Patent ID: 9707583
Date: 2017-07-18
CPC Classifications: B05B,B05C,B41J,G01B

Claim:
1. A method to detect substrate alignment during a printing process, the method comprising: providing a printing apparatus comprising at least one apparatus polarization area; providing at least one substrate comprising at least one substrate polarization area, wherein the at least one substrate polarization area comprises a filter that generates polarized light by filtering light passing through the filter, and wherein the at least one substrate polarization area polarizes light in a different manner from the at least one apparatus polarization area; aligning the at least one substrate on the printing apparatus such that the at least one apparatus polarization area and the at least one substrate polarization area overlap to form at least one alignment area; generating the polarized light by directing light at the at least one alignment area; printing at least one pattern on the at least one substrate using the printing apparatus; and monitoring at least one characteristic associated with the polarized light during the printing of the at least one pattern, wherein a variation in the at least one characteristic is indicative of a misalignment between the at least one substrate and the printing apparatus.