Nec Corporation

Tsutomu Uezono

Yasuhiro Funayama

Tomoyuki Yoshii

Takeshi Hori

Hiroyuki Endoh

Atsushi Oda

Satoru Toguchi

Hideki Asada

Tomohiko Otose

Jun Koyatsu

Ryouichi Yasuda

Jyun Koyatsu

Yoshinobu Takeda

An optical printer head with a plurality of light-emitting devices arranged in two dimensions is capable of providing a desired amount of exposure using light-emitting devices having even small luminance, ease of corrections to a sensitivity of a photosensitive body and to a positional displacement of an object to be printed, performing printing on multiple gray scales and implementing high density and miniaturization. The optical printer head is so configured that a picture element array including picture elements containing light-emitting devices arranged in line and string directions in two dimensions, a horizontal scanning circuit to feed data signals to each picture element string in the picture element array and a vertical scanning circuit to sequentially select and activate each picture element in the picture element array are formed on a same insulating substrate to support production of the above effects. The luminance of the picture elements is also made variable by use of a plurality of light-emitting devices and/or variable drive for each picture element to enhance the continuity of gray scale achieved.

Optical printer head with integrated drive circuitry

A liquid electrophotographic developing apparatus capable of preventing image drift and reducing the load in the squeezing process. A developing roller faces a photoreceptor belt with a predetermined spacing to supply a liquid developer to the photoreceptor belt while rotating at a peripheral velocity in the opposite direction to that of the photoreceptor belt in a developing region thereon. A peripheral velocity ratio of the peripheral velocity to a moving velocity of the photoreceptor belt is determined so as to maximize a solid component ratio of a developed toner layer on the photoreceptor belt.

Liquid electrophotographic imaging system with a maximized solid toner ratio

An image forming apparatus of the present invention includes a particle conveying body made up of a light-transmitting conductive layer, an insulative'screen provided on the conductive layer and formed with a number of pores, and a screen electrode formed on the screen. Photoconductive, colored particles are charged to negative polarity and then caused to fill the pores by an electric field. When the particles in the pores are exposed via the conductive layer, electron-hole pairs are generated in the particles. An electric field of as high as 10 V/cm or above is formed between the conductive layer and the screen electrode and separates the electrons and holes. The electrons leak to the conductive layer and cause the particles to be charged to positive polarity. An electric field formed between a facing electrode positioned behind a recording medium and the conductive layer causes the particles to fly toward and deposit on the medium.

Image forming apparatus and image forming method

In a wet-type developing apparatus in which a latent image carrying member and a squeeze roller are moved in the opposite directions to each other while they are not brought into contact with each other at the closest position thereof, a liquid toner layer on the latent image carrying member which is smaller in thickness than the gap interval between the latent image carrying member and the squeeze roller is made to invade into the gap, and the liquid toner invading into the gap between the squeeze roller and the latent image carrying member are brought into contact with the squeeze roller by electrical attractive force based on electric field formed between the squeeze roller and the latent image carrying member, thereby forming meniscus.

Wet-type developing apparatus and image forming apparatus using the same

Porous photosensitive body and method of manufacturing same

A drive roller is rotated and a high voltage periodically alternating between plus and minus based on the potential of a conductive portion of the drive roller,is applied by a high voltage power source,to an electric charger, so that the surface of the drive roller,is charged plus and minus alternately. Since the drive roller,is charged, a sleeve,is absorbed to and held by the drive roller,so as to be rotated and fed together with the drive roller. Moreover, the sleeve,is separated from the drive roller,by a separator so as to obtain a sag. When the drive roller rotates further, the sleeve,is again absorbed to and held by the drive roller,charged periodically plus and minus, so as to be rotated together with the drive roller. Thus, the present invention eliminates scratches which may be caused by friction on a developing roller or on a photosensitive body surface and also eliminates contamination with oil.

