Ricoh Company, Ltd.

Kazuhiro Egawa

Hidetoshi Kami

Yukio Fujiwara

Hiroshi Ikuno

Tetsuya Toshine

Naohiro Toda

Akihiro Sugino

Keisuke Shimoyama

Kohichi Ohshima

Toshihiro Ishida

Takafumi Iwamoto

Nobutaka Eguchi

Yohta Sakon

Masahiro Ohmori

Junichi Yamazaki

Shinji Nohsho

Kohsuke Yamamoto

Daisuke Nii

Mihoko Matsumoto

Mayumi Yoshihara

Noriyasu Saito

An image forming apparatus includes a photoconductor, a charger, an exposure device, a transfer device, a first and a second surface voltmeter, and a processor. At the first rotation of the photoconductor, the charger charges a charge area on the photoconductor, the exposure device exposes a part of an exposure area in an axial direction of the photoconductor, and the transfer device charges an exposed and unexposed area. At the second rotation, the charger charges the charge area, and the exposure device exposes the exposed and unexposed area at the first rotation. After the exposure at the second rotation, the first surface voltmeter measures a surface potential Vof the unexposed area at the first rotation, and the second surface voltmeter measures a surface potential Vof the exposed area at the first rotation. The processor evaluates a life of the photoconductor based on the surface potentials Vand V

Image forming apparatus and photoconductor evaluation method

A photoconductor includes an electroconductive substrate; an intermediate layer overlying the electroconductive substrate; and a photosensitive layer overlying the intermediate layer. The intermediate layer includes a metal oxide particle and a binder resin, and satisfies the following relations (1) and (2):cut/&#x2003;&#x2003;(1)0.4&#x2266;&#x2266;0.6&#x2003;&#x2003;(2)where Smr represents an areal ratio of concave parts; Sk represents a reference area; and a Scut represents a cross-sectional area obtained by cutting a three-dimensional curved surface obtained from the reference area with an average height surface, the average height surface being a surface constituted of averaged height of all measured height data.

Photoconductor, and image forming method and image forming apparatus using the photoconductor

A photoconductor, including an electroconductive substrate; an intermediate layer overlying the electroconductive substrate; and a photosensitive layer overlying the intermediate layer. The intermediate layer includes a metal oxide and a binder resin, and has a WRa (LLH) less than 0.12 &#x3bc;m and WRa (LHH) of from 0.03 to 0.2 &#x3bc;m in a curve.

Photoconductor, and image forming method and image forming apparatus using the same

An electrophotographic photoconductor, including: an electroconductive substrate; and at least a photoconductive layer and a surface layer in this order over the electroconductive substrate, wherein the surface layer includes a resin having no charge transport properties, and first inorganic fine particles, and wherein the first inorganic fine particles are inorganic fine particles having surfaces modified with at least one of a primary amino group and a secondary amino group, and a volume resistivity of the first inorganic fine particles is 1&#xd7;10&#x3a9;&#xb7;cm or less.

Electrophotographic photoconductor, image forming apparatus, and process cartridge

An electrophotographic photoreceptor, including an electroconductive substrate; a photosensitive layer overlying the electroconductive substrate; and a surface layer overlying the photosensitive layer, wherein the surface layer includes a resin having no charge transportability; and an inorganic particulate material, wherein the inorganic particulate material is a zinc oxide doped with a boron group, and wherein the electrophotographic photoreceptor has a surface specific resistivity (R1) not less than 10&#x3a9;/cmwhen the surface layer has an electric field intensity of 1&#xd7;10V/cm, and a ratio (R1/R15) of the surface specific resistivity (R1) to a surface specific resistivity (R15) when the surface layer has an electric field intensity of 1.5&#xd7;10V/cm of from 100 to 5,000.

Electrophotographic photoreceptor, image forming apparatus and process cartridge

An image forming apparatus including at least a photoreceptor; and a cleaning blade formed of a strip-shaped elastic blade to contact an edge line to the surface of the photoreceptor, wherein the photoreceptor includes a surface layer comprising a particulate material, and the edge line of the cleaning blade includes a substrate of the elastic blade; a mixed layer having a thickness not less than 1.0 &#x3bc;m, formed of the substrate and at least one of an acrylic resin and a methacrylic resin, located at the surface of the substrate; and a surface layer having a thickness not less than 0.1 &#x3bc;m, formed of at least one of an acrylic resin and a methacrylic resin, located on the surface of the substrate.

