Two-dimensional spatial image control using an electrochromic graduated filter with multiple electrode configuration

In the field of imaging, it is required to control the dynamic range by darkening of the overexposed parts of a scene. Up to now, conventional one-dimensional graduated filters with a fixed transmission profile are used. Making use of electrochromic materials, we present a tunable electrochromic graduated filter device with two-dimensional control. It combines multiple conventional filters in one device as its continuous transmission profile can be individually translated, rotated, stretched and adapted in absorption by means of a multiple electrode configuration. To calculate the spatial transmission and the required potential combination for the control electrodes, we establish a Finite Element Method based simulation model considering the non-linear transmission-potential response of our complementary electrochromic materials. We simulate several electrode configurations and optimize them for the highest correlation of specified and simulated transmission. Finally, we build the device using microsystem technology and demonstrate the successful operation with desired functionalities. •Electrochromic graduated filters allow spatially tunable transmission up to ΔOD1.•A potential drop along the working electrode produces the transmission distribution.•Eight contact pads are addressed with potentials in the range of +0.5 V to −1.6 V.•Prior to manufacturing, various contact pad configurations are simulated with FEM.•Graduated transmission profiles can be translated, stretched, darkened and rotated.