Abstract: A sheet conveying apparatus includes: a plurality of driving parts each connected to one end of corresponding one of a respective plurality of rotating shafts; a first torque adjuster connected to another end of each of the plurality of rotating shafts, the first torque adjuster applying first torque to the plurality of driving parts; a second torque adjuster that applies, to the driving parts, second torque for adjusting the first torque to be applied to the driving parts by the first torque adjuster; and a hardware processor that controls the second torque to be applied to the driving parts in the second torque adjuster in accordance with a number of revolutions of the driving part.

Abstract: A drive apparatus according to the present invention includes a stepping motor that transmits power to a rotating shaft of a conveyance roller, a brushless motor that transmits power to the rotating shaft of the conveyance roller, a first controller that controls an operation of the stepping motor so that the stepping motor rotates at a constant speed, and a second controller that controls an operation of the brushless motor. The second controller switches control of the brushless motor between, in accordance with a conveyance state of the sheet, assist control in which power of the brushless motor assists a rotation of the stepping motor, brake control in which power of the brushless motor prevents the rotation of the stepping motor, and neutral control in which power of the brushless motor does not affect the rotation of the stepping motor.

Abstract: A drive apparatus according to the present invention includes a first motor that transmits power to a rotating shaft of a conveyance roller for conveying a sheet, a second motor that transmits power to the rotating shaft of the conveyance roller, a storage that stores information indicating the driving force of the second motor during a period in which the conveyance roller conveys the sheet; and a controller that drives the second motor with the driving force indicated by the information during a period when the conveyance roller conveys the sheet, wherein the controller changes the information stored in the storage according to a load applied to the conveyance roller during the period when the conveyance roller conveys the sheet, and drives the second motor with a driving force indicated by the information after the change during a period when the conveyance roller conveys a next sheet.

Abstract: An image forming apparatus includes the following. An upstream second conveying roller and a downstream second conveying roller form a loop on the long sheet. A deviation amount detector detects a deviation amount of the long sheet. A loop amount detector detects a loop amount in two positions in a width direction. A speed controller controls a rotating speed of the upstream second conveying roller and the downstream second conveying roller based on a deviation amount and a difference of loop amounts in two positions. Each of the upstream second conveying roller and the downstream second conveying roller includes a near roller and a far roller. The speed controller controls the rotating speed of the near roller and the far roller based on the deviation amount and the difference of the loop amounts in the two positions.

Abstract: A sheet conveying apparatus includes: a plurality of conveyors provided along a sheet conveying direction; a plurality of main driving parts that is respectively provided to the plurality of conveyors and independently drives the conveyors; an auxiliary driving part that drives the plurality of conveyors; and a transmitter that transmits driving force between the plurality of conveyors and transmits driving force of the auxiliary driving part to the plurality of conveyors.

Abstract: A conveying driving device of the invention includes a first motor which transmits power to a drive shaft of a roller; a second motor which transmits power to the drive shaft along with the first motor at a torque smaller than that of the first motor; and a controller which sets each of drive current setting values of the first motor and the second motor so that a total value of a consumption current of the first motor and the second motor becomes minimal in a steady state in which the roller rotates at a constant setting speed.

Abstract: A drive apparatus according to the present invention includes a first motor that transmits power to a rotating shaft of a conveyance roller for conveying a sheet, a second motor that transmits power to the rotating shaft of the conveyance roller, a storage that stores information indicating the driving force of the second motor during a period in which the conveyance roller conveys the sheet; and a controller that drives the second motor with the driving force indicated by the information during a period when the conveyance roller conveys the sheet, wherein the controller changes the information stored in the storage according to a load applied to the conveyance roller during the period when the conveyance roller conveys the sheet, and drives the second motor with a driving force indicated by the information after the change during a period when the conveyance roller conveys a next sheet.

Abstract: A drive apparatus according to the present invention includes a stepping motor that transmits power to a rotating shaft of a conveyance roller, a brushless motor that transmits power to the rotating shaft of the conveyance roller, a first controller that controls an operation of the stepping motor so that the stepping motor rotates at a constant speed, and a second controller that controls an operation of the brushless motor. The second controller switches control of the brushless motor between, in accordance with a conveyance state of the sheet, assist control in which power of the brushless motor assists a rotation of the stepping motor, brake control in which power of the brushless motor prevents the rotation of the stepping motor, and neutral control in which power of the brushless motor does not affect the rotation of the stepping motor.

Abstract: A sheet conveying apparatus includes: a plurality of conveyors provided along a sheet conveying direction; a plurality of main driving parts that is respectively provided to the plurality of conveyors and independently drives the conveyors; an auxiliary driving part that drives the plurality of conveyors; and a transmitter that transmits driving force between the plurality of conveyors and transmits driving force of the auxiliary driving part to the plurality of conveyors.

Abstract: A sheet conveying apparatus includes: a plurality of driving parts each connected to one end of corresponding one of a respective plurality of rotating shafts; a first torque adjuster connected to another end of each of the plurality of rotating shafts, the first torque adjuster applying first torque to the plurality of driving parts; a second torque adjuster that applies, to the driving parts, second torque for adjusting the first torque to be applied to the driving parts by the first torque adjuster; and a hardware processor that controls the second torque to be applied to the driving parts in the second torque adjuster in accordance with a number of revolutions of the driving part.

