Observation apparatus with focal position control mechanism

Abstract

The invention provides an observation apparatus with focal position control mechanism. An AF device for a microscope has an observation optical system (6) having a CCD (imaging element)(5) for emitting, through one of interchangeable objective lenses (2), illumination light to an object (3) to be observed and observing reflection light from the object (3); a projection section (7) for emitting a laser beam (invisible light) to the object (3) through the objective lens (2) of the observation optical system (6); a focus point detection optical system (10) having a photodetector (photoelectric conversion section) (8) that is disposed on an image plane of an optical image of laser beam reflected by the object (3) and outputs a signal depending on the position, in the image plane, of the optical image and detecting a relative distance between the objective lens (2) and the object (3); an object position adjustment means (11) for adjusting a focus position of the object (3) based on the output signal from the focus detection optical system (10); and a restriction means (12) for regulating the area of projection of the laser beam into the imaging area of the CCD (5).

Description

technical field [0001] The invention relates to an observation device with a focus position control mechanism. [0002] This application claims priority based on Japanese Patent Application No. 2004-269669 filed in Japan on September 16, 2004, the content of which is incorporated herein by reference. Background technique [0003] Until now, observation devices such as microscopes capable of observing fine test materials as objects or recording observed images as video images have been widely used in inspection processes ranging from research in the biological field to industrial fields. In the case of using such a microscope, focus adjustment for observing a test material is usually performed by operating a focus handle to perform focusing work. However, in a case where the depth of focus is shallow and the focus range is narrow, as with a high-magnification objective lens, considerable skill is required to quickly perform focusing operations. [0004] When the operability...

AI Technical Summary

Problems solved by technology

[0012] However, in the above-mentioned conventional observation apparatus with a focus position control mechanism, since calculation processing is performed on all light spot projection signals reflected from the subject, there is a problem of a desired focus range such as being out of the imaging range. Influenced by the height difference or reflectivity of the outer pattern, but the focus position in the range that really wants to focus is shifted

Therefore, in the case of a device that performs defect inspection, it is difficult to accurately grasp the defect

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