Patent application number | Description | Published |
20110064423 | IMAGE FORMING APPARATUS AND CONTACT-CORROSION PREVENTION METHOD PERFORMED BY SAME - A main body of an image forming apparatus includes a switching circuit provided for switching between a normal current which should be applied at a time of normal operation and a contact-corrosion preventing current which is set larger than the normal current. Each of the currents is to be applied to an imaging unit through the contacts between the main body and the imaging unit. A control section controls the switching circuit so as to temporarily switch from the normal current to the contact-corrosion preventing current at specified timing. | 03-17-2011 |
20110286775 | FIXING DEVICE, IMAGE FORMING APPARATUS, AND HEAT GENERATION BELT - The present invention provides a fixing device for fixing an unfixed image onto a recording sheet by applying heat and pressure to the unfixed image while the recording sheet having the unfixed image formed thereon is passing through a fixing nip, the fixing nip being formed by pressing a pressurizing roller against a heat generation belt, wherein the heat generation belt rotates around a rotational axis and includes a resistive heat layer extending in a rotational axis direction thereof, the resistive heat layer configured to generate heat when electricity is supplied thereto and having a plurality of holes provided therein, and the holes are distributed unevenly in the resistive heat layer such that electrical resistivity of the resistive heat layer varies in the rotational axis direction. | 11-24-2011 |
20110293297 | FIXING DEVICE, IMAGE FORMING APPARATUS AND HEAT GENERATING ROTATIONAL BODY - The present invention provides a fixing device that can interrupt power supply to the resistive heat layer more reliably than the conventional technology, for example, at occurrence of abnormality. Electrodes | 12-01-2011 |
20120076521 | FIXING DEVICE AND IMAGE FORMATION APPARATUS - A fixing device for fixing an unfixed toner image on a recording sheet by passing the recording sheet through a fixing nip and applying heat and pressure to the recording sheet, the fixing device comprising: a heater including a resistance heater part and a supporting member, the resistance heater part having a positive resistance-temperature characteristic in a temperature range above a predetermined level, and the supporting member being insulative and supporting the resistance heater part such that the resistance heater part applies heat to the recording sheet; a current detector detecting a current supplied to the resistance heater part; and an abnormality determiner determining whether the resistance heater part has an abnormality, based on an initial current detected by the current detector at a predetermined time after a beginning of power supply to the resistance heater part and before the temperature of the resistance heater part reaches the predetermined level. | 03-29-2012 |
20120301162 | FIXING DEVICE AND IMAGE FORMING APPARATUS - A fixing device includes a temperature measuring unit, configured to measure the temperature in regions that extend partially along the outer surface of a heating rotating body, which includes a resistance heating layer, in the circumferential direction and are aligned in the direction of the axis of rotation of the heat rotating body, and a control unit configured to sample temperatures, measured by the temperature measuring unit in each of the regions, over the entire outer surface of the heating rotating body in the circumferential direction by causing the heating rotating body to rotate while supplying a predetermined amount of power to the resistance heating layer, and to determine whether an abnormality has occurred in the resistance heating layer based on the difference between the maximum temperature and the minimum temperature among the sampled temperatures in each region. | 11-29-2012 |
20140079425 | HEATER CONTROL DEVICE, FIXING DEVICE, AND IMAGE FORMING APPARATUS - A heater control device that performs phase control of AC power and supplies phase-controlled power to a heater, the heater control device including: a control unit configured to, in the phase control, gradually increase an on-duty ratio until a target power amount is supplied to the heater; and a judgment unit configured to judge whether or not the on-duty ratio is within a predetermined range of on-duty ratios including a 50% on-duty ratio. The control unit (i) increases the on-duty ratio by a first amount while the on-duty ratio is within the predetermined range, and (ii) increases the on-duty ratio by a second amount while the on-duty ratio is not within the predetermined range. The first amount is greater than the second amount. | 03-20-2014 |
20140286666 | IMAGE FORMING APPARATUS - An image forming apparatus having: an endless fixing belt; a heating member heating the fixing belt; a support member maintaining the fixing belt substantially circular; a pressing member in contact with the fixing belt to form a fixing nip portion; a temperature sensor; a position detector; a storage storing temperatures and positions of the fixing belt detected by the temperature sensor and the position detector; and a control unit. The control unit is operable in a characteristic storing mode and in a fixing mode. In the characteristic storing mode, temperatures of the fixing belt associated with positions are detected, and the detected temperatures and positions are stored in the storage. In the fixing mode, temperatures of the fixing nip portion are predicted with reference to the temperatures and positions stored in the storage, and the heating member is controlled such that the predicted temperatures become a target temperature. | 09-25-2014 |
20150030346 | IMAGE FORMING APPARATUS AND NON-TRANSITORY RECORDING MEDIUM HAVING RECORDED THEREIN TEMPERATURE CONTROL PROGRAM FOR USE IN IMAGE FORMING APPARATUS - An image forming apparatus forms a toner image of text on a recording sheet based on PDL data prescribing text data and one or more print conditions of thereof, and thermally fixes the toner image, and includes: condition acquisition unit analyzing the PDL data to acquire, as the conditions, one or more of character number, character spacing, and line spacing from the PDL data; judgment unit judging for each condition, by comparing the condition with reference value, the judgment indicating whether the condition is suitable for ensuring fixability of the toner image if thermally fixed at a temperature that is lower than predetermined temperature; and temperature control unit, when the judgment unit judges negatively for at least one condition, setting a fixing temperature for thermally fixing the toner image to the predetermined temperature, when the judgment unit judges affirmatively for all conditions, setting the fixing temperature to the lower temperature. | 01-29-2015 |