Plastic container sorting system and method

In a plastic container sorter a method of acquiring and processing image data, comprising the steps of:

• receiving transmittance and reflectance image data representative of the plastic container;
• processing the transmittance data to determine whether the plastic container is one of substantially transparent, substantially translucent, and substantially opaque;
• processing the reflectance data if the plastic container is substantially opaque to determine a reflected color of the plastic container;
• and
• processing the transmittance data further if the plastic container is one of substantially transparent and substantially translucent to determine whether the plastic container is a substantially green transmitted color.

A plastic container sorting apparatus, comprising:

• a presentation conveyor moving the plastic containers through an inspection zone;
• an illumination light source illuminating the plastic containers in the inspection zone to provide a source of reflected light;
• a first video camera receiving the reflected light from the plastic containers and generating a stream of reflectance image data;
• a background light source having a white light diffuser and a glare shield, the white light diffuser providing a source of background light that is transmitted through the plastic containers, and the glare shield preventing stray light from the background light source from being detected by the first video camera;
• a second video camera having a transmittance scanning plane that terminates on the white light diffuser such that the second video camera receives the light transmitted through the plastic containers and generates a stream of transmittance image data;
• a reflectance image data processor normalizing and binarizing the stream of reflectance image data to classify the plastic containers into color categories in response to the reflectance image data;
• and
• a transmittance image data processor normalizing and binarizing the stream of transmittance image data to classify the plastic containers into opacity categories in response to the transmittance image data.

A plastic container sorting apparatus, comprising:

• a presentation conveyor moving the plastic containers through an inspection zone;
• an illumination light source illuminating the plastic containers in the inspection zone to provide a source of reflected light;
• a first video camera receiving the reflected light from the plastic containers and generating a stream of reflectance image data;
• a background light source having a white light diffuser providing a source of background light that is transmitted through the plastic containers;
• a second video camera having a transmittance scanning plane that terminates on the white light diffuser such that the second video camera receives the light transmitted through the plastic containers and generates a stream of transmittance image data;
• a reflectance image data processor normalizing and binarizing the stream of reflectance image data to classify the plastic containers into color categories in response to the reflectance image data;
• and
• a transmittance image data processor normalizing and binarizing the stream of transmittance image data to classify the plastic containers into opacity categories in response to the transmittance image data.

A plastic container sorting apparatus, comprising:

• a presentation conveyor moving the plastic containers through an inspection zone;
• a pair of scanning cameras generating respective reflectance and transmittance image data streams in response to light received from the plastic containers in the inspection zone, the reflectance image data including container profile data;
• a processor classifying the plastic containers into sorting categories in response to the transmittance and reflectance image data streams;
• a substantially smooth surfaced ejection conveyor moving at a rate, receiving the plastic containers from the inspection zone, and conveying the plastic containers to predetermined locations adjacent to the ejection conveyor, each of the predetermined locations being associated with one or more of the sorting categories;
• and
• a photoelectric sensor positioned adjacent to at least one of the predetermined locations, the sensor generating a container tracking signal that the processor processes together with the rate and the container profile data to eject particular classified ones of the plastic containers from the predetermined location by directing an air ejector blast at a central portion of the particular classified ones of the plastic containers.