Method and apparatus for examining objects

Apparatus for operating on a plurality of objects comprising:

• conveyor means for conveying objects to be operated on through an inspection station, said conveyor means having a floor for supporting a plurality of objects across the width of the conveyor means and for moving with said objects to carry said objects through said inspection station with a plurality of objects disposed across the width of said conveyor means;
• means for illuminating the objects at the inspection station with electromagnetic radiation incident predominantly from a first direction transverse to the width of the conveyor means;
• a radiation detector for observing the objects along a second direction also transverse to the width of the conveyor means to detect radiation reflected by the objects;
• said direction of said observation being inclined to said direction of said illumination at an angle such that said detector does not observe any portion of said floor which is illuminated by said illuminating means;
• there being provided in association with either the illuminating means or the radiation detector, or with both, means for effecting a scanning operation across the width of the conveyor to provide from the detector a detection signal representing different reflected radiation from different regions along the path of scanning and for repeating the scanning operation to provide a series of scans across the objects;
• means for processing the detection signal to provide an information signal representative of a dimensional parameter of the size of the objects;
• and
• means for operating upon the objects by action dependent upon the information signal.

A method of sorting a plurality of objects, comprising the steps of:

• arranging the objects on a conveyor means with a plurality of objects across the width of the conveyor means transverse to the direction of movement of the conveyor means;
• illuminating the objects with electro-magnetic radiation incident predominantly from a first direction;
• observing the objects by a radiation detector along a second direction inclined to the first direction to detect radiation reflected by the objects;
• the illuminating and/or detecting steps including a scanning operation across the objects along a path transverse to the two said directions to provide from the detector a detection signal representing different reflected radiation from different regions along the path of scanning;
• producing relative movement between the objects and the path of scanning along a direction transverse to the path of scanning and repeating the scanning operation to provide a series of scans across the objects;
• processing the detection signal to provide an information signal representatives of a dimensional parameter of the objects;
• inspecting the objects and generating identifying signals identifying objects to be rejected;
• moving the objects to a plurality of routing devices positioned in an array transverse relative to the direction of travel of the conveyor means;
• operating selected groups of the routing devices to allow rejected objects to fall past the operated routing devices to a reject route of travel while acceptable objects are guided by unoperated routing devices to a non-reject route of travel;
• the method including the step of operating a group of routing devices in dependence upon both an identifying signal identifying an object to be rejected and an information signal representative of a dimensional parameter of a linear dimension of the object transverse to the direction of travel of the conveyor means, the information signal being provided by said processing step.

A method of operating on a plurality of objects comprising the steps of:

• arranging the objects on a conveyor means with a plurality of objects across the width of the conveyor means;
• moving the objects on the conveyor means through an inspection station;
• illuminating a plurality of objects at the inspection station with electromagnetic radiation incident predominantly from a first direction transverse to the width of the conveyor means;
• observing an illuminated surface of the object by a radiation detector along a second direction inclined to the first direction to detect radiation reflected by the object, the object having a boundary presented against a background which is dark relative to the illuminated surface, the illuminated boundary extending around a portion of the outer perimeter of the object;
• the illuminating and/or detecting steps including a scanning operation across the objects transverse to the direction of movement of the conveyor means to provide from the detector a detection signal representing different reflected radiation from different regions along the path of scanning, the path of scanning being such that the radiation detector observes the illuminated boundary on two sides of the illuminated portion of the object;
• repeating the scanning operation to provide a series of scans across the objects;
• processing the detection signal to derive an information signal representative of said illuminated boundary of the object including obtaining information from one scan in which the illuminated boundary is detected substantially at grazing incidence, and deriving information as to the separation between a point at which the radiation detector detects an illuminated boundary substantially at grazing incidence, and an approximate center line of the object, to give information as to approximately half the width of the object transverse to the line scan.

Apparatus for sorting objects comprising:

• conveyor means for conveying objects through an inspection area in an arrangement with a plurality of objects positioned across the width of the conveyor means transverse to the direction of movement of the conveyor means;
• selection means for generating identifying signals identifying the objects to be rejected after selection of the objects by an operator inspecting the objects at the inspection area;
• means for illuminating the objects with electromagnetic radiation incident predominantly from a first detection;
• a radiation detector for observing the objects along a second direction inclined to the first direction to detect radiation reflected by the object;
• there being provided in association with either the illuminating means or the radiation detector, or with both, means for effecting a scanning operation across the objects along a path transverse to the two said directions to provide from the detector a detection signal representing different reflected radiation from different regions along the path of scanning;
• said conveyor means producing relative movement between the object and the path of scanning along a direction transverse to the path of scanning, and said scanning means being arranged to repeat the scanning operation to provide a series of scans across the object;
• means for processing the detection signal to provide an information signal representative of a dimensional parameter of the objects;
• a plurality of routing devices positioned downstream of the inspection area in an array transverse relative to the direction of travel of the conveyor means;
• means for operating selected groups of the routing devices to allow rejected objects to fall past the operated routing devices to a non-reject route of travel;
• the operating means being arranged to operate a group of routing devices in dependence upon both an identifying signal identifying an object to be rejected and an information signal representative of a dimensional parameter of the object, the dimensional parameter consisting of a linear dimension of the object transverse to the direction of travel of the conveyor means, and the information signal being provided by said processing means.

Apparatus for operating on a plurality of objects comprising:

• conveyor means for conveying the objects through an inspection station in an arrangement with a plurality of objects across the width of the conveyor means;
• means for illuminating the objects at the inspection station with electromagnetic radiation incident predominantly from a first direction transverse to the width of the conveyor means;
• a radiation detector for observing the objects along a second direction also transverse to the width of the conveyor means and inclined to the first direction to detect radiation reflected by the objects, said illuminating means and detector being arranged so that an illuminating surface of an object is presented to the detector against a background which is dark relative to the illuminated surface, the illuminated boundary extending around a portion of the outer perimeter of the object;
• there being provided in association with either the illuminating means or the radiation detector, or with both, means for effecting a scanning operation across the width of the conveyor to provide from the detector a detection signal representing different reflected radiation from different regions along a path of scanning which observes the illuminated boundary on two sides of the illuminated portion, said illuminating means and detector being arranged so that the radiation detector obtains information from one scan in which the illuminated boundary is detected substantially at grazing incidence and for repeating the scanning operation to provide a series of scans across the objects to derive information as to the separation between a point at which the radiation detector detects an illuminated boundary substantially at grazing incidence, and an approximate center line of the object, to give information as to approximately half the width of the object transverse to the line scans;
• means for processing the detection signal to derive an information signal representative of said illuminated boundary of the object;
• and
• means for operating upon the objects by action dependent upon the information signal.