Patent application number | Description | Published |
20090034992 | IMAGE FORMING APPARATUS AND IMAGE FORMING METHOD - An image forming apparatus includes an endless belt type transfer member configured to carry an image formed with developer of a plurality of colors, a drive roller configured to drive the transfer member by rotating while contacting the transfer member, a first detection unit configured to detect a mark provided on the transfer member, a second detection unit configured to detect the mark at a position different from the position of the first detection unit in a conveyance direction of the transfer member, and a correction unit configured to correct a conveyance speed of the transfer member using a difference between respective times at which the first and second detection units detect the mark. The first and second detection units are located such that an interval between respective positions at which the first and second detection units detect the mark is an integral multiple of a perimeter of the drive roller. | 02-05-2009 |
20090136251 | IMAGE FORMING APPARATUS - An image forming apparatus capable of setting a criterion individually for respective image forming apparatuses, which is used in determining whether or not a developer is properly supplied to a developing unit, thereby stabilizing a developer toner density. With a shutter member closed, reflection light from a reflection sheet is received by a toner density detection sensor, and an output voltage is stored in a memory. After the shutter member is opened, reflection light from a developing sleeve is received by the sensor, and an output voltage is stored in the memory. If an amount of change in voltage per unit toner density calculated based on the output voltages does not fall within a predetermined range, an operation of a main unit of the image forming apparatus is stopped. If the amount of voltage change falls within the predetermined range, the amount of voltage change is stored in the memory. | 05-28-2009 |
20100046978 | IMAGE FORMING APPARATUS AND POWER CONTROL METHOD THEREFOR - An image forming capable of operating with reliability and shortening the down time. An operation unit forms an image. A power source unit supplies electric power supplied from an external power source to the operation unit. A storing unit stores successful data which shows that the image forming apparatus has started successfully. A mode selection unit selects a first mode in which regular electric power is supplied to the operation unit at a start-up when the storing unit stores the successful data, and a second mode in which electric power smaller than the regular electric power is supplied to the operation unit at the start-up when the storing unit does not store the successful data. A power control unit controls the electric power supplied from the power source unit to the operation unit according to the mode selected by the mode selection unit. | 02-25-2010 |
20110076037 | FIXING APPARATUS AND IMAGE FORMING APPARATUS - A fixing apparatus which heat-fixes a toner image transferred onto a sheet, including: a heating device configured to generate eddy currents in a conductive heating element using a magnetic core and an exciting coil to produce heat; a core moving unit configured to move the core; a current detecting unit configured to detect a current flowing through the exciting coil; and an abnormal signal output unit configured to output a signal indicating an abnormality when a difference between a first current value and a second current value is smaller than a predetermined threshold value, the first current value being detected by the current detecting unit before the core is moved by the core moving unit, the second current value being detected by the current detecting unit after the core is moved by the core moving unit. | 03-31-2011 |
20110243586 | IMAGE FORMING APPARATUS - An image forming apparatus including: a photosensitive member driving unit configured to rotate the photosensitive member; a charge unit having an opening portion and configured to charge the surface of the photosensitive member; a shield member movable between a closed position for closing the opening portion and an open position for opening the opening portion; a shield member driving unit configured to move the shield member between the closed position and the open position; and a control unit configured to control the photosensitive member driving unit to rotate the photosensitive member in a state in which the shield member is situated at the open position, and to prevent the photosensitive member from rotating in a state in which the shield member is situated at the closed position. | 10-06-2011 |
20110274446 | FIXING DEVICE CAPABLE OF DETECTING WRAP JAM OF RECORDING SHEET AND IMAGE FORMING APPARATUS - A fixing device capable of easily detecting a wrap jam of a recording sheet without increasing costs. A fixing roller fixes a toner image on a recording medium under heating control. A central thermistor and an end thermistor detect first and detected temperatures of the fixing roller in respective sheet-passing and non-sheet-passing areas. A first temperature difference-detecting circuit compares a temperature difference between the first and second detected temperatures and a first threshold and outputs a first comparison result. A second temperature difference-detecting circuit compares the temperature difference and a second threshold larger than the first threshold and outputs a second comparison result. A switching circuit selects one of the first and second comparison results according to a switching signal from a CPU, and the CPU controls heating of the fixing roller based on the selected comparison result. | 11-10-2011 |
20130058674 | IMAGE FORMING APPARATUS AND POWER CONTROL METHOD THEREFOR - An image forming capable of operating with reliability and shortening the down time. An operation unit forms an image. A power source unit supplies electric power supplied from an external power source to the operation unit. A storing unit stores successful data which shows that the image forming apparatus has started successfully. A mode selection unit selects a first mode in which regular electric power is supplied to the operation unit at a start-up when the storing unit stores the successful data, and a second mode in which electric power smaller than the regular electric power is supplied to the operation unit at the start-up when the storing unit does not store the successful data. A power control unit controls the electric power supplied from the power source unit to the operation unit according to the mode selected by the mode selection unit. | 03-07-2013 |
20140314454 | FIXING APPARATUS AND IMAGE FORMING APPARATUS - A fixing unit includes a current detection portion configured to detect a drive current of a pump unit and determines whether a valve unit is in an abnormal state corresponding to the output of the current detection portion. | 10-23-2014 |