Patent ID: 7993017
Filing Date: 2011-08-09
Classification: G03B,H04N

Abstract:
1. A projection display apparatus in an xyz coordinate system with a z-axis coincident with an optical axis, an x-axis orthogonal to the z-axis, and a y-axis orthogonal to the z-axis and the y-axis, the optical axis forming the origin of the xy plane, the projection display apparatus having: a light source section for emitting light; a first lens array with convex lenses the shape of which, on a first plane orthogonal to the z-axis, is rectangular with long sides in the x-axis direction and short sides in the y-axis direction, arranged in an array with a plurality of rows and a plurality of columns on the first plane, for uniformizing an illuminance distribution of the light emitted from the light source section; a second lens array with convex lenses the shape of which, on a second plane orthogonal to the z-axis, is rectangular with long sides in the x-axis direction and short sides in the y-axis direction, arranged in an array with a plurality of rows and a plurality of columns on the second plane, disposed in a position, spaced apart from the first lens array, such that the individual convex lenses of the first lens array face the individual convex lenses of the second lens array, for uniformizing the illuminance distribution of the light transmitted through the first lens array; a light valve for receiving the light transmitted through the second lens array and outputting light modulated according to an image signal; a projection optical system for projecting the light output from the light valve onto a screen; and a light quantity adjusting means disposed between the first lens array and the second lens array for adjusting a quantity of the light received by the light valve; wherein the light quantity adjusting means comprises one pair or a plurality of pairs of light blocking members for blocking light in transit from the first lens array to the second lens array, one pair or a plurality of pairs of rotational axes for turnably supporting each of the light blocking members on the xy plane, a turning mechanism for turning the light blocking members, and a turning control unit for controlling operations of the turning mechanism; wherein, of the one pair or the plurality of pairs of light blocking members, the light blocking members constituting each pair have xy coordinates that are symmetric with respect to the origin; wherein, of the one pair or the plurality of pairs of rotational axes, the rotational axes constituting each pair have xy coordinates that are symmetric with respect to the origin; and wherein the light blocking members and the rotational axes are positioned so that when the light blocking members are turned in a direction that increases the quantity of light blocked by the light blocking members, the turning range from a light blocking initiation position of the light blocking members at which the light blocking members, by being turned, start to block light in transit toward the second lens array to a maximum light blocking position of the light blocking members at which the light blocking members block a maximum quantity of the light in transit toward the second lens array is equal to or less than ninety degrees, and the light blocking members and the rotational axes are positioned so that when the light blocking members are at the light blocking initiation position, at least part of each light blocking member is on the x-axis or the y-axis.