Patent ID: 7494203
Filing Date: 2009-02-24
Classification: B41J

Abstract:
1. A method of determining an operating drive voltage of an ink-jet head which has an actuator and which ejects, as a result of driving of the actuator, ink droplets toward a recording medium during a relative movement of the ink-jet head and the recording medium for performing recording, the ink-jet head being configured such that an ejection speed of the ink droplets varies depending upon a drive voltage to be applied to the actuator, the method comprising: recording a first record pattern as a result of driving of the actuator by application of a tentatively determined first test voltage and a second record pattern as a result of driving of the actuator by application of a second test voltage different from the first test voltage,so that the first record pattern and the second record pattern are superposed on each other; and judging whether or not the first test voltage is proper as the operating driving voltage, based on an appearance of a superposed pattern formed by superposition of the first pattern and the second pattern on each other, wherein the first record pattern is composed of a plurality of dots which are formed by ejection of the ink droplets, and the second record pattern is composed of a plurality of dots which are formed by ejection of the ink droplets and which respectively correspond to the dots of the first record pattern constituting the first record pattern, wherein the first record pattern and the second record pattern are set such that an appearance of the superposed pattern changes depending upon a change in a positional relationship between each of the dots of the first record pattern and a position of each of the dots of the second record pattern which respectively correspond to the dots of the first record pattern, and a change in the positional relationship depends on a difference between the first test voltage and the second test voltage, and wherein at least one of a degree of superposition and a degree of separation by which the dots of the first record pattern and the corresponding dots of the second record pattern are superposed on each other and separated away from each other, respectively, changes depending upon the difference between the first test voltage and the second test voltage, whereby the first record pattern and the second record pattern are set such that the appearance of the superposed pattern changes depending upon a change in a tone of the superposed pattern.