Abstract: Disclosed is a paper supply unit having an improved paper supply structure. The paper supply unit includes a main body having an opening, a cassette configured to be attached to and detached from the main body through the opening. The cassette can include a first holding portion and a second holding portion, each configured to hold printing medium. The second holding portion configured to transfer printing medium from the second holding portion to the first holding portion. The paper supply unit can include a guide device disposed between the first holding portion and the second holding portion when the cassette is mounted in the main body and configured to guide the printing medium in the first holding portion.

Abstract: A cover opening and closing unit for an image forming apparatus, includes a cover removably mounted to a main body of the image forming apparatus mounting therein a developer cartridge, a developing unit, a transferring unit and a waste-developer receptacle, and a locking device fixing the cover to the main body of image forming apparatus. The locking device is released from the main body only after the waste-developer receptacle is removed from the main body.

Abstract: A paper feeding device which includes a pickup roller assembly picking up a sheet of paper and transferring the paper, a stopper controlling the paper so that a front end of the paper is located on a lower portion of the pickup roller, a sensing unit sensing whether the paper is loaded or not on the paper feeding board, and a probe unit that is rotated with the stopper and turns on/off the sensor unit. Therefore, the probe unit for turning the sensor unit on/off is operated with the stopper to reduce the number of components, thus reducing the cost and stabling the quality of product.

Abstract: Disclosed is a paper supply unit having an improved paper supply structure. The paper supply unit includes a main body having an opening, a cassette configured to be attached to and detached from the main body through the opening. The cassette can include a first holding portion and a second holding portion, each configured to hold printing medium. The second holding portion configured to transfer printing medium from the second holding portion to the first holding portion. The paper supply unit can include a guide device disposed between the first holding portion and the second holding portion when the cassette is mounted in the main body and configured to guide the printing medium in the first holding portion.

Abstract: A locking apparatus includes a lever unit disposed at an intermediate transfer belt frame to cause an intermediate transfer belt to contact a photosensitive medium; a locking unit disposed at a supporting cover to cause the supporting cover to be fixed to and separated from an engine frame; and a coupling unit to cause the lever unit to operate in association with the locking unit.

Abstract: A cover opening and closing unit for an image forming apparatus, includes a cover removably mounted to a main body of the image forming apparatus mounting therein a developer cartridge, a developing unit, a transferring unit and a waste-developer receptacle, and a locking device fixing the cover to the main body of image forming apparatus. The locking device is released from the main body only after the waste-developer receptacle is removed from the main body.

Abstract: An image forming apparatus including a photosensitive bodies fixing unit. The image forming apparatus includes: a main body frame; a fixing frame on which a plurality of photosensitive bodies are installed, the fixing frame being fixed at a predetermined position on the main body frame; a guide protruding portion formed on the fixing frame to guide the fixing frame to be coupled with the main body frame; a guide rail formed on the main body frame for the guide protruding portion to be inserted into; and a position determining portion formed on the guide rail to fix the guide protruding portion to a predetermined position. Accordingly, the parallel alignment between the scanning units and the photosensitive bodies may be relatively easily maintained and accurate color overlapping and color presentation are obtained to achieve high image quality.

Abstract: A locking apparatus includes a lever unit disposed at an intermediate transfer belt frame to cause an intermediate transfer belt to contact a photosensitive medium; a locking unit disposed at a supporting cover to cause the supporting cover to be fixed to and separated from an engine frame; and a coupling unit to cause the lever unit to operate in association with the locking unit.

Abstract: A driving apparatus for an office machine includes a driving motor rotating in first and second directions, a power transfer part transferring a power of the driving motor to a convey unit, a document discharge unit and a document supply unit, and a controller controlling the driving motor. A driving method for the office machine includes driving the driving motor in the first direction to operate the document supply unit and the convey unit in opposite directions with respect to a document-conveying direction till a front end of a document is arranged by the convey unit after the document is supplied by the document supply unit, determining whether the front end of the document is arranged, and driving the driving motor in the second direction to convey and discharge the document through the convey unit and the document discharge unit if the front end of the document is arranged.

