PROJECTION OPTICAL SYSTEM AND PROJECTION TYPE IMAGE DISPLAY DEVICE

Japanese Patent JP2016133756

A

PROBLEM TO BE SOLVED: To provide a projection optical system that is adaptable to high luminance and high resolution and can achieve a large angle of view.SOLUTION: A projection optical system 40 comprises, successively from an enlargement side, a first lens group to an n-th lens group, where n is 6 or 7. The first lens group G1 includes, successively from the enlargement side, a first-1 lens group G1-1 and a first-2 lens group G1-2. The distance between the group G1-1 and the group G1-2 is variable for correcting an image plane. Upon varying a power, groups from the second lens group G2 to the n-1-th lens group Gn-1 are moved while the first lens group G1 and the n-th lens group Gn are fixed, and a conditional expression 2