Abstract: An image forming apparatus includes: a first image forming unit for a monochrome printing including a first photosensitive member for black, a first charging member and a first collection member; a second image forming unit for a multi-color printing including a second photosensitive member for a color, a second charging member and a second collection member; and a control device configured to, at the color printing mode, apply a first charging bias to the second charging member and apply a first bias having a reverse polarity to a charged polarity of developer to the first and second collection members, and at the monochrome printing mode, apply a second charging bias to the second charging member, apply a second bias having the reverse polarity to the first collection member and apply a third bias to the second collection member.

Abstract: An image fanning apparatus includes: an image carrier, on which an electrostatic latent image is formed; a developing device, which accommodates a developer for developing the electrostatic latent image into a developer image, and which includes a developer carrier that carries the developer and supplies the developer to the image carrier; a remaining quantity calculation part that calculates a remaining quantity of the developer in the developing housing; a deterioration degree storage part that stores a relationship between the remaining quantity of the developer in the developing housing and a deterioration degree of the developer caused by the developing operation; and a life determination part that determines whether the developing device has reached an end of its life based on the remaining quantity calculated by the remaining quantity calculation part and the relationship stored in the deterioration degree storage part.

Abstract: An image forming device includes a plurality of developing devices, and a plurality of sloping members disposed in one-to-one correspondence with the plurality of developing devices. Each developing device includes a developer accommodating chamber and a developing roller disposed above the developer accommodating chamber. Each developing device is movable between a first position and a second position lower than the first position in a height direction generally parallel to a vertical direction. Each sloping member has a sloped surface movable in the height direction and a biasing member biasing the sloped surface upward in the height direction. Each sloping member is movable between a third position where the corresponding developing device is placed on the sloped surface and a fourth position where the corresponding developing device is released from being pressed by the sloped surface in a predetermined direction generally perpendicular to the vertical direction.

Abstract: An image forming device includes a developing device unit including a plurality of developing devices, and a plurality of sloping members disposed in one-to-one correspondence with the plurality of developing devices. Each developing device includes a developing roller defining an axis line and a developer accommodating chamber. Each developing device is movable in a first direction perpendicular to the axis line. Each sloping member has a sloped surface and a biasing member biasing the sloped surface upward in the first direction. Each sloping member is movable between a first position where the developing device is placed on the sloped surface and a second position where the developing device is disengaged from the sloped surface in a predetermined direction different from the first direction.

Abstract: An image forming apparatus includes: an image carrier; a developing housing that accommodates a developer for developing an electrostatic latent image into a developer image; a developer carrier, which carries the developer in the developing housing, and which supplies the developer to the image carrier; a developing bias supply part that supplies a developing bias to the developer carrier; a remaining quantity calculation part that calculates a remaining quantity of the developer in the developing housing; a deterioration grade storage part that stores a relationship between the remaining quantity of the developer in the developing housing and a deterioration degree of the developer caused by the developing operation; and a developing bias setting part that sets a value of the developing bias in accordance with the remaining quantity calculated by the remaining quantity calculation part and the relationship stored in the deterioration grade storage part.

Abstract: An image forming apparatus includes: photosensitive members; an endless belt facing the photosensitive members; developing rollers respectively supplying, to the photosensitive members, developer of different colors which is charged to a first polarity; cleaning rollers adjacent to the photosensitive members; a separating mechanism separating the developing roller from the photosensitive member in a single color printing. If in a multi color printing, a control unit applies a cleaning bias whose polarity is a second polarity opposite to the first polarity and which holds a first electric potential to each cleaning roller. If in the single color printing, the control unit executes a bias reduction control in which a cleaning bias applied to the cleaning roller not used in the single color printing is given the second polarity and is made to hold a second electric potential whose absolute value is smaller than that of the first electric potential.

Abstract: An image forming apparatus may include a photosensitive member, a plurality of developing devices each including a developing roller, a support member detachably supporting the plurality of developing devices, and a developing device move mechanism that moves each of the developing devices to a close position and a distant position. Each of the developing devices includes a cover member that is movable between a cover position and an exposure position. The image forming apparatus further includes a cover member move mechanism, which moves the cover member from the cover position to the exposure position in association with movement of the developing roller from the distant position to the close position, and which moves the cover member from the exposure position to the cover position in association with movement of the developing roller from the close position to the distant position.

