Ricoh Company, Ltd.

Yoshinori Inaba

Hiroshi Tamura

Tetsuro Suzuki

Hidetoshi Kami

Naohiro Toda

Tetsuya Toshine

Tomoyuki Shimada

Nozomu Tamoto

Tatsuya Niimi

Yukio Fujiwara

Yuuji Tanaka

Takafumi Iwamoto

Hiromi Tada

Norio Nagayama

An electrophotographic photoreceptor, including a charge generation layer and a charge transport layer on an electroconductive substrate, wherein the charge generation layer includes titanylphthalocyanine and a binder resin which is a crosslinked material of a resin comprising a polyvinylbutyrat site having the following formula (1) and an isocyanate compound having the following formula (2): wherein R1 and R2 independently represent an alkyl group having 1 to 3 carbon atoms; k, l, m and n represent composition ratios and k+1 is from 0.60 to 0.80, wherein k or 1 may be 0, m is from 0.02 to 0.03, and n is from 0.20 to 0.40; wherein A represents a substituted or unsubstituted organic group having 2 to 4 valences; and O represents an integer of from 2 to 4.

Electrophotographic photoreceptor, and image forming apparatus and process cartridge therefor using the photoreceptor

An electrophotographic photoreceptor including a conductive substrate and a photosensitive layer located overlying the conductive substrate. The photosensitive layer comprises a specific diamine compound.

Electrophotographic photoreceptor, image forming method, image forming apparatus, and process cartridge

An image bearing member including a substrate, a photosensitive layer, provided overlying the substrate and a cross linking charge transport layer provided overlying the photosensitive layer, wherein the area of the photosensitive layer which is most distant from the substrate contains a charge transport material, a binder resin and a filler.

Image bearing member, image forming method, and image forming apparatus

An image forming apparatus is provided, including an electrostatic latent image bearer; a charger charging the electrostatic latent image bearer; an irradiator irradiating the electrostatic latent image bearer with imagewise light having an image resolution not less than 1,200 dpi to form an electrostatic latent image thereon; an image developer developing the electrostatic latent image with a toner to form a toner image on the electrostatic latent image bearer; a transferer transferring the toner image onto a recording medium; and a fixer fixing the toner image on the recording medium, wherein a time for a given point on the electrostatic latent image bearer to travel from a position right in front of the irradiator to a position right in front of the image developer is shorter than 50 msec and longer than a transit time of the electrostatic latent image bearer, and an image forming method using the image forming apparatus.

Compact and high speed image forming apparatus and image forming method using the same

An image bearing member is provided, including a substrate and a surface layer formed by optically curing at least a radical polymerizable compound with a charge transport structure and a radical polymerizable monomer without a charge transport structure, wherein the transmission factor of the surface layer for light having a wavelength by 25 nm longer than an absorption end wavelength of photo-absorption spectrum of the surface layer prior to optical curing is not less than 65%.

Image bearing member, and image forming apparatus and process cartridge using the same

The present invention provides an image forming apparatus including a photoconductor, a charging unit configured to charge the photoconductor, a writing unit configured to form a latent electrostatic image, a toner image forming unit configured to form a toner image by developing the latent electrostatic image, the toner image forming unit having a plurality of developing devices housing a plurality of color developers for each color, a transfer unit configured to transfer the toner image formed on the photoconductor onto a transfer material, and a fixing unit configured to fix the transferred toner image on the transfer material, wherein the time spent by an arbitrary point on the photoconductor in moving from a position in which to face the writing unit to a position in which to face the developing unit is shorter than 50 ms and longer than the transit time of the photoconductor.

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Numazu, Japan

Yoshinori Inaba