Abstract: A paper guide is disposed at an introduction unit of a fixing device of an image forming device. The paper guide is disposed over a width direction of a transfer path through which a sheet is guided to the introduction unit. One end portion and another end portion, in the width direction, of the transfer path of the paper guide have a step-down surface that retracts from the sheet.

Abstract: A fixing device includes: a fixing belt; a facing member disposed on an inner side of the fixing belt; a pressure roller that presses against the fixing belt toward the facing member from outside to form a fixing nip area; a heat source; a non-passage area temperature measurer that measures a temperature of a sheet non-passage area; a pressure roller swinger that swings one end side of the pressure roller in a direction intersecting with a longitudinal direction of the fixing nip area; and a controller that performs meandering correction control for correcting a movement direction of the fixing belt by causing the pressure roller swinger to swing the pressure roller, and the controller has such a movement mode as to cause the pressure roller swinger to forcibly move the fixing belt in a direction away from the non-passage area temperature measurer while rotating the fixing belt.

Abstract: A sheet heating device includes: a heat roller including a lamp heater; a fixing frame supporting end parts of the heat roller and the lamp heater; and a heat-insulating cover member provided outside of the fixing frame. The fixing frame is disposed so as to cover the space above the heat roller. A plurality of heat retention spaces is provided inside of the cover member so as to be partitioned from one another and to be opened toward the fixing frame.

Abstract: A sheet heating device includes: a heat roller including a lamp heater; a fixing frame supporting end parts of the heat roller and the lamp heater; and a heat-insulating cover member provided outside of the fixing frame. The fixing frame is disposed so as to cover the space above the heat roller. A plurality of heat retention spaces is provided inside of the cover member so as to be partitioned from one another and to be opened toward the fixing frame.

Abstract: A sheet heating device includes: a heat roller including a lamp heater; a fixing frame supporting end parts of the heat roller and the lamp heater; and a heat-insulating cover member provided outside of the fixing frame. The fixing frame is disposed so as to cover the space above the heat roller. A plurality of heat retention spaces is provided inside of the cover member so as to be partitioned from one another and to be opened toward the fixing frame.

Abstract: A fixing device includes: a fixing belt; a facing member disposed on an inner side of the fixing belt; a pressure roller that presses against the fixing belt toward the facing member from outside to form a fixing nip area; a heat source; a non-passage area temperature measurer that measures a temperature of a sheet non-passage area; a pressure roller swinger that swings one end side of the pressure roller in a direction intersecting with a longitudinal direction of the fixing nip area; and a controller that performs meandering correction control for correcting a movement direction of the fixing belt by causing the pressure roller swinger to swing the pressure roller, and the controller has such a movement mode as to cause the pressure roller swinger to forcibly move the fixing belt in a direction away from the non-passage area temperature measurer while rotating the fixing belt.

Abstract: A sheet heating device includes: a heat roller including a lamp heater; a fixing frame supporting end parts of the heat roller and the lamp heater; and a heat-insulating cover member provided outside of the fixing frame. The fixing frame is disposed so as to cover the space above the heat roller. A plurality of heat retention spaces is provided inside of the cover member so as to be partitioned from one another and to be opened toward the fixing frame.

Abstract: A processing unit according to this invention includes a photosensitive drum, an initial detection gear, a rotation stop, and a stopper arm. The photosensitive drum forms an electrostatic latent image on a surface thereof. The initial detection gear is a member which is rotatable in a manner linked to rotation of the photoreceptor for identifying the processing unit as a new one or an old one. The rotation stop is provided on the photosensitive drum. The stopper arm is engageable with the rotation stop.

Abstract: A processing unit according to this invention includes a photosensitive drum, an initial detection gear, a rotation stop, and a stopper arm. The photosensitive drum forms an electrostatic latent image on a surface thereof. The initial detection gear is a member which is rotatable in a manner linked to rotation of the photoreceptor for identifying the processing unit as a new one or an old one. The rotation stop is provided on the photosensitive drum. The stopper arm is engageable with the rotation stop.

Abstract: An electrostatic charger according to the present invention includes a needle electrode, a support, and a cleaning member. The needle electrode has a linear array of needles. The support can move along the linear array. The cleaning member is supported by the support rotatably on an axis perpendicular to the linear array. While the support is moving with the cleaning member along the linear array, the cleaning member rotates, with the needles sinking in order into and subsequently coming in order out of the cleaning member. When the cleaning member makes each rotation while moving with the support, some of the needles sink in positions into the cleaning member where any other needles did not sink when the cleaning member made the previous rotation.

Abstract: A needle electrode and a cleaning member are provided. A plurality of needles are arrayed upon the needle electrode in a straight line, and protrude towards a surface of a photoreceptor. The cleaning member is disposed movably along the array direction of the plurality of needles between the surface of the photoreceptor and the needle electrode. When the cleaning member moves, the tip portion of each of the plurality of needles in the arranged order, after having been embedded from the surface of the cleaning member into its interior, then exits to the exterior of the cleaning member.

