Patent ID: 7083251

Claim:
A method of compensating a sheet feeding error in an ink-jet printer, the printer comprising a rotation measuring unit of a sheet feeding roller, a unit to measure a reciprocating movement of an ink cartridge mounted on a carriage, and a sensor to measure an image printed on a sheet of material, the method comprising: printing a test pattern on the sheet; scanning the printed test pattern using the image sensor and measuring a distance W 1 between a starting point X 1s and an ending point X 1e of the test pattern; driving the feeding roller and moving the sheet to a set distance H m so that the set distance H m is shorter than a length of the test pattern in a sheet feeding direction; scanning the test pattern using the image sensor and measuring a distance W 2 between a starting point X 2s and an ending point X 2e of the test pattern; calculating a feeding distance H, along which the sheet is actually fed, from a difference between the distances W 2 and W 1 ; calculating a sheet feeding error E of the sheet from a difference between the feeding distance H and the set distance H m ; and compensating for the sheet feeding error E at the set distance H m .