Patent ID: 7850311

Claim:
A mobile media station comprising: a cart; a screen attachable to the cart; and a projection display device disposed on the cart to provide an image to the screen, the device comprising: a projection module to project the image; and a docking station to receive the projection module, wherein the projection module comprises an optical engine comprising an illumination system, an imaging system, and a wide angle projection lens, wherein the optical engine outputs an image at a half field angle of at least 45° and wherein the image has substantially no distortion and requires substantially no keystone correction, and further wherein the wide-angle projection lens comprises the following components in sequential order from a screen side: a first lens group of negative refractive power, the first lens group having at least one aspheric surface; a second lens group of substantially zero refractive power and wherein an aperture stop lies within or near the second lens group; and a third lens group of positive refractive power, wherein the following Conditions (1) to (3) are satisfied: | F 1 /F|< 4.0 Condition (1) | F 2 /F|> 50 Condition (2) | F 3 /F|< 3.5 Condition (3) where F is the focal length of the wide-angle projection lens; F 1 is the focal length of the first lens group; F 2 is the focal length of the second lens group; and F 3 is the focal length of the third lens group.