| 摘要 |
PURPOSE: A finder with a variable magnifying power is provided to improve the assemblability by constructing an optical system having a variable 3-power over. CONSTITUTION: An object lens group comprises a first lens(10) having a positive refractive index, a second lens(20) having a negative refractive index, a third lens(30) having a positive refractive index, and fourth lens(40) having a positive refractive index. An eye lens group is comprised of a fifth lens(50) having a positive refractive index. The first lens(10) functions as a cover glass of a finder. The second lens(20) and the third lens(30) are installed so as to be moved for adjusting a magnifying power of an image. The third lens(30) moves between the second lens(20) and the fourth lens(40) to adjust the magnifying power. An image passing the first lens(10) is formed as an inverted real image around the fourth lens(40). |