Abstract: There is provided an image forming apparatus including: a photosensitive member; a plurality of developing devices each including a developing roller; a support member detachably supporting the plurality of developing devices; and a developing device move mechanism that moves each of the developing devices to a close position and a distant position. Each of the developing devices includes a cover member that is movable between a cover position and an exposure position. The image forming apparatus further includes a cover member move mechanism, which moves the cover member from the cover position to the exposure position in association with movement of the developing roller from the distant position to the close position, and which moves the cover member from the exposure position to the cover position in association with movement of the developing roller from the close position to the distant position.

Abstract: In an image forming apparatus, a first photoconductor drum for use in at least in a monochrome printing mode is located upstream, in a direction of transport of a medium, of a plurality of second photoconductor drums for use in a color printing mode. A transfer bias for each of transfer members is regulated in such a manner that a transfer bias applied in the monochrome printing mode between a second photoconductor drum located adjacently downstream of the first photoconductor drum and the corresponding transfer member is larger than that applied in the color printing mode. A developing bias for each of the development rollers is regulated in such a manner that an absolute value of a developing bias voltage applied to a development roller corresponding to the first photoconductor drum in the monochrome printing mode is smaller than that applied in the color printing mode.

Abstract: An image forming device includes a developing device unit including a plurality of developing devices, and a plurality of sloping members disposed in one-to-one correspondence with the plurality of developing devices. Each developing device includes a developing roller defining an axis line and a developer accommodating chamber. Each developing device is movable in a first direction perpendicular to the axis line. Each sloping member has a sloped surface and a biasing member biasing the sloped surface upward in the first direction. Each sloping member is movable between a first position where the developing device is placed on the sloped surface and a second position where the developing device is disengaged from the sloped surface in a predetermined direction different from the first direction.

Abstract: An image forming apparatus includes a plurality of image forming units, a patch forming unit which actuates the respective image forming units to form density detection patches of the respective colors, a density detecting unit that detects a density of the density detecting patches, a condition correcting unit that controls the density detecting unit to detect the density of the density detecting patches of the respective colors, and corrects the image forming conditions based on respective deviations, a patch re-forming unit that, for each color for which the respective deviation is greater than a threshold value, generates a re-formed density detecting patch of the color using the respective image forming condition previously corrected by the condition correcting unit, and a condition re-correcting unit that controls the density detecting unit to detect a density of the re-formed density detecting patch and re-correct the respective image forming condition.

Abstract: An image forming device includes a main casing, a photosensitive drum unit and a developing device unit. The photosensitive drum unit includes a plurality of photosensitive drums juxtaposed in a first direction orthogonal to an axis of each photosensitive drum. The developing device unit includes a plurality of developing devices disposed in one-to-one correspondence with the plurality of photosensitive drums and a supporting member. Each developing device includes a developing roller having a shaft extending in a second direction parallel to the axis of each photosensitive drum. The supporting member supports the developing devices to be movable between a first position for supplying toner to corresponding photosensitive drums and a second position retracted from the first position. The developing device unit is detachable from the main casing by moving the developing devices to the second position and drawing the supporting member.

Abstract: An image forming apparatus includes: photosensitive members; an endless belt facing the photosensitive members; developing rollers respectively supplying, to the photosensitive members, developer of different colors which is charged to a first polarity; cleaning rollers adjacent to the photosensitive members; a separating mechanism separating the developing roller from the photosensitive member in a single color printing. If in a multi color printing, a control unit applies a cleaning bias whose polarity is a second polarity opposite to the first polarity and which holds a first electric potential to each cleaning roller. If in the single color printing, the control unit executes a bias reduction control in which a cleaning bias applied to the cleaning roller not used in the single color printing is given the second polarity and is made to hold a second electric potential whose absolute value is smaller than that of the first electric potential.

