| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an autofocus device focusing an object lens to an arbitrary position of a sample and continuing tracking the sample. <P>SOLUTION: An autofocus device 1 has: an illumination optical system for focusing 5 radiating a slit image (a projection image) of a slit plate 22 on a specimen 18 through a first object lens 12; an image formation optical system for focusing 7 for receiving reflection light of the projection image from the specimen 18 through the first object lens 12 and carrying out image formation of the reflection image of this projection image; a CCD sensor for autofocusing 30 for detecting this reflection image; an adjusting lens for focal position 8 for moving a focal position of at least one of the projection image and the reflection image in the optical axis direction; and a signal processor for autofocus signal 31 for outputting a signal for controlling an action of a focus actuator. In this case, an adjustable diaphragm 2 is provided to at least one of the illumination optical system for focusing 5 and the image formation optical system for focusing 7 and a numerical aperture for the illumination light for focusing or a numerical aperture for the reflection light for focusing is varied. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
