Patent ID: 6010207
Filing Date: 2000-01-04
Classification: B41J,H04N

Abstract:
A color printer provided with ink jet heads comprising three trains of nozzle holes for respectively discharging different colored inks, each train of nozzle holes composed of a plurality of nozzle holes which are arranged at intervals of three pitches in an auxiliary scanning direction, and the nozzle holes of the three trains of nozzle holes are disposed at equal intervals in a main scanning direction while shifting every one pitch in the auxiliary scanning direction wherein said different colored inks are discharged and sequentially superimposed over one another on a recording medium to synthesize colors so as to make a color print; whereinthe color printer further comprises control means for controlling the ink jet heads to make a print which is regular in sequence of superimposition of colors in the manner of;discharging only one colored ink through the nozzle hole of a first train of nozzle holes which is any one of the three trains of nozzle holes to make a print on the recording medium as the ink jet heads are scanned in the main scanning direction in a first step;discharging ink through the nozzle holes of the first train of nozzle holes and the nozzle holes of a second train of nozzle holes adjacent to the first train of nozzle holes to make a print on the recording medium as the ink jet heads are scanned in the main scanning direction while they are shifted by one pitch in the auxiliary scanning direction relative to the recording medium in a second step;discharging ink through all nozzle holes of the first, second and remaining third trains of nozzle holes to make a print on the recording medium as the ink jet heads are scanned in the main scanning direction while they are shifted by one pitch in the auxiliary scanning direction relative to the recording medium in a third step;discharging ink through all nozzle holes of the second and third trains of nozzle holes and only through the last nozzle hole of the first train of nozzle holes in the auxiliary scanning direction to make a print on the recording medium as the ink jet heads are scanned in the main scanning direction while they are shifted by one pitch in the auxiliary scanning direction relative to the recording medium in a fourth step;discharging ink through all nozzle holes of the third train of nozzle holes and only through the last nozzle holes of the first and second trains of nozzle holes in the auxiliary scanning direction to make a print on the recording medium as the ink jet heads are scanned in the main scanning direction while they are shifted by one pitch in the auxiliary scanning direction relative to the recording medium in a fifth step;discharging ink through all nozzle holes of the first train of nozzle holes and only through the first nozzle holes of the second and third trains of nozzle holes in the auxiliary scanning direction to make a print on the recording medium as the ink jet heads are scanned in the main scanning direction while they are shifted by (n-1).times.3+1 pitches (n is the number of nozzle holes of each nozzle train) in the auxiliary scanning direction relative to the recording medium in a sixth step;discharging ink through all nozzle holes of the first and second trains of nozzle holes and only through the first nozzle hole of the third train of nozzle holes in the auxiliary scanning direction to make a print on the recording medium as the ink jet heads are scanned in the main scanning direction while they are shifted by one pitch in the auxiliary scanning direction relative to the recording medium in a seventh step;executing printing operations sequentially in the third to seventh steps;discharging ink only through the last nozzle holes of the second and third trains of nozzle holes in the auxiliary scanning direction to make a print on the recording medium as the ink jet heads are scanned in the main scanning direction while they are shifted by one pitch in the auxiliary scanning direction relative to the recording medium in a step following the fifth step when ending the printing; andthen discharging ink only through the last nozzle hole of the third train of nozzle holes in the auxiliary scanning direction to make a print on the recording medium while the ink jet heads are scanned in the main scanning direction while they are shifted by one pitch in the auxiliary scanning direction relative to the recording medium so as to end the printing.