Abstract: An image forming apparatus includes an image bearing member and a charging roller that charges a circumferential surface of the image bearing member to a positive polarity. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer, and satisfies formula (1) shown below. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. 0.60 ? V ( Q / S ) × ( d / ? r · ? 0 ) ( 1 ) In formula (1), Q represents a charge amount [C] of the circumferential surface of the image bearing member, S represents a charge area [m2] of the charged circumferential surface of the image bearing member, d represents a film thickness [m] of the photosensitive layer, co represents vacuum permittivity [F/m], and V represents a value calculated in accordance with formula V=V0?Vr.

Abstract: An image forming apparatus includes an image bearing member and a charging roller that charges a circumferential surface of the image bearing member to a positive polarity. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer, and satisfies formula (1) shown below. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. 0.60 ? V ( Q / S ) × ( d / ? r · ? 0 ) ( 1 ) In formula (1), Q represents a charge amount [C] of the circumferential surface of the image bearing member, S represents a charge area [m2] of the charged circumferential surface of the image bearing member, d represents a film thickness [m] of the photosensitive layer, co represents vacuum permittivity [F/m], and V represents a value calculated in accordance with formula V=V0?Vr.

Abstract: An image forming apparatus includes an image bearing member and a charging roller that charges a circumferential surface of the image bearing member to a positive polarity. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer, and satisfies formula (1) shown below. The charging roller includes a conductive shaft, a base layer covering a surface of the conductive shaft, and a surface layer covering a surface of the base layer. 0.60 ? V ( Q / S ) × ( d / ? r · ? 0 ) ( 1 ) In formula (1), Q represents a charge amount of the circumferential surface of the image bearing member. S represents a charge area of the circumferential surface of the image bearing member. d represents a film thickness of the photosensitive layer. ?r represents a specific permittivity of a binder resin contained in the photosensitive layer. ?0 represents a vacuum permittivity. V represents a value calculated according to formula (2) V=V0?Vr.

Abstract: An image forming apparatus includes an image bearing member and a charging roller that charges a circumferential surface of the image bearing member to a positive polarity. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer, and satisfies formula (1) shown below. The charging roller includes a conductive shaft, a base layer covering a surface of the conductive shaft, and a surface layer covering a surface of the base layer. 0.60 ? V ( Q ? / ? S ) × ( d ? / ? ? r · ? 0 ) ( 1 ) In formula (1), Q represents a charge amount of the circumferential surface of the image bearing member. S represents a charge area of the circumferential surface of the image bearing member. d represents a film thickness of the photosensitive layer. ?r represents a specific permittivity of a binder resin contained in the photosensitive layer. ?0 represents a vacuum permittivity. V represents a value calculated according to formula (2) V=V0?Vr.

Abstract: An image forming apparatus (1) includes an image bearing member (50), a charging section (51), a developing section (52), and a cleaning member (81). The image bearing member (50) contains filler particles (87). The charging section (51) is either in contact with or positioned close to the image bearing member (50) and is configured to electrically charge the image bearing member (50) by generating a proximity discharge between the charging section (51) and the image bearing member (50). The developing section (52) supplies toner to the circumferential surface of the charged image bearing member (50). The cleaning member (81) has a degree of hardness equal to or higher than 65° and a degree of impact resilience equal to or lower than 30%. The cleaning member (81) is brought into pressure contact with the circumferential surface of the image bearing member (50) being rotated, by applying linear pressure equal to or higher than 15 gf/cm.

Abstract: An image forming apparatus (1) includes a photosensitive drum (50), a cleaning blade (81), and a drive mechanism (90). The cleaning blade (81) is in pressed contact with a circumferential surface of the photosensitive drum (50). The drive mechanism (90) causes one of the photosensitive drum (50) and the cleaning blade (81) to reciprocate in a rotational axis direction (D) of the photosensitive drum (50). The drive mechanism (90) for example causes the photosensitive drum (50) to reciprocate in the rotational axis direction (D). The photosensitive drum (50) includes a photosensitive layer (85). An outermost layer of the photosensitive layer (85) contains a plurality of particles.

