| 摘要 |
PURPOSE:To eliminate the need of switching objective lenses and to facilitate the alteration of an observation magnification by using objective lenses as a fixed objective lens with a fixed magnification and independently providing variable power optical systems for altering an observation magnification. CONSTITUTION:The observing optical device has an observing optical system which variably magnifies the observation image of an object to be tested R into a prescribed magnification with the aid of observation light transmitting the object to be tested R and forms an image. The observing optical system is provided with objective lens systems 3 and 5 with fixed magnifications and variable power optical systems 9 and 11 variably magnifying the observation image caught by the objective lens 3. Since the objective lens 3 is one with a fixed magnification, it is not switched, but the magnification is changed by the independently provided variable power optical systems when the observation magnification is changed. Consequently, sliding part related to objective lens switching is eliminated, dust soiling the object R to be tested is hardly produced, and the troublesome adjustment in the case of altering the magnification is eliminated. |
