Patent application number | Description | Published |
20090202266 | IMAGE FORMING APPARATUS - The image forming apparatus, in the case where image forming is performed on a recording medium whose size covers a position of a second temperature detection element perpendicularly disposed to the recording medium conveyance direction, when the detected temperature rises to a predetermined temperature during execution of the first power supply control, a first power supply control is switched to a second power supply control. In the case where image forming is performed on a recording medium whose size does not cover a position of the second temperature detection element, when the detected temperature rises to a predetermined temperature during execution of the first power supply control, a conveyance control portion executes a control for extending the conveyance interval of the recording medium. Thus, an unduly large temperature rise in the non-sheet passing portion is prevented, and a good quality image can be provided without glossy unevenness in one sheet. | 08-13-2009 |
20090257793 | IMAGE FORMING APPARATUS - The image forming apparatus includes an image forming portion forming a toner image on a recording material, and a fixing portion heating and fixing the toner image formed on the recording material to the recording material, wherein the apparatus has a cleaning mode in which the fixing portion is cleaned, and when the cleaning mode is set, the image forming portion forms a predetermined toner image on the recording material, and the fixing portion then heats and fixes the predetermined toner image to the recording material to form a cleaning sheet which is heated and conveyed to clean the fixing portion. By the virtue of the present invention, it achieves high cleaning performance in which the fixing portion is cleaned by the cleaning sheet. | 10-15-2009 |
20100316404 | IMAGE FORMING APPARATUS - The image forming apparatus includes a fixing portion, a temperature detection element, and a power control portion, wherein the power control portion is capable of setting a first power supply control mode for supplying power according to the detected temperature for each one control cycle, a second power supply control mode for supplying power according to the detected temperature for each one control cycle and a third power supply control mode for supplying predetermined power, and switches, immediately before a leading edge of the recording material enters the fixing portion, a state of supplying the power in the first power supply control mode to a state of supplying the power in the second power supply control mode, and then switches the state of supplying the power in the second power supply control mode to a state of supplying the power in the third power supply control mode. | 12-16-2010 |
20110150548 | IMAGE FORMING APPARATUS - The present invention provides an image forming apparatus including an upstream conveying portion, a downstream conveying portion, and a loop detector, wherein the image forming apparatus further includes a driving portion which moves the contact portion to a projecting position where the sheet conveying path is in contact with a conveyed sheet and to a retracted position where the sheet conveying path is not in contact with the conveyed sheet, and a controlling portion which controls the driving portion such that the contact portion is moved from the projecting position to the retracted position before a tip end of a sheet which enters the sheet conveying path from the upstream conveying portion reaches the contact portion. | 06-23-2011 |
20110150549 | IMAGE FORMING APPARATUS - The present invention provides an image forming apparatus having an upstream conveying portion, a downstream conveying portion, and a contact loop detection portion to detect a loop of the sheet formed between the upstream conveying portion and the downstream conveying portion, wherein the loop detection portion, includes a sensor that outputs the detection signal, a contact portion that protrudes into a sheet conveyance path between the upstream conveying portion and the downstream conveying portion as if to come into contact with the sheet conveyed through the sheet conveyance path and causes the sensor to output the detection signal by moving in contact with the sheet, and a contact force changing portion that changes a contact force with which the contact portion comes into contact with the sheet conveyed through the sheet conveyance path according to a type of the sheet conveyed through the sheet conveyance path. | 06-23-2011 |
20110182632 | IMAGE FORMING APPARATUS - The image forming apparatus includes an image forming portion forming a toner image on a recording material, and a fixing portion heating and fixing the toner image formed on the recording material to the recording material, wherein the apparatus has a cleaning mode in which the fixing portion is cleaned, and when the cleaning mode is set, the image forming portion forms a predetermined toner image on the recording material, and the fixing portion then heats and fixes the predetermined toner image to the recording material to form a cleaning sheet which is heated and conveyed to clean the fixing portion. By the virtue of the present invention, it achieves high cleaning performance in which the fixing portion is cleaned by the cleaning sheet. | 07-28-2011 |
