ABSTRACT
A new stray light analysis method and some suppression principles of panoramic annular lens (PAL) are introduced in this paper. The proposed method is to find stray light paths which are caused by ray splitting on two refractive surfaces of the PAL block and then cut them off. Following this principle, the stray light paths can be eliminated in the design progress by adding specific merit functions into the optical software. The methods to reduce scatter, diffraction and other stray light are also proposed. A new PAL with a field of view (FOV) of 30° ~ 100° × 360° is designed. The stray light is suppressed more than 80% compared with a similar conventional PAL. The stray light path analysis method also can be used in other catadioptric optics.
Subject(s)
Algorithms , Artifacts , Computer-Aided Design , Lenses , Models, Theoretical , Computer Simulation , Equipment Design , Equipment Failure AnalysisABSTRACT
A novel panoramic stereo imaging system with double panoramic annular lenses (PAL) is introduced in this paper. The proposed system consists of two coaxial PAL units and images on one sensor. The imaging rings are concentric. The object position can be calculated by triangulation. The novelty of this system is that the central blind zone of one PAL unit is partly used by the other as an image zone. The stereo field of view is 60°~105° × 360°. The depth extracting resolution is about 500 mm at 1line/cm. The F# of the system is about 3, facilitating the system to be applied in low illumination environment. A design is presented and the depth extracting precision is analyzed.
Subject(s)
Image Enhancement/instrumentation , Imaging, Three-Dimensional/instrumentation , Lenses , Photogrammetry/instrumentation , Computer-Aided Design , Equipment Design , Equipment Failure AnalysisABSTRACT
A new method to improve the design of the panoramic annular lens (PAL) optical system with long focus is introduced. Cemented lenses are used in a PAL block to improve the design freedom. A multilayer diffractive optical element (MDOE) is used in relay optics to simplify the structure of the system and to increase diffractive efficiency of the design spectral range. The diffractive efficiency of MDOE in a wide spectral range is investigated theoretically. A seven piece PAL system with a total effective focal length of 10.8 mm is realized, and the diffractive efficiency of the whole design wavelength is above 99.3%. A PAL system with all spherical surfaces is described as a comparison.
