Imaging device containing an electrooptic material to adjust the effective focal length of a lens element

摘要

A first substrate (2) carries an array (3) of imaging elements (4). An array (5) of lens elements (6) is provided with each lens element (6) associated with at least one imaging element (4) for concentrating light (L) travelling on a light path between the imaging element (4) and the at least one lens element (6). An electro-optic material (8) having an electrically alterable refractive index is provided in a space defined between a second substrate (7) and one of the imaging element and the lens element arrays (3 and 5). Electrodes (8a,8b) are provided for applying an electrical potential across the electro-optic material (8) to adjust the effective focal length of the lens elements (6). The focal length of the lens elements (6) can thus be adjusted by applying or varying the potential applied across the electro-optic material so that the focus of the imaging device is not entirely dependent on the nature and construction of the lens elements (6 ).