Projection zoom lens system and projection type display apparatus

A projection zoom lens system comprising, in order from a magnification side:

• a first lens group having a negative refractive power;
• a second lens group having a positive refractive power;
• a third lens group having a positive refractive power;
• a fourth lens group having a positive refractive power;
• and
• a fifth lens group having a positive refractive power,
• wherein
• the first lens group has an aspheric surface,
• a lens closest to the magnification side in the fourth lens group has an aspheric surface, and
• the fifth lens group consists of one positive lens,
• wherein
• during zooming, the first and fifth lens groups remain stationary, while the second, third, and fourth lens groups are movable respectively, and
• during zooming from a wide-angle end to a telephoto end, the second, third, and fourth lens groups moves toward the magnification side along an optical axis, and
• wherein the following conditional expression (1) is satisfied:
• 0.8<d34/fw (1),
• where
• fw denotes a focal length of the whole system at the wide-angle end, and
• d34 denotes an air space between the third lens group and the fourth lens group at the wide-angle end.