Samsung Electronics Co., Ltd.

Woo-jung Shim

Min-seon Kim

Seung-deog An

Cheol-ju Yang

Yong-geun Kim

Chung-guk Baek

Seock-deock Hong

Jong-hwa Joo

Seog Bang

Jong-hwa Park

An image forming apparatus, a developing agent container and a controlling method of the same that improves a supply rate of developing agent from a developing agent container to a developing device that provides the developing agent to an image carrier.

Image forming apparatus to adjust driving rate of a supply unit and controlling method of the same

A color registration apparatus that independently forms images of predetermined respective colors and compensates a mis-registration between the overlapped images of respective colors employed in an image forming apparatus of forming a color image by overlapping the images of respective colors, includes a detecting unit to detect a contour form and positional information of respective color patterns formed on an image transfer path by the image forming apparatus proportional to a corresponding format of a printing medium where the color image will be transferred, and a controller to compensate a mis-registration between the overlapped images of respective colors through based on data detected by the detecting unit.

Color registration apparatus and method, image forming apparatus employing the same apparatus, and image output method of the image forming apparatus

A method of optimizing the amount of toner of an electrophotographic printer is provided. The method includes measuring a life span of the development roller in use. The speed of a development roller, which corresponds to the measured life span of the development roller, is calculated from a lookup table. The development roller speed is adjusted according to the calculated development roller speed.

Method of optimizing amount of toner of electrophotographic printer

A high developing voltage supply apparatus includes solenoid power switches, and a high developing voltage driver selectively outputting a solenoid driving signal to close one of the solenoid power switches to electrically close a corresponding mechanical contact, applying a high developing voltage to one of color development rollers corresponding to the mechanical contact closed and Kased on an image to be printed. A high developing voltage supply supplies the high developing voltage to developing roll shafts of the other color development rollers to stabilize potentials of the developing roll shafts, or, in the alternative, the high developing voltage supply apparatus may include a voltage supply supplying a self-biased voltage to the other color development rollers using the high developing voltage formed with a DC voltage Vand an AC voltage Vsuperimposed.

High developing voltage supply apparatus

A controlling method of an image forming apparatus for finely controlling the sensitivity of a density sensor in response to various changes of a printing environment. The controlling method of the image forming apparatus uses one or more of the following methods, alone or in any combination, to control the sensitivity of a density sensor. The methods can include a sensitivity correction method for controlling an output signal of the density sensor according to amount of light irradiated to an image carrier from a light source, a sensitivity correction method for correcting a reference value according to an output signal of the density sensor, and a sensitivity correction method for changing the signal output from the density sensor using a predetermined process.

Control method for correcting sensitivity of toner density sensor of image forming apparatus

Disclosed is a device for measuring the density of an image in regard to a liquid test patch. The device has: a fan for drying a test patch by blowing air to the test patch disposed on at least one of a photosensitive medium, a photosensitive belt and printing paper; a sensor for projecting infrared light to the dried test patch and measuring the density of the test patch based on the reflected light of the infrared light reflected from the test patch; and an adjustment unit for adjusting the mixing ratio of a toner and a carrier in accordance with the measured density. The device measures the amount of light reflected from the dried liquid test patch, thus allowing the density of the image to be measured accurately.

Device and method for measuring image density

A duplex electro-photographic developing machine including a printing medium tray loading a printing medium, a tray open/closed detecting unit detecting whether the printing medium tray has been opened and closed, a transferring roller transferring a toner image onto the printing medium, a resistance measuring unit measuring a resistance value of the printing medium passing the transferring roller, and a concentration controlling unit controlling a concentration of the toner image according to the measured resistance value measured by the resistance measuring unit in response to the printing medium tray having changed from an open state to a close state.

Duplex electro-photographic developing machine and method of controlling toner image concentration thereof

An image forming apparatus has developing rollers mounted to be spaced-apart from a photo-sensitive body and supplying a developing agent to the photo-sensitive body, a bias-applying part applying a predetermined bias to the developing rollers through respective current-conducting paths to the photo-sensitive body from the developing rollers, a current detection part detecting a current flowing through the developing rollers in accordance with a bias applied from the bias-applying part, and an engine control part applying a first test AC voltage having a set first frequency to the developing rollers, controlling the bias-applying part to apply a second test AC voltage having a set second frequency to the developing rollers, calculating a resistance of the developing rollers and a gap between the developing rollers and the photo-sensitive body using a current value detected from the current detection part respectively corresponding to the first and second frequencies, and setting a bias voltage of a driving condition corresponding to the resistance of the developing rollers and the gap which are calculated as a developing bias voltage in a printing mode.