Abstract: An image forming apparatus includes: a conveyor that conveys a sheet; a detector that detects an end position of the sheet conveyed by the conveyor in a second direction orthogonal to a first direction being a conveyance direction; a corrector that corrects deviation of the sheet by moving the sheet in the second direction on the basis of a detection result of the end position of the sheet in the second direction detected by the detector, and a hardware processor that obtains variation information based on the end position of the sheet detected by the detector, and adjusts an interval of the conveyed sheet while controlling operation of the corrector on the basis of the obtained variation information.

Abstract: An image forming apparatus includes the following. An upstream second conveying roller and a downstream second conveying roller form a loop on the long sheet. A deviation amount detector detects a deviation amount of the long sheet. A loop amount detector detects a loop amount in two positions in a width direction. A speed controller controls a rotating speed of the upstream second conveying roller and the downstream second conveying roller based on a deviation amount and a difference of loop amounts in two positions. Each of the upstream second conveying roller and the downstream second conveying roller includes a near roller and a far roller. The speed controller controls the rotating speed of the near roller and the far roller based on the deviation amount and the difference of the loop amounts in the two positions.

Abstract: An image forming apparatus detects that the temperature of a fixing member reaches a lower limit value at which the temperature once reduced by the start of a heating and fixing process to a paper turns to rise, after an image forming operation starts, and determines the type of the paper based on at least one of an elapsed time from a predetermined reference time point after the image forming operation starts to a time point at which it is detected that the temperature reaches the lower limit value, and a temperature difference between the temperature of the fixing member at the reference time point and the lower limit value.

Abstract: In an image forming apparatus according to the present invention, when an image forming operation is started from a standby state, electric power is supplied to a heater by switching to a first fixing control to turn on and off the heater to heat a heating roller with a fixed duty ratio based on the detected temperature of the heating roller, and thereafter, when detecting a state that the falling detected temperature reaches a lower limit value at which the detected temperature turns to rising, electric power is supplied to the heater by switching to a second fixing control which changes a duty ratio in accordance with a temperature difference between the detected temperature and a target control temperature.

Abstract: In an image forming apparatus according to the present invention, when an image forming operation is started from a standby state, electric power is supplied to a heater by switching to a first fixing control to turn on and off the heater to heat a heating roller with a fixed duty ratio based on the detected temperature of the heating roller, and thereafter, when detecting a state that the falling detected temperature reaches a lower limit value at which the detected temperature turns to rising, electric power is supplied to the heater by switching to a second fixing control which changes a duty ratio in accordance with a temperature difference between the detected temperature and a target control temperature.

Abstract: An image forming apparatus detects that the temperature of a fixing member reaches a lower limit value at which the temperature once reduced by the start of a heating and fixing process to a paper turns to rise, after an image forming operation starts, and determines the type of the paper based on at least one of an elapsed time from a predetermined reference time point after the image forming operation starts to a time point at which it is detected that the temperature reaches the lower limit value, and a temperature difference between the temperature of the fixing member at the reference time point and the lower limit value.

Abstract: An image forming apparatus forms decision registration mark for deciding whether or not a color registration correction for correcting color shifts in the color image carries out on an intermediate transfer belt. The decision registration mark is formed by registering four color registration marks. Color registration sensors detect a detection width of the decision registration mark along a sub scanning direction. A control portion receives the detection width of the decision registration mark and decides whether or not the color registration correction carries out based on whether or not the detection width of the decision mark detected by the detection portion exceeds the period of reference time. When the detection width of the decision mark detected by the detection portion exceeds the period of reference time, the control portion carries out the color registration correction.

Abstract: An image forming apparatus includes a plurality of heaters 56 for heating the fixing roller 52, a plurality of temperature sensors 57 for detecting the temperatures of the areas to be heated by the plurality of heaters 56 respectively, and a control unit 11 for turning on and off the plurality of heaters 56 on the basis of the temperatures detected by the plurality of temperature sensors 57. If one of the heaters 56 is on when the area to be heated by the other heater cools down to the ON temperature, the control unit 11 turns on the other heater with the same timing as the one heater is turned off.

Abstract: An image forming apparatus which allows a user to freely select a desired image quality is provided. The control unit 60 sets a of registration set value A1 for determining a color registration error suppression level and a dropout set value A2 for determining a dropout occurrence suppression level. Also, the control unit 60 sets a differential circumferential speed which is the difference between the circumferential speed of photoreceptor drums 1Y to 1K and the circumferential speed of an intermediate transfer belt 6 on the basis of the color registration set value A1 and the dropout set value A2. Then, the control unit 60 controls the belt drive motor 61 and the drum drive motor 62 on the basis of the differential circumferential speed which is set.

Abstract: An image forming apparatus forms decision registration mark for deciding whether or not a color registration correction for correcting color shifts in the color image carries out on an intermediate transfer belt. The decision registration mark is formed by registering four color registration marks. Color registration sensors detect a detection width of the decision registration mark along a sub scanning direction. A control portion receives the detection width of the decision registration mark and decides whether or not the color registration correction carries out based on whether or not the detection width of the decision mark detected by the detection portion exceeds the period of reference time. When the detection width of the decision mark detected by the detection portion exceeds the period of reference time, the control portion carries out the color registration correction.