Lars Henriksen

Image improvement in a laser projection display with a spatial light modulator with a deformable polymer

— The image quality of a laser projection display based on a spatial light modulator with a deformable polymer layer (SLMDPL) has been improved. Bias diffraction has been reduced by two methods: (1) by filling the spacings between electrodes with SiO2 followed by deposition of a slightly conductive thin film and (2) by splitting electrodes. Both methods resulted in a contrast ratio of ≃1200:1, which is significantly better than 50:1 measured for an earlier type of SLMDPL. Different methods of reducing the influence of electrical-charge movement on the image quality have also been investigated. Substantial improvement has been achieved by using an alternating mode for signal voltage pulses, by increasing the conductivity of the gel layer, and by increasing the surface conductivity of the substrate between electrodes. Cross-talk between neighboring pixels has been suppressed without a loss in the sensitivity by using a special layout of the electrodes in the SLMDPL.