JP2000326497A - Printing method for ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of the deviation of printing dots, white lines and uneven printing as a result of printing by setting larger size dots jetted out of a line type having a plurality of arranged nozzles at a constant cyde. SOLUTION: A printing head 100 is formed into a line type printing head on which a plurality of nozzles are arranged straightly and disposed in the direction crossing orthogonally to the carrying direction of a printing paper 101. When the printing for the portion of one dot line is carried out by the printing head 100, printing dots 110 of regular size and printing dots 111 of size larger than the regular size are printed alternately on one dot line, and also in the carrying direction of the paper 101, the regular dot size 110 and the larger dot size 111 are printed alternately on every other lines. The printing of high quality level in which white lines and uneven printing generated by the deviation of postions of printing dots are inconspicuous can be provided by the arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet printing method for an ink-jet printing apparatus, which uses a multi-nozzle head having a plurality of nozzles and performs printing by discharging ink from the head onto a printing medium.

[0002]

2. Description of the Related Art In a conventional ink jet printing apparatus, high-speed printing is performed by arranging a plurality of nozzles in a line (line shape) and performing printing by appropriately moving a printing medium.

[0003] However, due to manufacturing variations among the nozzles in the head, the printing dot position shifts due to the shift of the ink discharge amount and the discharging direction of each nozzle, the nozzle position, and the like, and white streaks and print unevenness occur in the printing result. Resulting in.

FIG. 2 shows an outline of a printing result in a conventional ink jet printing apparatus, and it is scattered that uneven printing occurs.

[0005]

In an ink jet printing apparatus having a serial head, printing unevenness is eliminated by dividing the printing into a plurality of printings in order to eliminate printing unevenness due to nozzle variations.

However, in a line type ink jet printing apparatus in which a head is fixed and mounted, banding prevention printing processing which is usually performed in a serial type ink jet recording apparatus in which a head is moved to perform printing is performed. Can not.

Therefore, in the present invention, in an ink jet printing apparatus in which a head is fixedly mounted, the printing is performed by the deviation of the ink discharge amount and the discharge direction of each nozzle, the nozzle position, etc. due to the manufacturing variation of each nozzle. It is an object of the present invention to prevent a dot position from shifting and a white streak or print unevenness from occurring in a print result.

[0008]

According to a first aspect of the present invention, there is provided a line type head in which a plurality of nozzles are arranged, and each line is provided by a driving element provided for each nozzle. In an ink jet printing apparatus that performs printing by causing ink droplets ejected from nozzles to adhere to a printing medium with the applied energy, the dot size ejected by a line-type head is increased at a constant cycle.

[0009] The dot size is changed by changing the waveform of the drive pulse applied to the drive element or by changing the number of drive pulses applied to the drive element and uniting a plurality of ink droplets. You.

A second configuration of the present invention for solving the above-mentioned problems uses a line type head in which a plurality of nozzles are arranged, and uses a line-type head in which a plurality of nozzles are arranged. In an ink jet printing apparatus that performs printing by attaching ink droplets ejected from a printing medium to a printing medium, the dot size ejected by a line type head is randomly increased.

In the ink jet printing apparatus of the present invention having the above-described structure, when printing is performed while the recording medium is being fed, the dot size to be printed is periodically changed. Can be made inconspicuous.

It is effective to increase the dot size to be printed one by one alternately, but it is also effective to change the dot size at random.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 3 is a schematic diagram showing the relationship between the print head and the printing paper. In the drawing, reference numeral 100 denotes a print head, and 101 denotes printing paper.

The print head 100 is a linear head in which a plurality of nozzles are linearly arranged.
Are arranged in a direction orthogonal to the conveying direction of the first direction.

When the print head 100 performs printing for one dot line, a paper transport device (not shown) transports the paper one dot line. Printing is performed by repeating this.

FIG. 1 shows a printing result based on the printing method of the present invention, and the printing method of the present invention will be described.

In FIG. 1, reference numeral 110 denotes a normal dot size, and 111 denotes a dot having a larger dot size than normal.

Here, every other print dot size on the same line is made larger than the normal size, and also in the paper transport direction, every dot line is made larger than the normal size. For this reason, what appeared as white streaks in the conventional print result becomes inconspicuous.

The method of changing the dot size can be performed by changing the waveform of a driving pulse applied to a driving element for driving a nozzle. Alternatively, it can be performed by changing the number of print dots forming one print dot (one dot is formed by a plurality of dots).

In the above-described example, the dot size is increased for each dot line, but it is also effective to change the dot size at arbitrary intervals or randomly.

Although the present invention has been described for the case of a linear fixed head, the present invention is also effective for a serial type ink jet printing apparatus in which the head is moved.

[0023]

As described above, according to the present invention, by changing the dot size to be printed periodically or randomly, the ink discharge amount and the discharge direction of each nozzle due to the manufacturing variation of each nozzle. In addition, it is possible to obtain high-quality printing in which white streaks and printing unevenness due to printing dot position shift due to nozzle position shift and the like are not noticeable.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a printing result as an example of a printing method of the present invention.

FIG. 2 is a schematic diagram of a printing result as an example of a conventional printing method.

FIG. 3 is a schematic front view showing the inkjet printing apparatus.

[Explanation of symbols]

100 is a print head, 101 is print paper, 110 is a dot of a normal size, and 111 is a dot of a size larger than usual.

Claims (4)

[Claims] An ink droplet ejected from a nozzle is attached to a printing medium by using a line type head having a plurality of nozzles arranged therein, and using energy given by each driving element provided for each nozzle. A printing method for an inkjet printing apparatus, comprising: increasing a dot size discharged by the line-type head at a constant cycle in an inkjet printing apparatus that performs printing by using a printing method. 2. The method according to claim 1, wherein the change of the dot size is performed by changing a waveform of a driving pulse applied to the driving element. 3. The ink jet printing apparatus according to claim 1, wherein the dot size is changed by changing the number of driving pulses applied to the driving element and uniting a plurality of ink droplets. Printing method. 4. Using a line type head having a plurality of nozzles arranged thereon, causing ink droplets ejected from the nozzles to adhere to a printing medium by energy given by each driving element provided for each nozzle. A printing method for an inkjet printing apparatus, comprising: randomly increasing a dot size discharged by the line-type head.