Abstract: A toner supply device includes a toner container, a detector, and a determiner. The toner container is configured to contain toner to be supplied to a developing device. The toner container is capable of discharging a prescribed amount of toner contained therein. The detector is configured to detect an amount of toner to be supplied to the developing device. The determiner is configured to estimate a timing at which toner remaining in the toner container is completely consumed, based on a driving amount applied for discharging toner from the toner container during a time period from when the prescribed amount of toner is discharged from the toner container until when the detector detects an amount of toner equal to the prescribed amount of toner.

Abstract: A toner supply device includes a toner container, a detector, and a determiner. The toner container is configured to contain toner to be supplied to a developing device. The toner container is capable of discharging a prescribed amount of toner contained therein. The detector is configured to detect an amount of toner to be supplied to the developing device. The determiner is configured to estimate a timing at which toner remaining in the toner container is completely consumed, based on a driving amount applied for discharging toner from the toner container during a time period from when the prescribed amount of toner is discharged from the toner container until when the detector detects an amount of toner equal to the prescribed amount of toner.

Abstract: An image forming apparatus comprises image forming sections for each color, each including a pressure receiving parts pair in a first outer region of a first rotary body and a second rotary body as an image carrier and a developing roller. A first image forming section includes a first pressure receiving part of the first rotary body and a second pressure receiving part of the second rotary body as the pressure receiving parts pair. A second image forming section includes a third pressure receiving part of the first rotary body and a fourth pressure receiving part of the second rotary body as the pressure receiving parts pair. A protruding distance of the first pressure receiving part is smaller than a protruding distance of the third pressure receiving part. A protruding distance of the second pressure receiving part is larger than a protruding distance of the fourth pressure receiving part.

Abstract: An image forming apparatus comprises image forming sections for each color, each including a pressure receiving parts pair in a first outer region of a first rotary body and a second rotary body as an image carrier and a developing roller. A first image forming section includes a first pressure receiving part of the first rotary body and a second pressure receiving part of the second rotary body as the pressure receiving parts pair. A second image forming section includes a third pressure receiving part of the first rotary body and a fourth pressure receiving part of the second rotary body as the pressure receiving parts pair. A protruding distance of the first pressure receiving part is smaller than a protruding distance of the third pressure receiving part. A protruding distance of the second pressure receiving part is larger than a protruding distance of the fourth pressure receiving part.

Abstract: The rotary power transmission mechanism includes a flange member fitted to one end of a cylindrical member, a shaft inserted through an axial center of the flange member, and a pin member inserted through the shaft in a radial direction of the shaft. The flange member has a first contact portion and a second contact portion that have point symmetry with respect to an axial center of the shaft. When the pin member is rotated in one direction by the shaft rotating in the one direction, the first contact portion contacts a first end portion of the pin member and the second contact portion contacts a second end portion of the pin member. The pin member, when rotating in the one direction, pushes against the first contact portion and the second contact portion, rotates the flange member in the one direction, and thereby transmits rotary power to the cylindrical member.

Abstract: A developing device forms an image by developing an electrostatic latent image on a photoreceptor rotating about a rotation axis. The developing device includes a housing having an opening opposite the photoreceptor, a developing sleeve disposed inside the housing, a magnetic body disposed in a central portion of the developing sleeve and not in no-magnet portions thereof at both sides of the central portion, and seal members supported by the housing. Each of the seal members shields either one of portions of the photoreceptor that are located opposite the no-magnet portions and is in surface contact with either one of end portions of the photoreceptor farther from a center of the photoreceptor than the no-magnet portions. Each of the seal members includes, at an end thereof closer to the center of the photoreceptor than the other end thereof, a non-contact portion that is not in contact with the photoreceptor.

Abstract: An exhaust fan, an exhaust duct through which a discharged gas flows and a filter which is provided in the exhaust duct are included. A curved portion is provided in the exhaust duct, and the filter is provided on a downstream side in a direction of flow of the gas with respect to the curved portion. On an inside wall of the curved portion of the exhaust duct on an outer side in a radial direction, a first flow control member that uniformizes the amount of the gas flowing through the filter is provided so as to be perpendicular to the shaft of the curved portion, and a space is formed between the first flow control member and an inside wall of the curved portion on an inner side in the radial direction.

