Automatic alignment of print heads
US6297888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1998 |
| Grant date | Oct 2, 2001 |
| Priority date | — |
| Expiry date | May 4, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J29/393
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Improved techniques for measuring misalignment between multiple print heads, or between forward and reverse printing for the same print head. Adverse effects of ink bleeding, paper cockling and other ink ejection effects are reduced by superimposingly printed alignment patterns in which less than all pixels of printed portions of the patterns are filled in. Carriage ringing and overshoot effects are reduced by printing the alignment patterns in multiple passes, and preferably with an offset in carriage starting location for each pass. Improved detection of darkest density regions of the superimposingly printed alignment pattern is obtained through detections based on differences between densities rather than absolute values of measured densities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.