Samsung Electronics Co., Ltd.

Sung Dae Kim

Soo Yong Kim

Sang Bum Woo

Hyun Ki Cho

Young Min Yoon

Sung Hoon Lim

Bong-Hwan Choi

Bong Hwan Choi

Gun Ho Kim

Seok Heon Chae

Su Kyoung Chae

Disclosed herein is an image forming apparatus that has a developing unit, an intermediate transfer body, and a transfer roller and may prevent contamination of the transfer roller and a printing medium by the toner remaining in a test pattern forming area of the intermediate transfer body. The image forming apparatus includes a developing unit to allow an image to be formed by a developing agent, an intermediate transfer body provided with an image forming area and a test pattern forming area, the image being transferred from the developing unit to the image forming area and the test pattern forming area, and a transfer roller allowing the image to be transferred from the image forming area to a printing medium, wherein a maximum transfer length of the transfer roller is less than a maximum image forming length of the developing unit.

Image forming apparatus having developing unit

An image forming apparatus and method which reduces time taken for color registration and reflects misregistration of colors in real time to correct color misregistration of prints are provided. Image forming apparatus may include photoconductor elements corresponding to colors; first sensing unit arranged between first and second photoconductor elements among photoconductor elements, and sensing toner images transferred to intermediate transfer body; final sensing unit arranged after final photoconductor element among photoconductor elements, and sensing transferred toner images; and controller calculating fixed errors of remaining colors except for first color among colors, with respect to first color corresponding to first photoconductor element, based on output values of final sensing unit before printing, calculating variable error based on output value of first sensing unit during printing, and adjusting scanning time of at least one color of remaining colors in real time in consideration of fixed errors and variable error.

Image forming apparatus and control method thereof

An image forming apparatus, which achieves reduced color registration time and real-time calibration of color position shift, and a control method for the same, is provided. The image forming apparatus includes plural photoconductors corresponding to plural colors, an exposure unit to form an electrostatic latent image by emitting light to the photoconductors, a developing unit to form a toner image by feeding toner to the photoconductors, an intermediate transfer body to which the toner image, formed on each photoconductor, is transferred, a sensing unit to sense the toner image formed on the intermediate transfer body, and a controller which forms images in respective image forming sections of the intermediate transfer body and test-pattern sets for color registration in respective blanks between the neighboring image forming sections, the controller implementing color registration calibration using color registration calibration values acquired from four test pattern sets among the formed test pattern sets.

Image forming apparatus and control method for the same

To restrict a period velocity change of a photoconductor that is an immediate cause of a color registration error, a gap change of a color registration error detection pattern caused by a linear velocity change of the photoconductor is acquired and a linear velocity change of the photoconductor is reduced based on a relationship between the gap change and a velocity of a motor, whereby a reduced color registration error is accomplished.

A color image forming apparatus includes a plurality of mark sensing devices are arranged between a plurality of photoconductors arranged on an intermediate transfer belt to sense a mark transferred to a region of the intermediate transfer belt corresponding to an interval between successive recording media. As an exposure time to form an electrostatic latent image on a photoconductor, on which a following developer image will be formed, is determined, minimized mis-registration and consequently, improved color registration correction efficiency are accomplished. Also, automatic color registration correction is performed on per printing operation basis, resulting in improvement in image quality.

Color image forming apparatus

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.

Growing community of inventors

Suwon-si, South Korea

Sung Dae Kim