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

Abstract

Abstract— 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.

Speckle suppression in projection displays by using a motionless changing diffuser

“…3. The SLMDPL has been investigated earlier for such applications as laser projection displays 15 and variable optical attenuators for telecommunication applications 16 . Its main advantages are high diffraction efficiency (>96%), short on-off time (∼1µs), linear gray-scale characteristic, low light absorption in the visual and IR range (<1%) and handling of high light power.…”

“…The spatial configuration of these beamlets is changed dynamically by electric signals applied to the SLM. It can be, for example, a liquid-crystal (LC) SLM [15]. One of the possible issues with the LC-SLM is that it can be damaged by too large laser power which is often needed in projection displays.…”

Enhanced electro-mechanical performance of TiO<inf>2</inf> nano-particle modified polydimethylsiloxane (PDMS) as electroactive polymers

“…In this work, polydimethylsiloxane (PDMS) was chosen as the host polymer because of its remarkable durability and resistance to temperature, UV radiation and weathering [11]. Titanium dioxide particles were used as filling material owing to its relatively high permittivity, chemical inertness, non-toxicity and easily dispersed in silicone matrix [1].…”

Speckle reduction in laser displays using a MEMS tandem modulator

“…Last but not least, the dynamic gratings are made of deformable polymer material, such as polydimethylsiloxane (PDMS), which is low cost, lightweight, reliable, and easily processed. From experiments, it can stand 80°C, 80% humidity, and long-time laser exposure without any degradation [5], providing the capability to work in harsh environments.…”