| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact zoom lens for projection of high performance, capable of projecting an image from a light modulator comprising a plurality of elements producing an image by changing the light reflecting direction such as a DMD(digital mirror device), onto a screen. SOLUTION: In this zoom lens, a first lens group G1 of negative refracting power, and a second lens group G2 of positive refracting power are successively arranged from a side of a screen 9, and an outer diameter LD of the final lens closest to a DMD(digital mirror device) 2, of the second lens group G2 and a back focus Bfw on a wide angle end of the zoom lens for projection satisfy an expression: 0.3<LD/Bfw<0.5. At least one surface of the final lens L25 is aspherical, whereby the compact projector lens of long back focus, superior in the aberration performance with the small number of lens (9 sheets of lens) can be realized, regardless of a small diameter of the final lens.
|
