Abstract: An image forming apparatus includes a fixing device, a conveyance rollers pair, a curved path and a first guide roller. The fixing device fixes a toner image on a sheet. The conveyance rollers pair conveys the sheet on which the toner image is fixed by the fixing device. The curved path is provided between the fixing device and the conveyance rollers pair, and the sheet is conveyed along the curved path with a toner image fixed surface facing an inner peripheral side of the curved path. The first guide roller is shiftable between a guide position protruding in the curved path from the inner peripheral side and the inner peripheral side. When the sheet is conveyed along the curved path, the first guide roller is pushed by the sheet while rotating following the sheet and then is shifted from the guide position to the inner peripheral side.

Abstract: An image forming apparatus includes a fixing device, a conveyance rollers pair, a curved path and a first guide roller. The fixing device fixes a toner image on a sheet. The conveyance rollers pair conveys the sheet on which the toner image is fixed by the fixing device. The curved path is provided between the fixing device and the conveyance rollers pair, and the sheet is conveyed along the curved path with a toner image fixed surface facing an inner peripheral side of the curved path. The first guide roller is shiftable between a guide position protruding in the curved path from the inner peripheral side and the inner peripheral side. When the sheet is conveyed along the curved path, the first guide roller is pushed by the sheet while rotating following the sheet and then is shifted from the guide position to the inner peripheral side.

Abstract: The fixing device includes a heated rotating body, a pressure rotating body, a heating unit configured to heat the heated rotating body, a separation claw, and a gap rolling member. The pressure rotating body is pressed against the heated rotating body to form a fixing nip portion. The separation claw separates the recording medium from the heated rotating body or the pressure rotating body. The gap rolling member is rotatably supported by the separation claw and abuts against an outer peripheral surface of the heated rotating body or the pressure rotating body to define a gap between the heated rotating body or the pressure rotating body and a tip portion of the separation claw. The separation claw has a conveyance surface facing the recording medium passing through the fixing nip portion, and a part of an outer peripheral surface of the gap rolling member protrudes from the conveyance surface.

Abstract: The fixing device includes a heated rotating body, a pressure rotating body, a heating unit configured to heat the heated rotating body, a separation claw, and a gap rolling member. The pressure rotating body is pressed against the heated rotating body to form a fixing nip portion. The separation claw separates the recording medium from the heated rotating body or the pressure rotating body. The gap rolling member is rotatably supported by the separation claw and abuts against an outer peripheral surface of the heated rotating body or the pressure rotating body to define a gap between the heated rotating body or the pressure rotating body and a tip portion of the separation claw. The separation claw has a conveyance surface facing the recording medium passing through the fixing nip portion, and a part of an outer peripheral surface of the gap rolling member protrudes from the conveyance surface.

Abstract: A fixing device includes a heating body, a pressurizing body, a separation claw, and a supporting member. The heating body heats a medium where a toner image is formed while the heating body rotates around a shaft. The pressurizing body forms a nip with the heating body and applies pressure to the medium that passes through the nip while the pressurizing body rotates around a shaft. The separation claw includes a protrusion that contacts the medium after having passed through the nip and separates the medium from the heating body. The supporting member supports the separation claw in state of causing the separation claw into contact with the heating body. The supporting member supports the separation claw while the supporting member causes the separation claw to slide in a direction separating from the heating body when the medium is brought into contact with the protrusion to press the protrusion.

Abstract: A fixing device includes a heating body, a pressurizing body, a separation claw, and a supporting member. The heating body heats a medium where a toner image is formed while the heating body rotates around a shaft. The pressurizing body forms a nip with the heating body and applies pressure to the medium that passes through the nip while the pressurizing body rotates around a shaft. The separation claw includes a protrusion that contacts the medium after having passed through the nip and separates the medium from the heating body. The supporting member supports the separation claw in state of causing the separation claw into contact with the heating body. The supporting member supports the separation claw while the supporting member causes the separation claw to slide in a direction separating from the heating body when the medium is brought into contact with the protrusion to press the protrusion.

