Patent US 4,584,704

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 of in-focus objects may be accomplished by converting the scanned image of each plane into electrical signals which can be filtered or otherwise discriminated to identify in-focus areas. The individual image planes may be stored in memory and processed to provide information of interest regarding the objects within the field of view. Such information may include identification, detection, color, shape, etc. and it exists in machine-usable form.