Abstract: An open-close discriminating apparatus includes an output portion configured to output a DC voltage having been converted from an AC voltage; a switch portion having an end connected with the output portion, the switch portion being configured to supply the DC voltage outputted to the output portion to a load when the switch portion is in a closed state, and to shut off the supply when the switch portion is in an open state; a capacitor connected with the other end of the switch portion; and a discriminating portion configured to discriminate whether the switch portion is in the open state or the closed state on the basis of a change amount of a voltage of the other end of the switch portion in a predetermined time period.

Abstract: An open-close discriminating apparatus includes an output portion configured to output a DC voltage having been converted from an AC voltage; a switch portion having an end connected with the output portion, the switch portion being configured to supply the DC voltage outputted to the output portion to a load when the switch portion is in a closed state, and to shut off the supply when the switch portion is in an open state; a capacitor connected with the other end of the switch portion; and a discriminating portion configured to discriminate whether the switch portion is in the open state or the closed state on the basis of a change amount of a voltage of the other end of the switch portion in a predetermined time period.

Abstract: In an image forming apparatus, the overall length of a heat generating resistor is set longer than the width of a recording paper, which is the greatest of widths of standard size recording papers that can be used on the image forming apparatus. An electrical resistance of an edge area of the heat generating resistor per unit length is set smaller than that of a center area of the heat generating resistor. The position of a boundary between the center area and the edge area is set so that the position of the side edge of the recording paper whose width is the greatest exists within the edge area and so that if the recording paper having the second greatest width is fed by a one edge-aligned paper feeding method, the position of the side edge of a recording paper whose width is the greatest of the widths of the standard size recording papers that can be used on the image forming apparatus except the width of the recording paper that is the greatest thereof is set at a position within the center area.

Abstract: The image forming apparatus includes a determination unit configured to determine whether or not a polygon mirror has converged to the number of rotations that allows image formation to be performed, and the determination unit is capable of detecting a first timing and a second timing and determines that the polygon mirror has converged to a number of rotations that allows the image formation to be performed based on an earlier one of the first timing and the second timing.

Abstract: The image forming apparatus includes a determination unit configured to determine whether or not a polygon mirror has converged to the number of rotations that allows image formation to be performed, and the determination unit is capable of detecting a first timing and a second timing and determines that the polygon mirror has converged to a number of rotations that allows the image formation to be performed based on an earlier one of the first timing and the second timing.

Abstract: The image forming apparatus includes a determination unit configured to determine whether or not a polygon mirror has converged to the number of rotations that allows image formation to be performed, and the determination unit is capable of detecting a first timing and a second timing and determines that the polygon mirror has converged to a number of rotations that allows the image formation to be performed based on an earlier one of the first timing and the second timing.

Abstract: The image forming apparatus includes a determination unit configured to determine whether or not a polygon mirror has converged to the number of rotations that allows image formation to be performed, and the determination unit is capable of detecting a first timing and a second timing and determines that the polygon mirror has converged to a number of rotations that allows the image formation to be performed based on an earlier one of the first timing and the second timing.

Abstract: An image forming apparatus prevents the occurrence of the combinations of output wave numbers which are ineffective to suppress flicker in a case where a set heater temperature is significantly reduced. If the set temperature is significantly reduced from 200° C. to 130° C., for example, so that the reduced temperature does not require current to be applied to a ceramic heater, which can occur at the time of starting reverse conveyance of the recording sheet in the double-faced printing mode, temperature control is temporarily suspended and the output wave number of power controlled by a controller is varied to 0 waves based on the previously set combinations of 12, 10, 4 and 0 waves, for example, if the output wave number is varied from 12.

Abstract: In an image forming apparatus, the overall length of a heat generating resistor is set longer than the width of a recording paper, which is the greatest of widths of standard size recording papers that can be used on the image forming apparatus. An electrical resistance of an edge area of the heat generating resistor per unit length is set smaller than that of a center area of the heat generating resistor. The position of a boundary between the center area and the edge area is set so that the position of the side edge of the recording paper whose width is the greatest exists within the edge area and so that if the recording paper having the second greatest width is fed by a one edge-aligned paper feeding method, the position of the side edge of a recording paper whose width is the greatest of the widths of the standard size recording papers that can be used on the image forming apparatus except the width of the recording paper that is the greatest thereof is set at a position within the center area.

Abstract: In the case where a set temperature is significantly reduced, the image forming apparatus which prevents the occurrence of the combinations of output wave numbers which are ineffective to suppress flicker. If the set temperature is significantly reduced from 200° C. to 130° C., for example, to such a temperature that current does not need to be applied to the ceramic heater, as indicated by 5a at the time of starting the reverse conveyance in the double-faced printing mode, it is configured such that a temperature control is temporarily suspended and the output wave number is varied to 0 waves based on the previously set combinations of 12, 10, 4 and 0 waves, for example, as indicated by 5b, if the output wave number is varied from 12.