Abstract: A first shutter covers a first supply port formed in an outer peripheral surface of a main body, and can move in an outer peripheral direction along the outer peripheral surface of the main body. A pair of guiding members respectively formed on both ends of the first shutter guide the first shutter in the outer peripheral direction. A lock mechanism fixes the first shutter to achieve a closed state of the first supply port. The lock mechanism includes a protrusion provided to the first shutter, the protrusion being capable of engaging with a recess formed in the outer peripheral surface. Fixing by the lock mechanism is released when the protrusion elastically deforms and is disengaged from the recess. The protrusion, the recess, and the first supply port are disposed along a virtual curve between the pair of guiding members.

Abstract: An exhaust fan, an exhaust duct through which a discharged gas flows and a filter which is provided in the exhaust duct are included. A curved portion is provided in the exhaust duct, and the filter is provided on a downstream side in a direction of flow of the gas with respect to the curved portion. On an inside wall of the curved portion of the exhaust duct on an outer side in a radial direction, a first flow control member that uniformizes the amount of the gas flowing through the filter is provided so as to be perpendicular to the shaft of the curved portion, and a space is formed between the first flow control member and an inside wall of the curved portion on an inner side in the radial direction.

Abstract: A developing device forms an image by developing an electrostatic latent image on a photoreceptor rotating about a rotation axis. The developing device includes a housing having an opening opposite the photoreceptor, a developing sleeve disposed inside the housing, a magnetic body disposed in a central portion of the developing sleeve and not in no-magnet portions thereof at both sides of the central portion, and seal members supported by the housing. Each of the seal members shields either one of portions of the photoreceptor that are located opposite the no-magnet portions and is in surface contact with either one of end portions of the photoreceptor farther from a center of the photoreceptor than the no-magnet portions. Each of the seal members includes, at an end thereof closer to the center of the photoreceptor than the other end thereof, a non-contact portion that is not in contact with the photoreceptor.

Abstract: In a transport pipe having a first opening portion through which toner is fed in from a toner hopper and a second opening portion through which the toner is discharged to a development device, a transport screw in which a helical blade is formed on a rotational shaft is rotatably provided. The width of the first opening portion in the direction of the rotational shaft is greater than the pitch (L0) of the blade at the first opening portion, and, at the downstream end of the first opening portion in the transport direction, the pitch of the blade is switched from the pitch (L0) to a pitch (L1) which is narrower than the pitch (L0). In this way, the amount of transport of the toner from the toner hopper to the development device with the transport screw is stabilized.

Abstract: A toner supply system having: a receiving section that is set in a body of an image forming apparatus so as not to rotate; and a substantially cylindrical toner container that is mountable in and dismountable from the receiving section and that can be driven to rotate on an axis while being mounted in the receiving section, wherein: the toner container has a first toner feeder for feeding toner stored therein toward the receiving section while the toner container is rotated; and the receiving section has a supply port that permits toner fed thereto with rotation of the toner container to drop down and a toner stirrer that extends to a position close to the first toner feeder located inside the toner container while the toner container is mounted in the receiving section.

Abstract: The rotary power transmission mechanism includes a flange member fitted to one end of a cylindrical member, a shaft inserted through an axial center of the flange member, and a pin member inserted through the shaft in a radial direction of the shaft. The flange member has a first contact portion and a second contact portion that have point symmetry with respect to an axial center of the shaft. When the pin member is rotated in one direction by the shaft rotating in the one direction, the first contact portion contacts a first end portion of the pin member and the second contact portion contacts a second end portion of the pin member. The pin member, when rotating in the one direction, pushes against the first contact portion and the second contact portion, rotates the flange member in the one direction, and thereby transmits rotary power to the cylindrical member.

