Patent ID: 8485626

Claim:
An image forming device comprising: an endless transport belt in which a plurality of through holes are formed, the transport belt circulating to carry sheets; a recording head with a plurality of nozzles through which ink droplets are discharged, the nozzles being arranged in a width direction of the transport belt; a sensor that detects at least one element to be detected formed on the transport belt when the transport belt circulates; and means for calculating a detected time difference between a time at which a first one of the elements to be detected is detected by the sensor and a time at which an adjacent, second one of the elements to be detected is detected by the sensor, controlling timings of discharge, in a preliminary discharge, of ink droplets from the nozzles into the through holes located in an area delimited between the first and second ones of the elements to be detected, based on a calculated difference between the detected time difference and an expected time difference, and based on distances of the through holes from the first one of the elements to be detected in a longitudinal direction of the transport belt, and performing the preliminary discharge of ink droplets through the nozzles into the through holes at the timings.