Development of Wide Angle Fovea Lens for High-Definition Imager Over 3 Mega Pixels

Abstract

This paper presents a high-quality wide-angle fovea lens, i.e., the WAF lens, for the autonomous robot's and vehicle's super-sensing vision system. The WAF lens is well-known in the field of robotic vision with respect to its unique design concept, biologically-inspired from a visual system of the primates. The WAF lens achieves the following two conflicting properties in imaging simultaneously: (1) wide field of view (FOV) and (2) high magnification factor (although only the central FOV achieves it partially). In this paper, the authors designs the WAF lens for the high-resolution photosensitive imaging chip more than 3M pixels. For this design, we decide the following targets on the assumption of applying this WAF lens for the stereo vision system: (1) The WAF lens can measure a very far distance over 100m ahead from the imager accurately. (2) The WAF lens can observe approximately 100-degree wide FOV on the same time. We produce a prototype of this WAF lens with much higher optical performance than our previous developments. The compound system of the prototype includes four aspherical surfaces in its front part to project enough bright images so that the WAF lens is available not only at daytime but also in dark situations at night. The authors experiment and demonstrate the projection tests using the prototype, and discuss about the results as the inspection of this challenging development.