In this paper, a new structure of horizontal parallax light field 3D floating image display system was proposed. The structure consists of pico-projectors, Fresnel lens, micro-lens array and sub-lens array with freeform shape. By the functions of optical components, each light field of projectors could be controlled as a fan ray, which has high directivity in horizontal and wide scattered angle in vertical. Furthermore, according to the reverse light tracing and integral image display technique, horizontal parallax floating 3D could be demonstrated in the system. Simulated results show that the proposed 3D display structure has a good image quality and the crosstalk is also limited below 22.9%. Compared with other 3D technologies, this structure could have more benefits, including displaying real high resolution floating image, unnecessary of physical hardware on the image plane, scalability of large size system, without the noise from spinning component, and so on.
The optical design of projection zoom lens by using special surfaces, such as aspherical surface and grin lens are presented in this paper. The techniques to approach the special design from all-spherical design are described. The results show that the use of grin lens and glass modeling asphere can effectively reduce the element number and the image quality is kept meanwhile.
A 3-5 µm zoom lens system is designed with four moving components. Even though the optical system is designed to provide high resolution throughout the 4:1 zoom range, it is still compact. A special optimization method is used for finding the cam solution of the zoom lens . The polynomial equations from the optimization method are used for fitting zoom run during the optimization process. This method can minimize the cam sensitivity at the start of the first order design. The concept to achieve aberration balance is described. The detail design was accomplished through the use of a computer optimization program. A cam modification procedure is used to compensate the image shift after the final design. The one mrad image resolution requirement is achieved throughout the zoom range.