A spatial imaging system includes a variable focus lens for scanning a visual field. The depth of field of the lens system is narrow relative to the range of the field to be scanned so that visual in-focus image planes of the entire field can be obtained as the focal plane is scanned in range. Detection...http://www.google.com.tw/patents/US4584704?utm_source=gb-gplus-share專利 US4584704 - Spatial imaging system
