Techniques for print ink droplet measurement and control to deposit fluids within precise tolerances

摘要

An ink printing process employs per-nozzle droplet volume measurement and processing software that plans droplet combinations to reach specific aggregate ink fills per target region, guaranteeing compliance with minimum and maximum ink fills set by specification. In various embodiments, different droplet combinations are produced through different printhead/substrate scan offsets, offsets between printheads, the use of different nozzle drive waveforms, and/or other techniques. These combinations can be based on repeated, rapid droplet measurements that develop understandings for each nozzle of means and spreads for expected droplet volume, velocity and trajectory, with combinations of droplets being planned based on these statistical parameters. Optionally, random fill variation can be introduced so as to mitigate Mura effects in a finished display device. The disclosed techniques have many possible applications.

主权项

1. A method of producing a permanent thin film in target regions of a substrate using an ink jet printer having a print head with nozzles, the nozzles to eject respective droplets of ink, the ink carrying a material that will form the permanent thin film, the method comprising:
using a droplet measurement device to individually measure a parameter of each one of multiple droplets from each one of the nozzles of the print head, the parameter free to vary from droplet-to-droplet, to develop a statistical population of measurements for each nozzle representing droplets ejected from that nozzle; assigning an expected value of the parameter to each nozzle based on a respective one of the statistical populations; depositing ink droplets via the ink jet printer in the target regions in a manner that utilizes combinations of droplets from different ones of the nozzles, the combinations respective to the target regions, each combination selected by at least one processor to include droplets from one or more nozzles dependent on the assigned expected values, in a manner to obtain an expected aggregate volume for each of the target regions that is restricted to lie within a predefined volume tolerance range for the target region, wherein droplets associated with at least some of the combinations are concurrently deposited from respective nozzles of the print head; and processing the deposited ink to solidify the deposited ink.