WORKPIECE HOLDER AND METHOD USING SAME FOR DETECTING LATERAL DISPLACEMENT OF WORKPIECE
First Claim
1. A workpiece holding apparatus, which is configured to hold a workpiece with an adhesive pad mounted on a support plate, the workpiece holding apparatus comprising:
- a capacitance measuring device comprising an electrode pair formed of first and second electrodes and arranged at least at a part of a position corresponding to a peripheral edge portion of the workpiece, the capacitance measuring device being configured to measure capacitance of the electrode pair; and
a comparator circuit configured to compare the measured capacitance with a predetermined reference value, to thereby detect lateral displacement of the workpiece in a planar direction of the support plate.
1 Assignment
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Accused Products
Abstract
Provided are a workpiece holding apparatus capable of detecting lateral displacement of a workpiece (w) in a planar direction, and a method of detecting lateral displacement of a workpiece (w) with use of the workpiece holding apparatus. The workpiece holding apparatus, which is configured to hold the workpiece (w), with an adhesive pad (2) mounted on a support plate, includes: a capacitance measuring device (5) including an electrode pair formed of first and second electrodes (3a, 3b) and arranged at least at a part of a position corresponding to a peripheral edge portion of the workpiece (w), the capacitance measuring device (5) being configured to measure capacitance of the electrode pair; and a comparator circuit (6) configured to compare the measured capacitance with a predetermined reference value, to thereby detect lateral displacement of the workpiece (w) in a planar direction of the support plate (1). Further, the method of detecting lateral displacement of a workpiece (w) includes comparing the capacitance input to the comparator circuit (6) with a predetermined reference value, to thereby detect the lateral displacement of the workpiece (w).
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Citations
9 Claims
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1. A workpiece holding apparatus, which is configured to hold a workpiece with an adhesive pad mounted on a support plate, the workpiece holding apparatus comprising:
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a capacitance measuring device comprising an electrode pair formed of first and second electrodes and arranged at least at a part of a position corresponding to a peripheral edge portion of the workpiece, the capacitance measuring device being configured to measure capacitance of the electrode pair; and a comparator circuit configured to compare the measured capacitance with a predetermined reference value, to thereby detect lateral displacement of the workpiece in a planar direction of the support plate. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of detecting lateral displacement of a workpiece in a planar direction of a support plate in a workpiece holding apparatus configured to hold the workpiece with an adhesive pad mounted on the support plate,
the workpiece holding apparatus comprising: -
a capacitance measuring device comprising an electrode pair formed of first and second electrodes and arranged at least at a part of a position corresponding to a peripheral edge portion of the workpiece, the capacitance measuring device being configured to measure capacitance of the electrode pair; and a comparator circuit configured to input the measured capacitance, the method comprising comparing the capacitance input to the comparator circuit with a predetermined reference value, to thereby detect the lateral displacement of the workpiece. - View Dependent Claims (9)
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Specification