Patent ID: 7532402

Claim:
An imaging device for imaging a long object, comprising at least one front vertical cylinder lens device which concentrates light from the long object in a vertical direction being transverse to a horizontal direction, which is parallel to a longitudinal axis of the long object, and a plurality of lens elements arranged in matrix form in at least one lens row behind the vertical cylinder lens device in a propagation direction being an axis of light propagation through the imaging device and being transverse to the horizontal direction and the vertical direction, wherein each of the lens elements concentrates light from the long object in the horizontal direction, wherein each of the plurality of lens elements includes at least one horizontal collecting layer transparent to the light from the long object and having a refractive index which has a gradient in the horizontal direction and no gradient in the vertical direction; and wherein an optical thickness in the propagation direction of the at least one transparent horizontal collecting layer for each of the lens elements is selected to generate an image that has the same orientation as the long object after passing through the at least one transparent horizontal collecting layer.