| 摘要 |
Projection lenses for use with pixelized panels (PP) are provided. The projection lenses have first and second lens units (U 1 ,U 2 ), with the first lens unit having a negative power and the second lens unit having a positive power. The first lens unit has a first lens element (L 1 ) having a generally meniscus shape and a second lens element (L 2 ) having a biconcave shape when its surface configurations are described by best fit spherical surfaces. The second lens element (L 2 ) has an Abbe number (v<SUB>L2</SUB>) which is (a) less than or equal to 55 and (b) less than the Abbe number (V<SUB>L1</SUB>) of the first lens element (L 1 ). The second lens element (L 2 ) also has an optical power (phi<SUB>L2/0.7CA</SUB>) at 0.7 of the clear aperture of its short conjugate surface which is negative and has a magnitude which is greater than the second lens element's on-axis optical power (phi<SUB>L2</SUB>). This combination of lens shapes, Abbe numbers, and optical powers provides higher order lateral color correction without the need for abnormal partial dispersion glasses.
|
