Abstract: An image forming apparatus includes an engine to form an image on an image forming medium, a paper transfer device to pick up a printing paper and transfer the paper to a transfer path, a sensor to sense a printing paper at a predetermined position on the transfer path, and a processor to determine whether a transfer delay occurs, when the printing paper is sensed, and adjust a pickup timing to advance a pickup of a printing paper of a next page.

Abstract: An image forming apparatus includes an engine to form an image on an image forming medium, a paper transfer device to pick up a printing paper and transfer the paper to a transfer path, a sensor to sense a printing paper at a predetermined position on the transfer path, and a processor to determine whether a transfer delay occurs, when the printing paper is sensed, and adjust a pickup timing to advance a pickup of a printing paper of a next page.

Abstract: An image forming apparatus includes an image obtaining unit configured to obtain an image of a document, a document supplying unit configured to supply a document to the image obtaining unit, an image forming unit configured to form the image on a printing medium, a storing unit configured to store supply status information of the document, and a controller configured to perform a preparation for an image forming operation in response to at least one of the document being supplied to one of the image obtaining unit and the document supplying unit and an option setting command of the image forming operation being input. The controller, in response to the option setting command being input after the preparation for the image forming operation is stopped, is configured to perform the preparation for the image forming operation again based on the supply status information of the document.

Abstract: An image forming apparatus includes an image obtaining unit configured to obtain an image of a document, a document supplying unit configured to supply a document to the image obtaining unit, an image forming unit configured to form the image on a printing medium, a storing unit configured to store supply status information of the document, and a controller configured to perform a preparation for an image forming operation in response to at least one of the document being supplied to one of the image obtaining unit and the document supplying unit and an option setting command of the image forming operation being input. The controller, in response to the option setting command being input after the preparation for the image forming operation is stopped, is configured to perform the preparation for the image forming operation again based on the supply status information of the document.

Abstract: An image forming device includes a sensor to detect whether a paper is discharged or not, a determiner to determine a paper width according to whether a sensing signal is output from the sensor when a printing job is executed, and a controller to control a subsequent printing operation according to the determination result of the determiner. After the printing job is initiated, the determiner determines a normal width when the sensing signal is output within a preset time, and the determiner determines a narrow width when the sensing signal is not output within the present time. Accordingly, using an existing sensor, the paper width can be detected and the appropriate printing process can be performed.

Abstract: An image forming apparatus, including a display part to input information about a print medium; a print medium tray to load the print medium; a paper guide to align the loaded print medium in the print medium tray; a sensor to sense information about the a of the print medium according to movement of the print medium guide; and a control unit to receive the sensed print medium size information from the sensor and to input the print medium size into the display part.

Abstract: A printing device that includes: a printing unit that performs double-sided printing on special paper; and a control unit that controls the printing unit to print one side of the special paper at a first printing rate, and to print the other side of the special paper at a different second printing rate. Accordingly, an overall printing rate is faster than a conventional printing device, a fixing quality is maintained, and printing performance is improved. The printing device can include a interface unit or a UI unit, to set the first and second printing rates.

Abstract: In an image forming apparatus and a control method thereof, it is determined whether an error has occurred in an output signal of a sensor for detecting a paper transferred in order to print an image, and a state change permission interval with respect to the output signal is newly set when the output signal is in an abnormal state, so that the detection time of the paper can be precisely recognized.

Abstract: An image forming apparatus includes a main controller to output a printing command for each page of printing data if the printing data are received; a printing unit to print the printing data according to the printing command; and a printing controller to maintain the printing unit in a standby state until a printing command of a following page is received, if the printing of the currently printed page is completed in the case in which there exists a following page of the page currently being printed in the printing unit. Accordingly, when the printing command of the following page is received, the time for driving the printing unit again can be shortened.

