Abstract: An image forming apparatus includes an image bearing member, a charger, a light exposure device, a development device, a transfer belt, a primary transfer device, a secondary transfer device, and a cleaning member. The cleaning member is pressed against a circumferential surface of the image bearing member and collects residual toner remaining on the circumferential surface of the image bearing member as a result of primary transfer of a toner. The transfer belt has a surface resistivity of at least 6 Log ? and no greater than 11 Log ?. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is at least 10 N/m and no greater than 40 N/m. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer. The image bearing member satisfies formula (1): 0.06 ? V ( Q / S ) × ( d / ? r · ? 0 ) .

Abstract: Provided is an image forming system capable of reliably preventing others from removing and taking printed matter even though printing is executed beforehand. The confidential notation reading unit reads a confidential notation. The user storage tray has a structure from which outputted printed matter cannot be removed unless the opening/closing door is opened. The locking mechanism locks the opening/closing door. The sorting mechanism sorts the printed matter outputted from the image forming apparatus and outputs the printed matter to either the open tray or the user storage tray. The sorting control unit outputs printed matter to which a confidential notation is not added to the open tray, and outputs a printed matter to which a confidential notation is added to the user storage tray, respectively.

Abstract: An image forming apparatus includes an image bearing member, a charger, a light exposure device, and a development device. The charger charges a circumferential surface of the image bearing member to a positive polarity. The light exposure device exposes the charged circumferential surface of the image bearing member to light to form an electrostatic latent image on the circumferential surface of the image bearing member. The development device supplies a toner to the electrostatic latent image through application of a developing bias. The developing bias is a voltage of an alternating current voltage superimposed on a direct current voltage. The alternating current voltage has a frequency of 4 kHz or higher and 10 kHz or lower. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer. The image bearing member satisfies formula (1) 0.

Abstract: An image forming apparatus includes an image bearing member, a charger, a light exposure device, a development device, a transfer belt, a primary transfer device, a secondary transfer device, and a cleaning member. The cleaning member is pressed against a circumferential surface of the image bearing member and collects residual toner remaining on the circumferential surface of the image bearing member as a result of primary transfer of a toner. The transfer belt has a surface resistivity of at least 6 Log ? and no greater than 11 Log ?. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is at least 10 N/m and no greater than 40 N/m. The image bearing member includes a conductive substrate and a photosensitive layer of a single layer. The image bearing member satisfies formula (1): 0.

Abstract: An image forming apparatus includes a plurality of image forming portions, an intermediate transfer belt, a belt displacement detector, an attraction force changer, and a controller. The intermediate transfer belt is an endless belt wound around drive and driven rollers. The belt displacement detector detects displacement of the intermediate transfer belt in a rotation axis direction of the driven roller. The attraction force changer is operable to change electrostatic attraction force of the driven roller with respect to the intermediate transfer belt exerted on each of opposite end sides of the driven roller in the rotation axis direction thereof. When the belt displacement detector detects displacement of the intermediate transfer belt, the controller makes the attraction force changer increase the electrostatic attraction force of the driven roller with respect to the intermediate transfer belt exerted on a side opposite to a side toward which the displacement has taken place.

Abstract: An image forming apparatus includes a plurality of image forming portions, an intermediate transfer belt, a belt displacement detector, an attraction force changer, and a controller. The intermediate transfer belt is an endless belt wound around drive and driven rollers. The belt displacement detector detects displacement of the intermediate transfer belt in a rotation axis direction of the driven roller. The attraction force changer is operable to change electrostatic attraction force of the driven roller with respect to the intermediate transfer belt exerted on each of opposite end sides of the driven roller in the rotation axis direction thereof. When the belt displacement detector detects displacement of the intermediate transfer belt, the controller makes the attraction force changer increase the electrostatic attraction force of the driven roller with respect to the intermediate transfer belt exerted on a side opposite to a side toward which the displacement has taken place.

Abstract: Provided is an image forming system capable of reliably preventing others from removing and taking printed matter even though printing is executed beforehand. The confidential notation reading unit reads a confidential notation. The user storage tray has a structure from which outputted printed matter cannot be removed unless the opening/closing door is opened. The locking mechanism locks the opening/closing door. The sorting mechanism sorts the printed matter outputted from the image forming apparatus and outputs the printed matter to either the open tray or the user storage tray. The sorting control unit outputs printed matter to which a confidential notation is not added to the open tray, and outputs a printed matter to which a confidential notation is added to the user storage tray, respectively.

