Color contrast gauge
US3998556A · kind A · utility
2Cited by
2References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 23, 1975 |
| Grant date | Dec 21, 1976 |
| Priority date | — |
| Expiry date | Jun 23, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2019/06225
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A color contrast gauge to determine and test the proper contrast of a light background to a darker machine-readable symbol printed thereon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.