Patent ID: 6530639
Filing Date: 2003-03-11
Classification: B41J

Abstract:
An image forming device using an ink jet recording method, said device forming a color image using a plurality of heads each of which has a plurality of ink ejection nozzles thereon, said device comprising:means for printing a print pattern at a predetermined density using the plurality of ink ejection nozzles, one head at a time, on a print paper; a reflective-type optical sensor which reads the print pattern in each color while scanning the print pattern in a nozzle column direction; and density calculating means for calculating a density of the print pattern in each color based on an output of said reflective-type optical sensor, wherein said reflective-type optical sensor comprises a light emitting element which emits a light including all lights in red/blue/green regions on an optical wavelength and a plurality of light receiving elements each of which detects a light in one of the red/blue/green regions on optical wavelength, and wherein, based on an output of the light receiving element for a complementary color light of each pattern color and an output of a light receiving element for a non-complementary color light of the pattern color, said destiny calculating means calculates a difference between the two outputs to detect a density level on a nozzle position basis for the print pattern printed by each-head.