Abstract:
A shadowless illumination system (10) according to the present invention includes a spherical chamber (14) having a chamber entrance opening (18) and a chamber exit opening (20). The inside surface (32) of the spherical chamber is coated with highly reflective flat white paint. A clear rigid plastic cylindrical tube (22) is positioned in the spherical chamber between the chamber entrance and exit openings. A circular fluorescent ring lamp (36) is positioned inside the spherical chamber to form an annulus around the tube. The lamp and the white inside surface of the spherical chamber provide shadowless illumination for articles (30) that are dropped or otherwise projected through the tube. The articles are inspected as they pass through the tube by at least two video inspection cameras (52 and 62) that view opposite sides of the articles through respective viewing openings (44 and 48). Whenever no articles are present in the image plane of a camera, the lamp provides a saturated background for the camera. A ballast (140) controls the voltage to the lamp to provide constant light intensity.
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 classified container is effected by an air ejector (64) blast that is timed in response to sensing a particular container adjacent to an appropriate side discharge station (60).
Abstract:
A sorting apparatus according to the present invention includes a conveyor belt having a solid translucent sheet segment for carrying a stream of randomly-arranged articles, ones of which are translucent and others of which are opaque. Preferably, the translucent articles are pieces of post-consumer plastic products (e.g., beverage containers) and the opaque articles are foreign matter, such as aluminum or polypropylene container tops or caps of the beverage containers. The conveyor belt carries multiple articles simultaneously through an inspection zone. A background light source is positioned in the inspection zone opposite the translucent sheet segment from the articles to direct light through the translucent sheet segment toward the articles. A video camera is positioned to receive light from the background light source transmitted through the translucent sheet segment and translucent ones of the articles. The opaque ones of the articles prevent light from the background light source from reaching the video camera. The video camera generates a video signal from which a system processor identifies the opaque articles and activates a separator to remove the opaque articles from the stream of articles.
Abstract:
A detectable cutter knife (100) is useful as a replacement for a conventional cutter knife (12) used in product inspection and cutting systems (2) of the type having a cutting wheel assembly (10). The cutting wheel assembly (10) includes a knife guide (14) having angularly spaced radially oriented knife support slots (16) through which cutter knives (12, 100) having tangs extending therefrom move between a retracted noncutting position and an extended cutting position. The detectable cutter knife (100) includes a shank (102), a tang (114), and an amount of metallic material in the shank sufficient to stimulate a metal detector (13). The use of metallic material in the shank permits automatic and efficient detection of a broken cutter knife (100) and its removal from product flow (7). Preferably, the metallic material takes the form of a ball bearing (152) secured within a hole (150) positioned in a low-stress area (154) of shank (102).
Abstract:
A stabilizing system (12, 14, 112, 112b, 262) stabilizes articles carried on conveyors for automated bulk processing equipment. In a preferred embodiment, a flow of gas (64, 118b, 278) (e.g., air) is projected along a conveyor belt (18, 18a, 18b, 18c) in a direction generally parallel to that in which articles are carried by the belt. The air flow has a velocity (i.e., speed and direction) substantially the same as that of the belt to reduce aerodynamic resistance that would otherwise bear against the articles. As a result, the articles may be transported on the conveyor belt at high speeds with substantially increased stability or throughput.
Abstract:
A color line scan video camera (50) for inspecting articles (18) includes a prismatic beam splitter arrangement (52) that receives a wide spectrum of visible light from a variable magnification objective lens arrangement (54) to provide improved multi-color inspection capability. The prismatic beam splitter separates the light received from the scanned articles into three preselected spectral bands of light, each of which is imaged upon a different charge-coupled device line scan sensor that generates a corresponding color component video signal. The light transmission characteristics of the lens are "color-corrected" to transmit uniformly the light received from the scanned articles.