Image measuring apparatus

An image measuring apparatus comprising:

• a table on which a workpiece is placed;
• an imaging section including a low-magnification optical system comprising a low-magnification imaging element that images the workpiece at a low magnification to generate a low-magnification image, and a high-magnification optical system that has an optical axis which is coaxial with a same optical axis of the low-magnification optical system, the high-magnification optical system comprising a high-magnification imaging element that images the workpiece at a magnification higher than the low magnification to generate a high-magnification image;
• a driving section that changes an imaging position of the imaging section by driving at least one of the table and the imaging section such that the table and the imaging section relatively move in an XY direction;
• a processor that controls the driving section and the imaging section and generates a plurality of low-magnification images and high-magnification images for different portions of the workpiece;
• an image connecting section that generates a connected image by connecting the generated at least one low-magnification image of the plurality of low-magnification images and at least one high-magnification image of the plurality of high-magnification images;
• and
• a memory that stores the connected image and position correction information for correcting a relation between a position of the low-magnification image generated by the low-magnification imaging element and a position of the high-magnification image generated by the high-magnification imaging element,
• wherein, before a setting mode and a measurement mode, the processor corrects a coordinate of the low-magnification image and the high-magnification image based on the position correction information,
• wherein, in the setting mode, the processor stores in the memory a reference image for pattern search generated by imaging by the imaging section at least a part of the connected image or a position designated by a user in the connected image, measurement location information including position information indicating a relative relation of a plurality of measurement locations designated by the user in the connected image to a coordinate of the reference image, and imaging setting information indicating at which magnification of the low magnification and the high magnification each imaging position is imaged and at which focal position each imaging position is imaged, and,
• in the measurement mode, the processor
• controls the imaging section and acquires a target image for pattern search,
• executes a pattern search on the target image for pattern search using the reference image for pattern search stored in the memory,
• specifies a plurality of imaging positions for imaging each of the plurality of measurement locations based on the measurement location information associated with both of the coordinate of the reference image for pattern search and each of the plurality of measurement locations stored in the memory, and a result of the pattern search,
• generates the low-magnification image and the high-magnification image by causing the driving section to drive at least one of the table and the imaging section to sequentially set an imaging position of the imaging section to each of the plurality of imaging positions and by causing the imaging section to perform imaging at the magnification and the focal position according to the imaging setting information at each of the plurality of imaging positions, and
• measures, for a measurement location corresponding to each imaging position, a dimension of the measurement location based on the low-magnification image and the high-magnification image acquired for each of the plurality of imaging positions and a dimension of an edge extracted from the high-magnification image and an edge extracted from the low-magnification image with the coordinate of the high-magnification image and the low-magnification image corrected by the processor.