SHORT-FOCUS LENS Russian patent published in 2010 - IPC G02B9/28 

FIELD: physics.

SUBSTANCE: short-focus lens can be used together with matrix photodetectors. The lens has three lens components. The first component is a single negative meniscus whose convex side faces the object. The second component is a positive lens made from a positive meniscus glued to a biconvex lens. The third component is a positive lens made from a biconvex lens glued to a negative meniscus. The single meniscus can be made from glass having refraction index n_℮<1.50 and dispersion coefficient v_℮>85.

EFFECT: higher aperture ratio with good image quality.

2 cl, 1 dwg, 2 tbl