Abstract: An image forming apparatus includes an image bearing member, a charger, and a cleaning member. The charger charges a circumferential surface of the image bearing member to a positive polarity. The cleaning member is pressed against the circumferential surface of the image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. A linear pressure N of the cleaning member on the circumferential surface of the image bearing member is at least 14 N/m and no greater than 40 N/m. A rebound resilience R of the cleaning member at a temperature of 25° C. is at least 38%. The leaner pressure N and the rebound resilience R satisfy mathematical formula (1A). The image bearing member satisfies mathematical formula (1B). R < 13.771 × N 0.4043 ( 1 ? A ) 0.

Abstract: An image forming apparatus includes an image bearing member, a charger, and a cleaning member. The charger charges a circumferential surface of the image bearing member to a positive polarity. The cleaning member is pressed against the circumferential surface of the image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. A linear pressure N of the cleaning member on the circumferential surface of the image bearing member is at least 14 N/m and no greater than 40 N/m. A rebound resilience R of the cleaning member at a temperature of 25° C. is at least 38%. The leaner pressure N and the rebound resilience R satisfy mathematical formula (1A). The image bearing member satisfies mathematical formula (1B) R < 13.771 × N 0.4043 ( 1 ? A ) 0.

Abstract: An image forming apparatus includes an image bearing member, a charger, and a cleaning member. The charger charges a circumferential surface of the image bearing member to a positive polarity. The cleaning member is pressed against the circumferential surface of the image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is at least 10 N/m and no greater than 40 N/m. The image bearing member includes a conductive substrate and a single-layer photosensitive layer. The single-layer photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The image bearing member satisfies formula (1) 0.60 ? V ( Q / S ) × ( d / ? r · ? 0 ) .

Abstract: An intermediate transfer unit includes an endless intermediate transfer belt to which a toner image is primarily transferred from an image carrying member, a driving roller that conveys the intermediate transfer belt with the primarily transferred toner image to a secondary transfer position for a sheet material, and a cleaning device which cleans a peripheral surface of the driving roller around which the intermediate transfer belt is wound.

Abstract: An intermediate transfer unit includes an endless intermediate transfer belt to which a toner image is primarily transferred from an image carrying member, a driving roller that conveys the intermediate transfer belt with the primarily transferred toner image to a secondary transfer position for a sheet material, and a cleaning device which cleans a peripheral surface of the driving roller around which the intermediate transfer belt is wound.

Abstract: In order to prevent interference between a primary transfer bias voltage and a secondary transfer bias voltage, and to prevent occurrence of an image defect due to interference between these bias voltages, an image forming apparatus includes a plurality of primary transfer rollers, an intermediate transfer belt, a drive roller, a secondary transfer roller, and a rectifier roller. A primary transfer bias voltage of a polarity opposite to the polarity of toner is applied to a primary transfer bias applying unit. A secondary transfer bias voltage of a same polarity as the polarity of toner is applied to the drive roller. The rectifier roller is disposed between a most-downstream primary transfer roller and the drive roller. A bias voltage of the same polarity as the polarity of the primary transfer bias voltage or the polarity of the secondary transfer bias voltage is applied to the rectifier roller.

Abstract: In order to prevent interference between a primary transfer bias voltage and a secondary transfer bias voltage, and to prevent occurrence of an image defect due to interference between these bias voltages, an image forming apparatus includes a plurality of primary transfer rollers, an intermediate transfer belt, a drive roller, a secondary transfer roller, and a rectifier roller. A primary transfer bias voltage of a polarity opposite to the polarity of toner is applied to a primary transfer bias applying unit. A secondary transfer bias voltage of a same polarity as the polarity of toner is applied to the drive roller. The rectifier roller is disposed between a most-downstream primary transfer roller and the drive roller. A bias voltage of the same polarity as the polarity of the primary transfer bias voltage or the polarity of the secondary transfer bias voltage is applied to the rectifier roller.

