Abstract: An image forming apparatus includes a main body frame, an image forming unit disposed inside of the main body frame to form an image, a door unit disposed in such a manner to make a conjoin rotation to thereby approach to a paper transfer path disposed inside of the main body frame, a roller assembly disposed on the paper transfer path, and an opening and closing coupling unit to couple the door unit with the roller assembly, wherein the roller assembly is opened/closed when the door unit is opened/closed.

Abstract: A fixing apparatus for a printer includes a paper separating unit. The fixing apparatus also includes a heating unit which fixes an image on paper by heating paper passing through a developing unit, a pressing unit which contacts the heating unit, presses paper passing through an interface with the heating unit and helps to fix the image on the paper, and a paper separating unit which includes a separation member having a sharp end contacting the heating unit to separate paper, an arm member having one end to which the separation member is attached and pivots, centering on a hinge shaft at a predetermined angle, and an elastic member which is connected to the other end of the arm member and applies an elastic force so that the arm member is maintained in a correct position.

Abstract: A method and apparatus to control the fusing temperature of an image forming apparatus. This method of controlling the fusing temperature of an image forming apparatus having a fan to exhaust the internal air to the outside includes counting the accumulated number of sheets of paper printed in response to print commands, lowering a set point of the fusing temperature and controlling the fan to increase the amount of air to be exhausted when the accumulated number of sheets of printed paper is greater than a predetermined value. According to the method, without installing an additional temperature sensor inside the image forming apparatus, the temperature therein can be presumed and controlled by controlling the fusing temperature of the fusing roller and a fan flow rate to lower the temperature of the paper, and consequently, preventing the formation of creases in the paper.

Abstract: A sheet separating apparatus for a fusing unit separates a sheet being conveyed through a fusing unit from a heating roller and guides the sheet to a discharging roller without causing damages to a surface of a fusing roller. The sheet separating apparatus comprises a separating claw rotatably disposed toward a discharging side of a heating roller, for separating a sheet from the heating roller, and a contact spring pivoting the separating claw so that a front end of the separating claw is in contact with the heating roller with a predetermined constant pressure. The front end of the separating claw has rounded corners. It is preferred that the front end of the separating claw is chamfered. Also, it is preferred that the separating claw is made of stainless steel.

Abstract: A fixing apparatus for a printer includes a paper separating unit. The fixing apparatus also includes a heating unit which fixes an image on paper by heating paper passing through a developing unit, a pressing unit which contacts the heating unit, presses paper passing through an interface with the heating unit and helps to fix the image on the paper, and a paper separating unit which includes a separation member having a sharp end contacting the heating unit to separate paper, an arm member having one end to which the separation member is attached and pivots, centering on a hinge shaft at a predetermined angle, and an elastic member which is connected to the other end of the arm member and applies an elastic force so that the arm member is maintained in a correct position.

Abstract: An apparatus and method of controlling the temperature of an image fixing unit having a developer fixed on a recording medium under a predetermined temperature in an image forming apparatus is provided. The temperature of the image fixing unit is set to one of a plurality of different temperatures stored in a controller of the image forming apparatus depending on an printing operation status of the image forming apparatus. The image fixing unit is heated and warmed-up to a predetermined ready temperature. If a print command is not received until the warm-up is completed, the ready temperature is maintained. The printing operation starts upon completion of the warm-up if the print command is received before the warm-up is completed.