Abstract: An image forming apparatus is described. The image forming apparatus may include a developer cartridge and a photosensitive unit. The developer cartridge may include a first casing accommodating a developing agent, a developing agent carrier supported by the first casing and carrying the developing agent, a memory element storing predetermined information, and a first terminal electrically connected with the memory element. The photosensitive unit may include a second casing to which the developer cartridge is detachably attached, a photosensitive member, with which the developing agent carrier is brought into pressure contact when the developer cartridge is attached to the second casing, supported by the second casing, and a second terminal electrically connected with the first terminal when the developing agent carrier is brought into pressure contact with the photosensitive member.

Abstract: In an image forming apparatus, a first photoconductor drum for use in at least in a monochrome printing mode is located upstream, in a direction of transport of a medium, of a plurality of second photoconductor drums for use in a color printing mode. A transfer bias for each of transfer members is regulated in such a manner that a transfer bias applied in the monochrome printing mode between a second photoconductor drum located adjacently downstream of the first photoconductor drum and the corresponding transfer member is larger than that applied in the color printing mode. A developing bias for each of the development rollers is regulated in such a manner that an absolute value of a developing bias voltage applied to a development roller corresponding to the first photoconductor drum in the monochrome printing mode is smaller than that applied in the color printing mode.

Abstract: An image fanning apparatus includes: an image carrier, on which an electrostatic latent image is formed; a developing device, which accommodates a developer for developing the electrostatic latent image into a developer image, and which includes a developer carrier that carries the developer and supplies the developer to the image carrier; a remaining quantity calculation part that calculates a remaining quantity of the developer in the developing housing; a deterioration degree storage part that stores a relationship between the remaining quantity of the developer in the developing housing and a deterioration degree of the developer caused by the developing operation; and a life determination part that determines whether the developing device has reached an end of its life based on the remaining quantity calculated by the remaining quantity calculation part and the relationship stored in the deterioration degree storage part.

Abstract: An image forming apparatus includes: an image carrier; a developing housing that accommodates a developer for developing an electrostatic latent image into a developer image; a developer carrier, which carries the developer in the developing housing, and which supplies the developer to the image carrier; a developing bias supply part that supplies a developing bias to the developer carrier; a remaining quantity calculation part that calculates a remaining quantity of the developer in the developing housing; a deterioration grade storage part that stores a relationship between the remaining quantity of the developer in the developing housing and a deterioration degree of the developer caused by the developing operation; and a developing bias setting part that sets a value of the developing bias in accordance with the remaining quantity calculated by the remaining quantity calculation part and the relationship stored in the deterioration grade storage part.

Abstract: A shape evaluation device performs simulation by using an annular light source or concentric light source instead of a rectilinear light source and calculates a characteristic line for performing shape evaluation. The shape evaluation device includes a calculation device (2) having: a distance vector calculation unit (2a) for acquiring a distance vector representing a distance between the circle and the vector, a distance function unit (2b) for acquiring a distance function from the distance vector, and a distance function calculation unit (2c) for acquiring a point on a curved surface where the value of the distance function is a predetermined value. By performing simulation using the annular or concentric light source, it is possible to obtain a characteristic line capable of observing distortion in all the directions by one calculation.

Abstract: There is provided an image forming apparatus including: a photosensitive member; a plurality of developing devices each including a developing roller; a support member detachably supporting the plurality of developing devices; and a developing device move mechanism that moves each of the developing devices to a close position and a distant position. Each of the developing devices includes a cover member that is movable between a cover position and an exposure position. The image forming apparatus further includes a cover member move mechanism, which moves the cover member from the cover position to the exposure position in association with movement of the developing roller from the distant position to the close position, and which moves the cover member from the exposure position to the cover position in association with movement of the developing roller from the close position to the distant position.

Abstract: An image forming device includes a main casing, a photosensitive drum unit and a developing device unit. The photosensitive drum unit includes a plurality of photosensitive drums that forms electrostatic images thereon, each photosensitive drum having an axis, the plurality of photosensitive drums being juxtaposed along a line extending in a first direction orthogonal to the axis. The developing device unit includes a plurality of developing devices and a supporting member. The developing devices are disposed in one-to-one correspondence with the plurality of photosensitive drums, each developing device including a developing roller that supplies toner to corresponding photosensitive drum to develop the electrostatic images formed thereon and having a shaft extending in a second direction parallel to the axis of the photosensitive drum.