Abstract: A developing apparatus includes an electrostatic latent image bearer, a developing sleeve, a case, and an air filter. The case accommodates a two-component developer and the developing sleeve. The air filter is attached to the case. The air filter has a thickness of 2 to 20 mm and has a density gradient with a pressure loss of 2 to 40 Pa at a wind speed of 10 cm/s. The air filter forms an airflow sucked into the case from a gap between the developing sleeve and the case and forms an airflow discharged from the case through the air filter. The two-component developer accommodated in the case contains a magnetic particle a surface of which is coated with a resin layer. The resin layer contains at least one type of chargeable particle.

Abstract: Provided is a semiconductor device including a transistor portion, in which the transistor portion has a drift region of a first conductivity type provided in a semiconductor substrate, a base region of a second conductivity type provided above the drift region, an accumulation region of the first conductivity type provided above the drift region, a plurality of trench portions provided to extend from a front surface of the semiconductor substrate to the drift region, and a trench bottom portion of the second conductivity type provided in bottom portions of the plurality of trench portions, and the accumulation region has a doping concentration with a half width of 0.3 ?m or more.

Abstract: A filter holding device includes an opening portion and a filter. The opening portion communicates an inside of the filter holding device with an outside of the filter holding device. The filter includes a first side and a second side. The first side faces the inside of the filter holding device. The second side faces the outside of the filter holding device. The filter has a lower weight density per unit volume at the first side than at the second side. At least a side face of the first side of the filter is covered with an air-impermeable member. The side face is a lateral face of the filter at the first side.

Abstract: A filter holding device includes an opening portion and a filter. The opening portion communicates an inside of the filter holding device with an outside of the filter holding device, and has a rim that extends in a communication direction from the inside of the filter holding device toward the outside of the filter holding device. The filter is disposed in the opening portion, and has a first side and a second side. The first side faces the inside of the filter holding device. The second side faces the outside of the filter holding device. The filter has a larger weight density per unit volume at the second side facing the outside of the filter holding device than at the first side facing the inside of the filter holding device in a state in which the filter is disposed in the opening portion.

Abstract: A developing apparatus includes an electrostatic latent image bearer, a developing sleeve, a case, and an air filter. The case accommodates a two-component developer and the developing sleeve. The air filter is attached to the case. The air filter has a thickness of 2 to 20 mm and has a density gradient with a pressure loss of 2 to 40 Pa at a wind speed of 10 cm/s. The air filter forms an airflow sucked into the case from a gap between the developing sleeve and the case and forms an airflow discharged from the case through the air filter. The two-component developer accommodated in the case contains a magnetic particle a surface of which is coated with a resin layer. The resin layer contains at least one type of chargeable particle.

Abstract: A developing device includes a developing case, a filter, and a filter holder. The developing case stores developer inside to develop a latent image formed on a surface of an image bearer and has an opening portion that communicates between an inside and an outside of the developing device. The filter has a lower weight density per unit volume at a first side of the filter facing the inside of the developing device than a weight density per unit volume at a second side of the filter facing the outside of the developing device. The filter holder is detachably attached to the opening portion of the developing case with the filter held by the filter holder.

Abstract: A filter holding device includes an opening portion and a filter. The opening portion communicates between an inside and an outside of the filter holding device. The filter is disposed in the opening portion and includes a first side and a second side. The first side is located adjacent to the inside of the filter holding device. The second side is located adjacent to the outside of the filter holding device. The filter has a larger weight density per unit volume at the second side than a weight density per unit volume at the first side and has a larger area of a surface intersecting a communication direction at the second side than an area of a surface intersecting the communication direction at the first side.

Abstract: A filter includes a sticker and a filter body. The filter body has a smaller weight density per unit volume at a first side than at a second side opposite the first side. The sticker is disposed around a surface of the second side of the filter body.

Abstract: A filter holding device includes an opening portion and a filter. The opening portion communicates an inside of the filter holding device with an outside of the filter holding device. The filter includes a first side and a second side. The first side faces the inside of the filter holding device. The second side faces the outside of the filter holding device. The filter has a lower weight density per unit volume at the first side than at the second side. At least a side face of the first side of the filter is covered with an air-impermeable member. The side face is a lateral face of the filter at the first side.

Abstract: A developing device includes a developing roller to rotate in a predetermined direction of rotation and opposed to or in contact with an image bearer to form a development range, a cover to cover the developing roller downstream from the development range in the predetermined direction of rotation, a sheet member cantilevered by the cover to contact the developing roller with a flat face of the sheet member while trailing along the predetermined direction of rotation at a position downstream from the development range. The cover includes a large gap portion to form a first gap in a first predetermined range in the predetermined direction of rotation and a small gap portion disposed adjacent to and downstream from the large gap portion in the predetermined direction of rotation to form a second gap smaller than the first gap in a second predetermined range in the predetermined direction of rotation.

