Method for aligning droplets expelled from an ink jet printer

A method of adjusting alignment positions of ink dots printed with at least one printhead that is mounted on a moving carriage of an ink jet printer that produces ink dots that are each composed of a main dot and at least one satellite, said method comprising the steps of:

• printing ink dots an a testchart while the carriage moves over the testchart at a predetermined speed (V′c);
• measuring a relative dislocation (ΔY′) of the ink dots;
• and
• correcting the alignment of the ink dots by adjusting the position and/or the timing of activation of the printhead in accordance with the measured result;
• and
• reducing the predetermined speed (V′c) relative to a specific predetermined nominal speed (Vc) to such an extent that the satellites are essentially absorbed in the main dots when the test chart is printed,
• wherein said predetermined speed (V′c) is smaller than the specific predetermined nominal speed (Vc) of the carriage when the carriage is moved over a recording medium during a print process, and a misalignment (ΔY) of the ink dots that will be printed when the printhead is moved at the specific predetermined nominal speed (Vc) is calculated from said measured relative dislocation (ΔY′) said predetermined speed (V′c) and said specific predetermined nominal speed (Vc).

An apparatus for adjusting alignment positions of ink dots printed with at least one printhead that is mounted on a moving carriage of an ink jet printer that moves at a specific predetermined nominal speed (Vc) of the carriage when the carriage is moved over a recording medium during a print process, said apparatus comprising:

• a control unit that controls the printer to move the carriage at a predetermined speed (V′c) that is smaller than the specific predetermined nominal speed (Vc) of the carriage when the carriage is moved over a recording medium during a print process;
• a sensor that detects a relative dislocation (ΔY′) of ink dots that have been printed with the printer on a testchart;
• and
• a processor that calculates a misalignment (ΔY) of the ink dots that will be printed when the printhead is moved at the specific predetermined nominal speed (Vc) on the basis of the detected relative dislocation (ΔY′), said predetermined speed (V′c) and said specific predetermined nominal speed (Vc) of the carriage.

An apparatus for adjusting alignment positions of ink dots printed with at least one printhead that is mounted on a moving carriage of an ink jet printer that produces ink dots that are each composed of a main dot and at least one satellite, said apparatus comprising:

• a control unit that controls the printer to move the carriage at a predetermined speed (V′c) that is smaller than a the specific predetermined nominal speed (Vc) of the carriage when the carriage is moved over a recording medium during a print process;
• a sensor that detects a relative dislocation (ΔY′) of ink dots that have been printed with the printer on a testchart;
• and
• a processor that calculates a misalignment (ΔY) of the ink dots that will be printed when the printhead is moved at the specific predetermined nominal speed (Vc) on the basis of the detected relative dislocation (ΔY′), said predetermined speed (V′c) and said specific predetermined nominal speed (Vc) of the carriage,
• wherein said control unit reduces the predetermined speed (V′c) relative to the specific predetermined nominal speed (Vc) to such an extent that the satellites are essentially absorbed in the main dots when the test chart is printed.

A method of adjusting alignment positions of ink dots printed with at least one printhead that is mounted on a moving carriage of an ink jet printer, said method comprising the steps of:

• printing ink dots on a testchart while the carriage moves over the testchart at a predetermined speed (V′c) that is slower than a different predetermined nominal speed (Vc) at which the carriage moves in a making a normal print;
• measuring a relative dislocation (ΔY′) of the ink dots printed on the test chart;
• calculating a misalignment (ΔY) of the ink dots that will be printed when the printhead is moved at the different predetermined speed based on the relative dislocation (ΔY′);
• and
• correcting the alignment of the ink dots by adjusting the position and/or the timing of activation of the printhead in accordance with the measured relative dislocation (ΔY′).

A method of adjusting alignment positions of ink dots printed with at least one printhead that is mounted on a moving carriage of an ink jet printer, said method comprising the steps of:

• printing ink dots made up of main drops and satellite drops on a testchart while the carriage moves over the testchart at a predetermined speed (V′c) that is slower than a different predetermined nominal speed (Vc) at which the carriage moves in a making a normal print such that satellite dots are substantially completely absorbed in their main dots;
• measuring a relative dislocation (ΔY′) of the ink dots printed on the test chart;
• calculating a misalignment (ΔY) of the ink dots that will be printed when the printhead is moved at the different predetermined speed based on the relative dislocation (ΔY′);
• and
• correcting the alignment of the ink dots by adjusting the position and/or the timing of activation of the printhead in accordance with the measured relative dislocation (ΔY′).