Transfer device including a selectively outputting power supply, image forming apparatus including the same, and method of transferring developer to sheet

摘要

A transfer device includes a direct-current (DC) power supply configured to output a DC voltage; an alternating-current (AC) power supply configured to selectively output a superimposed voltage in which an AC voltage is superimposed on the DC voltage output from the DC power supply or the DC voltage output from the DC power supply; and a transfer unit configured to transfer a developer to a sheet using the voltage output from the AC power supply.

主权项

1. A transfer device, comprising:
a direct-current (DC) power supply configured to output a DC voltage; an alternating-current (AC) power supply configured to selectively switch between a first output and a second output, the first output being a superimposed voltage in which an AC voltage is superimposed on the DC voltage output from the DC power supply, and the second output being only the DC voltage output from the DC power supply; and a transfer unit configured to transfer a developer to a sheet using the voltage output from the AC power supply, wherein the DC power supply includes a DC high voltage transformer that produces the DC voltage, the DC high voltage transformer including a primary winding and a secondary winding, the AC power supply includes an AC high voltage transformer that produces the AC voltage and an AC driving unit that drives the AC high voltage transformer, the AC high voltage transformer including a primary winding and a secondary winding, the secondary winding of the DC high voltage transformer, the secondary winding of the AC high voltage transformer, and the transfer unit are electrically connected in series in this order, when the AC power supply outputs the first output, the AC high voltage transformer is driven by the AC driving unit to produce the AC voltage and outputs, from the secondary winding of the AC high voltage transformer, the first output that is the superimposed voltage in which the AC voltage produced is superimposed on the DC voltage output from the secondary winding of the DC high voltage transformer, andwhen the AC power supply outputs the second output, the AC high voltage transformer outputs the second output from the secondary winding of the AC high voltage transformer to the transfer unit, the second output being the DC voltage output from the secondary winding of the DC high voltage transformer.