Étendue-density homogenization lamps with light concentration function

— In order to increase the screen brightness of Digital Micromirror Device™ projectors (DMD™ projectors), we designed a new compact lamp. In our previous work, we discussed a lamp that has an aspherical lamp reflector and an aspherical front glass, which we called EHLa. Although EHLas improve the light convergence at the entrance of rod integrators, they require external lenses for light condensation. We, therefore, discuss a new EHLa that can converge light without the need for external lenses. The new lamp corresponds to conventional elliptic reflector-type lamps, which are widely used for mobile-type DMD™ projectors. Our simulations demonstrated that the ratio of increased brightness is 17.1% for the new lamp design versus conventional lamps in a 0.7-in.-diagonal DDR DMD™ panel.