Sharp Kabushiki Kaisha Corporation

Yohichi Takesawa

Eiichi Kido

Tatsuhiro Morita

Shinya Mimura

Shigeki Hayashi

Hiroshi Sugimura

Takatsugu Obata

Akihiro Kondoh

Hisayuki Utsumi

Fumito Mizoguchi

Kotaro Fukushima

Toshio Nishino

Tomoko Kanazawa

Katsuya Takano

An electrophotographic photoreceptor of high durability capable of providing stable excellent electrical characteristics over a prolonged period of time, which electrophotographic photoreceptor excels in mechanical strength. A photosensitive layer () of an electrophotographic photoreceptor () includes a polyarylate resin having structural units, for example, those of formula (1) and an enamine compound represented by, for example, formula (2) The variables R, R, R, R, R&#x2dc;R, X, Ar, Ar, Ar, Ar, Ar, R, R, R, R, a, m, and n are as defined in the specification. By virtue of these, the electrophotographic photoreceptor () of excellent mechanical strength and favorable electrical characteristics can be realized.

Electrophotographic photoreceptor and image forming apparatus including the same

A blade cleaning jig includes a cleaning portion and a gripping portion. The cleaning portion includes a support body of stainless steel or the like and polishing tape provided on the upper face of this support body, and moreover a cushioning material is inserted between the support body and the polishing tape. A protective member for preventing damage to the surface of a developer roller is attached to the entire lower face of the support body. This protective member is attached bent at a circumferential end portion such that the protective member covers from the lower face of the support body via a circumferential edge portion to an upper face circumferential edge portion.

Blade cleaning jig

A development apparatus includes an auger conveyor member for stirring and conveying developer, the gravity of the developer being eccentrically distributed with respect to a center of rotation, a drive transfer member for driving and rotating the auger conveyor member, the drive transfer member being capable of being engaged and disengaged, and a rotation detector for detecting a rotational state of the auger conveyor member. The remaining amount of the developer is detected based on the rotational state detected by the rotation detector. Alternatively, a development apparatus includes the auger conveyor member and the drive transfer member, in which the eccentric gravity distribution is achieved by a rod-like weight member eccentrically provided with respect to a rotational axis, the auger conveyor member includes a first coil spring having an inner diameter larger than an outer diameter of the weight member, and the first coil spring is inserted around the weight member in a manner which allows the first coil spring to be rotated and limits an angle of rotation of the first coil spring to a predetermined angle. Alternatively, a development apparatus includes the auger conveyor member and the drive transfer member, in which the auger conveyor member is provided near a development supply roller, and a uniforming member for making the developer uniform is provided in a space portion between the development supply roller and the auger conveyor member.

Developing agent detecting mechanism section of developing apparatus

An electrophotographic photoreceptor using a non-contact type charging process has a creep value Cof is 2.70% or more, preferably 3.00% or more, and a Vickers hardness (HV) at its surface of 20&#x2266;HV&#x2266;25 in a case where a maximum indenting load of 30 mN is loaded to the surface under a circumstance at a temperature of 25&#xb0; C. and at a relative humidity of 50%. Since such an electrophotographic photoreceptor is excellent in flexibility and has plasticity not too soft nor exhibiting fragility, the amount of film reduction due to wear is decreased during long time use, excellent surface smoothness is ensured, and there is no occurrence of injury or unevenness in density to the formed images.

Electrophotographic photoreceptor and image forming apparatus having the same

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Toyonaka, Japan

Yohichi Takesawa