Mita Industrial Co., Ltd.

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Osaka Gas Company Limited

Masashi Tanaka

Toshiyuki Fukami

Hideo Nakamori

Masato Katsukawa

Keizo Kimoto

Tadashi Sakuma

Shigekazu Yamauchi

Hirotsugu Nishikawa

Hiroki Sakamoto

Keisuke Sumida

Mikio Kakui

Yasufumi Mizuta

Hiroaki Iwasaki

Hiroshi Tanaka

Sakae Saito

Hiroaki Murase

Yoshiaki Kato

Ichiro Yamazato

Maki Uchida

Shinichi Kawasaki

Mitsuji Tsujita

Nariaki Muto

Hiroshi Takemoto

Mitsuaki Yamada

Yuka Nakamura

Tsuyoshi Fujiki

Hiroshi Shiomi

Masaru Mikita

Youichi Takesawa

Mika Kawaguchi

Takashi Tanaka

Yoichi Taniguchi

Masaru Fukunaga

A top surface layer of an electrophotographic photosensitive element (e.g., a charge-transporting layer) is rendered to contain a cyclic polysilane represented by the following formula (1).  In the formula, Rand Rare the same or different from each other and each represents a group such as an alkyl group, an aryl group, and 'm' denotes an integer of not less than 4. The cyclic polysilane may be a copolysilane. The content of the cyclic polysilane may be about 0.01 to 10% by weight relative to the whole components of the top surface layer.

Electrophotographic photoreceptor and electrophoto-graphic apparatus equipped with the same

There is disclosed an electrophotosensitive material using a binding resin of a bisphenol C type, bisphenol Z type, bisphenol Z type containing a substituent or bisphenol C-copolymer type polycarbonate in combination with a hole transferring material of a specific benzidine or phenylenediamine derivative. This photosensitive material is superior in mechanical strength and repeat characteristics and has a high glass transition temperature and a high sensitivity.

Electrophotosensitive material

An image-forming apparatus employing a reversal developing system and using a photosensitive material capable of being charged into both positive and negative polarities and further using a transfer roller made of an electrically conducting sponge rubber. The photosensitive material and the transfer roller are press-contacted to each other with a suitable force, and a DC voltage is applied to the transfer roller, the DC voltage having a polarity opposite to the polarity of the potential created by the main charger and having a value larger than a charge start voltage of the photosensitive material but being so set that the potential on the surface of the photosensitive material after discharged is not larger than 50 V in an absolute value. This apparatus permits a toner image formed on the surface of the photosensitive material to be transferred at a high efficiency and enables the photosensitive material to be uniformly charged in a next cycle of forming image.

Image-forming apparatus employing a reversal developing system

An obstacle detection apparatus includes a rubber-like elastic body interspersed with electroconductive particles, and means for applying a voltage to the rubber-like elastic body to obtain an ultrasonic wave reception signal from a change in electrical resistance of the elastic body. An ultrasonic wave transmission apparatus is mounted on a support member for transmitting an ultrasonic wave outward. The rubber-like elastic body interspersed with electroconductive particles is provided along an outer periphery of the support member, and a voltage is applied to the rubber-like elastic body to obtain an ultrasonic wave reception signal from a change in electrical resistance of the elastic body as a result of receiving the ultrasonic wave reflected from an obstacle.

Ultrasonic wave reception apparatus and obstacle detection apparatus

The present invention relates to a benzidine derivative represented by the general formula (1): ##STR1## wherein R.sup.1 to R.sup.6, m and n are as defined in the present specification. The benzidine derivative improves durability and heat resistance of a membrane containing the same while maintaining high hole transferring capability. Therefore, an electrophotosensitive material, which comprises a photosensitive layer containing the benzidine derivative, has high sensitivity and is superior in durability and heat resistance.

Benzidine derivative and electrophotosensitive material using the same

A reversal developing system using a photosensitive material that can be electrically charged into both a positive polarity and a negative polarity, and a DC voltage applied to the transfer roller has a polarity opposite to and more than 1.5 times as great than that of the charge start potential by the primary charger, and is so set that the potential on the surface of the photosensitive material after discharge is 50 V or smaller in absolute value. Therefore, the discharging is effectively carried out after the image has been formed, the photosensitive material is uniformly and effectively charged by the main charger even in the subsequent cycle of forming image, a good image is formed without image spots, and the toner image formed on the photosensitive material is transferred maintaining a high transfer efficiency. The transfer roller is arranged to have a gap between the transfer roller and photosensitive surface between 0.3 to 0.7 mm.

Reversal developing system preventing occurrence of image spots

An electrophotographic photoconductor includes: a conductive substrate and a photosensitive layer formed on the conductive substrate, wherein the photosensitive layer includes charge generating particles, a charge transporting material, and a binder resin, and the charge generating particles are made of a composition including a charge generating material dispersed in a binding medium.

