Abstract: A mobile image forming apparatus is provided that comprises a casing, a support frame to surround a printing medium roll from which a printing medium is supplied and to guide the printing medium, an image forming unit to form an image on the printing medium guided by the support frame and a printing medium receiving portion disposed between the casing and the support frame to receive therein the printing medium on which the image is formed by the image forming unit. The mobile image forming apparatus may further comprise a roll support core disposed in the support frame to rotatably support the printing medium roll.

Abstract: An image forming apparatus having a first image forming unit and a second image forming including a printing medium supplier which supplies a printing medium, a selection guide which selectively guides the printing medium from the printing medium supplier to one of a first supplying path of the first image forming unit and a second supplying path of the second image forming unit, and a first feed roller which is disposed between the selection guide and the printing medium supplier, and transfers the printing medium from the printing medium supplier to the selection guide.

Abstract: A liquid crystal display device and a method for driving the same are disclosed. The device includes a gamma voltage generation circuit for generating first to ith positive gamma reference voltages having different levels, and first to ith negative gamma reference voltages having different levels, and a plurality of data drive chips, each of the data drive chips converting digital data input thereto into a positive data voltage and a negative data voltage and supplying the positive data voltage and negative data voltage to a liquid crystal display panel, and adjusting a level of the positive data voltage based on a positive gamma reference voltage supplied thereto, among the first to ith positive gamma reference voltages, and adjusting a level of the negative data voltage based on a negative gamma reference voltage supplied thereto, among the first to ith negative gamma reference voltages.

Abstract: An image forming apparatus is provided and includes a platen roller and a thermal printing head. The thermal printing head is elastically biased toward the platen roller and rotates about a pivot of the platen roller for moving between first and second positions to faces first and second surfaces of a medium. A transfer portion has driving and driven rollers which are rotatably engageable with each other to transfer the media. A guiding unit reduces a difference of media transfer force of the transfer portion when the thermal printing head is respectively located in the first and second positions.

Abstract: A thermal printer and a printing method are provided. The thermal printer includes a thermal printhead for applying a predetermined amount of heat to a thermal recording paper to develop a print layer provided on the thermal recording paper; a feeding roller for feeding the thermal recording paper, a platen roller for facing the thermal printhead to support the thermal recording paper, wherein the thermal recording paper passes between the thermal printhead and the platen roller, a first encoder sensor for detecting a rotation of the platen roller, a second encoder sensor for detecting rotation of the feeding roller; a counting unit for counting first and second pulse signals generated from the first and second encoder sensors, respectively, and a switching unit of the first and second pulse signals as a variable to control the feeding of the thermal recording paper.

Abstract: A thermal image forming apparatus is provided. The thermal image forming apparatus includes an image forming unit including a thermal printhead and a platen that face each other and are elastically biased towards each other; a cassette including a knock-up plate on which a medium is stacked, a pickup roller that picks up the medium from the cassette, and a pickup unit that raises the knock-up plate in a direction in which the medium stacked on the knock-up plate contacts the pickup roller and lowers the knock-up plate in a direction in which the medium is separated from the pickup roller.

Abstract: A thermal image forming apparatus includes a platen roller which supports a medium, a print head, including a heating unit which applies heat to the medium to form an image thereon, which rotates around the platen roller and moves the heating unit to a first location facing a first surface of the medium and a second location facing a second surface of the medium, and a restricting element which rotates together with the print head. The restricting element restricts the movement of the platen roller in a transport direction of the medium so that the heating unit is placed at a printing nip formed by the platen roller and the print head when the print head is located at the first and second locations.

Abstract: A thermal image forming apparatus to form an image on a recording medium having first and second sides, the apparatus including a recording head to form the image by heating the recording medium, wherein the recording head rotates between first and second locations to respectively face the first and second sides of the recording medium; and a rotation guide to rotate along with the recording head to guide the recording medium to the recording head.

Abstract: An image forming apparatus which does not require securing a separate space for feeding a print medium, and a paper-feeding method thereof are disclosed. The image forming apparatus comprises: an image forming apparatus body; an image forming unit provided within the image forming apparatus body; and a paper-feeding unit movably installed in relation to the image forming apparatus body, the paper-feeding unit feeding a print medium to the image forming unit after turning the print medium in a reverse direction at least one time.

Abstract: An image forming apparatus that uses a thermal printing head (TPH) is provided. The image forming apparatus includes a platen roller. A TPH unit faces the platen roller and pivots to contact or separate from the platen roller. A first elastic member elastically biases the TPH unit toward the platen roller. A pair of cam levers are provided on both sides of the TPH unit. A pair of rotation cams contact the pair of cam levers and allow the TPH unit to pivot according to a rotation angle of the rotation cams.

Abstract: A thermal image forming apparatus is provided. A platen roller supports a recording medium having first and second sides opposite to each other. A recording head includes a heating part that applies heat to the recording medium for image formation. The recording head rotates around the platen roller to move the heating part to first and second locations respectively facing the first and second sides of the recording medium. A conveying part conveys the recording medium. When the recording head is positioned at the first and second locations, locations of the heating part are symmetrical with each other with respect to a reference line, which passes through the conveying part and a center of the platen roller.