Abstract: A discharge unit is disposed downstream of a principal transport path of a compound machine, and a shifter function is provided in this discharge unit. By shifting the paper passage position relative to a photosensitive drum when printing the front side and the paper passage position relative to the photosensitive drum when printing the back side, the region in which the surface electric potential of the photosensitive drum increases is diminished, and the region in which photographic fog is generated is made smaller. Thus, when printing the second and subsequent sheets, even when a slight amount of displacement of the transport position of the recording paper occurs, it is possible to suppress that recording paper making contact in the photographic fog region on the photosensitive drum, and defective printing can be prevented.

Abstract: An image forming apparatus is constituted so as to be equipped with transfer apparatus(es) having transfer roller(s) electrostatically transferring development image(s) from photosensitive drum(s) to transfer medium/media, and so as to be provided with transfer medium guide unit disposed downstream in transfer medium transport path(s) from location(s) at which photosensitive drum(s) oppose transfer roller(s), and such that transfer medium guide location(s) of transfer medium guide means is/are variable.

Abstract: An electrostatic charger according to the present invention includes a needle electrode, a support, and a cleaning member. The needle electrode has a linear array of needles. The support can move along the linear array. The cleaning member is supported by the support rotatably on an axis perpendicular to the linear array. While the support is moving with the cleaning member along the linear array, the cleaning member rotates, with the needles sinking in order into and subsequently coming in order out of the cleaning member. When the cleaning member makes each rotation while moving with the support, some of the needles sink in positions into the cleaning member where any other needles did not sink when the cleaning member made the previous rotation.

Abstract: A needle electrode and a cleaning member are provided. A plurality of needles are arrayed upon the needle electrode in a straight line, and protrude towards a surface of a photoreceptor. The cleaning member is disposed movably along the array direction of the plurality of needles between the surface of the photoreceptor and the needle electrode. When the cleaning member moves, the tip portion of each of the plurality of needles in the arranged order, after having been embedded from the surface of the cleaning member into its interior, then exits to the exterior of the cleaning member.

Abstract: A paper separator may be equipped with plurality of paper-separating fingers for separating sheet(s) of paper for image formation and abutting and/or backed off from photosensitive body or bodies, paper separator optionally comprising finger body or bodies capable of abutting photosensitive body or bodies; spur(s)—capable of touching so as to guide sheet(s) of paper for image formation which has or have separated from photosensitive body or bodies; and/or support component(s) pivotably supporting paper-separating finger(s) so as to impart restoring force(s) thereto urging paper-separating finger(s) to under the force(s) of its or their own weight(s) bring finger body or bodies into abutting engagement with photosensitive body or bodies, and so as to, when spur(s) is or are touching sheet(s) of paper for image formation, cause finger body or bodies to at least partially overcome restoring force(s) produced by weight(s) of paper-separating finger(s) or portion(s) thereof and back off from photosensitive body or

Abstract: A transfer device is provided including an intermediate transfer belt and transfer rollers associated with respective of photosensitive drums. Each of the transfer rollers and the intermediate transfer belt define therebetween a contact range of which center lies downstream of the center of a contact range (transfer nip region) defined between the associated photosensitive drum and the endless belt in the direction of movement of the endless belt. The transfer roller deforms the path of movement of the intermediate transfer belt by contacting the intermediate transfer belt, and the resulting deformation causes the intermediate transfer belt to contact the periphery of the photosensitive drum over a predetermined range.

Abstract: A transfer device has a control circuit. The control circuit initiates supplying transfer power to one or more first transfer rollers and to a second transfer roller when a first transfer operation is initiated by a first transfer roller positioned most upstream with respect to a direction in which an intermediate transfer belt travels. The control circuit stops supplying the transfer power to the one or more first transfer rollers and to the second transfer roller when a second transfer operation is completed by the second transfer roller. The transfer power supplied to the one or more first transfer rollers and to the second transfer roller, respectively, is free from fluctuation during a period from the initiation of the first transfer operation performed first to the completion of the second transfer operation.

Abstract: A rotation speed of a heating roller 39a and a pressure roller 39b is variably controlled by a CPU 542 based on a sheet size to be printed, a direction the sheet is to be passed, and a number of sheets to be printed. Specifically, variable control of the rotation speeds of the heating roller 39a and the pressure roller 39b by the CPU 542 is based on an occurrence of a pass-through area 39b1 and a non-pass-though area 39b2 by a sheet of recording paper with respect to a roller lengthwise direction (axial direction) of a position at which the sheet of recording paper passes between the heating roller 39a and the pressure roller 39b, and controlled based on a thermal expansion coefficient of a roller diameter of the non-pass-though area 39b2 of the pressure roller 39b.

Abstract: A transfer device is provided including an intermediate transfer belt and transfer rollers associated with respective of photosensitive drums. Each of the transfer rollers and the intermediate transfer belt define therebetween a contact range of which center lies downstream of the center of a contact range (transfer nip region) defined between the associated photosensitive drum and the endless belt in the direction of movement of the endless belt. The transfer roller deforms the path of movement of the intermediate transfer belt by contacting the intermediate transfer belt, and the resulting deformation causes the intermediate transfer belt to contact the periphery of the photosensitive drum over a predetermined range.