Simulation and analysis on visibility enhancement for laser beam projected on display panels using black matrix with scattering particles

With an attempt to enhance the visibility of laser beam projected on a display panel, we investigate the single-layered black matrix (BM) structure where light scattering particles are embedded in BM and the double-layered BM structure in which the scattering layer is separated from BM. By a ray tracing tool, we perform simulations, and then calculate the scattered ray distribution and detected power for those BM structures. It is observed from the results for both structures that the visibility is enhanced with increasing scattering particle density, but lowered with increasing oblique incidence of the laser beam. It is also demonstrated that the double-layered BM structure shows higher visibility than the single-layered BM structure. However, there exists a trade-off between the visibility of the projected laser beam on display panels and color mixing among pixels on the selection of those BM structures. Although color mixing is still unavoidable, our study shows that the scattered power into the active pixel area (pixel aperture) is as low as 1% of the incident laser power.