Position measurement technique
AssigneeCanon Kabushiki Kaisha
InventorNozomu Hayashi
Life of this patent
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Abstract
A position measurement apparatus for measuring a position of a mark includes an image capturing unit, a calculating unit which obtains variation in image data captured by the image capturing unit, and a setting unit which sets a parameter concerning a light receiving amount of the image capturing unit based on variations respectively obtained by the calculating unit with respect to a plurality of image data acquired by the image capturing unit at different light receiving amounts.
Claims27
A position measurement apparatus for measuring a position of a mark, said apparatus comprising:
- an image capturing unit configured to capture an image of the mark;
- a calculator configured to calculate variation in image data captured by said image capturing unit;
- and
- a controller configured to set a parameter concerning a light amount to be received by said image capturing unit, based on variations respectively calculated by said calculator with respect to a plurality of image data acquired by said image capturing unit at light amounts received by said image capturing unit, the light amounts being different from each other.
A position measurement method of measuring a position of a mark, said method comprising steps of:
- capturing an image of the mark using an image capturing unit;
- calculating a variation of image data acquired in said capturing step;
- and
- setting a parameter concerning a light amount to be received by the image capturing unit, based on variations respectively calculated in said calculating step with respect to a plurality of image data acquired in said capturing step at light amounts received by the image capturing unit, the light amounts being different from each other.
Dependencies are inferred from the claim text.