Design of small-caliber dual-channel dome screen projection lens

To improve the image quality of dome screen projection, a scheme of dual-channel projection for dome screen was designed.And based on the scheme, a dual-channel dome projection lens for 3.05 cm (1.2 inch) projector with 3-digital micromirror devices (DMD) chip technique was designed.According to the projection scheme, the design indices were determined, the initial structure selection was analyzed reasonably, the optical design process was expounded, and the optimization of the aberration and the evaluation of the design result were given.To avoid the barycentre instability problem caused by the lens aperture being too large, the aperture of the first lens of the lens was greatly compressed by reasonably controlling the incident height of the light, and the final aperture is only 102 mm. The image quality of the designed dome dual-channel projection lens is high and uniform, its F^# is 2.5, the inverted-telephoto ratio is 6:1, the modulation transfer function (MTF) of 1.0 field-of-view(FOV) is 0.5 at the Nyquist frequency of 38 lp/mm, the MTF within 0.85 FOV is above 0.65, and the maximal chromatic aberration is 4.7 μm, less than 0.5 pixel.