US 4,378,494 A · Apparatus and method for detecting defects in glass bottles using event proximity

Abstract

An apparatus and a method for identifying defects in objects, such as glass bottles, utilizing data signals generated from a photodiode camera and light source. Event signals are generated when the magnitudes of adjacent data signals differ by an amount which exceeds a threshold level. Signals are also generated to identify the location of each event signal with respect to a corresponding photodiode and to identify during which vertical sweep of the object the event signal was generated to associate the event signal with a point on the object. The event signals are processed to identify defects. Events in proximity in the same sweep are identified as a string. Event magnitudes and totals in a string are compared with predetermined values to identify defects. Strings in proximity are identified as a blob. Event magnitudes and totals and blob width are compared with predetermined values to identify defects.

Claims32

Dependent claims

An inspection device in an apparatus for detecting defects in successive objects and for providing a plurality of pixel signals each representing the magnitude of light received from a corresponding point on an object, said inspection device comprising:

an interface means responsive to the pixel signals for comparing successive adjacent pixel signals and generating an event signal when said comparison indicates the presence of a defect, said interface means storing a readable group of characteristic signals representing the total number of event signals generated by a corresponding object, each characteristic signal including a first signal indicating the magnitude of a corresponding event signal and a second signal indicating the location of the point on the object from which the event signal is generated;
and
first and second control means respectively responsive to successive groups of characteristic signals corresponding to successive objects for processing said characteristic signals and providing a reject signal to discard the corresponding object when one of said first and second control means indicates that a rejectable defect is present.

an interface means responsive to successive adjacent pixel signals for generating an event signal when the absolute-value of the difference between the magnitude of adjacent pixel signals exceeds a predetermined threshold value associated with the location of a corresponding point on the object, said interface means storing a readable group of characteristic signals representing the total number of event signals generated by a corresponding object, each characteristic signal including a first signal indicating the magnitude of the corresponding events signal and a second signal indicating the location of the point on the object from which the event signal is generated;
and
first and second control means respectively responsive to successive groups of characteristic signals corresponding to successive objects for processing said characteristic signals and providing a reject signal to discard the corresponding object when one of said first and second control means indicates that a rejectable defect is present.

an interface means responsive to the pixel signals for comparing successive adjacent pixel signals and generating an event signal when said comparison indicates the presence of a defect, said interface means storing a readable group of characteristic signals representing the total number of event signals generated by a corresponding object, each characteristic signal including a first signal indicating the magnitude of a corresponding event signal and a second signal indicating the location of the point on the object from which the event signal is generated;
first and second control means respectively responsive to successive groups of characteristic signals corresponding to successive objects for processing said characteristic signals and providing a reject signal to discard the corresponding object when one of said first and second control means indicates that a rejectable defect is present;
and
a master control means connected to said first and second control means for alternately connecting one of said first and second control means to said interface means so that one reads a group of said characteristic signals for one object while the other processes a group of said characteristic signals for a preceding object.

1 more element

A method for detecting defects in an object being inspected by an apparatus providing a plurality of pixel signals each representing the magnitude of light received from a corresponding point on an object, comprising the steps of:

(a) generating an event signal when the absolute value of the difference between the magnitudes of adjacent pixel signals exceeds a predetermined threshold value associated with the location of a corresponding point on the object indicating the presence of a defect at that point;
(b) storing a readable group of characteristic signals representing the total number of event signals generated by a corresponding object, each characteristic signal including a first signal indicating the magnitude of a corresponding event signal and a second signal indicating the location of the point on the object from which the event signal is generated;
(c) processing a group of characteristic signals to identify the presence of a defect in a corresponding object;
and
(d) providing a reject signal to discard the object when a rejectable defect is identified.

2 more elements

Dependencies are inferred from the claim text.

Apparatus and method for detecting defects in glass bottles using event proximity

Life of this patent

Apparatus and method for detecting defects in glass bottles using event proximity

Life of this patent

Abstract

Claims32