Ricoh Company, Ltd.

Daisuke Nii

Tetsuro Suzuki

Eiji Kurimoto

Tomoharu Asano

Toshihiro Ishida

Kazuhiro Egawa

Noriyasu Saito

A photoconductor including a conductive support, an undercoat layer, a charge-generating layer, and a charge-transporting layer, at least the undercoat layer, the charge-generating layer, and the charge-transporting layer being disposed on the conductive support in an order mentioned, wherein the undercoat layer includes a binder resin and metal oxide particles, and the charge-generating layer includes a binder resin, a titanyl phthalocyanine pigment, and a salicylic acid derivative.

Photoconductor, image forming apparatus, and process cartridge

An electrophotographic photoconductor including a support, an undercoat layer, and a photoconductive layer, the undercoat layer and the photoconductive layer being disposed on the support in an order mentioned, wherein the undercoat layer includes zinc oxide particles, a urethane bond-containing resin, and methylethyl ketone oxime, and the undercoat layer satisfies a formula below:10&#x3c;&#x3c;400&#x2003;&#x2003;(Formula)where M is a ratio (ppm) of the methylethyl ketone oxime included in the undercoat layer, and L is an average thickness (&#x3bc;m) of the undercoat layer.

Electrophotographic photoconductor, image forming apparatus, and process cartridge

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 undercoat layer overlying the electroconductive substrate; and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a urethane resin, a metal oxide particle and a compound having the following formula (1): wherein R1 to R8 independently represent a hydrogen atom, a nitro group, a cyano group, a halogen atom, a hydroxyl group, a saturated or an unsaturated aliphatic hydrocarbon group optionally having a substituent, an aromatic hydrocarbon group optionally having a substituent, an alkoxy group optionally having a substituent, an aryloxy group optionally having a substituent, a sulfo group optionally having a substituent, an amino group, a dialkylamino group optionally having a substituent or an diarylamino group optionally having a substituent; and R3 and R4, R4 and R5, R6 and R7, and R7 and R8 may be bonded with each other to form an aromatic ring.

A photoconductor including: a conductive support; an undercoat layer; and a photoconductive layer, the undercoat layer being disposed over the conductive support, the photoconductive layer being disposed over the undercoat layer, wherein the undercoat layer includes zinc oxide particles, wherein when a film thickness of the undercoat layer is 20 &#x3bc;m, the undercoat layer has transmittance of 50% or more to light having a wavelength in a range of 500 nm or more but 800 nm or less, wherein a lowest transmittance of light is 85% or less in the range, and wherein when an electric field of 5 V/&#x3bc;m is applied to the undercoat layer, volume resistivity of the undercoat layer is 1.0&#xd7;10&#x3a9;&#xb7;cm or more but 5.0&#xd7;10&#x3a9;&#xb7;cm or less at an environment of 23&#xb0; C. and 55% RH.

Provided is a photoconductor including a conductive support, an intermediate layer containing metal oxide particles, and a photoconductive layer. The intermediate layer and the photoconductive layer are provided over the conductive support in the order of reciting. An elastic power (We/Wt value) of the intermediate layer is greater than or equal to 20.0% but less than 35.0%. A Martens hardness (HM) of the intermediate layer is greater than or equal to 350 [N/mm] but less than 450 [N/mm].

Photoconductor, electrophotographic method, electrophotographic apparatus, and electrophotographic process cartridge

A electrophotographic photoconductor is provided. The electrophotographic photoconductor includes a conductive support, an undercoat layer overlying the conductive support, and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a metal oxide particle, binder resin, and a compound having a urea group.

An electrophotographic photoconductor including a support, an undercoat layer overlying the support, and a photosensitive layer overlying the undercoat layer is provided. The undercoat layer includes zinc oxide particles and a binder resin. The undercoat layer has a voltage (V)-current (I) characteristics such that, when S1 is a value obtained by integrating current (I [A]) in terms of voltage (V [V]) from 0 to a distribution voltage V[V] distributed to the undercoat layer, and S2 is a value obtained by integrating a line connecting two points at a voltage (V [V]) of 0 and the distribution voltage V[V] in terms of voltage (V [V]) from 0 to the distribution voltage V[V], S1 is within a range of from 1.0&#xd7;10to 1.0&#xd7;10and a ratio (S1/S2) of S1 to S2 is 0.50 or less.

An electrophotographic photoreceptor includes a substrate, an undercoat layer overlying the substrate, and a photosensitive layer overlying the undercoat layer. The undercoat layer includes a binder resin, a metal oxide particle and a compound having a thiol group.

Electrophotographic photoreceptor, image forming apparatus, and process cartridge

A photoconductor is provided. The photoconductor includes an electroconductive substrate; an intermediate layer located overlying the electroconductive substrate; and a photosensitive layer located overlying the intermediate layer. The intermediate layer includes at least a resin, and a particulate zinc oxide that includes sodium, sulfur and calcium in amounts of from 10 ppm to 200 ppm, from 50 ppm to 500 ppm, and from 10 ppm to 200 ppm, respectively.

Electrophotographic photoconductor, and image forming method, image forming apparatus, and process cartridge using the electrophotographic photoconductor

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Shizuoka, Japan

Daisuke Nii