| 摘要 |
Eyepiece optical systems having arrangements of surfaces where light is refracted or diffracted provide eyepieces with fewer elements and more compact designs than comparable, conventional eyepiece designs. These eyepiece optical systems have three elements each with positive focussing power, and provide a wide field-of-view of about 70 DEG and an eye relief of approximately 80% of the total focal length of the eyepiece. One embodiment has (from the eye side) a refracting, meniscus, positive element with a surface concave toward the eye, a bi-convex element having a refracting convex surface and a second refracting convex surface, and a refractive/diffractive doublet element with a refracting convex surface and diffracting surface (each element being of positive power). Another embodiment, from the eye side has a first diffractive/refractive doublet having a diffracting surface and a convex refracting surface, an equi-convex element having two refracting convex surfaces and a second refracting/diffracting element having a diffracting surface and a convex refracting surface.
|
