摘要 |
A portable projection device can be implemented as a personal gaming system and can also be configured as a portable, fully integrated video gaming system that allows gamers to plug in and play at nearly any location, with only a wall or other viewing surface being used to view the projected image. In one aspect, the portable projection device comprises a housing, a handle, and an optical engine. The optical engine comprises an illumination source, an imaging system, and a wide angle projection lens that includes a first lens group (G1) of negative power, a second lens group (G2), and a third lens group (G3) of positive power. For the wide angle projection lens, the following inequalities (1) to (4) are satisfied: |F 1 /F|‰¥4.5 (condition (1)); 2.5‰¤|F 2 /F|‰¤6.0 (condition (2)); 3.8‰¤|F 3 /F|‰¤5.0 (condition (3)); and 0.8‰¤BFL/F‰¤1.4 (condition (4)). |