Patent ID: 8644717
Filing Date: 2014-02-04
Classification: B41J

Abstract:
1. An image forming apparatus comprising: an image forming unit configured to discharge ink onto a sheet to form an image on the sheet; a transfer unit configured to perform a first conveying operation of conveying the sheet in a state in which a first surface thereof faces the image forming unit, and a second conveying operation of conveying the sheet in a state in which a second surface thereof faces the image forming unit after the first conveying operation; a detecting unit configured to detect whether a jam of the sheet subjected to the second conveying operation occurred; a setting unit configured to set a dry time for drying the ink discharged onto the first surface of the sheet, and wherein the setting unit sets the dry time for a current sheet; a control unit configured to control the transfer unit to start the second conveying operation after the dry time has elapsed after the first conveying operation; an acquiring unit configured to acquire, as an acquired amount of ink, an amount of ink discharged from the image forming unit onto the first surface of the sheet; a storage unit configured to store a plurality of default times and a plurality of amounts of ink, each of the default times being associated with one of the amounts of ink, and one of the amounts of ink corresponding to the acquired amount of ink, wherein the control unit controls the storage unit to further store: wherein the control unit is further configured to determine whether one of the limit times stored in the storage unit is associated with the one of the amounts of ink that corresponds to the acquired amount of ink, wherein, when the control unit determines that one of the limit times stored in the storage unit is associated with the one of the amounts of ink that corresponds to the acquired amount of ink, the setting unit sets said one of the limit times as the dry time for the current sheet, wherein, when the control unit determines that none of the limit times stored in the storage unit is associated with the one of the amounts of ink that corresponds to the acquired amount of ink and the previous dry time is not stored in the storage unit, the setting unit sets the one of the default times that is associated with the one of the amounts of ink that corresponds to the acquired amount of ink as the dry time for the current sheet, wherein, when the control unit determines that none of the limit times stored in the storage unit is associated with the one of the amounts of ink that corresponds to the acquired amount of ink and the previous dry time is stored in the storage unit, the control unit determines whether the detecting unit detects the jam of the previous sheet according to the jam detection result, wherein, when the control unit determines according to the jam detection result that the jam did not occur in the previous sheet, the control unit sets the provisional dry time to be less than the previous dry time, wherein, when the control unit determines according to the jam detection result that the jam did occur in the previous sheet, the control unit sets the provisional dry time to be greater than the previous dry time, wherein, after the control unit sets the provisional dry time, the control unit determines whether the amount of ink discharged to the first surface of the current sheet is equal to the previous ink amount of the previous sheet, wherein, when the control unit determines that the amount of ink discharged to the first surface of the current sheet is equal to the previous ink amount of the previous sheet, the setting unit sets the dry time for the current sheet to be equal to the provisional dry time, wherein, when the control unit determines that the amount of ink discharged to the first surface of the current sheet is not equal to the previous ink amount of the previous sheet, the control unit determines whether the amount of ink discharged to the first surface of the current sheet is greater than the previous ink amount of the previous sheet, wherein, when the control unit determines that the amount of ink discharged to the first surface of the current sheet is greater than the previous ink amount of the previous sheet, the setting unit sets the dry time for the current sheet to be greater than the provisional dry time, wherein, when the control unit determines that the amount of ink discharged to the first surface of the current sheet is less than the previous ink amount of the previous sheet, the setting unit sets the dry time for the current sheet to be less than the provisional dry time, wherein, when the detecting unit does not detect the jam of the current sheet and the dry time for the current sheet is less than the one of the shortest times that is associated with the one of the amounts of ink that corresponds to the acquired amount of ink, the control unit controls the storage unit to store the dry time for the current sheet as said one of the shortest times, and wherein, when the detecting unit detects the jam of the current sheet and one of the shortest times stored in the storage unit is associated with the one of the amounts of ink that corresponds to the acquired amount of ink, the control unit controls the storage unit to store said one of the shortest times as the one limit time associated with the one of the amounts of ink that corresponds to the acquired amount of ink.