20110305475 | IMAGE FORMING APPARATUS - The image forming apparatus, in the case where image forming is performed on a recording medium whose size covers a position of a second temperature detection element perpendicularly disposed to the recording medium conveyance direction, when the detected temperature rises to a predetermined temperature during execution of the first power supply control, a first power supply control is switched to a second power supply control. In the case where image forming is performed on a recording medium whose size does not cover a position of the second temperature detection element, when the detected temperature rises to a predetermined temperature during execution of the first power supply control, a conveyance control portion executes a control for extending the conveyance interval of the recording medium. Thus, an unduly large temperature rise in the non-sheet passing portion is prevented, and a good quality image can be provided without glossy unevenness in one sheet. | 12-15-2011 |
20120148281 | IMAGE FORMING APPARATUS HAVING FIXING UNIT FOR FIXING UNFIXED TONER IMAGE FORMED ON RECORDING MATERIAL ONTO RECORDING MATERIAL BY HEAT - Corrected power for compensating for a reduction in the temperature of an endless belt that accompanies the entry of a recording material into a fixing nip portion is adjusted by correcting the power supplied to a fixing unit when the recording material enters the fixing unit with a correction power based on a difference between the update time of a power updating period and the time of the entry of the recording material. | 06-14-2012 |
20120148282 | IMAGE FORMING APPARATUS CONTROLLING POWER SUPPLIED TO FIXING UNIT - Adjusting the start timing for conveying a printing material from a printing material conveying unit based on a power supply update period for power supplied to a heater allows proper power correction timing to be attained for compensating for a drop in temperature of the endless belt following the printing material entering a fixing nip portion. | 06-14-2012 |
20120308253 | FIXING APPARATUS - A fixing apparatus includes: two rotatable members, for forming a nip, including a region where an outer diameter is increased from a longitudinal central portion toward a longitudinal end portion; a heater; and a controller for controlling a heat generation distribution of the heater. The controller is capable of controlling the heater so that the heat generation distribution of the heater is such that a heat generation amount at the longitudinal end portion is larger than that at the longitudinal central portion in a period from start of the heater until the recording material reaches the nip. A ratio of the heat generation amount at the longitudinal end portion to that at the longitudinal central portion is larger when a cumulative amount of use of the fixing apparatus is larger than a predetermined amount than when the cumulative amount of use is smaller than the predetermined amount. | 12-06-2012 |
20130011157 | HEAT FIXING DEVICE - A heat fixing device includes a rotatable member for heating, a pressing roller configured to form a fixing nip portion that nips and conveys a recording material bearing a toner image, and a cooling fan configured to cool a recording material non-passing region in the rotatable member for heating in a direction orthogonal to a recording material conveying direction, wherein the pressing roller includes a rubber layer, between a cored bar and a release layer, containing a needle-shaped heat conductive filler oriented in a roller axis direction. | 01-10-2013 |
20130028622 | Image Heating Apparatus - The image heating apparatus includes an unit for spacing each of a buck-up member and a pressure roller apart from a flexible belt member which is electrified to generate heat, or heated by a source of heat at start-up, i.e. in a previous stage to heating an image, or an unit for controlling a pressure to decrease a contact area in the direction of the axis of rotation compared with the contact area for a period to heat an image. This can control, as much as possible, heat conduction from the flexible belt which is electrified to generate heat, or heated by the source of heat to the back-up member and the pressure roller at the start-up, i.e. the previous stage to heating an image. | 01-31-2013 |
20130108299 | IMAGE FORMING APPARATUS | 05-02-2013 |
20130209130 | IMAGE FORMING APPARATUS - The image forming apparatus includes a fixing portion, a temperature detection element, and a power control portion. The power control portion is capable of setting a first power supply control mode for supplying power according to the detected temperature for each one control cycle, a second power supply control mode for supplying power according to the detected temperature for each one control cycle and a third power supply control mode for supplying predetermined power, and switches, immediately before a leading edge of the recording material enters the fixing portion, a state of supplying the power in the first power supply control mode to a state of supplying the power in the second power supply control mode, and then switches the state of supplying the power in the second power supply control mode to a state of supplying the power in the third power supply control mode. | 08-15-2013 |