Abstract: A developing device includes a developing roller to rotate in a predetermined direction of rotation and opposed to or in contact with an image bearer to form a development range, a cover to cover the developing roller downstream from the development range in the predetermined direction of rotation, a sheet member cantilevered by the cover to contact the developing roller with a flat face of the sheet member while trailing along the predetermined direction of rotation at a position downstream from the development range. The cover includes a large gap portion to form a first gap in a first predetermined range in the predetermined direction of rotation and a small gap portion disposed adjacent to and downstream from the large gap portion in the predetermined direction of rotation to form a second gap smaller than the first gap in a second predetermined range in the predetermined direction of rotation.

Abstract: An image forming apparatus includes a fixing member, a pressing member, heat generators, temperature detectors, a power source, and a heat controller. The heat generators include a first heat generator and second heat generators corresponding to an imaged area and a blank area, respectively, of a recording medium. The heat controller controls a power source according to data provided by the temperature detectors, such that a heating area of the fixing member heated by one of the second heat generators located adjacent to the first heat generator acquires a temperature of T1??T, where T1 is a temperature corresponding to the imaged area higher than a temperature T2 corresponding to the blank area, and ?T is a temperature lower than a difference between T1 and T2. The heat controller changes ?T between when a first side thereof is printed upon duplex printing and upon single-sided printing.

Abstract: An image forming apparatus includes an image bearer, a charger, an exposure device, a developing device, an image density sensor, and a controller. The controller is configured to charge the image bearer, expose the image bearer with a first exposure that saturates potential of the image bearer after exposure to form a latent image pattern on the image bearer, develop the latent image pattern into a toner pattern while changing a developing electrical field, detect a first image density of the toner pattern, determine developing bias and charging bias, form patterns with the first exposure and a second exposure smaller than the first exposure, detect a second image density of the patterns, and determine an exposure to output an image based on the second image density, the first exposure, and the second exposure.

Abstract: A powder refilling device includes a refill powder chamber to accommodate a powder bag containing powder, an opener to open the powder bag inside the refill powder chamber, and a squeezer to squeeze the opened powder bag to discharge powder therefrom and reduce a volume of the opened powder bag.

Abstract: An image forming apparatus capable of continuous image formation on multiple pages includes an image bearer to bear an image, a latent image forming unit to form a latent image on the image bearer, a developing device to develop the latent image with toner, a temperature sensor to detect temperature inside the developing device or adjacent to the developing device, a controller to impose a limit on a quantity of pages in continuous image formation and cancel the limit according to a detection result generated by the temperature sensor, and a report unit to report time data indicating when the limit is imposed.

Abstract: An image forming apparatus includes a fixing member, a pressing member, heat generators, temperature detectors, a power source, and a heat controller. The heat generators include a first heat generator and second heat generators corresponding to an imaged area and a blank area, respectively, of a recording medium. The heat controller controls a power source according to data provided by the temperature detectors, such that a heating area of the fixing member heated by one of the second heat generators located adjacent to the first heat generator acquires a temperature of T1??T, where T1 is a temperature corresponding to the imaged area higher than a temperature T2 corresponding to the blank area, and ?T is a temperature lower than a difference between T1 and T2. The heat controller changes ?T between when a first side thereof is printed upon duplex printing and upon single-sided printing.

Abstract: An image forming apparatus capable of continuous image formation on multiple pages includes an image bearer to bear an image, a latent image forming unit to form a latent image on the image bearer, a developing device to develop the latent image with toner, a temperature sensor to detect temperature inside the developing device or adjacent to the developing device, a controller to impose a limit on a quantity of pages in continuous image formation and cancel the limit according to a detection result generated by the temperature sensor, and a report unit to report time data indicating when the limit is imposed.

Abstract: An image forming apparatus capable of executing continuous image forming operation forming images on more than one page includes a temperature detector that detects internal or surrounding temperature of a developing device correspondingly changing to temperature of a developer bearer. A temperature information acquiring device acquires information of ambient temperature outside of the image forming apparatus. A controller switches a current operation mode to an intermittent image forming operation mode intermittently including a braking time period not to allow image formation and cancels the intermittent image forming operation mode in accordance with detection result of the temperature detector. The intermittent image forming operation mode allowed to continuously form images only on a prescribed limited number of sheets. The controller varies the braking time period in accordance with the ambient temperature detected by the temperature information acquiring device.

Abstract: A powder refilling device includes a refill powder chamber to accommodate a powder bag containing powder, an opener to open the powder bag inside the refill powder chamber, and a squeezer to squeeze the opened powder bag to discharge powder therefrom and reduce a volume of the opened powder bag.

Abstract: The image forming apparatus includes a latent image bearing member; a charging device charging the surface of the latent image bearing member; a latent image forming device forming an electrostatic latent image on the surface of the latent image bearing member; a developing device supplying toner to the electrostatic latent image to form a toner image; a cover film supplying device supplying a cover film to the surface of the latent image bearing member at a cover film supplying position located on an upstream side from the development position so that the toner image is formed on the cover film covering the surface of the latent image bearing member; and a cover film separating device separating the cover film bearing the toner image thereon from the surface of the image bearing member before the cover film bearing the toner image thereon reaches the cover film supplying position.