Patent ID: 7963624
Filing Date: 2011-06-21
Classification: B41J

Abstract:
1. A printing apparatus that performs printing to a conveyed printing medium, said apparatus comprising: a plurality of rollers operable individually or in combination to convey the printing medium along a conveying path in at least first, second and third conveying phases; forming means for forming, on the printing medium, a test pattern used for detecting a conveying error for each of the plurality of rollers; acquiring means for acquiring, using the test pattern, a correction value for correcting the conveying error; conveying correction means operable during the first conveying phase and the second conveying phase to employ the correction value for at least one roller involved in the conveying among the plurality of rollers to correct the conveying errors in the first conveying phase and the second conveying phase, and operable during the third conveying phase that are different from the first conveying phase and the second conveying phase in a combination of rollers involved in the conveying of the first conveying phase and the second conveying phase to employ the correction value for at least one roller involved in the conveying of the third conveying phase from among the plurality of rollers to correct conveying errors in the third conveying phase, wherein the correction value includes a first correction value for correcting a conveying error that depends on the eccentricity of each of the plurality of rollers, the first correction value being associated with the rotational angle of the roller from a reference position, and a second correction value for correcting a conveying error that depends on the outer diameter of the roller, and said acquiring means acquires the first correction value based on the test pattern and then acquires the second correction value based on the first correction value and the test pattern.