Patent ID: 7645009

Claim:
A printing system that creates dots on a printing medium in the course of a main scan and thereby prints an image, said printing system comprising: a print head including a plurality of nozzles, each nozzle being configured to create n variable dots (where n is an integer of not less than 2), which at least partly include dots of an identical ink but different ink quantities, in response to driving signals so as to print an image on a printing medium; a memory configured to store output timings of n driving signals corresponding to the n variable dots, which are to be created by each nozzle, to adjust positional misalignments of the n variable dots; a driving signal output unit configured to output at least part of the n driving signals to said print head in the course of the main scan, according to dots to be created in respective pixels; a timing adjustment unit configured to individually adjust the output timings stored in said memory with regard to each of the n variable dots in advance execution of printing based on instructions by a user; a test pattern printing unit configured to print a predetermined test pattern, which is set to enable detection of a relative positional misalignment of dots created under different printing conditions, with regard to each of the n variable dots; an inter-dot comparison pattern printing unit configured to print predetermined patterns, in each of which dots created under different printing conditions are mixed, with regard to at least two variable dots of interest creatable by said print head, in a specific arrangement that enables mutual comparison; and a selecting instruction input unit configured to input a selecting instruction to select a specific dot among the at least two variable dots of interest, which are subjected to printing by said inter-dot comparison pattern printing unit, wherein said test pattern printing unit prints the predetermined test pattern with regard to the selected specific dot, and wherein said timing adjustment unit adjusts the output timing based on a relation to a printed result of the predetermined test pattern.