Abstract: A method of detecting the amount of remaining sheets of paper in a paper feeding cassette of a printing apparatus, wherein the printing apparatus receives a paper feeding cassette having a knock-up plate on which paper is placed, and which pivots as paper is removed therefrom, a pickup roller installed in the printing apparatus which elastically moves up and down within a predetermined range to contact the paper, the pickup roller being made to rotate in close contact with the paper to sequentially feed the paper into the printing apparatus, a lifting mechanism which lifts the knock-up plate step by step according to the consumption of paper, thereby placing the loaded paper against the pickup-roller, calculating a difference in the number of operations of the lifting mechanism for lifting the knock-up plate toward the pickup roller when a maximum number of sheets of paper is loaded into the paper feeding cassette and when only a single sheet of paper is placed in the paper feeding cassette, calculating an am

Abstract: A paper feeding apparatus for a printing apparatus includes a pickup roller, which rotates in close contact with a sheet of paper loaded in a cassette and which allows the paper to enter in a paper feeding path of the printing apparatus, and a moving device, which allows the pickup roller to be selectively close to or separated from the paper loaded in the cassette while moving the pickup roller up and down.

Abstract: A universal paper cassette for feeding paper sheets comprising a case, a pair of side guide members installed within the case to be parallel to the side walls of the case and to be slidable widthwise according to the width of the paper sheets for supporting both sides of received paper sheets, finger members assembled to the respective side guide members to move together therewith, a lengthwise guide member installed within the case to be slidable lengthwise according to the length of the paper sheets for supporting the front ends of the paper sheets, a paper pressing plate assembled to both sides of the case by pins to vertically pivot, and at least one spring installed within the case for elastically biasing the paper pressing plate upward. The universal paper cassette further comprises an elastic unit for connecting the side guide members or the lengthwise guide member with the paper pressing plate and controlling an elastic force against the paper pressing plate.

Abstract: A paper feeding apparatus, of a printing machine which includes a cassette for receiving paper that is detachably coupled with a body of the printing device, guide members for supporting side portions of the received paper, slidingly installed in the cassette, and a pair of pick-up rollers for drawing the paper out from the cassette. The pick-up rollers are positioned for tight contact with the top of the received papers and are movably installed on a rotating shaft so as to be capable of moving along the shaft. The paper feeding apparatus also includes a moving mechanism, interlocking with the guide member, for moving the pick-up roller along the shaft.

Abstract: A paper feeding unit for an electrophotographic printing apparatus which can prevent print media from being drawn to the right or left during conveyance.