Kyocera Mita Corporation

Kyocera Document Solutions Inc.

Makoto Shishido

Shiho Okawa

Tomofumi Shimizu

Eiichi Miyamoto

Yasufumi Mizuta

Kensuke Okawa

A single-layer photosensitive layer included in an electrophotographic photosensitive member contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The binder resin includes a polyarylate resin. The polyarylate resin includes repeating units represented by formulas (1), (2), (3), and (4). The percentage of the number of repeats of the repeating unit represented by formula (3) relative to a total of the number of repeats of the repeating unit represented by formula (1) and the number of repeats of the repeating unit represented by formula (3) is greater than 0% and less than 20%.

Electrophotographic photosensitive member, process cartridge, and image forming apparatus

A positively chargeable single-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and an electron accepting compound. The hole transport material includes a benzidine derivative. The electron transport material includes at least one compound selected from the group consisting of compounds represented by general formulae (1), (2), (3), and (4) shown below. The electron accepting compound includes at least one compound selected from the group consisting of compounds represented by general formulae (5) and (6) shown below. 

Positively chargeable single-layer electrophotographic photosensitive member, process cartridge, and image forming apparatus

A photosensitive layer in a multilayer electrophotographic photoconductor includes a charge-generation layer including a charge-generating material having, as a major component, a titanyl phthalocyanine crystal which satisfies the conditions (A) and (B) below and a base resin, and a charge-transport layer including a charge-transporting material, the charge-generating material having, as a major component, the titanyl phthalocyanine crystal which has absorption at a wavelength of a charge-neutralizing light and which satisfies the conditions (A) and (B) or an X-form metal-free phthalocyanine crystal which has absorption at the wavelength of the charge-neutralizing light, and a binder resin. (A) In a Cu&#x2014;K&#x3b1; characteristic X-ray diffraction spectrum, one peak is present at a Bragg angle 2&#x3b8;&#xb1;0.2&#xb0;=27.2&#xb0;. (B) In a differential scanning calorimetry, one peak is present in a range of 270&#xb0; C. to 400&#xb0; C. except for peaks attributed to vaporization of adsorption water.

Multilayer electrophotographic photoconductor and image-forming apparatus

An image forming method includes using a charging device to charge a surface of a monolayer-type electrophotographic photoconductor that contains a specific amine compound, setting a projection area of the charging device per time relative to the photo sensitive layer surface of the electrophotographic photoconductor to be S (cm), applying a current value to the charging device to be I(&#x3bc;A) and setting an inflow current value represented by I/S (&#x3bc;A/cm) to a value within the range of from 5 to 25 &#x3bc;A/cm.

Image forming method and method of suppressing fogging in an image forming apparatus

An image forming apparatus capable of reducing white streaks in gray images and an image forming method using the same are provided. The image forming apparatus including a charging means, a developing means, a transferring means, and a discharging means which are arranged in sequence around a monolayer type electrophotographic photoconductor. The charging means is a means for positively charging the surface of the monolayer type electrophotographic photoconductor, and the pre-charging means has a conductive brush composed of a conductive substrate and conductive brush filaments and is arranged between the charging means and the discharging means. The conductive filaments on the surface of the photoconductor have a bending ratio that is calculated so that the conductive brush filament tips are properly curved near the surface of the photoconductor so as to reduce abnormal discharge between the conductive brush and the surface of the photoconductor.

Image forming apparatus with cleaning means and image forming method using the same

An image forming apparatus which can exhibit an excellent charge eliminating effect by erasing a transfer memory using a precharging device with optimized conditions even when a positively-charged single-layer-type electrophotographic photoconductor is used as a photoconductor. In the image forming apparatus which sequentially arranges a charging device, a developing device, a transfer device, and a charge eliminating device around a single-layer-type electrophotographic photoconductor, the charging device charges a surface of the single-layer-type electrophotographic photoconductor with a positive polarity, a precharging device having a conductive member is arranged on an upstream side of the charge eliminating device, the conductive member is brought into contact with the electrophotographic photoconductor, and a current density I(&#x3bc;A/m) of the injected current into the photoconductor from the conductive member is set to a value of 700 (&#x3bc;A/m) or more.

Image forming device using a single-layer-type electrophotographic photoconductor and image forming method using the same

The present invention provides an image forming apparatus which can, by uniformly leveling the particles which are non-uniformly adhered to the surface of the photoconductor by using a leveling means having a predetermined shape, and can maintain the excellent image characteristics for a long period even when a contact charging method is adopted as a charging means and an image forming method which uses the image forming apparatus. In an image forming apparatus which sequentially arranges a charging means, a developing means, a transferring means and a charge eliminating means around an electrophotographic photoconductor, the charging means is constituted of a contact-type charging means, and a leveling means which levels particles on a surface of the electrophotographic photoconductor is arranged between the transferring means and the charge eliminating means.

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Osaka, Japan

Makoto Shishido