Patent ID: 7346287
Filing Date: 2008-03-18
Classification: G03G

Abstract:
1. A transfer device that transfers a visual image from an image carrier to a recording medium, comprising: a first transfer element configured to move and receive the visual image from the image carrier on a first surface of the first transfer element, the first transfer element being in a shape of a belt; a second transfer element provided opposite to the first surface of the first transfer element to pinch and convey the recording medium through a transfer nip part formed between the first surface of the first transfer element and the second transfer element; a facing roller provided on a second surface of the first transfer element opposite to the first surface of the first transfer element, the facing roller facing the second transfer element via the first transfer element and including a core metal provided as a centermost portion of the facing roller and functioning as an electrode, and a medium resistance member formed around the core metal and in contact with the first transfer element; a constant-current power supply configured to apply an electric current voltage to the core metal of the facing roller to transfer the visual image on the first surface of the first transfer element to the recording medium, wherein the electric current voltage applied to the core metal has a polarity equal to a polarity of the visual image and is subjected to a constant-current control; and a lower guide plate at an upstream side of the transfer nip, and an electric current detecting device configured to detect an amount of an electric current passing through the recording medium, and through the lower guide plate, and a control device configured to control the constant-current power supply to change a value of the electric current voltage applied to the core metal based on a detection output of the electric current.