JPH0635258Y2 - Cleaning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a blade type cleaning device for removing toner remaining on a photoconductor, and more particularly to a cleaning blade having excellent heat resistance.

(Prior Art) Conventionally, an electrostatic latent image formed by charging and exposing a photoconductor is developed with powder toner, and at the same time, the toner image is transferred to a base material such as copy paper to fix the toner image. Therefore, an image forming apparatus for forming a copied image is widely used. Further, in the image forming apparatus, the transfer efficiency of the toner image is 80%.
It is about 90%, and toner that does not contribute to image formation remains on the photoconductor.Therefore, remove the residual toner remaining on the photoconductor with the cleaning blade of the cleaning device to clean the surface of the photoconductor. There is.

In the blade type cleaning device, as shown in FIG. 1, a blade is provided along the width direction of the photoconductor 11, and the tip of the blade is pressed against the surface of the photoconductor to scrape off the remaining toner. Cleaning is in progress. Then, in order to enhance the cleaning effect with this method, the blade may be strongly pressed against the photoconductor,
Due to the frictional force generated by the rubbing of the photosensitive member and the blade, the tip of the blade may be damaged or the blade may curl up and turn over. In order to solve such a problem, a fluorine resin, especially a polyvinylidene fluoride resin fine powder is sprinkled on the blade tip, or a polyvinylidene fluoride resin powder as seen in JP-A-61-255375. It has been conventionally practiced to incorporate the above into a blade to provide lubricity to reduce frictional force.

However, when used for a long period of time or when cleaning is performed by pressing the blade against a high-speed machine where the rotation speed of the photosensitive drum is particularly high, the contact surface is heated to a considerably high temperature due to the rubbing of the blade tip and the photosensitive member. The mixture of styrene and vinylidene fluoride may be melted by the heat and adhere to the photoreceptor. These things are especially noticeable when the photoconductor is amorphous silicon having a heater inside and the surface temperature of the photoconductor is high, or when copying is performed in a high temperature and high humidity environment. Then, the cleaning effect is deteriorated by the adhering matter, and the obtained copy image is inferior because black streaks are generated.

Therefore, an object of the present invention is to solve the above-mentioned problems and to use a high-speed rotating photoconductor drum, or a blade having stable cleaning performance without deterioration even when used for a long time under high temperature and high humidity. The purpose is to provide a cleaning device of the type.

(Means for Solving the Problems) According to the present invention, in a cleaning device provided with a cleaning blade for removing toner remaining on the photoconductor, the cleaning blade is formed of an elastic body, The above problems can be solved and the object can be achieved by using a cleaning blade in which the tip of the blade to be pressed is coated or containing fine silicone resin powder.

The present invention will be described in detail below.

The silicone resin fine powder used in the present invention is characterized by having water resistance and lubricity peculiar to the silicone resin, and being very excellent in heat resistance as compared with the organic fine powder. The fine powder has a spherical shape with a particle diameter of 0.1 μm to 10 μm and exhibits good dispersibility and non-aggregating property. Therefore, it is mixed in the blade or sprinkled on the tip of the blade for use.

When a cleaning blade containing or coated with the above silicone resin fine powder is used, the silicone resin fine powder as a lubricant does not deteriorate due to heat generated by friction between the surface of the photosensitive drum and the tip of the blade. A good cleaning effect is exhibited for a long period of time without contaminating the photosensitive drum.

Hereinafter, the present invention will be described in detail based on embodiments and attached drawings.

(Embodiment) FIG. 1 is a schematic view of a main part of a cleaning device, and FIG. 2 is a schematic view of a copying machine as an image forming apparatus.

The photoconductive drum (11) is provided on the outer periphery of the photoconductive drum (11).
A charging device (12) for uniformly charging the surface of the document, an optical system (not shown) that exposes the document and guides the reflected light from the document to the surface of the photoconductor drum (11), and the exposure Developing device (13) for developing an electrostatic latent image formed corresponding to the original image by the transfer, and transfer for transferring the toner image formed on the photosensitive drum (11) by the development to a base material such as copy paper. Remaining on the photoconductor drum (11), and a transfer device (14) composed of a charger and the like, a separation device (15) composed of a separation charger and the like for separating the base material on which the toner image is transferred from the photoconductor drum (11). A cleaning device (16) for removing the generated toner is sequentially arranged. Therefore, the charging device (1
2) An electrostatic latent image is formed on the surface of the photoconductor drum (11) by guiding the original image onto the photoconductor drum (11) that is uniformly charged by the above optical system, and the electrostatic latent image is formed in the developing device (13). Visualized as a toner image by the powder toner stored in
The transfer device (14) transfers the toner image onto the base material conveyed through the resist roller (not shown), and the separating device (15) separates the equipment, and the photoconductor drum (11).
The toner remaining on the surface of the photosensitive drum (11) can be cleaned by removing it with a cleaning device (16). Further, the base material separated from the photoconductor drum (11) can be guided to the fixing device (17) to fix the toner image.