Image forming apparatus and process cartridge

An electrophotographic photoconductor having a photosensitive layer and a crosslinked resin surface layer over a support, wherein shapes of concaves and convexes in a surface of the electrophotographic photoconductor are measured by a surface roughness/profile measuring device to obtain one-dimensional data arrays, the arrays are subjected to multiresolution analysis (MRA-1) through wavelet transformation to be separated into six frequency components including HHH, HHL, HMH, HML, HLH and HLL to obtain one-dimensional data arrays, the arrays of the HHL are thinned out to be reduced 1/10 to 1/100, thereby producing one-dimensional data arrays, which are then subjected to multiresolution analysis (MRA-2) through wavelet transformation to be separated into six frequency components including LHH, LHL, LMH, LML, LLH and LLL to thereby obtain 12 frequency components in total; and a center-line average roughness (WRa) of the 12 frequency components satisfies relationship (i) below.1&#x2212;597&#xd7;WRa(HML)+238&#xd7;WRa(HLH)&#x2212;95&#xd7;WRa(LHL)+84&#xd7;WRa(LMH)&#x2212;79&#xd7;WRa(LML)+55&#xd7;WRa(LLH)&#x2212;17&#xd7;WRa(LLL)&#x3e;0&#x2003;&#x2003;(i)

Electrophotographic photoconductor, production method of the same, image forming apparatus, and process cartridge

An electrophotographic photoreceptor including a conductive substrate, a photosensitive layer, and a cross-linked resin surface layer comprising a cross-linked resin having a charge transport structure, which satisfies the following inequations:0.01&#x3c;()&#x3c;0.04&#x2003;&#x2003;(1-1)0.01&#x3c;()&#x3c;0.04&#x2003;&#x2003;(1-2)0.01&#x3c;()&#x3c;0.04&#x2003;&#x2003;(1-3)0.01&#x3c;()&#x3c;0.04&#x2003;&#x2003;(1-4)()&#x3e;()&#x2003;&#x2003;(2-1)()&#x3e;()&#x2003;&#x2003;(2-2)()&#x3e;()&#x2003;&#x2003;(2-3)()&#x3e;()&#x2003;&#x2003;(2-4)()&#x3e;()&#x2003;&#x2003;(2-5)()&#x3e;()&#x2003;&#x2003;(2-6)wherein WRa (&#x3bc;m) represents an arithmetic average roughness according to JIS-B0601:2001 of frequency components that are obtained by subjecting a one-dimensional data array of a surface profile of the electrophotographic photoreceptor to a wavelet transformation multiresolution analysis.

Electrophotographic photoreceptor, method of manufacturing electrophotographic photoreceptor, process cartridge, and image forming apparatus

To provide an electrophotographic photoconductor including: a conductive substrate; a photosensitive layer; and a surface layer having grooves which do not intersect each other, the photosensitive layer and the surface layer being laid over the conductive substrate, wherein the grooves each have a width of 60 &#x3bc;m to 100 &#x3bc;m and a depth of 0.2 &#x3bc;m to 2 &#x3bc;m, wherein the standard deviation of the depths of the grooves is 1/10 or less of the average value of the depths of the grooves measured at any four places, and wherein the grooves are formed in a direction which diagonally crosses a main scanning direction and a sub-scanning direction of the electrophotographic photoconductor.

Electrophotographic photoconductor, method for producing electrophotographic photoconductor, and image forming apparatus

The image forming apparatus includes a photoreceptor bearing an electrostatic image; a developing device developing the electrostatic image with a developer including a toner to form a toner image on the photoreceptor; a transferring device transferring the toner image onto a receiving material; and a cleaning device having a cleaning blade cleaning the surface of the photoreceptor. The photoreceptor includes an electroconductive substrate, a photosensitive layer and an outermost layer having projected portions thereon. The outermost layer and projected portions include the same crosslinked charge transport material. The outermost layer has a surface roughness property such that the number of projected portions having height greater than Rz/2 is from 40 to 90 in a length of 12 mm, wherein Rz represents ten-point mean roughness of the outermost layer. The tip of the cleaning blade is contacted with the photoreceptor at a linear pressure of from 80 g/cm to 150 g/cm.

