Method and apparatus for sorting objects by color including stable color transformation
US5533628A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 19, 1994 |
| Grant date | Jul 9, 1996 |
| Priority date | — |
| Expiry date | Aug 19, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S209/939
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A color sorting apparatus has a singulator section, a color sorter and a conveyor which drops the sorted objects into appropriate collection bins. Objects for sorting are transported on an endless conveyor on wheels through the singulation and color sorting section. An independently adjustable speed belt rotates in the same direction as the wheels and operates to provide a view of each of four sides of the object to an imaging device. The imaging device, such as a camera, supplies red, green and blue signals to an image processor which performs a color transformation and obtains a single composite hue value for each object or piece of fruit to be sorted. Based on a comparison of the hue value to user programmed grading criteria, signals are provided to the conveyor so that the objects are ultimately deposited in appropriate sorting bins. The apparatus also provides one or more of color calibration with respect to predetermined color standard references, a dynamic color calibration, a fine tuning adjustment, color correction based on size, shape measurement and a hue value transformation that provides a stable hue value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.