Method and apparatus for reducing strip effect caused by printers
US5995715A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1996 |
| Grant date | Nov 30, 1999 |
| Priority date | — |
| Expiry date | May 31, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/2132
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for printing images wherein printing of individual dots is controlled by employing binary masks. M different complementary binary masks each having the form of a matrix of points occupying N rows and P columns are defined in such a manner that each of the N.times.P elements of a mask has a first binary value or a second binary value, each point of the matrix corresponding to an element having the first binary value in one mask and in one mask only. Each portion of the image is printed in M passes of the print head while using the M different masks in succession, such that during each pass, the print head scans a strip of the print medium, the same mask being used repetitively for each group of P columns and N rows, an image dot being released for printing during a pass when the corresponding element of the mask has the first binary value. The masks used are of sufficiently large dimensions to avoid perceptible repetitive patterns appearing, the elements having the first binary value being distributed therein in a manner that is pseudo-random and substantially uniform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.