Detailed Eye-Safety Analysis of Laser-Based Scanned-Beam Projection Systems

Recently, an analysis of current scanned-beam laser projection systems was presented and showed that the maximum achievable Class 2 eye-safe luminous flux levels are fundamentally limited by the nature of the projection architecture. In this paper, an improved estimate for the maximum Class 2 eye-safe luminous flux is derived by considering unidirectional and bidirectional scan patterns. It is shown that, due to pulse spacing conditions at the edge of the projected image, the maximum Class 2 eye-safe luminous flux could be significantly lower when employing a bidirectional scan pattern than for the unidirectional case.