Automatic calibration of drop-on-demand ink jet ejector.

摘要

A method of calibrating a scanning carriage drop-on-demand ink jet ejector (1) wherein the ejector is traversed past a droplet detection light beam while droplets are ejected. By knowing the position of the ejector and relating it to the amount of light blocked by droplets, horizontal errors in drop position can be detected. Similarly, by measuring the amount of time elapsing between droplet ejection and droplet detection, the velocity of the droplets can be determined. Corrections can be made by adjusting the time of ejection and/orthe drive pulse amplitude and/or width.