Designing a laser scanning picoprojector. Part 1: characteristics of the optical displaying system and color-management-related issues

When designing a laser scanning picoprojector, one has to deal with important aspects that do not strictly involve design of hardware and software. We have identified two issues that play a decisive role in the final specifications of a laser scanning picoprojector: the characteristics of the optical displaying system and color management. Regarding the optical system, we have studied the diameter requirements of the laser beam emitted from a picoprojector from the point of view of image quality. Resolution is assessed by calculating the image modulation produced by a projected laser spot over a range of projection distances and image sizes. We also show that a suitable election of the RGB wavelengths increases the lumens-per-watt ratio and thereby improves efficiency of a laser-based picoprojector.