Abstract: A curl correcting device includes a pair of fixed guides and a change-over guide. The pair of fixed guides composes a curved part of a conveyance path. The change-over guide is provided to be contactable with a sheet from a radial outer side of the curved part. An outer guide includes a pair of side pressing parts and a bulge part. The pair of side pressing parts is formed at both ends in a width direction. The bulge part is formed between the pair of side pressing parts so as to bulge toward the radial outer side of the curved part. The change-over guide is configured to move to a first correcting position when the sheet curled along the conveyance direction is conveyed through the conveyance path and to move to a second correcting position when the sheet curled along the width direction is conveyed through the conveyance path.

Abstract: A curl correcting device includes a pair of fixed guides and a change-over guide. The pair of fixed guides composes a curved part of a conveyance path. The change-over guide is provided to be contactable with a sheet from a radial outer side of the curved part. An outer guide includes a pair of side pressing parts and a bulge part. The pair of side pressing parts is formed at both ends in a width direction. The bulge part is formed between the pair of side pressing parts so as to bulge toward the radial outer side of the curved part. The change-over guide is configured to move to a first correcting position when the sheet curled along the conveyance direction is conveyed through the conveyance path and to move to a second correcting position when the sheet curled along the width direction is conveyed through the conveyance path.

Abstract: In a fixing device, on a receiving surface of a separating plate provided at a downstream side of a nip part formed between the fixing roller and the pressing roller, a catch part is formed in an edge part facing the nip part. When a direction of a sheet ejected from the nip part comes close to the fixing roller, a front end part of the sheet is caught by the catch part, and the sheet is largely bent or leaps up. A position detector detects the bending or leaping up of the sheet and recognizes that the direction of the sheet ejected from the nip part comes close to the fixing roller. The controller decreases force for pressing the fixing roller and the pressing roller or a fixing temperature, whereby the direction of the sheet ejected from the nip part is deviated from the fixing roller.

Abstract: In a fixing device, on a receiving surface of a separating plate provided at a downstream side of a nip part formed between the fixing roller and the pressing roller, a catch part is formed in an edge part facing the nip part. When a direction of a sheet ejected from the nip part comes close to the fixing roller, a front end part of the sheet is caught by the catch part, and the sheet is largely bent or leaps up. A position detector detects the bending or leaping up of the sheet and recognizes that the direction of the sheet ejected from the nip part comes close to the fixing roller. The controller decreases force for pressing the fixing roller and the pressing roller or a fixing temperature, whereby the direction of the sheet ejected from the nip part is deviated from the fixing roller.

Abstract: An image forming apparatus has a fusing device in which a recording medium carrying an unfused toner image is nipped at a fusing nip formed between a heated member and a pressing member to fuse and fix the unfused toner image to the recording medium, and an exhaust duct unit through which air around the fusing device is expelled outside. The exhaust duct unit allows a choice between a first exhaust path through which outside air sucked into the image forming apparatus is passed through a space around the fusing device and is then expelled out of the image forming apparatus, and a second exhaust path in which a filter for collecting particles contained in an air stream is arranged and through which the air around the fusing device is passed through the filter and is then expelled out of the image forming apparatus.

Abstract: An image forming apparatus has a fusing device in which a recording medium carrying an unfused toner image is nipped at a fusing nip formed between a heated member and a pressing member to fuse and fix the unfused toner image to the recording medium, and an exhaust duct unit through which air around the fusing device is expelled outside. The exhaust duct unit allows a choice between a first exhaust path through which outside air sucked into the image forming apparatus is passed through a space around the fusing device and is then expelled out of the image forming apparatus, and a second exhaust path in which a filter for collecting particles contained in an air stream is arranged and through which the air around the fusing device is passed through the filter and is then expelled out of the image forming apparatus.

Abstract: A corrosion resistant member made of the Y2O3 sintered material that contains 99.9% by weight or more Y in terms of Y2O3, and has a difference in mean crystal grain size between the surface and the inside region of the Y2O3 sintered material not larger than 30 ?m.

