Correction value acquisition method, correction value acquisition program, and liquid ejection recording apparatus

A correction value acquisition program which is stored in a memory and acquires a correction value used when densities of dot lines formed in an intersection direction intersecting a predetermined direction with ink ejected from nozzle lines lined up in the predetermined direction are corrected, the correction value acquisition program comprising:

• forming parts of a test pattern, in which dot lines formed in the intersection direction intersecting the predetermined direction are lined up in the predetermined direction, and a linear scale, in which scales are lined up in the predetermined direction, on a medium of which a length in the predetermined direction is shorter than a length of the test pattern in the predetermined direction according to the print data used to form the test pattern and the linear scale;
• detecting positions of the scales of the linear scale from image data obtained by reading the test pattern and the linear scale formed on the medium;
• obtaining a read density of the image data for each of the dot lines at positions corresponding to the dot lines of the image data in the predetermined direction based on the detected positions of the scales;
• and
• calculating a correction value corresponding to each of the dot lines based on the read density corresponding to each of the dot lines.

A liquid ejection recording apparatus comprising:

• a head unit including nozzle lines lined up in a predetermined direction and forming dots by ejecting a liquid on a medium;
• and
• a controller controlling the head unit,
• wherein the controller
• forms parts of a test pattern, in which dot lines formed in an intersection direction intersecting the predetermined direction are lined up in the predetermined direction, and a linear scale, in which scales are lined up in the predetermined direction, on a medium of which a length in the predetermined direction is shorter than a length of the test pattern in the predetermined direction according to print data used to form the test pattern and the linear scale,
• detects positions of the scales of the linear scale from image data obtained by reading the test pattern and the linear scale formed on the medium,
• obtains a read density of the image data for each of the dot lines at positions corresponding to the dot lines of the image data in the predetermined direction based on the detected positions of the scales, and
• calculates a correction value corresponding to each of the dot lines based on the read density corresponding to each of the dot lines.