| 摘要 |
A compact projection lens for a cathode ray tube having a field angle as great as 73 DEG which may utilize only three lens elements where the first lens element from the image side has two aspheric surfaces in the shape of an overall meniscus which goes from positive optical power at the optical axis to relatively strong negative optical power at the limit of the clear aperture of the lens. The spacing between the first and second lens elements is chosen to aid in contributing to correction of field curvature.
|
