Abstract: A projection display apparatus includes a light valve, a light source for producing light directed to the light valve, an integrator lens disposed in an optical path extending from the light source to the light valve and including a first lens array and a second lens array, and a light amount adjustment mechanism disposed in the optical path between the first lens array and the second lens array. The light amount adjusting mechanism includes a pair of light shielding elements pivoting in the form of a pair of double doors. The pair of light shielding elements have an opening formed in a region of tip portions thereof which corresponds to lens cells in contact with the optical axis of the second lens array. A region of the opening corresponding to one lens cell in contact with the optical axis of the second lens array is of a triangular configuration.