Ink jet recording apparatus and ink jet recording method
AssigneeCanon Kabushiki Kaisha
InventorHideki Tanaka
Life of this patent
Estimating the term…
Abstract
A gray scale level data of each pixel is obtained as data taking 5 levels between 0 and 4 corresponding to the number of ejections from 4 individual discharging portions by the pseudo-halftoning processing. The pointer directs sequentially the memories every time an ejection data is set in responsive to the 5 level data. As a result, in forming a plurality of pixels sequentially, 4 individual discharging portions are used sequentially. So far, it will be appreciated that even if ejection failures occur in either of a plurality of discharging portions of the ink jet recording head, relatively high-quality recorded images are obtained and the lifetime of the recording head can be increased.
Claims17
An ink jet printing apparatus for scanning a printing medium a plurality of times with a printing head having a plurality of discharging portions to form a line of pixels extending in a scanning direction of the printing head, said apparatus comprising:
- data assigning means for assigning driving data for the line of pixels to be formed by the plurality of times of scanning, said data assigning means assigning the driving data for each of the plurality of times of scanning,
- plural memories provided in correspondence to each of the plurality of times of scanning so as to store the driving data assigned to said each of the plurality of times of scanning;
- and
- driving means for causing the printing head to discharge ink during each of the plurality of times of scanning, based on driving data assigned to said each scanning,
- wherein said data assigning means, for each of the driving data for the line of pixels to be formed by the plurality of times of scanning, repeats selecting one of said plurality of memories by means of a pointer and storing the driving data in the selected memory, so as to assign the driving data for the line of pixels to the plurality of times of scanning.
An ink jet recording apparatus for scanning a recording head having a plurality of discharging portions, from which ink is ejected, on a recording medium and ejecting the ink from the recording head to the recording medium to form a line of pixels extending in a scanning direction of the recording head, said apparatus comprising:
- driving means for making said recording head eject the ink droplet according to driving data;
- and
- data assigning means for assigning the driving data corresponding to the line of pixels to each of different discharging portions, which eject the ink of the same color and are used for forming said line of pixels, so as to form each one pixel of said line of pixels by means of one discharging portion,
- wherein said data assigning means sequentially assigns the driving data to the different discharging portions so that said different discharging portions are sequentially used when forming the line of pixels.
An ink jet printing method of scanning a printing medium a plurality of times with a printing head having a plurality of discharging portions to form a line of pixels extending in a scanning direction of the printing head, said method comprising the steps of:
- assigning driving data for the line of pixels to be formed by the plurality of times of scanning the driving data being assigned for each of the plurality of times of scanning;
- providing plural memories in correspondence to each of the plurality of times of scanning so as to store the driving data assigned to said each of the plurality of times of scanning;
- and
- driving the printing head to discharge ink during each of the plurality of times of scanning, based on driving data assigned to said each scanning,
- wherein said assigning step, for each of the driving data for the line of pixels to be formed by the plurality of times of scanning, repeats selecting one of said plurality of memories by means of a pointer and storing the driving data in the selected memory, so as to assign the driving data for the line of pixels to the plurality of times of scanning.
An ink jet recording method of scanning a recording head having a plurality of discharging portions, from each of which ink is ejected, on a recording medium and ejecting the ink to the recording medium to be capable of forming a line of pixels extending in a scanning direction of the recording head, said method comprising the steps of:
- assigning the driving data corresponding to the line of pixels to each of different discharging portions, which eject the ink of the same color and are used for forming said line of pixels, so as to form each one pixel of said line of pixels by means of one discharging portion;
- and
- driving the different discharging portions to eject the ink based on the driving data assigned in said data assigning step to form the line of pixels,
- wherein said data assigning step sequentially assigns the driving data to the different discharging portions so that said different discharging portions are sequentially used when forming the line of pixels.
Dependencies are inferred from the claim text.