Image recording device and image recording method

An image recording device having a conveyance mechanism for generating conveyance information about a record medium when the record medium is conveyed after received upstream from a conveyance path, and a plurality of recording units, each of which is provided with at least one nozzle array formed by a plurality of nozzles in a direction orthogonal to a direction of conveyance of the record medium, at predetermined intervals in a direction of conveyance so as to discharge ink by driving the plurality of nozzles of each recording unit, thereby performing a recording process on the record medium, comprising at least:

• an encoder signal cycle measuring device for measuring an encoder signal cycle as the conveyance information about the record medium;
• a first nozzle drive cycle replacement device for replacing a nozzle drive cycle with a set cycle when the encoder signal cycle measured by the encoder signal cycle measuring device is shorter than the predetermined set cycle;
• a second nozzle drive cycle replacement device for replacing a predetermined period of the nozzle drive cycle with an optimum cycle between the set cycle and the measured encoder signal cycle when the encoder signal cycle measured by the encoder signal cycle measuring device changes from a point at which the cycle is shorter than the predetermined set cycle to a point at which the cycle is longer than the predetermined set cycle;
• and
• a third nozzle drive cycle replacement device for controlling timing of discharge drive of the nozzle arrays subordinate to the recording unit downstream in the direction of conveyance depending on an image position recorded by the nozzle arrays subordinate to the recording unit upstream in the direction of conveyance of the record medium.