Angular, azimuthal and displacement insensitive spectrophotometer for color printer color control systems
US6633382B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 22, 2001 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Aug 2, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J3/513
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved and lower cost color spectrophotometer, especially suitable for an on-line color printer color control system, in which plural different spectra LEDs sequentially perpendicularly illuminate a common and substantially circularly illuminated color test area, which may be variably spaced and variably oriented relative to the spectrophotometer, through a common central lens system, and also the reflected illumination therefrom may be measured at 45 degrees thereto by averaging the outputs of photodetectors spaced around that circularly illuminated color test area, to provide reduced sensitivity to the variable angular or azimuthal orientation of the color test area relative to the spectrophotometer, and which photodetectors may be so illuminated by 1:1 optics for spatial insensitivity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.