In addition, the cleaning device (16) body (18),
A cleaning blade (19) as a removing means for removing the toner remaining on the photosensitive drum (11), and a photosensitive drum (11) and a cleaning device main body (18) located below the cleaning blade (19). And a sealing blade (20) for sealing between and. The cleaning blade (19) is held by the holder (21). Further, the toner scraped off by the cleaning blade (19) is guided to the bottom of the cleaning device main body (18) by the seal blade (20), and is rotatable provided on the bottom of the cleaning device main body (18). The toner is collected in the toner collecting container (23) by the conveying action of the spiral (22).

The toner collection container (23) is detachably attached to the toner collection container cover of the cleaning device main body (18).

Examples of the material of the cleaning blade (19) include polyurethane, styrene-butadiene copolymer, chloroprene, butadiene rubber, and elalen-proylene-
Various materials such as diene rubber, chlorosulfonated polyethylene rubber, fluorine rubber, silicone rubber, acrylic rubber, and other elastomers can be used, but polyurethane that does not damage the photoconductor drum (11) due to friction and has great wear resistance can be used. preferable.

And as the silicone resin fine powder which is preferably used in the present invention to be applied or contained on the tip of the cleaning blade, it can be obtained from Stpearl 120, Tospers 240 (both manufactured by Toshiba Silicone Co., Ltd., trade name) and the like. . Then, as shown in FIG. 3, the silicone resin fine powder (32) is sprinkled on the tip of the blade (31) to be uniformly attached to the tip for use. When the silicone resin fine powder is contained in the blade, for example, a reinforcing agent (carbon black or the like) is added to a polyol-based (ethylene glycol, triisopropanolamine or the like) oligomer and premixed. Then, an isocyanate-based (3.3'-dimethyl-4.4'-diphenylene diisocyanate or the like) monomer and a silicone resin fine powder are added to and mixed with the premix oligomer. This is poured into a molding machine for cleaning blades, heated at a predetermined temperature for one day and then left at room temperature for 1 to 2 hours, taken out and cut into blades for use.

Hereinafter, the present invention will be described in more detail with reference to experimental examples, but the present invention is not limited thereto.

(Experimental Example 1) Silicone resin fine powder Tospearl 120 (trade name, manufactured by Toshiba Silicone Co., Ltd., average particle size: 2 μm) was uniformly applied to the tip of a cleaning blade made of urethane rubber.

And DC-50 which has a heater in the photoconductor drum
Using a modified 55 (Mita Kogyo Co., Ltd.) machine, attach the above urethane rubber blade to the holder and press it against the photoconductor at a contact pressure of 11 g / cm, at room temperature and normal humidity (25 ° C, 65%) and high temperature and high humidity ( 35 ° C,
The printing endurance test of 20,000 sheets was performed under the environment of 85%). The results are shown in Table-1.

(Experimental Example 2) Instead of the silicone resin in Example 1, polyvinylidene fluoride resin fine powder KAINA (KYNAR-Benwald
The same operation was performed and the same test was performed except that (trademark of Corporation) was used. The results are shown in Table-1.

As a result of the printing durability test, when a blade sprinkled with polyvinylidene fluoride resin fine powder is used as shown in Table 1, cleaning failure occurs every time the number of copies is increased. After passing the number of sheets, black streaks were found everywhere in the copy. On the other hand, when the cleaning blade sprinkled with the silicone resin fine powder was used, as shown in Table 1, no image stain was generated even under such high temperature and high humidity, and a clear image stood up to 20,000 sheets.

Furthermore, when the photoconductor and the cleaning blade after the printing durability test were observed, in Experiment 2, black deposits were found on the photoconductor, and the tip of the blade was a welded mixture of polyvinylidene fluoride and toner The smoothness of the surface was lost. On the other hand, the photoconductor used in Experimental Example 1 had no deposit and was not much different from the photoconductor surface before the printing durability test. No toner adhered to the blade tip.

(Effects of the Invention) According to the present invention, by coating or containing the silicone resin fine powder on the blade tip, the silicone resin fine powder does not deteriorate even when it is exposed to heat due to friction between the blade and the photoconductor, and is stable. It gives the lubricity. Therefore, the cleaning blade can be strongly pressed against the photoconductor, and the cleaning performance is not deteriorated even when continuous copying is performed for a long period under a high temperature and high humidity environment. Further, the toner and the lubricating powder (silicone resin fine powder) due to the frictional heat do not adhere to the photoconductor, so that the generation of black streaks in the copy can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of a cleaning device. FIG. 2 is a schematic diagram of a copying machine. FIG. 3 is an enlarged view of the tip of the cleaning blade 11 ... Photosensitive drum, 16 ... Cleaning device, 18 ... Cleaning device body, 19, 31 ... Cleaning blade 32 ... Silicone resin fine powder

Claims (2)

[Scope of utility model registration request] 1. A cleaning device equipped with a cleaning blade for removing toner remaining on a photoreceptor,
The cleaning blade is formed of an elastic body,
A cleaning device, wherein fine particles of a silicone resin are applied or contained on the tip of a blade that comes into pressure contact with a photoreceptor. 2. The particle size of the silicone resin fine powder is 0.1 μm.
The cleaning device according to claim 1, wherein the cleaning device has a thickness of m to 10 μm.