Sharp Kabushiki Kaisha Corporation

Tatsuhiro Morita

Mikio Kakui

Masayuki Sakamoto

Yoshihide Shimoda

Tomoko Kanazawa

Sayaka Fujita

Tadashi Nakamura

Satoshi Katayama

Rikiya Matsuo

Hiroshi Sugimura

Koichi Toriyama

Kazushige Morita

Akihiko Kawahara

Shinya Mimura

Yohichi Takesawa

Kiyofumi Morimoto

Takatsugu Obata

Akihiro Kondoh

Hisayuki Utsumi

Kotaro Fukushima

Shintaro Miyanishi

Makoto Kurokawa

Satoshi Machino

Katsuya Takano

Hiroko Ishibashi

Takahiro Teramoto

Tomomi Nakamura

Yoichi Takesawa

A hybrid particle according to the present invention includes an inorganic core particle, an electron transport layer covering a surface of the inorganic core particle, and a light absorption layer covering the electron transport layer. The light absorption layer contains a compound having an organic-inorganic hybrid perovskite crystal structure or a metal complex. The compound or the metal complex is grown in a crystalline form on a surface of the electron transport layer.

Hybrid particle, photoelectric conversion element, photosensitive body, and image forming apparatus

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

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

It is an object of the invention to inspect defects of a film formed on a relatively rough surface of a substrate by the light interference method. A substrate on which a film is formed is irradiated with light of a longer wavelength than the surface roughness Rmax or Rz of the substrate to obtain interference fringes to inspect defects of the film formed on the substrate. Especially, it is preferable that when the surface roughness Rmax or Rz is 0.5 &mgr;m or more, the substrate is irradiated with light of a wavelength beyond a little longer wavelength than the surface roughness Rmax or Rz. The surface of the substrate is subjected to a cutting process. Specifically, it is possible to inspect defects of the electric charge generation layer, electric charge transport layer, or undercoat layer of an electrophotographic photoreceptor. This photoreceptor is mounted in a digital copier or printer. Further, monochromatic light is preferably applied. Alternatively, indirect light of the light reflected from a reflector plate or the light diffused by a diffusing plate is preferably applied.

Film defect inspection method for a film formed on a substrate

The invention provides an electrophotographic photoreceptor, in which suppression of image defects and high sensitivity are compatible, and a method for production thereof. The invention also provides a coating fluid for forming a photosensitive layer and a method for production thereof, as well as an image-forming apparatus using said electrophoto-graphic photoreceptor. Briefly, the electrophoto-graphic photoreceptors may be constructed by forming an undercoating layer on a conductive support, and then forming a photosensitive layer on the undercoating layer. The undercoating layer contains titanium oxide particles in at least either needle shape or dendrite shape. The photosensitive layer contains an electric charge-generating material of which the primary particle size and cohesive particle size are in a range of 0.01 &mgr;m-10 &mgr;m. Accordingly, in the electrophotographic photoreceptors, it is possible to maintain high sensitivity and excellent durability and to form an image with no defect. The photosensitive layer in the electrophotographic photoreceptor has a multilayer structure consisting of a charge-generating layer and a charge-transporting layer. The charge-generating material is a phthalocyanine pigment.

Electrophotographic photoreceptor, process for production thereof, and image-forming apparatus using same

Test method and control method for coating liquid for electrophotographic photoconductor

An organic electrophotographic receptor comprising at least an undercoating layer, an electric charge generating layer, and an electric charge transferring layer which are laminated in said order, wherein a coating fluid for forming said electric charge generating layer comprising an electric charge generating material, a binding resin, a silicon oil having a surface tension of 22 mN/m or less, and an organic solvent is stored inside a tank and a photosensitive base supported by a chucking device is dipped into said coating tank so as to form said electric charge generating layer.

Coating fluid for electric charge generating layer, organic electrophotographic receptor, and method to manufacturing the same

An electrophotographic photosensitive element is provided with a photosensitive layer containing a charge generating substance and a charge transport substance on a conductive support. X-type metal-free phthalocyanine and a disazo compound are contained as a charge generating substance. With the photosensitive element, sufficient sensitivity is achieved so as to cause virtually no problem, and it is possible to reduce possibility of causing an instable electrostatic property such as a reduction in a charge potential and an increase in a remained potential, even in the case of frequent reuse.

Electrophotographic photosensitive element and manufacturing method thereof

Highly sensitive and highly durable electrophotographic photoreceptors which generate faultless images can be produced by forming the under-coating layer on the conductive support and forming the photoreceptive layer on the layer. The under-coating layer contains dendritic titanium oxide. The under-coating layer contains the dendritic titanium oxide of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s). The photoreceptive layer contains a phthalocyanine pigment, and the under-coating layer contains dendritic or needle-like titanium oxide of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s). The photoreceptive layer contains a phthalocyanine pigment, and the under-coating layer contains dendritic or needle-like titanium oxide, of which the surface is coated with (a) metal oxide(s) and/or (an) organic compound(s), and an alcohol soluble polyamide resin.

Electrophotographic photoreceptor, process for production thereof, and

An object of the invention is to provide an electrophotographic photoconductor featuring uniform chargeability to a predetermined potential, low residual potential and excellent stability in the operating environment and repeated use thereof, as well as a method of producing the same. An undercoat layer between a substrate and a photosensitive layer is formed by the use of a coating fluid for undercoat layer containing a coupling agent having an unsaturated bond, a metal oxide, a binder and a mixture solvent. The coupling agent increases affinity of the metal oxide for the binder so that the coating fluid does not suffer the aggregation of the metal oxide or gelation thereof, presenting homogeneity and excellent can-stability. Thus is obtained a uniform undercoat layer. A photoconductor having this undercoat layer is adapted to be uniformly charged to a predetermined potential and to suppress the rise of residual potential and particularly the rise of residual potential due to a use thereof under low-temperature, low-humidity conditions or the repeated use thereof over an extended period of time, thus offering a high photosensitivity in a stable manner.

Electrophotographic photoconductor and method of producing same

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Kashiba, Japan

Tatsuhiro Morita