| 摘要 |
PROBLEM TO BE SOLVED: To make usable an eye point height-variable lens barrel which is suitable for the microscope of a finite correction optical system and has a simple structure by arranging a projection optical system projecting the image forming position of a final image unmagnifiedly without forming an intermediate image in a position far from an objective lens. SOLUTION: The projection optical system 8 is formed of a front group 8a and a back group 8b having positive refraction power and both groups are joint lenses. An intermediate image is not formed after luminous flux is emitted from an image transmission optical system 7 until it passes through the projection optical system 8 and is made incident on an eyepiece 11 through an eye point height variable lens barrel 9. It is desirable that the magnification of the projection optical system 8 is almost unmagnified. Thus, the eye point height variable lens barrel 9 with a simple structure can be used by incorporating the projection optical system 8. Thus, a prism whose cost is generally high can be used in common and the inexpensive observation lens barrel can be supplied to a user with the reduction of development cost.
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