With an attempt to suppress the moiré effect induced by the interference between the black matrix (BM) of a display panel and the grid line in an image sensor of a digital camera, we have fabricated rigid and flexible anti-moiré filters by slot-coating hollow light-diffusing particles (LDPs) using table and roll slot-die coaters. We have achieved large-area uniform coating of LDPs with an average diameter of 20 μm using the slot-die head having the manifold volume as high as 5 mm×2 mm×150 mm, providing a uniformly pressurized reservoir and thus equal flow rates across the width of the slit nozzle. Such an anti-moiré filter is shown to suppress the moiré phenomenon (aliasing) to a great extent by breaking the periodicity of the panel, which is induced by light diffusion. To quantify the moiré strength, we have calculated the brightness ratio from the measured moiré patterns. In the presence of the filter with 7 wt% LDPs, the brightness ratio of an ultra-high definition (UHD) TV is decreased from 123.79 % to 103.5 %, indicating that the moiré phenomenon is considerably suppressed. It is also found that the moiré suppression capability of the filter depends sensitively on the BM structure (i.e., the narrower the BM, the weaker the moiré fringes), which is in qualitatively good agreement with simulation results by the ray tracing algorithm.
