Apparatus and methods for optically monitoring thickness
First Claim
1. An apparatus for monitoring thickness variations of an object having first and second opposing surfaces, the apparatus comprising:
- a first source positioned to project a first fringe pattern at a first location on the first surface;
a second source positioned to project a second fringe pattern at a first location on the second surface;
a first detector positioned to detect the first fringe pattern at the first location on the first surface, the first detector generating a first signal in response to the first fringe pattern at the first location;
a second detector positioned to detect the second fringe pattern at the first location on the second surface, the second detector generating a second signal in response to the second fringe pattern at the first location;
a processor adapted to calculate variations in the thickness of the object in response to the first and the second signals; and
a control system locating the first and second fringe patterns to second locations on the first and second surfaces, respectively, the first and second detectors generating third and fourth signals, respectively in response to the first and second fringe patterns at the second locations, the processor adapted to calculate variations in the thickness of the object in response to the first, second, third and fourth signals.
2 Assignments
0 Petitions
Accused Products
Abstract
In one aspect, the invention relates to an apparatus for monitoring thickness variations of an object having first and second opposing surfaces. The apparatus includes a first source positioned to project a first fringe pattern at a first location on the first surface and a second source positioned to project a second fringe pattern at a first location on the second surface. The apparatus further includes a first detector positioned to detect the first fringe pattern at the first location on the first surface, the first detector generating a first signal in response to the first fringe pattern at the first location. The apparatus also includes a second detector positioned to detect the second fringe pattern at the first location on the second surface, the second detector generating a second signal in response to the second fringe pattern at the first location. The apparatus further includes a processor adapted to calculate variations in the thickness of the object in response to the first and the second signals.
85 Citations
22 Claims
-
1. An apparatus for monitoring thickness variations of an object having first and second opposing surfaces, the apparatus comprising:
-
a first source positioned to project a first fringe pattern at a first location on the first surface;
a second source positioned to project a second fringe pattern at a first location on the second surface;
a first detector positioned to detect the first fringe pattern at the first location on the first surface, the first detector generating a first signal in response to the first fringe pattern at the first location;
a second detector positioned to detect the second fringe pattern at the first location on the second surface, the second detector generating a second signal in response to the second fringe pattern at the first location;
a processor adapted to calculate variations in the thickness of the object in response to the first and the second signals; and
a control system locating the first and second fringe patterns to second locations on the first and second surfaces, respectively, the first and second detectors generating third and fourth signals, respectively in response to the first and second fringe patterns at the second locations, the processor adapted to calculate variations in the thickness of the object in response to the first, second, third and fourth signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method for monitoring thickness variations of an object having first and second opposing surfaces, the method comprising the steps of:
-
illuminating the first surface with radiation from a first source to produce a first fringe pattern at a first location on the first surface;
illuminating the second surface with radiation from a second source to produce a second fringe pattern at a first location on the second surface;
detecting the first and second fringe patterns at the first locations on the first and second surfaces, respectively;
moving the first and second fringe patterns to second locations on the first and second surfaces, respectively;
detecting the first and second fringe patterns at the second locations on the first and second surfaces, respectively; and
calculating variations in the thickness of the object in response to a comparison between the first and second fringe patterns at the first locations, and the first and second fringe patterns at the second locations. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. An apparatus for monitoring the flatness of an object having a surface, the apparatus comprising:
-
a source positioned to project a fringe pattern at a first location on the surface;
a detector positioned to detect the fringe pattern at the first location on the surface;
wherein the detector generates a first signal in response to the fringe pattern at the first location;
a processor adapted to monitor variations in the flatness of the object in response to the first signal; and
a control system for locating the fringe pattern at a second location on the surface, wherein the detector generates a second signal in response to the fringe pattern at the second location and the processor is adapted to monitor variations in the flatness of the object in response to the first and second signals.
-
-
18. A method for monitoring variations in the flatness of an object having a surface, the method including the steps of:
-
illuminating the surface with radiation from a source to produce a fringe pattern at a first location on the surface of the object;
detecting the fringe pattern at the first location on the surface of the object;
monitoring the variations in the flatness of the object in response to the detected fringe pattern at the first location on the surface;
moving the fringe pattern to a second location on the surface, detecting the fringe pattern at the second location on the surface, and monitoring the variations in the flatness of the object in response to a comparison between the fringe pattern at the first location, and the fringe pattern at the second location. - View Dependent Claims (19, 20, 21, 22)
-
Specification