Alignment apparatus
First Claim
1. An apparatus for aligning two objects in a predetermined relationship using alignment marks, comprising:
- means for producing a beam used to illuminate the alignment marks;
means for detecting an area on which the beam impinges;
means for effecting scanning by relative movement between the beam and the alignment marks;
means for sequentially converting analog data produced by said detecting means in accordance with the scanning to digital data at predetermined intervals, while the scanning is being effected; and
means for processing the digital data from said converting means to align the two objects, wherein said processing means includes a first memory for storing data corresponding to a peak of the analog data among the digital data of said converting means upon completion of the scanning deflection.
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Accused Products
Abstract
An alignment apparatus includes an illumination source for illuminating an object having a mark, a photoreceptor for receiving light reflected by the object, a converter for digitizing the output signal level of the photoreceptor, a circuit for determining a slice level on the basis of the data digitized by said converter, a device for comparing the digitized data and the slice level to extract a signal relating to the mark and determining the interval between the mark and a reference, and a device for causing relative movement between the object having the mark and the object having the reference mark to place them into alignment with each other.
12 Citations
9 Claims
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1. An apparatus for aligning two objects in a predetermined relationship using alignment marks, comprising:
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means for producing a beam used to illuminate the alignment marks; means for detecting an area on which the beam impinges; means for effecting scanning by relative movement between the beam and the alignment marks; means for sequentially converting analog data produced by said detecting means in accordance with the scanning to digital data at predetermined intervals, while the scanning is being effected; and means for processing the digital data from said converting means to align the two objects, wherein said processing means includes a first memory for storing data corresponding to a peak of the analog data among the digital data of said converting means upon completion of the scanning deflection. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification