Samsung Electronics Co., Ltd.

Lg Electronics Inc.

Hewlett-packard Development Company, L.p.

Lg Innotek Co., Ltd.

Hp Printing Korea Co., Ltd.

Gun Ho Kim

Young Min Yoon

Sung Dae Kim

Myung Ho Kyung

Won Chul Jung

Byoung Chul Bae

Su Kyoung Chae

Cheol Ju Yang

An image forming apparatus and a method of controlling the same is provided. A plurality of cells formed at the surface of a transfer roller is filled with a developing agent to initialize the transfer roller, thereby suppressing contamination and electrical non-uniformity of the transfer roller. A method of controlling an image forming apparatus includes determining whether a transfer roller mounted in the image forming apparatus is a new one and, upon determining that the transfer roller is a new one, feeding a developing agent to the surface of the transfer roller and filling a plurality of cells formed at the surface of the transfer roller with the developing agent to initialize the transfer roller.

Image forming apparatus and method of initializing and cleaning a transfer roller therin

An apparatus and a method recognizing the error of a toner sensor that is capable of correctly recognizing the error factor of the toner sensor for sensing the amount of the toner of a developing device main body. The output value and the set value of the sensor are compared with each other to display the corresponding error code. Therefore, a service engineer or a user easily recognizes the error factor to take proper measures corresponding to the error factor.

Apparatus and method for recognizing error of toner sensor for developing device

A multi-pass type color image forming apparatus. The multi-pass type color image forming apparatus includes an indicating member which is provided at a camshaft and has a plurality of indicating portions, a sensing part which detects the plurality of indicating portions, and a control unit which receives a signal from the sensing part when the indicating member passes by the sensing part by the rotation of the camshaft, and determines a home position by a rotational position of the camshaft when a signal pattern from a sequence of signals from the sensing part corresponds with a preset reference pattern. Accordingly, the home position of the camshaft can be determined in a short amount of time regardless of the slip between the cams and the push caps, so that the warm up time can be shortened and the generation time of noise caused by the contact between the cams and the push caps can be minimized. Also, the reliability about the home position of the camshaft can be increased, thereby transmitting the power timely to the correct developing device.

Multi-pass type color image forming apparatus

Growing community of inventors

Seoul, South Korea

Gun Ho Kim