Abstract: An image forming apparatus (1) includes an image bearing member (50), a charging section (51), a developing section (52), and a cleaning member (81). The image bearing member (50) contains filler particles (87). The charging section (51) is either in contact with or positioned close to the image bearing member (50) and is configured to electrically charge the image bearing member (50) by generating a proximity discharge between the charging section (51) and the image bearing member (50). The developing section (52) supplies toner to the circumferential surface of the charged image bearing member (50). The cleaning member (81) has a degree of hardness equal to or higher than 65° and a degree of impact resilience equal to or lower than 30%. The cleaning member (81) is brought into pressure contact with the circumferential surface of the image bearing member (50) being rotated, by applying linear pressure equal to or higher than 15 gf/cm.

Abstract: An image forming apparatus (1) includes a photosensitive drum (50), a cleaning blade (81), and a drive mechanism (90). The cleaning blade (81) is in pressed contact with a circumferential surface of the photosensitive drum (50). The drive mechanism (90) causes one of the photosensitive drum (50) and the cleaning blade (81) to reciprocate in a rotational axis direction (D) of the photosensitive drum (50). The drive mechanism (90) for example causes the photosensitive drum (50) to reciprocate in the rotational axis direction (D). The photosensitive drum (50) includes a photosensitive layer (85). An outermost layer of the photosensitive layer (85) contains a plurality of particles.

Abstract: An image forming apparatus includes a photosensitive drum and a brush roller. The photosensitive drum has a circumferential surface on which a toner image is to be formed. The brush roller rotates while in contact with the circumferential surface of the photosensitive drum to charge the photosensitive drum. The brush roller removes toner remaining on the circumferential surface of the photosensitive drum.

Abstract: An image forming apparatus includes a photosensitive drum and a brush roller. The photosensitive drum has a circumferential surface on which a toner image is to be formed. The brush roller rotates while in contact with the circumferential surface of the photosensitive drum to charge the photosensitive drum. The brush roller removes toner remaining on the circumferential surface of the photosensitive drum.

Abstract: An image forming apparatus includes an image carrier, a charging member, a voltage applying part, a current measuring part and a controlling part. The image carrier carries a toner image. The charging member electrically charges the image carrier. The voltage applying part applies voltage to the charging member. The current measuring part measures current flowing into the charging member. The controlling part controls applied voltage of the voltage applying part. The controlling part decides, when a predetermined voltage is applied to the charging member for a predetermined time by the voltage applying part, if an increase quantity of the current measured by the current measuring part exceeds a predetermined threshold value, that at least one of the image carrier and the charging member is in an abnormal state.

Abstract: The present invention provides an image forming apparatus, including: an image carrier configured by a positively charged single-layer electrophotographic photosensitive body; a charging device which is based on a contact charging method for charging a circumferential surface of the image carrier while making contact with the circumferential surface of the image carrier; and a transfer unit which transfers a toner image on the circumferential surface of the image carrier to a transfer receiving body by gripping the transfer receiving body with the image carrier, wherein the transfer unit includes an application unit to which a transfer bias is applied, and a region having a volume resistivity of 107 to 109 ?·cm exists between the image carrier and the application unit.

Abstract: An image forming apparatus includes a positively-charged single layer type electrophotographic photoreceptor, a charging device with a contact charging roller for charging a surface of the photoreceptor and an exposure device for exposing the charged surface of the photoreceptor to light to form an electrostatic latent image thereon. A developing device develops the electrostatic latent image into a toner image and a transfer device transfers the toner image to a transferred body. The charging roller is made of electrically conductive rubber having an Asker-C rubber hardness of 62 to 81°. A roller surface roughness of the charging roller has an average distance (Sm) between asperity peaks on a cross-sectional curve of 55 to 130 ?m and that a ten-point average roughness (Rz) is 9 to 19 ?m. The image forming apparatus is capable of preventing carrier trapping, film peeling and uneven charging in the photoreceptor.