Abstract: A corrosion resistant member made of the Y2O3 sintered material that contains 99.9% by weight or more Y in terms of Y2O3, and has a difference in mean crystal grain size between the surface and the inside region of the Y2O3 sintered material not larger than 30 ?m.

Abstract: There is provided a ceramic member for semiconductor manufacturing equipment which is formed of an alumina-based sinter containing an yttrium-aluminum-garnet at the amount of 3 to 50 wt %, silicon oxide at the amount of not more than 0.2 wt %, preferably 0.1 wt %, and the balance substantially alumina, wherein the sinter has dielectric loss of not more than 4×10?4 particularly 2.5×10?4 or less in the frequency range of 10 MHz to 5 GHz. Such a member may be formed of a ceramic sinter including an aluminum phase having mean crystal grain size in a range of 2 to 10 ?m and a yttrium-aluminum-garnet phase having a mean crystal grain size in a range of 1.5 to 5 ?m, wherein the ratio of the mean crystal grain size of the alumina phase to that of the yttrium-aluminum-garnet phase is larger than 1 and smaller than 7.

Abstract: An image forming apparatus which includes a fixing device including a fixing roller, a pressure roller pressed into contact with the fixing roller, and a thermistor in contact with a non-paper-passage region on the surface of the fixing roller, the fixing roller incorporating a first halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in a middle region thereof is higher than heat in opposite-end regions thereof, and a second halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in opposite-end regions thereof is higher than heat in a middle region thereof; and a controller for controlling power supply to the first and second halogen heaters. The controller starts power supply to the first and second halogen heaters to start warm-up of the fixing device, and cuts off power supply to the first halogen heater for a predetermined period of time during the warm-up.

Abstract: An image forming apparatus comprising: a fixing device including a fixing roller, a pressure roller pressed into contact with the fixing roller, and a thermistor in contact with a non-paper-passage region on the surface of the fixing roller, the fixing roller incorporating a first halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in a middle region thereof is higher than heat in opposite-end regions thereof, and a second halogen heater whose heat distribution based on the axial direction of the fixing roller is set such that heat in opposite-end regions thereof is higher than heat in a middle region thereof; and a controller for controlling power supply to the first and second halogen heaters. The controller starts power supply to the first and second halogen heaters to start warm-up of the fixing device, and cuts off power supply to the first halogen heater for a predetermined period of time during the warm-up.

Abstract: There is provided a ceramic member for semiconductor manufacturing equipment which is formed of an alumina-based sinter containing an yttrium-aluminum-garnet at the amount of 3 to 50 wt %, silicon oxide at the amount of not more than 0.2 wt %, preferably 0.1 wt %, and the balance substantially alumina, wherein the sinter has dielectric loss of not more than 4×10−4 particularly 2.5×10−4 or less in the frequency range of 10 MHz to 5 GHz. Such a member may be formed of a ceramic sinter including an aluminum phase having mean crystal grain size in a range of 2 to 10 &mgr;m and a yttrium-aluminum-garnet phase having a mean crystal grain size in a range of 1.5 to 5 &mgr;m, wherein the ratio of the mean crystal grain size of the alumina phase to that of the yttrium-aluminum-garnet phase is larger than 1 and smaller than 7.

Abstract: A transfer roller is spaced away from the outer surface of a photosensitive drum by a specified distance to prevent the abrasion and damage of the photosensitive drum by the contact of the transfer roller and the photosensitive drum. The transfer roller not in contact with the photosensitive drum can be formed to have a sufficient hardness without damaging the outer surface of the photosensitive drum. Further, since the transfer roller has a sufficient hardness, cleaning blades can be held in without damaging the transfer roller with a sufficiently large force without damaging the transfer roller, thereby securely scraping off toner and the line adhered to the transfer roller and preventing the rear surface of a transfer sheet from being smeared.

Abstract: In an image forming apparatus, a sheet that has been transported in a certain direction is selectively transported to one of first and second transport routes by a route changer mechanism. A first cover and a second cover are openably provided on a main body of the apparatus to respectively allow the first and second transport routes to be accessible to outside of the apparatus main body when set in an opened state. An operative mechanism is provided to open the first cover in association with opening of the second cover.