Retrofocus lens system and projection display apparatus

A projection display apparatus comprising:

• a light source for emitting light;
• a light valve for two-dimensionally modulating the light from said light source;
• and
• a retrofocus lens system for projecting at a magnification the light modulated by said light valve;
• wherein said retrofocus lens system comprising, in order from a large conjugate side:
• a first lens group having a negative refracting power;
• a second lens group having a positive refracting power;
• and
• a third lens group having a positive refracting power;
• said first lens group including, in order from the large conjugate side, a first lens from which projection light is sent out, a meniscus-shaped second lens which has a negative refracting power and. a convex surface facing the large conjugate side, a third lens having a negative refracting power, and a fourth lens;
• said second lens group including a fifth lens having a positive refracting power;
• said third lens group including, in order from the large conjugate side, a sixth lens having a negative refracting power, both surfaces of which are concave, a seventh lens having a positive refracting power, both surfaces of which are convex, said seventh lens being joined with said sixth lens, an eighth lens having a positive refracting power, both surfaces of which are convex, and a ninth lens having a positive axial refracting power;
• wherein said retrofocus lens system satisfies the following conditional expressions (1) to (4):
• 1.23<f2/f3<1.8 (1)
• 1.5<|f1|/f<2.7 (2)
• |f4|/f>30 (3)
• f5/f>6 (4)
• where f is a focal distance of the whole lens system, |f1| is an absolute value of a focal distance of said first lens group, f2 is a focal distance of said second lens group, f3 is a focal distance of said third lens group, |f4| is an absolute value of a focal distance of said first lens, and f5 is an axial focal distance of said ninth lens;
• wherein said first lens has an aspherical surface, and said ninth lens has an aspherical surface.