摘要:
An image forming apparatus includes a fixing unit fixing a toner image onto a sheet. The fixing unit includes a heating member having a sheet conveyed region that is set in accordance with the size of the sheet. The fixing unit further includes a coil generating magnetic field, a fixed core forming a magnetic path, movable cores forming a magnetic path together with the fixed core and arranged along the sheet conveyed region, a shielding member arranged on at least one movable core and shielding magnetism, and a magnetism adjustment unit rotating at least one movable core to switch the position of the shielding member between a shielding position where the shielding member is positioned inside the sheet conveyed region to shield the magnetism and a retracted position where the shielding member is positioned outside the sheet conveyed region to permit pass of the magnetism.
摘要:
An image forming apparatus includes a fixing unit fixing a toner image onto a sheet. The fixing unit includes a heating member having a sheet conveyed region that is set in accordance with the size of the sheet. The fixing unit further includes a coil generating magnetic field, a fixed core forming a magnetic path, movable cores forming a magnetic path together with the fixed core and arranged along the sheet conveyed region, a shielding member arranged on at least one movable core and shielding magnetism, and a magnetism adjustment unit rotating at least one movable core to switch the position of the shielding member between a shielding position where the shielding member is positioned inside the sheet conveyed region to shield the magnetism and a retracted position where the shielding member is positioned outside the sheet conveyed region to permit pass of the magnetism.
摘要:
An image forming apparatus has an image forming station and a fixing unit. The fixing unit includes a coil for generating a magnetic field for induction heating the heating member. A first core made of a magnetic material is arranged fixedly around the coil. A second core made of a magnetic material is between the first core and the heating member in a generation direction of the magnetic field to form a magnetic path in cooperation with the first core and capable of changing a posture thereof. A shield made of a nonmagnetic metal is arranged along the outer surface of the second core to shield magnetism in the magnetic field and a magnetic shielding portion for changing the posture of the second core between a first posture where the shield shields the magnetism and a second posture where the shield does not shield the magnetism.
摘要:
An image forming apparatus includes an image forming unit and a fixing unit. The fixing unit includes a heating member; a coil arranged along an outer surface of the heating member for generating a magnetic field for induction heating the heating member; a core arranged to face the heating member with the coil located therebetween in order to form a magnetic path around the coil and made of a magnetic material; a shielding member arranged near the magnetic path generated by the coil, including a closed frame portion and made of a nonmagnetic metal; and a magnetic shielding portion for displacing the shielding member between a retracted position for permitting a magnetic flux to pass along a frame surface virtually formed inside the closed frame portion and a shielding position for shielding magnetism by the penetration of a magnetic flux inside the frame surface.
摘要:
A fixing unit (14) of an image forming apparatus (1) includes a heating member (48) having a first area where a sheet does not come into contact with the heating member (48) and a second area where the sheet comes into contact with the heating member (48). The fixing unit (14) further includes a coil (52) forming a magnetic field, cores (54,56) forming a magnetic path near the coil (52), a nonmagnetic magnetism adjusting member (90) arranged on the magnetic path and having a closed frame, and a switcher (58,60) capable of switching the magnetism adjusting member (90) between a first state where the magnetism adjusting member (90) generates an induction current resulting from the magnetic field to shield the magnetism in the first area, and a second state where the magnetism adjusting member (90) generates no induction current and the magnetism is not shielded in the first area.
摘要:
An image forming apparatus has an image forming station and a fixing unit. The fixing unit includes a coil for generating a magnetic field for induction heating the heating member. A first core made of a magnetic material is arranged fixedly around the coil. A second core made of a magnetic material is between the first core and the heating member in a generation direction of the magnetic field to form a magnetic path in cooperation with the first core and capable of changing a posture thereof. A shield made of a nonmagnetic metal is arranged along the outer surface of the second core to shield magnetism in the magnetic field and a magnetic shielding portion for changing the posture of the second core between a first posture where the shield shields the magnetism and a second posture where the shield does not shield the magnetism.
摘要:
A fixing unit (14) of an image forming apparatus (1) includes a heating member (48) having a first area where a sheet does not come into contact with the heating member (48) and a second area where the sheet comes into contact with the heating member (48). The fixing unit (14) further includes a coil (52) forming a magnetic field, cores (54,56) forming a magnetic path near the coil (52), a nonmagnetic magnetism adjusting member (90) arranged on the magnetic path and having a closed frame, and a switcher (58,60) capable of switching the magnetism adjusting member (90) between a first state where the magnetism adjusting member (90) generates an induction current resulting from the magnetic field to shield the magnetism in the first area, and a second state where the magnetism adjusting member (90) generates no induction current and the magnetism is not shielded in the first area.
摘要:
An image forming apparatus includes an image forming unit and a fixing unit. The fixing unit includes a heating member; a coil arranged along an outer surface of the heating member for generating a magnetic field for induction heating the heating member; a core arranged to face the heating member with the coil located therebetween in order to form a magnetic path around the coil and made of a magnetic material; a shielding member arranged near the magnetic path generated by the coil, including a closed frame portion and made of a nonmagnetic metal; and a magnetic shielding portion for displacing the shielding member between a retracted position for permitting a magnetic flux to pass along a frame surface virtually formed inside the closed frame portion and a shielding position for shielding magnetism by the penetration of a magnetic flux inside the frame surface.
摘要:
An image forming apparatus is provided with an image forming station and a fixing unit including a heating member. The fixing unit includes a coil for generating a magnetic field for induction heating the heating member; a first core arranged to face the heating member with the coil located therebetween; a bar-shaped second core including a cut-off portion and arranged in a magnetic path between the first core and the heating member, when seen in a magnetic field generation direction by the coil, to form the magnetic path together with the first core; and a magnetic adjusting mechanism for changing the posture of the second core between a first posture for guiding a magnetic field by retracting the cut-off portion from the magnetic path and a second posture for increasing magnetic resistance by locating the cut-off portion in the magnetic path by rotating the second core about an axis thereof.
摘要:
An image forming apparatus is provided with a photoconductor to have an electrostatic latent image formed thereon, a developing device for developing the electrostatic latent image with a toner, a toner replenishing device for replenishing the toner into the developing device, and a controller for controlling an image developing operation by the developing device and a toner replenishing operation by the toner replenishing device. The controller executes a non-replenishment mode for causing the developing device to perform image development without being replenished with the toner from the toner replenishing device, a discharge mode, following the non-replenishment mode, for discharging the toner remaining in the developing device and a refill mode, following the discharge mode, for refilling the toner into the developing device by the toner replenishing device.