Patent · US Expired

Plastic container sorting system and method

US5443164A · kind A · utility

84Cited by
18References
17Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 10, 1993
Grant dateAug 22, 1995
Priority date
Expiry dateAug 10, 2013

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S209/938
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A plastic container sorter (10) moves labeled plastic containers (14, 20, 48, 54, 58) of various colors and transparencies through an inspection zone (18). A pair of line-scanning color cameras (22, 24) capture respective transmittance and reflectance images of the containers and generate raw transmittance and reflectance image data. The raw container data are digitized, normalized, and binarized to provide accurate transmittance and reflectance container RGB image data and binarized image data for differentiating container image data from background data. Container sorting entails eroding (120) the binarized transmittance image and merging (122) the eroded image with the transmittance image data to yield a transmittance image. The eroded transmittance image is analyzed (124, 126) to determine whether the container is opaque. If the container is opaque, color analysis proceeds by analyzing the reflectance image data. If, however, the container is not opaque, transmittance image data are used to classify the container as green transparent (140), translucent (142), or clear transparent (142). Classified containers are transferred to an ejection conveyor (46). Side discharge of a clas…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.