Abstract: An image forming apparatus (1) includes photosensitive drums (41y, 41c, 41m, and 41k), static eliminators (45y, 45c, 45m, and 45k), transfer rollers (54y, 54c, 54m, and 54k), a power source (55a) for transfer, and load resistors (47y, 47c, 47m, and 47k). The static eliminators (45y, 45c, and 45m) perform static elimination on adjacently upstream or downstream photosensitive drums (41y, 41c, 41m, and 41k) in a movement direction of a transfer target. The transfer rollers (54y, 54c, 54m, and 54k) are disposed opposite to the respective photosensitive drums (41y, 41c, 41m, and 41k). The power source (55a) for transfer applies potential to the transfer rollers (54y, 54c, 54m, and 54k). The load resistors (57y, 57c, 57m, and 57k) are respectively connected in parallel to one another and in series between the power source (55a) for transfer and the respective transfer rollers (54y, 54c, 54m, and 54k).

Abstract: A cleaning device includes a housing, a cleaning blade, and first and second sealing members. The housing has formed therein an opening facing an image carrying member. The cleaning blade removes toner that remains attached to the image carrying member while being in contact with the circumferential surface of the image carrying member. The first and second sealing members prevent waste toner inside the housing from leaking out through a gap between the housing and the image carrying member, owing to the first and second sealing members abutting on the circumferential surface of the image carrying member.

Abstract: An image forming apparatus includes an intermediate transfer belt, a driving roller, a driven roller, a belt cleaning device, and a counter roller. Toner images formed on image carriers are transferred onto the intermediate transfer belt. The driving and driven rollers rotatably stretch the intermediate transfer belt. The belt cleaning device has a cleaning blade that removes residual toner adhered to the intermediate transfer belt. The counter roller is disposed facing the cleaning blade with the intermediate transfer belt interposed therebetween. The belt cleaning device is disposed at a position that is downstream of the driving roller in a rotation direction of the intermediate transfer belt but is upstream of the driven roller in the rotation direction of the intermediate transfer belt. A leading end edge portion of the cleaning blade is disposed upstream of a top of the counter roller in the rotation direction of the intermediate transfer belt.

Abstract: An image forming apparatus (1) includes image bearing members (31), transfer members (52), and a power supply section (57). The image bearing members (31) each bear one of toner images in different colors from one another. The transfer members (52) are located opposite to the image bearing members (31). The power supply section (57) charges the transfer members (52). Through the above, the toner images on the respective image bearing members (31) are transferred to a moving transfer target (51). The power supply section (57) includes a power supply device (58 or 58a) connected to at least two of the transfer members (52). The transfer members (52) connected to the power supply device (58 or 58a) are each located at a position shifted upstream or downstream of a corresponding one of the image bearing members (31) in a moving direction (X) of the transfer target (51).

Abstract: An image forming apparatus (1) includes photosensitive drums (41y, 41c, 41m, and 41k), static eliminators (45y, 45c, 45m, and 45k), transfer rollers (54y, 54c, 54m, and 54k), a power source (55a) for transfer, and load resistors (47y, 47c, 47m, and 47k). The static eliminators (45y, 45c, and 45m) perform static elimination on adjacently upstream or downstream photosensitive drums (41y, 41c, 41m, and 41k) in a movement direction of a transfer target. The transfer rollers (54y, 54c, 54m, and 54k) are disposed opposite to the respective photosensitive drums (41y, 41c, 41m, and 41k). The power source (55a) for transfer applies potential to the transfer rollers (54y, 54c, 54m, and 54k). The load resistors (57y, 57c, 57m, and 57k) are respectively connected in parallel to one another and in series between the power source (55a) for transfer and the respective transfer rollers (54y, 54c, 54m, and 54k).

Abstract: An image forming apparatus (1) includes image bearing members (31), transfer members (52), and a power supply section (57). The image bearing members (31) each bear one of toner images in different colors from one another. The transfer members (52) are located opposite to the image bearing members (31). The power supply section (57) charges the transfer members (52). Through the above, the toner images on the respective image bearing members (31) are transferred to a moving transfer target (51). The power supply section (57) includes a power supply device (58 or 58a) connected to at least two of the transfer members (52). The transfer members (52) connected to the power supply device (58 or 58a) are each located at a position shifted upstream or downstream of a corresponding one of the image bearing members (31) in a moving direction (X) of the transfer target (51).