Image forming apparatus and control method thereof

A method of controlling a charging potential of an organic photoconductive cell (OPC) includes a first operation of applying two charging voltages Vcand Vchaving respective duties Dand Destablished in an engine controller unit (ECU) to a conductive roller via a high voltage power supply (HVPS) to charge the OPC, a second operation of measuring sensing voltages Vsand Vsthrough a sensing resistor Rs coupled to the conductive roller so that the ECU establishes a target charging current it and calculates a new charging voltage Vcand a new duty D, a third operation of applying the new charging voltage Vcand the new duty Dto the conductive roller via the HVPS to charge the OPC and measuring a charging current Icof the conductive roller, and a fourth operation of comparing a difference between the charging current Icof the conductive roller and the target charging current It with a tolerance value TOL to control the charging potential by using the target charging current when the difference is smaller than the tolerance value TOL. The method maintains the charging potential by compensating for a residual potential of the OPC, thus improving a performance of a printer.

Method of controlling charging potential of conductive roller in printer and apparatus therefor

A squeezing device of a wet printer for separating a liquid carrier element that is not used for forming an image from ink supplied to the photosensitive belt, includes a squeezing roller mounted to be opposite to the photosensitive belt, a bias applying unit for biasing the squeezing roller with a certain potential, and a plurality of backup rollers mounted side by side to be opposite to the squeezing roller across the photosensitive belt placed between the plurality of backup rollers and the squeezing roller, in order to extend a contact width between the photosensitive belt and the squeezing roller. A printer to which the squeezing device of a wet printer is applied secures a sufficient charging time of the photosensitive belt and lowers a voltage for generating a townsend discharge, to thereby enhance charging performances and printing qualities.

Squeezing device of a wet printer and a developing unit employing the same

A toner reproduction curve (TRC) control method is provided. The TRC method for controlling a printer including a color toner density (CTD) sensor includes the steps of (a) measuring a development potential V , a charging potential V , an exposure potential V , and a development current Id and evaluating a development vector V , which is the difference between the development potential V and the exposure potential V , and a backplating vector V , which is the difference between the charging potential V and the exposure potential V ; (b) forming a TRC space using TRC data detected from the CTD sensor; (c) obtaining a TRC characteristic function from the TRC data, the development vector V &equals;x, the backplating vector V &equals;y, and the development current Id&equals;z; (d) forming an RTRC by setting TRC data, whose covariance is smaller than a threshold value among the detected TRC data, as RTRC data; and (e) measuring TRC data, comparing the measured TRC data with the RTRC data to calculate control parameter values, and controlling the printer using the control parameter values. The TRC method does not require other sensors but the CTD sensor. By using internal parameters covering environmental changes, the charging potential of a photosensitive body, a state of a developer, and the efficiency of a charger can be estimated, thereby realizing efficient TRC control.

Tone reproduction curve control method

A computer with a fixed casing accommodating at least one computer component and having an upward opening, a movable casing covering at least a part of the opening of the fixed casing and equipped with at least one computer component on its inner surface, a pair of hinges adjacent to opposite sides of the opening and rotatably supporting the movable casing, and a latch provided either the fixed casing or the movable casing, engaging and disengaging the movable casing to and from the fixed casing. With this configuration, the present invention provides the computer having the casing which is simply assembled and disassembled, thereby allowing a user easily repair and to exchange the computer components.

Computer

A case for a computer body may be constructed with a first case portion and a second case portion, forming a space by combination thereof along a first and a second coupling lines; a first coupling part for coupling the first and second cases along the first coupling line; a latch unit having a latch body slidable relative to the first case along the second coupling line, and at least one latch extended from the latch body along the second coupling line to be protruded toward the second case; and an engagement member provided in the second case, being engaged into or disengaged from the latch according to sliding of the latch unit. With this configuration, it is easy to assemble and disassemble the case and the computer body.

Growing community of inventors

Suwon-si, South Korea

Woo-jung Shim