Fiber optic solder joint inspection system
First Claim
1. A method for determining the shape of an object having a specular surface comprising the steps of:
- (a) projecting sequentially toward the object the light from each of a plurality of point light sources which are arranged in a fixed configuration about a common site at which the object is placed for inspection;
(b) viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface;
(c) interpreting the light patterns to determine the surface orientation of points on the object surface; and
(d) reconstructing the object surface profile using the surface orientations of points on the object.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention is an automated solder joint inspection system for determining the quality of a specular soldered joint through examination of the shape of the joint surface using a series of point light sources and the associated highlight reflections from the joint surface. The light from the point light sources, which is directed toward the solder joint, is reflected in a pattern from the solder joint to an array of light responsive transducers, such as a camera, at a fixed location. Utilizing the intensity values from the light responsive transducer array, a binary grid map is generated for the reflections from each point light source. Using known surface features of solder joints along with curve fitting techniques, a series of grid maps may be mathematically interpreted to reconstruct the solder joint surface. A rule-based system, through comparison with acceptable solder joint surface features, evaluates and classifies the joint for an acceptability determination.
86 Citations
17 Claims
-
1. A method for determining the shape of an object having a specular surface comprising the steps of:
-
(a) projecting sequentially toward the object the light from each of a plurality of point light sources which are arranged in a fixed configuration about a common site at which the object is placed for inspection; (b) viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface; (c) interpreting the light patterns to determine the surface orientation of points on the object surface; and (d) reconstructing the object surface profile using the surface orientations of points on the object. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A non-contact inspection apparatus for determining the shape of an object having a specular surface comprising:
-
(a) an array of point light sources spaced apart from one another in a fixed configuration about a common site at which the object is placed for inspection; (b) means for sequentially projecting each of the point light sources for emitting light toward the object; (c) a means for viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface; (d) a means for interpreting the light patterns to determine the surface orientation of points on the object; and (e) a means for reconstructing the object surface profile using the surface orientation of points on the object. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
-
-
16. A non-contact inspection apparatus for determining the shape of an object having specular surfaces comprising:
-
(a) an array of point light sources spaced apart from one another in a fixed hemispherical configuration about a common site at which the object is placed for inspection; (b) means for sequentially activating each of the point light sources for emitting light toward the object; (c) means for detect the variety of light patterns caused by the reflections of light from each point light source at each location from the object surface; (d) means for interpret the series of light patterns to determine the surface orientation of points on the object; and (e) means for reconstruct the object profile using the surface orientation of a variety of points on the object.
-
-
17. A method for determining the shape of an object having a specular surface comprising the steps of:
-
(a) projecting sequentially toward the object the light from each of a plurality of point light sources which are arranged in a fixed hemispherical configuration about a common site at which the object is placed for inspection; (b) means for viewing the object at the common site to detect light patterns caused by the reflections of light of each point light source from the object surface wherein viewing the object at the common site is done from a single direction at a fixed location; (c) interpreting the light patterns to determine the surface orientation of points on the object surface; and (d) reconstructing the object surface profile using the surface orientations of points on the object.
-
Specification