Abstract: An image forming device includes a sensor to detect whether a paper is discharged or not, a determiner to determine a paper width according to whether a sensing signal is output from the sensor when a printing job is executed, and a controller to control a subsequent printing operation according to the determination result of the determiner. After the printing job is initiated, the determiner determines a normal width when the sensing signal is output within a preset time, and the determiner determines a narrow width when the sensing signal is not output within the present time. Accordingly, using an existing sensor, the paper width can be detected and the appropriate printing process can be performed.

Abstract: An electrophotographic image-forming apparatus and a charging voltage control method therefor. The electrophotographic image-forming apparatus has a charging roller applying a predetermined voltage to a photosensitive medium, a developing roller for developing with a developing agent an electrostatic latent image formed on the photosensitive medium by a laser scanning unit, a transfer roller transferring onto a sheet of recording paper the image developed by the developing agent, and a high voltage power supply (HVPS) applying predefined voltages to the respective rollers.

Abstract: A charging voltage controller of an image forming apparatus includes a charging roller charging a photoconductive drum with a predetermined charging voltage, a high voltage supply unit supplying the predetermined charging voltage to the charging roller, an electric current detecting unit detecting an electrical current flowing the charging roller, and a control unit supplying first and second test voltages of different degrees to the charging roller, determining a first reference voltage to be applied to the charging roller based on data from the electric]current detecting unit outputted in response to the first test voltage, calculating slope data based on the electrical current data detected from the electric current detecting unit in response to the first and second test voltages, and determining the charging voltage to be applied to the charging roller as a sum of the first reference voltage and a preset offset voltage that corresponds to the slope data.

Abstract: A control method to control a lamp, which is used as a heat generator, including detecting a temperature of lamp, comparing the detected temperature of the lamp with a predetermined reference temperature, turning off a power supply to the lamp when the detected temperature of the lamp exceeds the predetermined reference temperature, and when the lamp stays in a turned-off state for more than a first time amount, supplying a half wavelength pulse to the lamp at intervals according to a second time amount. According to the lamp control method, reducing the inrush of current to the lamp is possible without requiring additional hardware. When applied to electronic apparatuses, the lamp control method reduces maximum value of the inrush of current in the stand-by mode.

Abstract: A paper transfer control method for an image forming device having a plurality of paper feeding cassettes for storing paper sheets; a pickup roller for picking up a paper sheet from one of the plurality of paper feeding cassettes to load the picked up paper on a paper transfer path; a transfer roller for feeding the loaded paper sheet; an image forming unit having a photosensitive medium for forming an image on the paper sheet; a driving motor for driving the photosensitive medium, the transfer roller and the pickup roller; and a plurality of sensors for sensing whether the paper sheet is transferred. The method includes: selecting a paper feeding cassette which picks up a paper sheet according to a received printing command; transmitting a linear-velocity control command to the driving motor, the linear-velocity control command based on a paper transfer path of the selected paper feeding cassette; and picking up the paper sheet, and transferring the picked up paper along the paper transfer path.

Abstract: An electrophotographic image-forming apparatus and a charging voltage control method therefor. The electrophotographic image-forming apparatus has a charging roller applying a predetermined voltage to a photosensitive medium, a developing roller for developing with a developing agent an electrostatic latent image formed on the photosensitive medium by a laser scanning unit, a transfer roller transferring onto a sheet of recording paper the image developed by the developing agent, and a high voltage power supply (HVPS) applying predefined voltages to the respective rollers.

Abstract: A charging voltage controller of an image forming apparatus includes a charging roller charging a photoconductive drum with a predetermined charging voltage, a high voltage supply unit supplying the predetermined charging voltage to the charging roller, an electric current detecting unit detecting an electrical current flowing the charging roller, and a control unit supplying first and second test voltages of different degrees to the charging roller, determining a first reference voltage to be applied to the charging roller based on data from the electric]current detecting unit outputted in response to the first test voltage, calculating slope data based on the electrical current data detected from the electric current detecting unit in response to the first and second test voltages, and determining the charging voltage to be applied to the charging roller as a sum of the first reference voltage and a preset offset voltage that corresponds to the slope data.