Method of accurately measuring control film density regions
US6223585A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 1998 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Dec 21, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03D13/002
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of accurately measuring control film density regions comprising: exposing a photosensitive film to a modulated laser beam at three known laser beam intensities representing maximum, midrange and minimum intensities to form corresponding separate sequential density regions in said film having maximum density D.sub.max, midrange D.sub.min and minimum density D.sub.min, using a densitometer, taking a first set of density readings of said maximum density region of said film, taking a second set of density readings of said midrange density region of said film, and taking a third set of readings of said minimum density region of said film; wherein said density readings are sequentially taken as said film is moved past said densitometer; and as a first try, determining D.sub.max as the average of a subset of said first set of density readings which are taken in the control portion of said maximum density region; determining D.sub.min as a preselected value; and determining D.sub.mid =D.sub.min +a(D.sub.max -D.sub.min) where a is a fraction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.