Sleeve rotation-feed apparatus, developing apparatus, image formation apparatus, and fixation apparatus

A porous photosensitive unit has a transparent conductive layer formed on a surface of a transparent substrate. A photoconductive layer is formed on a surface of the transparent conductive layer. A porous insulating layer formed on a surface of the photoconductive layer has a plurality of holes for holding conductive color particles. The plurality of holes includes a first hole and the adjacent second and third holes. An upper or screen electrode is formed on a surface of the porous insulating layer except where the holes are formed. The photosensitive unit includes an optical arrangement in which, when a light source emits light to cause conductive color particles to fly out of the first hole only, the light exposes a region, within the photoconductive layer, which substantially coextends with a surface portion of the photoconductive layer that is exposed by the first hole.

Photosensitive unit, light source and image forming apparatus

An image recording apparatus and an image recording method enable high density and without blank space between pixels printed on a recording medium to be printed. The image recording apparatus comprises a multi-hole photoreceptor provided with a transparent conductive layer, photoconductive layer, and multi-hole layer having a plurality of holes arranged with equal interval, on a transparent supporting structure, and an opposite electrode arranged so as to be opposite to the multi-hole photoreceptor with interval while inserting a recording medium. Conductive colored particles which fly in order from a plurality of holes of the multi-hole photoreceptor form respective pixels by driving the multi-hole photoreceptor corresponding to the pixel.

Image recording apparatus and image recording method

Disclosed herein is a photoreceptor for electrophotography having an over coating layer formed on a substrate and prepared by applying a composition containing silica particles, an organic compound chemically bonded thereto and a photo polymerization initiator and by curing said composition; said organic compound having an polymerizable unsaturated group, a group designated by Formula (1) or a group designated by Formula (2), and said silica particles and said organic compound being bonded with each other through a silyloxy group. The photoreceptor for electrophotography has not only excellent durabilities and an excellent resistance to printing but also excellent electrophoto characteristics such as sensitivity and a residual potential. ##STR1## (wherein --X-- is selected from --NH--, --O-- and --S--, --Y-- is an oxygen atom or a sulfur atom, and when --X-- is --O--, Y is said sulfur atom).

Photoreceptor for electrophotography and method of manufacturing the same

A method for manufacturing a photoreceptor includes the steps of consecutively forming a transparent conductive layer, a photoconductive layer, insulation layer and an electrode layer on a transparent support member, covering the electrode layer with a photo-setting dry film having a mask pattern therein, and sand-blasting the electrode layer and the insulation layer through the mask pattern to form an array of pores in the electrode layer and the insulation layer. A porous layer having a uniform thickness and uniform arrangement of pores can be obtained.

Porous photoreceptor and method for manufacturing the same

This invention provides a process for the preparation of triphenylamine compounds useful as charge transport materials. According to this process, a triphenylamine compound of the general formula (2) ##STR1## of the general formula (1) ##STR2## into a lithio compound, and reacting the lithio compound with a nitrogen trihalide. In the above formulae, Ar.sub.1 to Ar.sub.8 each represent an optionally substituted phenyl radical, R.sub.1 to R.sub.8 each represent a hydrogen atom or a methyl group, and X represents a halogen atom.

Process for preparing triphenylamine compounds by using a nitrogen

An image recording apparatus with a photosensitive unit 100A which is rotatably structured, having a transparent conductive layer 2, a photoconductive layer 3, and a porous insulating screen 4 with an electrode layer 5 on its top surface which are sequentially stacked on a transparent substrate. An electric field is applied between the transparent conductive layer 2 and the electrode layer 5. Therefore, when a light is irradiated to the photoconductive layer 3 via the transparent layer 2, a photoconductive phenomenon takes place. The electrode layer 5 has a potential so that the conductive particles returns to an electrode member 11. The electrode member 11 for holding conductive color particles on its surface is opposite to the photosensitive unit 100A with a gap between. The conductive particles filled between the porous insulating screen 4 are transferred to a record medium.

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Tokyo, Japan

Tsutomu Uezono