Abstract: A first shutter covers a first supply port formed in an outer peripheral surface of a main body, and can move in an outer peripheral direction along the outer peripheral surface of the main body. A pair of guiding members respectively formed on both ends of the first shutter guide the first shutter in the outer peripheral direction. A lock mechanism fixes the first shutter to achieve a closed sate of the first supply port. The lock mechanism includes a protrusion provided to the first shutter, the protrusion being capable of engaging with a recess formed in the outer peripheral surface. Fixing by the lock mechanism is released when the protrusion elastically deforms and is disengaged from the recess. The protrusion, the recess, and the first supply port are disposed along a virtual curve between the pair of guiding members.

Abstract: A toner supply system having: a receiving section that is set in a body of an image forming apparatus so as not to rotate; and a substantially cylindrical toner container that is mountable in and dismountable from the receiving section and that can be driven to rotate on an axis while being mounted in the receiving section, wherein: the toner container has a first toner feeder for feeding toner stored therein toward the receiving section while the toner container is rotated; and the receiving section has a supply port that permits toner fed thereto with rotation of the toner container to drop down and a toner stirrer that extends to a position close to the first toner feeder located inside the toner container while the toner container is mounted in the receiving section.

Abstract: In a transport pipe having a first opening portion through which toner is fed in from a toner hopper and a second opening portion through which the toner is discharged to a development device, a transport screw in which a helical blade is formed on a rotational shaft is rotatably provided. The width of the first opening portion in the direction of the rotational shaft is greater than the pitch (L0) of the blade at the first opening portion, and, at the downstream end of the first opening portion in the transport direction, the pitch of the blade is switched from the pitch (L0) to a pitch (L1) which is narrower than the pitch (L0). In this way, the amount of transport of the toner from the toner hopper to the development device with the transport screw is stabilized.

Abstract: A photoreceptor unit is inserted into an image forming apparatus in the predetermined insertion direction, and includes a photoreceptor, a light-shielding sheet covering a part of the photoreceptor on the front side in the insertion direction; a rigid cover made of resin and provided adjacent to the light-shielding sheet on the rear side in the insertion direction; and a cushioning member interposed between the rigid cover and the photoreceptor. The rigid cover has a length that allows the photoreceptor unit to be gripped at the rigid cover. The light-shielding sheet, the rigid cover and the cushioning member can be removed together from the photoreceptor.

Abstract: A photoreceptor unit is inserted into an image forming apparatus in the predetermined insertion direction, and includes a photoreceptor, a light-shielding sheet covering a part of the photoreceptor on the front side in the insertion direction; a rigid cover made of resin and provided adjacent to the light-shielding sheet on the rear side in the insertion direction; and a cushioning member interposed between the rigid cover and the photoreceptor. The rigid cover has a length that allows the photoreceptor unit to be gripped at the rigid cover. The light-shielding sheet, the rigid cover and the cushioning member can be removed together from the photoreceptor.

Abstract: In a belt type fixing apparatus having a heat roller temperature sensor that detects the temperature of a heat roller that contains a heater for heating a fixing belt, and a fixing belt temperature sensor that is set to contact a pressure roller and indirectly detects the temperature of the fixing belt, the heater that heats the fixing belt is controlled in such a way that the temperature detected by the heat roller temperature sensor matches the target temperature of the heat roller that is set based on the temperature detected by the fixing belt temperature sensor.

Abstract: A fixing apparatus includes a fixing belt that pressure-thermally fixes unfixed toner images on sheets, and an oil coating roller that holds silicone oil for preventing the offset phenomenon to be coated on the fixing belt. The oil coating roller consists of an inner oil holding layer formed of paper and a surface oil holding layer formed of aramid fibers. The oil diffusing capacity and the oil holding capacity are reduced from the inner oil holding layer toward the surface oil holding layer. Thus, it is possible to suppress the oil coating amount in the initial period of the roller life to a level that does not cause problems such as oil stains, increase the oil coating amount in the final period of the roller life to a level that does not cause problems such as offsets, and prevent image noises.