Abstract: A developing device includes a developing container, a first stirring member and a second stirring member, and a developing roller. The developing container includes a first stirring chamber, a second stirring chamber, and a communication portion. The first stirring member includes a reverse spiral vane that conveys a developer in a direction reverse to a circulation direction. An air discharge duct is formed on a wall portion of the first stirring chamber opposed to the reverse spiral vane and in an area excluding the communication portion and discharges air from the first stirring chamber to an outside of the developing container via an air discharge port at a distal end of the air discharge duct. A filtration portion is disposed in the air discharge duct adjacently to the air discharge port and restricts leakage of the developer through the air discharge port.

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: A developing device includes a developer container, a developer carrier, and a stirring/conveying member. The developer container stores developer containing toner. The developer carrier carries on its surface the toner in the developer container. The stirring/conveying member includes a rotary shaft rotatably supported on the developer container and a stirring blade formed around the outer circumferential face of the rotary shaft and stirs and conveys the developer in the developer container. The stirring/conveying member to be used can be selected from a plurality of types of stirring/conveying members with rotary shafts with different shaft diameters.

Abstract: A developing device includes a developer container, a developer carrier, and a stirring/conveying member. The developer container stores developer containing toner. The developer carrier carries on its surface the toner in the developer container. The stirring/conveying member includes a rotary shaft rotatably supported on the developer container and a stirring blade formed around the outer circumferential face of the rotary shaft and stirs and conveys the developer in the developer container. The stirring/conveying member to be used can be selected from a plurality of types of stirring/conveying members with rotary shafts with different shaft diameters.

Abstract: A developing device includes a developing container, a first stirring member and a second stirring member, and a developing roller. The developing container includes a first stirring chamber, a second stirring chamber, and a communication portion. The first stirring member includes a reverse spiral vane that conveys a developer in a direction reverse to a circulation direction. An air discharge duct is formed on a wall portion of the first stirring chamber opposed to the reverse spiral vane and in an area excluding the communication portion and discharges air from the first stirring chamber to an outside of the developing container via an air discharge port at a distal end of the air discharge duct. A filtration portion is disposed in the air discharge duct adjacently to the air discharge port and restricts leakage of the developer through the air discharge port.

Abstract: An image forming apparatus includes an image bearing member and a static elimination device. The static elimination device irradiates static elimination light onto a circumferential surface of the image bearing member. The image bearing member includes a conductive substrate and a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The static elimination light has a wavelength of at least 600 nm and no greater than 800 nm. The photosensitive layer has an optical absorption coefficient of at least 600 cm?1 and no greater than 1,500 cm?1 with respect to light having a wavelength of 660 nm.

Abstract: An image forming apparatus includes an image bearing member and a static elimination device. The static elimination device irradiates static elimination light onto a circumferential surface of the image bearing member. The image bearing member includes a conductive substrate and a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The static elimination light has a wavelength of at least 600 nm and no greater than 800 nm. The photosensitive layer has an optical absorption coefficient of at least 600 cm?1 and no greater than 1,500 cm?1 with respect to light having a wavelength of 660 nm.

Abstract: A developing device has a developer container, a first stirring member, and a first stirring chamber. The developer container stores toner. The first stirring member conveys toner while stirring it. The first stirring chamber is in the developer container. The first stirring member is in the first stirring chamber. In a top surface of the first stirring member is a toner supply port through which toner is supplied from outside by action of gravity. The first stirring member has, on the downstream side of the toner supply port in the toner conveying direction, a reduced conveying power portion exerting reduced conveying power to toner. The first stirring chamber has a developer stagnation portion at a position facing the reduced conveying power portion. The inner surface of the developer stagnation portion has a smaller surface roughness than the inner surface of the stirring chamber except for the developer stagnation portion.

Abstract: A developing device includes a housing, a developing roller, a developer conveyance path, a partition plate, a developer supply port and a developer conveying member. The developer conveying member rotates such that an outer peripheral part thereof moves from top to bottom in a first area between a second shaft portion and the partition plate and moves from bottom to top in a second area between the second shaft portion and the side wall. The developer supply port is obliquely open above the second area. The housing includes a first space formed above the second area of the first conveyance path and a second space formed up to a position higher than the partition plate to communicate with the first conveyance path above the first area of the first conveyance path and communicating with the first space in a horizontal direction.

Abstract: A developing device includes a housing, a developing roller, a developer conveyance path, a partition plate, a developer supply port and a developer conveying member. The developer conveying member rotates such that an outer peripheral part thereof moves from top to bottom in a first area between a second shaft portion and the partition plate and moves from bottom to top in a second area between the second shaft portion and the side wall. The developer supply port is obliquely open above the second area. The housing includes a first space formed above the second area of the first conveyance path and a second space formed up to a position higher than the partition plate to communicate with the first conveyance path above the first area of the first conveyance path and communicating with the first space in a horizontal direction.

Abstract: A developing device has a developer container, a first stirring member, and a first stirring chamber. The developer container stores toner. The first stirring member conveys toner while stirring it. The first stirring chamber is arranged in the developer container, has the first stirring member arranged therein, and has in a top surface thereof a toner supply port through which toner is supplied from outside by the action of gravity. The first stirring member has a reduced conveying power portion arranged on the downstream side of the toner supply port in the conveying direction of toner and exerting reduced conveying power to toner. The first stirring chamber has a developer stagnation portion arranged at a position facing the reduced conveying power portion. The inner surface of the developer stagnation portion has a smaller surface roughness than the inner surface except for the developer stagnation portion.

