Evaluation of potential eye hazard associated with viewing of continuous wave and pulsed light emissions from small exit pupil’s laser illuminated projectors Available to Purchase

Laser Illuminated Projectors (LIPs) are laser products developed to project display images without the use of scanning with collimated laser beams. However, since LIPs produce extended source light emissions with increased optical radiant values, the LIP safety classification and evaluation is performed in compliance with the international lamp safety standard IEC 62471-5:2015 Photobiological safety of lamps and lamp systems - Image projectors. This standard specifies a measurement distance of 1 m for determination of Risk Groups (RGs). The existing literature [1,2] provides a justification for this less restrictive distance based on a perfectly uniform image profile, a Continuous Wave (CW) emission pattern, an 11 mrad angle of acceptance, and an exit pupil sources not smaller than 11 mrad for RG2 Risk Group. The present study examines in detail retinal thermal hazard for RG2 LIPs for CW for angular subtense of exit pupils in the range of 5 mrad ≤ α ≤ 11 mrad, which is addressed by the Table 1 in the CDRH Laser Notice 57 [3]. Furthermore, a comprehensive comparison analysis between pulse emissions criteria for LIPs with angular subtense of exit pupils smaller than 11 mrad for measurement distances 20 cm and 1 m is presented. Based on the performed multivariable eye hazard analysis, the study provides also a rational for potential revisions of IEC 62471-5 to address deficiencies identified in the presented standard measurements and classification procedures related to CW and pulsed light emissions from small exit pupil’s laser illuminated projectors.