Abstract: An image forming apparatus includes an image carrier, a charging member, a voltage applying part, a current measuring part and a controlling part. The image carrier carries a toner image. The charging member electrically charges the image carrier. The voltage applying part applies voltage to the charging member. The current measuring part measures current flowing into the charging member. The controlling part controls applied voltage of the voltage applying part. The controlling part decides, when a predetermined voltage is applied to the charging member for a predetermined time by the voltage applying part, if an increase quantity of the current measured by the current measuring part exceeds a predetermined threshold value, that at least one of the image carrier and the charging member is in an abnormal state.

Abstract: An image forming apparatus has: a positively-charged single layer type electrophotographic photoreceptor; a charging device with a contact charging roller for charging a surface of the photoreceptor; an exposure device for exposing the charged surface to light to form an electrostatic latent image on the surface of the photoreceptor; a developing device for developing the electrostatic latent image into a toner image; and a transfer device for transferring the toner image to a transferred body. The photoreceptor has a conductive substrate and a photosensitive layer that contains a charge generating agent, a charge transport agent and a binder resin. The binder resin has a yield point strain of 9 to 29%, and the contact charging roller has a conductive layer with a thickness of 1 mm to 3 mm. The image forming apparatus is environmentally responsive and having a long-lasting positively-charged single layer type photoreceptor and charging roller.

Abstract: An image forming apparatus includes a positively-charged single layer type electrophotographic photoreceptor, a charging device with a contact charging roller for charging a surface of the photoreceptor and an exposure device for exposing the charged surface of the photoreceptor to light to form an electrostatic latent image thereon. A developing device develops the electrostatic latent image into a toner image and a transfer device transfers the toner image to a transferred body. The charging roller is made of electrically conductive rubber having an Asker-C rubber hardness of 62 to 81°. A roller surface roughness of the charging roller has an average distance (Sm) between asperity peaks on a cross-sectional curve of 55 to 130 ?m and that a ten-point average roughness (Rz) is 9 to 19 ?m. The image forming apparatus is capable of preventing carrier trapping, film peeling and uneven charging in the photoreceptor.

Abstract: An image forming apparatus includes a positively-charged single layer type electrophotographic photoreceptor, a charging device with a contact charging roller for charging a surface of the photoreceptor and an exposure device for exposing the charged surface of the photoreceptor to light to form an electrostatic latent image thereon. A developing device develops the electrostatic latent image into a toner image and a transfer device transfers the toner image to a transferred body. The charging roller is made of electrically conductive rubber having an Asker-C rubber hardness of 62 to 81°. A roller surface roughness of the charging roller has an average distance (Sm) between asperity peaks on a cross-sectional curve of 55 to 130 ?m and that a ten-point average roughness (Rz) is 9 to 19 ?m. The image forming apparatus is capable of preventing carrier trapping, film peeling and uneven charging in the photoreceptor.

Abstract: An image forming apparatus has first and second image carriers that are configured by positively-charged single layer type electrophotographic photoreceptors, and a controller that controls an operation for charging or destaticizing circumferential surfaces of these image carriers. The controller switches between a first mode for causing the first and second image carriers to perform image formation while rotating these image carriers, and a second mode for causing only the first image carrier to perform image formation while rotating the first and second image carriers. In the second mode, the second image carrier is applied with a charging bias and subjected to a destaticizing operation without undergoing a developing operation. The first image carrier is applied with the charging bias and subjected to the developing operation and the destaticizing operation.

Abstract: An image forming apparatus, having: an image carrier configured by a positively charged single-layer electrophotographic photosensitive body; a charging device which is based on a contact charging method for charging a circumferential surface of the image carrier while making contact with the circumferential surface of the image carrier; a developing roller which is disposed so as to oppose the image carrier and carry and convey toner on the circumferential surface; and a voltage application unit which applies a developing bias to the developing roller, wherein the frequency of an AC component of the developing bias applied by the voltage application unit is 2.6 to 4.2 kHz.

Abstract: A charging unit in an image forming apparatus includes a charging roller that charges a photosensitive drum using a charging bias, an insulating casing surrounding the charging roller, and a metal shield member. The shield member is positioned so as to surround the casing in close contact with the outer peripheral surface of the casing.