Patent attributes
A projection display apparatus for expanding and projecting an image, which is formed by an optical modulator, using a projection lens. A light source illuminates the optical modulator. A first lens array divides light emitted from the light source into a plurality of partial luminous fluxes. A second lens array superimposes the plurality of partial luminous fluxes emitted from the first lens array onto the optical modulator. A diaphragm mechanism is disposed between the light source and the optical modulator, and controls an amount of light from the light source. A traveling direction of the light emitted from the light source is defined as a Z-axis, a direction perpendicular to the Z-axis is defined as an X-axis, and a direction perpendicular to a plane formed by the Z-axis and the X-axis is defined as a Y-axis. An area of an opening of the diaphragm mechanism changes in a direction of the X-axis or the Y-axis.