Abstract: A method for correcting a printing error in an inkjet printer having a printer head on which the 1st through 2Nth nozzles are provided, in which N is a positive integer greater than 0, and a feed roller, the method including: determining whether a trailing end of a print paper has escaped from the feed roller which periodically moves the print paper the width of the printer head; if the trailing end of the print paper is determined to have escaped from the feed roller, moving the print paper half the width of the printer head and printing a reference line by ejecting ink at a predetermined interval using a kth nozzle (1?k?N) among the 1st though Nth nozzles disposed above the print paper; moving the print paper on which the reference line is printed half the width of the printer head and printing comparison lines by ejecting ink at a predetermined interval using the (N+1)th through 2Nth nozzles disposed above the print paper; detecting an error distance between the reference line and the comparison line print

Abstract: A method and an apparatus for forming an image on a medium having first and second surfaces wherein an image is formed on the first surface of the medium using a printing unit. After the image formation on the first surface of the medium is completed, the medium is returned to the printing start location, and a location change unit is used to move the printing unit from a first position to a second position facing a second surface of the medium, then an image is formed on the second surface of the medium using the printing unit.

Abstract: An image forming apparatus includes a conveying roller to convey a paper, a guide member to guide the paper conveyed by the conveying roller, a pressurizing roller to pressurize the paper guided by the guide member, and a heat transferring unit faced towards the pressurizing roller, the heat transferring unit being contacted with the paper to sequentially heat a surface of the paper. Thus, the image forming apparatus prevents a front end of the paper which is conveyed in an image forming unit from being caught during the conveyance.

Abstract: An image forming apparatus using a thermal printing head (TPH) and a printing method thereof to print a borderless image on both sides of a printing medium. The image forming apparatus includes first and second feeding units respectively disposed at front and rear sides of the TPH to transfer the printing medium at a predetermined printing speed and a pair of out-feed rollers that co-rotates and feeds out the printing medium, in which one of the out-feed rollers rotates in contact with the pick-up roller. A platen roller co-rotates in contact with the printing medium fed by the first and second feeding units The TPH has a printing position in which the TPH is pressed towards the platen roller to form a printing nip, and an open position in which the TPH is separated from the platen roller. The knock-up plate has a pick-up position where the printing medium comes in contact with the pick-up roller and a stand-by position where the printing medium loaded thereon is separated from the pick-up roller.

Abstract: An inkjet printer driving a maintenance apparatus using a power to a feed roller. In the inkjet printer, the maintenance of the maintenance apparatus is started by a carriage. The maintenance apparatus includes a maintenance member which cleans and covers the nozzle of a print head, a maintenance cam which controls the maintenance member through a rotating motion, a maintenance gear which is disposed at one end of the maintenance cam and has a cut off portion in which a part of gear teeth is partially cut off in a face width direction, and a connection gear disposed on a shaft of the feed roller to be able to move in a shaft direction by the carriage and transmit the power of the feed roller. During the printing operation of the carriage, the connection gear is placed on the cut off portion, and then engaged with the teeth of the maintenance gear disposed adjacent to the cut off portion by the pushing of the carriage.

Abstract: An image forming apparatus using a thermal printing head, the image forming apparatus including a printing unit having a thermal printing head to print an image by applying heat to a medium and a platen roller facing the thermal printing head to support the medium, a conveying unit to convey the medium at a predetermined printing speed, and a guide roller disposed between the conveying unit and the printing unit to guide the medium, the guide roller having a curved portion formed in a width direction of the medium.

Abstract: An image forming apparatus that uses a thermal printing head (TPH) is provided. The image forming apparatus includes a platen roller. A TPH unit faces the platen roller and pivots to contact or separate from the platen roller. A first elastic member elastically biases the TPH unit toward the platen roller. A pair of cam levers are provided on both sides of the TPH unit. A pair of rotation cams contact the pair of cam levers and allow the TPH unit to pivot according to a rotation angle of the rotation cams.

Abstract: A paper feeding apparatus of an image forming device having a feeder opening and closing unit to automatically rotate a paper feeder between a storing position and a paper feeding-standby position selectively employing a driving source driving a transporting unit with a pickup roller and a feed roller. The paper feeding apparatus automatically opens the paper feeder to the paper feeding-standby position when the image forming device is used, and automatically closes the paper feeder to the storing position to minimize space when the image forming device is not in use, thereby accommodating a user and minimizing a size of the image forming device.

Abstract: A paper discharge unit for an inkjet printer which ejects a sheet on which image printing is completed by an ink cartridge out of a printer main body. The paper discharge unit for an inkjet printer includes paper discharge rollers rotatably mounted in the printer main body to feed the printing-completed sheet out of the printer main body; and paper discharge guides disposed downstream of the paper discharge rollers in a direction the sheet is fed, and guiding upward the front end portion of the sheet ejected from the paper discharge rollers to prevent the rear end portion of the sheet from being lifted. Accordingly, the front end portion of the sheet is deformed by the paper discharge guides to restrain the end portion of the sheet facing a nozzle part of the ink cartridge from being in contact with the nozzle part when the sheet is ejected, so that image printing becomes possible up to the end portion of the sheet, to thereby improve the printing efficiency of the inkjet printer.