Image forming apparatus with nozzles discharging inks each having brightness, method for forming image with inks each having brightness, and program
An image forming apparatus includes a head unit that moves in a predetermined scanning direction and on which a first nozzle which discharges first ink including a black color material, a second nozzle which discharges second ink having higher brightness than that of the first ink, and a third nozzle which discharges third ink having higher brightness than that of the first ink are arrayed in the scanning direction, and a control portion. The control portion is set to perform a conversion processing which sets a type and amount of the ink which is discharged from the head unit according to color data included in the image data and use the first ink, the second ink, and the third ink according to the color data of the darkest point in the conversion processing.
1. An image forming apparatus that forms an image on a medium based on image data, the image forming apparatus comprising:
a head unit that moves in a predetermined scanning direction and on which a first nozzle which discharges first ink including a black color material and having a brightness, a second nozzle which discharges second ink having a brightness that is higher than the brightness of the first ink, and a third nozzle which discharges third ink having a brightness that is higher than the brightness of the first ink are arrayed in the scanning direction, the first, second and third inks having achromatic color, the brightness of the second ink being different from the brightness of the third ink; and
a control portion that performs image forming processing which forms the image on the medium by discharging ink from the head unit and thus forming dot array while moving the head unit in the scanning direction,
wherein the control portion performs a conversion process which sets a type and an amount of the ink which is discharged from the head unit according to color data included in the image data and which sets to use all of the first ink, the second ink, and the third ink for the darkest point of the color data.
2. The image forming apparatus according to claim 1 ,
wherein the first nozzle is positioned between the second nozzle and the third nozzle in the scanning direction.
3. The image forming apparatus according to claim 1 ,
wherein, in a case where the scanning direction is a first scanning direction and a direction which is opposite to the first scanning direction is a second scanning direction, the control portion selectively performs a first image forming processing that forms the image by discharging the ink from the head unit, only while moving the head unit in the first scanning direction, and a second image forming processing that forms the image by combining a first scanning processing which discharges the ink from the head unit while moving the head unit in the first scanning direction and a second scanning processing which discharges the ink from the head unit while moving the head unit in the second scanning direction.
4. The image forming apparatus according to claim 1 ,
wherein, in a case where an actual proportion of a discharging amount of ink of the nozzle per a unit area to the maximum value of ink amount which is capable of being discharged per the unit area on the medium from the same nozzle is used as a nozzle use proportion, the nozzle use proportion in the second nozzle is 5% to 15%, when the image area having the darkest point is formed.
5. The image forming apparatus according to claim 1 ,
wherein, in a case where an actual proportion of a discharging amount of ink of the nozzle per a unit area to the maximum value of ink amount which is capable of being discharged per the unit area on the medium from the same nozzle is used as a nozzle use proportion, the nozzle use proportion in the third nozzle is 5% to 15%, when the image area having the darkest point is formed.
6. The image forming apparatus according to claim 1 ,
wherein, in a case where an actual proportion of a discharging amount of ink of the nozzle per a unit area to the maximum value of ink amount which is capable of being discharged per the unit area on the medium from the same nozzle is used as a nozzle use proportion, the nozzle use proportion in the first nozzle is 90% to 100%, when the image area having the darkest point is formed.
7. The image forming apparatus according to claim 1 ,
wherein the head unit further includes a fourth nozzle which discharges a fourth ink including black color material, and
wherein the control portion selects the fourth ink as ink in place of the first ink, based on the type of the medium.
8. The image forming apparatus according to claim 1 ,
wherein the head unit further includes a fifth nozzle which discharges a fifth ink of which density is lower than that of the third ink, and
wherein the first nozzle is positioned between the second nozzle and the third nozzle and the third nozzle is positioned between the first nozzle and the fifth nozzle in the scanning direction.
9. The image forming apparatus according to claim 1 ,
wherein the head unit further includes a first color ink nozzle which discharges a first ink having chromatic color and a second color ink nozzle which discharges a second ink having chromatic color, and
wherein the first nozzle, the second nozzle, and the third nozzle are positioned between the first color ink nozzle and the second color ink nozzle in the scanning direction.