Envelope reflectance meter evaluating print contrast
US5157253A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1990 |
| Grant date | Oct 20, 1992 |
| Priority date | — |
| Expiry date | Sep 20, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/12753
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An envelope reflectance meter for evaluating the contrast between ink on a pre-printed envelope and the envelope itself and for calculating and displaying the print contrast ratio and the print reflectance difference is described. The device includes a portable housing having internally a pair of light sources which generate a reflected image of the envelope. The image passes through a lens, is reflected from a mirror, and is then displayed on a viewplate. An aperture is provided in the viewplate which passes a beam of light. The beam of light is then split and the two beams resulting analyzed for red content and green content. The analog signal produced is then converted to digital and the print contrast ratio and print reflectance difference calculated. A display is provided within the housing adjacent the viewplate whereby selectively the values for red light and for green light and comparisons between the readings for ink and the readings for the envelope are selectively displayed for an operator.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.