Method and apparatus for measuring assembly and alignment errors in sensor assemblies
First Claim
1. A target for measuring assembly and alignment errors in a multi-segment sensor assembly, the target comprising:
- a) a background;
b) at least two marks that contrast with the background, each mark positioned such that it can be detected by only one segment of the multi-segment sensor assembly; and
c) an operative vertical edge on each mark.
2 Assignments
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Accused Products
Abstract
A target, method, and apparatus are disclosed for measuring assembly and alignment errors in scanner sensor assemblies. The sensor assembly comprises at least two sensor segments. The target comprises edges defined by changes in reflectance. At least one vertical edge corresponds to each sensor segment, and can be detected only by its corresponding segment, even when the segments are misaligned to the maximum extent of their placement tolerances. The target may optionally comprise a horizontal edge spanning the sensor segments. The target is scanned, and the resulting digital image is analyzed to detect the apparent locations of the target edges. The apparent edge locations provide sufficient information to locate the sensor segments. The target may optionally be incorporated into a scanner, or into a separate alignment fixture. The analysis may be performed in a scanner, in a fixture, or in a host computer attached to a scanner or a fixture.
112 Citations
14 Claims
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1. A target for measuring assembly and alignment errors in a multi-segment sensor assembly, the target comprising:
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a) a background;
b) at least two marks that contrast with the background, each mark positioned such that it can be detected by only one segment of the multi-segment sensor assembly; and
c) an operative vertical edge on each mark. - View Dependent Claims (2)
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3. A target for measuring assembly and alignment errors in a multi-segment sensor assembly, the target comprising:
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a) a background; and
b) a set of edges defined by areas contrasting with the background, the edges including;
i. at least one horizontal edge spanning, substantially parallel to a main scanning direction, an area to be scanned by the sensor assembly; and
ii. at least one vertical edge for each sensor assembly segment, each vertical edge generally perpendicular to the main scanning direction and positioned so that it may be detected by only one sensor assembly segment. - View Dependent Claims (4)
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5. A method of measuring assembly and alignment errors in a multi-segment sensor assembly, the method comprising the steps of:
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a) scanning a target using a multi-segment sensor assembly, the target comprising at least one operative vertical edge for each sensor segment, the operative vertical edges positioned such that each edge can be detected by only one sensor segment;
b) creating a digital image of the target;
c) analyzing the digital image to detect the apparent locations of the target edges; and
d) computing locations of the sensor segments from the apparent target edge locations. - View Dependent Claims (6, 7, 8)
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9. A scanner, comprising:
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a) a multi-segment sensor assembly;
b) a target comprising at least one operative vertical edge for each sensor segment, the operative vertical edges positioned such that each edge can be detected by only one sensor segment; and
c) a microprocessor programmed to perform the following method;
i. scanning the target;
ii. creating a digital image of the target;
iii. analyzing the digital image to detect the apparent locations of the target edges; and
iv. computing locations of the sensor segments from the apparent target edge locations.
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10. A fixture for characterizing a multi-segment sensor assembly, comprising:
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a) a target comprising at least one operative vertical edge for each sensor segment, the operative vertical edges positioned such that each edge can be detected by only one sensor segment; and
b) a computer programmed to perform the following method;
i. scanning the target;
ii. creating a digital image of the target;
iii. analyzing the digital image to detect the apparent locations of the target edges; and
iv. computing locations of the sensor segments from the apparent target edge locations. - View Dependent Claims (11)
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12. A system, comprising:
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a) a scanner comprising;
i. a multi-segment sensor assembly; and
ii. a target comprising at least one operative vertical edge for each sensor segment, the operative vertical edges positioned such that each edge can be detected by only one sensor segment; and
b) a computer;
the system programmed to perform the following method;
i. scanning the target;
ii. creating a digital image of the target;
iii. analyzing the digital image to detect the apparent locations of the target edges; and
iv. computing locations of the sensor segments from the apparent target edge locations.
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13. A scanner, comprising:
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a) a multi-segment sensor assembly;
b) a target comprising at least one operative vertical edge for each segment of the multi-segment sensor assembly, each operative vertical edge detectable by only one sensor segment;
c) means for scanning the target with the multi-segment sensor assembly and creating a digital image;
d) means for analyzing the digital image to detect the apparent locations of the target edges; and
e) means for computing the positions of the sensor segments from the apparent locations of the target edges. - View Dependent Claims (14)
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Specification