IMAGE FORMING DEVICE Russian patent published in 2016 - IPC G03G15/16 

FIELD: image forming device.

SUBSTANCE: present invention relates to an image forming device of electrophotographic type, for example copying device, printer or the like. Stated image forming devices include image bearing element for transferring the toner image; an intermediate transfer element for holding the toner image transferred from the image bearing element into a primary transfer position; transfer element having a possibility of contact with the outer peripheral surface of the intermediate transfer element to transfer the toner image from the intermediate transfer element onto the recording material at a secondary transfer position; a constant voltage element electrically connected between the intermediate transfer element and the earth potential, in order to maintain a predetermined voltage by flowing current therethrough; power source to form an electric field in the secondary transfer position of the secondary transfer electric field and a primary transfer position in the primary transfer by applying a voltage to the transfer element for passing current through a constant voltage element; detecting section for detecting current flowing through the transfer element; executing section to execute the test mode in which the test voltage is applied to the power source transfer element to detect using current detection area when there is no any recording material in the secondary transfer position; and a controller for controlling the voltage to be applied by the power source to the transfer element when the recording material is in the secondary transfer position on the basis of a current detected by detecting section in the test mode, wherein the controller controls the test voltage applied by the power supply so that constant voltage element can maintain predetermined voltage at least in an overlapping period between the period of a test mode and a period during which toner image is transferred to the primary transfer position.

EFFECT: technical result consists in elimination of defect formation, capable to form in case where schedules of primary transfer and applying voltage to transfer element are partially coincide, as well as lower probability of improper primary transfer.

14 cl, 13 dwg, 3 tbl