Abstract: A developer replenishing apparatus includes a developer housing container and a sensor. The developer housing container includes a container main body having a wall that partitions an internal space, a shaft section arranged so as to extend in a first direction in the internal space, a moving wall which moves from an upstream side to a downstream side in the first direction along the shaft section and which conveys the developer, and a developer discharge port which is arranged near a downstream end in the first direction of the container main body. The sensor is arranged at a position that enables the sensor to generate different outputs between before and after the moving wall reaches a prescribed position on a movement route. The determining unit determines a state where there is no developer in the developer housing container when the sensor generates an output determined in advance.

Abstract: A developer replenishing apparatus includes a developer housing container and a sensor. The developer housing container includes a container main body having a wall that partitions an internal space, a shaft section arranged so as to extend in a first direction in the internal space, a moving wall which moves from an upstream side to a downstream side in the first direction along the shaft section and which conveys the developer, and a developer discharge port which is arranged near a downstream end in the first direction of the container main body. The sensor is arranged at a position that enables the sensor to generate different outputs between before and after the moving wall reaches a prescribed position on a movement route. The determining unit determines a state where there is no developer in the developer housing container when the sensor generates an output determined in advance.

Abstract: A developer supply device includes a shaft portion arranged in a container main body, a moving wall movable along the shaft portion, a developer discharge port and a shutter mechanism. A control unit causes the moving wall to be arranged at a first position when a remaining amount of the developer is a predetermined first remaining amount and moves the moving wall to a second position closer to the developer discharge port than the first position in the first direction when the remaining amount is a second remaining amount smaller than the first remaining amount, and causes the shutter mechanism to be set in a first open state with a predetermined opening degree when the moving wall is at the first position and causes the shutter mechanism to be set in a second open state larger than the first open state when the moving wall is at the second position.

Abstract: A developer supply device includes a shaft portion arranged in a container main body, a moving wall movable along the shaft portion, a developer discharge port and a shutter mechanism. A control unit causes the moving wall to be arranged at a first position when a remaining amount of the developer is a predetermined first remaining amount and moves the moving wall to a second position closer to the developer discharge port than the first position in the first direction when the remaining amount is a second remaining amount smaller than the first remaining amount, and causes the shutter mechanism to be set in a first open state with a predetermined opening degree when the moving wall is at the first position and causes the shutter mechanism to be set in a second open state larger than the first open state when the moving wall is at the second position.

Abstract: A developer storage container includes a container main body, a tubular portion projecting from the container main body, and a rotary member extending from the container main body to the tubular portion. The rotary member includes a first section located in the container main body and a second section located in the tubular portion. A first conveying member for conveying developer in a first conveying direction is arranged on the second section of a rotary shaft, and a second conveying member for conveying the developer in a second conveying direction is arranged radially outwardly of the first conveying member around the first section. A first flexible member radially extending to a side outward of the second conveying member and a second flexible member radially extending to a side outward of the second conveying member and having a shorter length than the first flexible member are mounted on the rotary shaft.

Abstract: A developing device includes: a housing, a refill developer storage part, a developing roller, a developer conveyance path, a developer receiving port, a conveyance member, and a magnetic member. The developing roller is driven into rotation in the developing housing and carries a toner on a circumferential surface thereof. The toner is conveyed inside the first conveyance path and the second conveyance path of the developing housing in a circulating manner. A first stirring screw is disposed on the first conveyance path and conveys the toner in a first direction. Downstream of the toner refill port, a magnet is arranged. The magnetic member forms a magnetic brush from a top panel of the developing housing towards the first stirring screw. A refill toner flowed-in through the toner refill port is so conveyed as to fall below the magnetic brush whereby the refill toner is favorably stirred with a surrounding toner.

Abstract: A developer case includes a main body, a first transportation portion, a first transportation member, a supply member, a discharge port, and a second transportation portion. The main body contains developer. The first transportation portion has a first region that receives developer from the main body and a second region that extends from the first region in a first direction. The first transportation member transports developer in the first direction. The supply member supplies developer to the first region. Developer is discharged through the discharge port. The second transportation portion has an inlet port communicating with the second region. Developer that has not been discharged through the discharge port is supplied to the second transportation portion through the inlet port. The second transportation portion transports developer in a second direction.

Abstract: A developing apparatus according to one aspect of the present disclosure includes a developing roller, a development housing, a first agitating screw, a toner supply inlet, a downstream-side reduction wall, and an upstream-side reduction wall. The developing roller is driven to rotate in the development housing, and carries toner on the circumferential surface thereof. Toner is circulated and conveyed in a first conveying path and a second conveying path in the development housing. The first agitating screw is disposed in the first conveying path, and conveys toner in a first direction. The downstream-side reduction wall is disposed downstream of the toner supply inlet. Further, the upstream-side reduction wall is disposed upstream of the toner supply inlet. An accumulation portion for toner is formed downstream and upstream of the toner supply inlet due to the downstream-side reduction wall and the upstream-side reduction wall.

Abstract: A developing device includes: a housing, a refill developer storage part, a developing roller, a developer conveyance path, a developer receiving port, a conveyance member, and a magnetic member. The developing roller is driven into rotation in the developing housing and carries a toner on a circumferential surface thereof. The toner is conveyed inside the first conveyance path and the second conveyance path of the developing housing in a circulating manner. A first stirring screw is disposed on the first conveyance path and conveys the toner in a first direction. Downstream of the toner refill port, a magnet is arranged. The magnetic member forms a magnetic blush from a top panel of the developing housing towards the first stirring screw. A refill toner flowed-in through the toner refill port is so conveyed as to fall below the magnetic blush whereby the refill toner is favorably stirred with a surrounding toner.