Abstract: A laser scanning device for use with an image forming apparatus, including an optical housing, a light source installed in the optical housing to generate a laser beam, a deflection unit to deflect the laser beam emitted from the light source, a focusing lens to focus the laser beam deflected by the deflection unit onto a laser scanning surface, a reflective mirror to change the path of the laser beam and thereby, scan the laser beam onto a position of the laser scanning surface, and a mirror assembly unit to diversify installation angles of the reflective mirror to facilitate an assembly thereof.

Abstract: An image forming apparatus, including a first image forming unit, including a first photoconductor and a first developing device that develops an image by supplying toner onto an electrostatic latent image formed on the first photoconductor, a second image forming unit, including a second photoconductor and a second developing device that develops an image by supplying toner onto an electrostatic latent image formed on the second photoconductor, and a control unit to control operations of the second image forming unit, so that, when the first image forming unit is not installed in the image forming apparatus, the image is printed in response to desired image data by an operation of the second image forming unit.

Abstract: An image forming apparatus including a photosensitive bodies fixing unit. The image forming apparatus includes: a main body frame; a fixing frame on which a plurality of photosensitive bodies are installed, the fixing frame being fixed at a predetermined position on the main body frame; a guide protruding portion formed on the fixing frame to guide the fixing frame to be coupled with the main body frame; a guide rail formed on the main body frame for the guide protruding portion to be inserted into; and a position determining portion formed on the guide rail to fix the guide protruding portion to a predetermined position. Accordingly, the parallel alignment between the scanning units and the photosensitive bodies may be relatively easily maintained and accurate color overlapping and color presentation are obtained to achieve high image quality.

Abstract: There is provided an image forming apparatus. In the image forming apparatus, a paper feeder is detachably installed in the image forming apparatus and feeds the paper to the image forming unit. The paper feeder comprises a first paper feed unit for feeding the paper to the image forming unit along a first paper passage and a second paper feed unit for feeding the paper to the image forming unit along a second paper passage. Also, the paper feeder comprises a guide surface that forms a portion of the paper passage. Therefore, jammed paper can be easily removed after pulling the paper feeder out of the image forming apparatus, thereby increasing the stability of the image forming apparatus and user's convenience. Further, jammed paper at the first paper passage and/or the second paper passage can be easily removed due to the integral form of the first and second feed unit.

Abstract: An image forming machine driving apparatus includes a first one direction power transfer part transferring or cutting off a dynamic power of a driving motor to or from a feeding part according to rotation directions of the driving motor, and a feeding part power-engaging removal device cutting off a jammed paper-removing force not to be transferred to the driving motor when the jammed paper-removing force is applied to the feeding part in a power transfer direction of the first one direction power transfer part, thereby preventing the jammed paper from being torn off or damaged when the paper jammed in the feeding part is removed during supplying or feeding the paper.

Abstract: A paper feeding device which includes a pickup roller assembly picking up a sheet of paper and transferring the paper, a stopper controlling the paper so that a front end of the paper is located on a lower portion of the pickup roller, a sensing unit sensing whether the paper is loaded or not on the paper feeding board, and a probe unit that is rotated with the stopper and turns on/off the sensor unit. Therefore, the probe unit for turning the sensor unit on/off is operated with the stopper to reduce the number of components, thus reducing the cost and stabling the quality of product.

Abstract: An image forming machine driving apparatus includes a first one direction power transfer part transferring or cutting off a dynamic power of a driving motor to or from a feeding part according to rotation directions of the driving motor, and a feeding part power-engaging removal device cutting off a jammed paper-removing force not to be transferred to the driving motor when the jammed paper-removing force is applied to the feeding part in a power transfer direction of the first one direction power transfer part, thereby preventing the jammed paper from being torn off or damaged when the paper jammed in the feeding part is removed during supplying or feeding the paper.

Abstract: A driving apparatus for an office machine includes a driving motor rotating in first and second directions, a power transfer part transferring a power of the driving motor to a convey unit, a document discharge unit and a document supply unit, and a controller controlling the driving motor. A driving method for the office machine includes driving the driving motor in the first direction to operate the document supply unit and the convey unit in directions opposite to each other with respect to a document-conveying direction till a front end of a document is arranged by the convey unit after the document is supplied by the document supply unit, determining whether the front end of the document is arranged, and driving the driving motor in the second direction to convey and discharge the document through the convey unit and the document discharge unit if the front end of the document is arranged.