Electrophotographic photoconductor having a photosensitive layer with

Disclosed is an organic photosensitive material for electrophotography which is characterized by containing a specific diphenoquinone derivative in an organic photosensitive layer of the material. The diphenoquinone derivative is a compound represented by the following general formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are alkyl groups, alkoxy groups, aryl groups or aralkyl groups, and at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is an aryl group or an aralkyl group, and at least 2 of the remaining R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are alkyl groups or alkoxy groups, the organic photosensitive material mentioned above has excellent sensitivity and residual potential.

Organic photosensitive material for electrophotography

A process for producing an organic photosensitive material preventing brushing by applying an organic solvent solution or a dispersion of an organic photosensitive material onto the surface of a blank tube consisting of an electrically conducting substrate such as of aluminum, wherein when the thickness of the blank tube is denoted as t (cm) and the thickness of the photosensitive material layer as d (cm), the thickness of said photosensitive material layer is so set as to satisfy the following equation, d=kt, wherein k is a number which is 0.13 or smaller. The brushing can be effectively prevented by controlling only the thickness of the blank tube which is forming the photosensitive layer and the thickness of said photosensitive layer.

Process for producing an organic photosensitive material preventing

The image forming apparatus in this invention uses a positive corona discharger as a main charger. A photosensitive material having a charge accepting ability per run-off current of at least 40 V/.mu.A from a corona discharger (measured by using a discharge length of 230 mm and by taking the peripheral speed of the photosensitive material as 48 mm/sec) is used, and a DC voltage is impressed on the positive corona discharger so that the average ozone concentration of an atmosphere of the photosensitive material 2 ppm or less and the ozone concentration immediately below the corona discharger becomes 5 ppm or less to perform main charging. According to this apparatus, the amount generated of ozone can be decreased, and charging unevenness can be prevented to form a good image.

Image forming apparatus

An image carrier of an organic photosensitive material containing a charge-generating agent and a charge-transporting agent, and a transfer roller using an electrically conducting polyurethane rubber composition which is so cured as to exhibit a rubber hardness of higher than 50.degree. (JIS A), are disposed being spaced apart maintaining a small gap which is greater than the thickness of the transfer material enabling the toner to be transferred onto the transfer material. This makes it possible to prevent the occurrence of image defects such as white spots and the like, to form transferred image favorably and stably over an extended period of time maintaining a high density without fogging and consuming a small transfer current.

Transfer device in an image-forming apparatus

An electrophotographic organic photosensitive layer is formed by using a diphenoquinone derivative A and a diphenoquinone derivative B having a larger absolute value for reduction potential as electron transport materials. The diphenoquinone derivative A is, for example, 3,5-dimethyl-3',5'-di-t-butyl-4,4'-diphenoquinone. The diphenoquinone derivative B is, for example, 3,3',5,5'-tetra-t-butyl-4,4'-diphenoquinone. The diphenoquinone derivative B is included in the proportion of 3 to 50 wt % on the basis of the total weight of the electron transport materials (the diphenoquinone derivatives A and B).

Electrophotographic organic photoconductor

The organic photosensitive material for electrophotography in accordance with this invention is characterized in that a non-symmetrically substituted diphenoquinone derivative represented by the following formulae ##STR1## wherein each of R.sub.1 and R.sub.2 represents an alkyl or aryl group, R.sub.2 having larger carbon atoms than R.sub.1, is used as an electron transporting agent. This photosensitive material has a residual potential limited to a low level, and shows excellent sensitivity in both positive charging and negative charging.

Electrophotographic organic photosensitive material with diphenoquinone

An oxygen sensor includes a hollow tubular element made of a solid electrolyte capable of conducting oxygen ions. The inner surface of the element is exposed to the atmosphere, and the outer surface thereof is exposed to an exhaust gas of which the oxygen concentration is to be detected. First and second electrodes are arranged on the inner and outer surfaces of the element, respectively. The second electrode is provided with a coating which contains a catalyst for causing and promoting a water gas reaction of carbon monoxide contained in the exhaust gas approaching the second electrode. Alternatively, a large number of pellets containing the catalyst are charged in the space between the tubular element and a protective tube surrounding the element.

Oxygen sensor

Disclosed is a laminate type photosensitive material for the electrophotography, which comprises a charge-generating layer and a charge-transporting layer, which are formed on an electroconductive substrate, wherein the charge-transporting layer comprises a first charge-transporting material having an ionization potential smaller than that of a charge-generating material used for the charge-generating layer and a second charge-transporting material having an ionization potential larger than that of the charge-generating material. In this photosensitive material, by using a charge-transporting material having an ionization potential larger than that of the charge-generating material in combination with the charge-transporting material having an ionization potential smaller than that of the charge-generating material, a good residual potential can be maintained without disturbing injection of holes in the charge-transporting layer, the stability of the surface potential at the repeated use is improved and a good charging capacity can be attained.

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Osaka, Japan

Masashi Tanaka