Samsung Electronics Co., Ltd.

Bong-Hwan Choi

Jin-soo Lee

Sung Hoon Lim

Jin-Soo Lee

Hyun Ki Cho

Sung Dae Kim

Seok Heon Chae

Dong-hyup Shin

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.

Image forming apparatus and control method thereof

A door opening and closing unit is provided for an image forming apparatus. The image forming apparatus includes a main body, and a door rotatably mounted on the main body. The door opening and closing unit includes a door speed control unit coupling the door to the main body that includes a coupling boss; and a guide groove that engages the coupling boss and along which the coupling boss moves as the door rotates relative to the main body; wherein the door speed control unit controls a frictional force between the coupling boss and the guide groove according to a rotating angle of the door relative to the main body to control a rotating speed of the door as the door rotates relative to the main body.

Door opening and closing unit to control door rotating speed and image forming apparatus having the same

An image forming apparatus is provided with a laser scanning unit having at least two laser diodes to form an electrostatic latent image on a photosensitive body with laser beams emitted from the laser diodes; an engine driving unit having at least one driving motor to drive a plurality of built-in units; and a control unit arranged to control one of the laser scanning unit and the engine driving unit so as to adjust a process speed of the engine driving unit or a scan speed of the laser scanning unit with a certain rate depending on a selected resolution in order to enhance a resolution of an image.

Image forming apparatus and laser scanning method thereof

A discharge mechanism capable of discharging a sheet facedown is advantageous to miniaturization of a duplex printing apparatus. The discharge mechanism includes a discharge roller gear engaged with a driving gear; a pair of discharge rollers rotatable by the discharge roller gear, keeping in contact with each other; a disklike support member having a shaft fixed on a same line of a shaft of the driving gear, intervening between the driving gear and the discharge rollers; a friction disk attached to the discharge roller gear, for transferring a driving force of the driving gear to the disklike support member; a compression coil spring interposed between the friction disk and the disklike support member, a shaft of a selected one of the discharge rollers passing through the compressing coil spring; and a solenoid for restricting rotation of the disklike support member when unactuated and for allowing rotation of the disklike support member when supplied with a current. The disklike support member has a pair of opposite stoppers formed at its outer circumference. Each of the stoppers has two opposite protrusions, one of which has a perpendicular outer wall, another of which has a slope.

Paper discharging mechanism for an image processing apparatus

A method for separately retrieving used developing material on a developing roller and supplying new developing material, while balancing the retrieval of the used developing material with the supply of the new developing material in accordance with an increase in the number of papers being printed. The method is directed to retrieving and supplying developing material in an electrophotography forming apparatus which includes a developing roller, a retrieval roller and a supply roller. The method includes the steps of: rotating the retrieval roller connected to the developing roller in the same direction as the direction of rotation of the developing roller; and applying voltages to the developing roller, the retrieval roller and the supply roller in accordance with a predetermined relationship.

Method and arrangement for retrieving/supplying developing material in

According to this invention, the contact and separation conditions between an OPC drum and a charger roller are controlled by utilizing a tension spring, which is connected between a frame and a bearing through which the shaft of the charger roller extends, for separating a driving gear of the OPC drum and a driven gear of the charger roller by a predetermined distance in order that the OPC drum and the charger roller can be separated while the OPC drum is at standstill, in order to prevent the charger roller from deforming or contaminating the OPC drum. The force of the tension spring is overcome by the force generated by the driving gear engaging the driven gear to enable the OPC drum and the charger roller to again contact each other while the OPC drum is rotated.

Growing community of inventors

Suwon-si, South Korea

Bong-Hwan Choi