Sharp Kabushiki Kaisha Corporation

Masayuki Sakamoto

Makoto Kurokawa

Yasutaka Maeda

Mikio Kakui

Hideaki Taniguchi

Masaya Tsugoshi

Tatsuhiro Morita

Tadashi Nakamura

Koichi Toriyama

Yoshihide Shimoda

Rikiya Matsuo

Sayaka Fujita

Masanori Matsumoto

Hiroshi Sugimura

Satoshi Katayama

Kazushige Morita

Tomoko Kanazawa

Yuji Tanaka

Masaki Hashimoto

Hisayuki Utsumi

Akihiko Kawahara

Hiroko Ishibashi

Yoichi Takesawa

Takashi Yoshioka

There is provided a layer forming apparatus for forming a photosensitive layer of an electrophotographic photoreceptor, containing no bubbles in a coating liquid. In the layer forming apparatus for forming the photosensitive layer of the electrophotographic photoreceptor through the dip coating method, a lower end port of a dipping cylinder is distanced away in a horizontal direction from a coating liquid discharge port, and the coating liquid discharge port is disposed above the lower end port of the dipping cylinder, in order to prevent a bubble from moving into a coating liquid portion used for actual coating even when a bubble exits in the course of circulation of the coating liquid.

Layer forming apparatus for electrophotographic photoreceptor

The object of the invention is to prevent interference fringes of images and allow precise measurement of the thickness of a layer by the optical interferometry by limiting the surface roughness of a conductive substrate. The surface roughness of the conductive substrate provided in an electrophotographic photoreceptor is such that the maximum peak-to-valley roughness height (Ry)=0.8 to 1.4 &#x3bc;m, the centerline average roughness (Ra)=0.10 to 0.15 &#x3bc;m, the ten-point average roughness (Rz)=0.7 to 1.3 &#x3bc;m, the average peak-to-peak distance (Sm)=5 to 30 &#x3bc;m, and the peak count Pc=60 to 100. In such an electrophotographic photoreceptor, light for exposure can be scattered to an appropriate extent, so that interference fringes can be prevented, and an interference pattern is formed during measurement of the thickness of the photosensitive layer by the optical interferometry so that the thickness of the layer can be measured with a high precision.

Electrophotographic photoreceptor and method for producing the same

A vibration insulating member fitting method includes the steps of: positioning and wrapping a sheet-like vibration insulating memberaround a shafthaving an air suction/exhaust portion; holding the sheet-like vibration insulating memberonto the shaftby air suction; and inserting the shaftthat sucks the sheet-like vibration insulating memberby the air suction into a hollow cylinderof a photosensitive drumto stop the air suction, causing the sheet-like vibration insulating memberto be tightly fitted onto the inner wall surface of the photosensitive drumby a restoring force of the sheet-like vibration insulating member. A vibration insulating member recovering method includes the steps of: inserting a shafthaving an air suction portion into a sheet-like vibration insulating memberfitted on an inner wall surface of a hollow cylinderof a photosensitive drum; starting air suction to suck and hold the sheet-like vibration insulating memberonto the shaft; detaching the sheet-like vibration insulating memberfrom the inner wall surface of the hollow cylinderof the photosensitive drum; and taking the shaftout of the hollow cylinderof the photosensitive drum, with the sheet-like vibration insulating memberbeing sucked and held on the shaft

VIBRATION INSULATING MEMBER FITTING METHOD, VIBRATION INSULATING MEMBER FITTING DEVICE, VIBRATION INSULATING MEMBER, VIBRATION INSULATING MEMBER RECOVERING METHOD, AND VIBRATION INSULATING MEMBER RECOVERING DEVICE

In the present invention, a filler element formed of a viscoelastic material with a compressive residual strain of 10% or less and a 25% compressive load of 1 kg/cm , having a specific shape, is mounted in a drum-shaped electrophotographic photosensitive body (photosensitive drum) . The filler element has a sufficient restoring force when deformed, so that it can be fixed to position without an adhesive. Also, the filler element is not moved by vibration or shock during repeated use, and good anti-vibration effect can be maintained.

Electrophotographic photosensitive body with hollow base and filler element, electrophotographic apparatus using 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

A photosensitive body for electrophotographical use has a conductive base body and a marking area provided thereon. The maximum surface roughness of a photosensitive layer provided right on the marking area is specified not to exceed 2.5 &mgr;m. And also, a ratio of the optical reflective index of the marking area to the optical reflective index of the non-marking area is specified to be in a range of 0.3 to 0.7. In this manner, even when the photosensitive layer is thin (not exceeding 25 &mgr;m), it is possible to prevent problems such as inadequate cleaning and toner falling. Hence, it is possible to offer a photosensitive body for electrophotographical use which can constantly produce high quality copied images.

Photosensitive body for electrophotographical use 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

A photosensitive body for electrophotographical use has a conductive base body and a marking area provided thereon. The maximum surface roughness of a photosensitive layer provided right on the marking area is specified not to exceed 2.5 .mu.m. And also, a ratio of the optical reflective index of the marking area to the optical reflective index of the non-marking area is specified to be in a range of 0.3 to 0.7. In this manner, even when the photosensitive layer is thin (not exceeding 25 .mu.m), it is possible to prevent problems such as inadequate cleaning and toner falling. Hence, it is possible to offer a photosensitive body for electrophotographical use which can constantly produce high quality copied images.

Growing community of inventors

Nabari, Japan

Masayuki Sakamoto