both ends of the cleaning blade are
A cleaning device according to claim 1, wherein the cleaning device is constructed by cutting off both ends of the support member.

(2) A cleaning device according to claim 1, wherein the stress relief means near both ends of the cleaning blade are formed by thin-walled portions near both ends of the blade.

(3) Effects of the Invention As can be seen from the above description, according to the present invention, in a cleaning device configured such that the cleaning blade is brought into pressure contact with the image bearing member, occurrence of blade curling and transfer defects is prevented as much as possible. Since the desired cleaning function can be stably maintained over a long period of time, it greatly contributes to obtaining high-quality images.

[Brief explanation of the drawing]

Figures IA and 1B are a front view and a side view of a cleaning blade applied to the cleaning device of the present invention, and Figures 2A, 3A, and 4A are a front view and a side view showing other embodiments of the cleaning blade. 2B, 3B, and 4B are front views of the cleaning blade, and FIG. 5 is a schematic side view illustrating the operation of the known cleaning device. 1... Image carrier, 2... Cleaning device, 3...
Cleaning blade, 5... support member. Fig. 1A Fig. 7B Fig. 2A Fig. 28 Fig. 3A Fig. 3B et al. Fig. 4A Fig. 4B j

Claims (1)

[Scope of Claims] A cleaning device in which an elastic cleaning blade integrally formed with a support member is brought into pressure contact with the surface of a traveling image carrier, wherein means for relieving stress in the portion is disposed near both ends of the cleaning blade. A cleaning device that does this.