Image forming apparatus

An electrophotographic photoreceptor, including an electroconductive substrate; a photosensitive layer; a crosslinked surface layer comprising &#x3b1;-alumina and tin oxide, wherein a first one-dimensional data array obtained from measuring a concavo-convex shape of the surface of the photoreceptor is subjected to a wavelet conversion to be separated into 6 frequency components, the one-dimensional data array of the lowest frequency component is further thinned so as to have 1/40 data arrays to obtain a second one-dimensional data array, the second one-dimensional data array is further subjected to the wavelet conversion to be separated into additional 6 frequency components, and wherein when relationships between respective arithmetic average roughness (WRa) (y-axis) of the 12 frequency components and the frequency components (x-axis) are graphed, at least WRa (214 to 551 &#x3bc;m) and WRa (26 to 106 &#x3bc;m) have a folding point or a maximum point.

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

An electrophotographic photoreceptor, including an electroconductive substrate; a photosensitive layer, located overlying the electroconductive substrate; and an outermost layer comprising a convexity, wherein each of the outermost layer and the convexity includes a crosslinked body including a structural unit having a same charge transportable structure, and wherein the number of convexity having a height not less than &#xbd;&#xd7;RzJIS is from 30 to 300 in a measurement length of 12 mm, wherein RzJIS is an average of ten-point mean roughness specified in JIS B0601 of 2001 and measured at least 4 random positions in an area the outermost layer is formed on, and wherein the height of the convexity is a distance from the deepest valley to a top of the convexity in the measurement length of 12 mm.

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

An electrophotographic photoreceptor including a conductive substrate, a photosensitive layer, and a surface layer, which satisfies the following inequations:0.005&#x3c;()&#x3c;0.03&#x2003;&#x2003;(i)0.010&#x3c;()&#x3c;0.03&#x2003;&#x2003;(ii)0.005&#x3c;()&#x3c;0.20&#x2003;&#x2003;(iii)()&#x3e;()&#x2003;&#x2003;(iv)()&#x3e;()&#x2003;&#x2003;(v)wherein WRa (&#x3bc;m) represents a center-line average roughness of frequency components LHH, LHL, LMH, LML, LLH, and LLL that are obtained by subjecting a one-dimensional data array of a surface profile of the electrophotographic photoreceptor to wavelet transformation multiresolution analysis so as to be separated into 6 frequency components; thinning a one-dimensional data array of the lowest frequency component so that the number of data array is reduced to 1/40; and subjecting the thinned one-dimensional data array to wavelet transformation multiresolution analysis so as to be separated into the 6 frequency components LHH, LHL, LMH, LML, LLH, and LLL.

Electrophotographic photorecptor, method of manufacturing electrophotographic photorecptor, image forming apparatus, and process cartridge

A photoreceptor including an electroconductive substrate, a photosensitive layer located overlying the electroconductive substrate, and a surface layer located overlying the photosensitive layer, wherein the surface layer is a cross linked surface layer comprising filler particulates on which linear scar is formed along the circumference direction, and the filler particulates form concave portions on a groove formed by the linear scar, and wherein the ten point average roughness Rz along the direction of the rotation axis of the photoreceptor measured on the circumference surface thereof is from 0.17 to 2.00 &#x3bc;m and the average distance Sm of concavities and convexities along the direction of the rotation axis of the photoreceptor measured on the circumference surface thereof is from 20 to 500 &#x3bc;m, and the ten point average roughness Rz along the circumference direction of the photoreceptor measured on the circumference surface thereof is from 0.13 to 0.50 &#x3bc;m and the average distance Sm of concavities and convexities along the circumference direction of the photoreceptor measured on the circumference surface thereof is from 10 to 40 &#x3bc;m.

Photoreceptor, image formation method, image forming apparatus and process cartridge

An image forming apparatus including an image bearing member which has an electroconductive substrate, a photosensitive layer overlying the electroconductive substrate and a cross-linked resin surface layer overlying the photosensitive layer and bears a latent electrostatic image on the surface thereof, an application device to apply a solid lubricant to the image bearing member; a charging device to charge the surface of the image bearing member, an irradiation device to irradiate the surface of the image bearing member with light to form the latent electrostatic image thereon, a development device to develop the latent electrostatic with toner to obtain a developed image, a transfer device to transfer the developed image to a recording medium, and; a cleaning device to clean the surface of the image bearing member, wherein the cross-linked resin surface layer includes a cross-linked body of trimethylol propane triacrylate and particulates including silicon and an average diameter of agglomeration areas of the particulates containing silicon on the surface of the cross-linked resin surface layer is from 0.5 to 2.2 &#x3bc;m.

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Shizuoka, Japan

Kazuhiro Egawa