Photobiological safety of household led projectors

The article discusses the influence of LED projector radiation indicators on photobiological and thermal hazards to the human body. The obtained results of the levels of visible radiation of the optical spectrum and the thermal effect of image spotlights intended for use in domestic conditions are presented. The dependences of the energy brightness on the harmfulness function of the spectrum of visible radiation, on the ratio of the field of view angle γ and the solid angle of the light source α, as well as on the measurement distance have been established. It has been shown that when the distance from the observer to the projector increases by more than 1.25 m, the radiation from projectors does not pose any danger and corresponds to the risk group RG0. At a distance of up to one meter from the projector (the range where the degree of visible radiation of the optical spectrum is regulated), the type of light source studied is classified as low hazard RG1 and meets the established requirements of the standard. When the observation range is up to 0.3 m, the level of influence of the danger of visible radiation the optical spectrum increases to the second category. At a distance of 1 m, the luminance LR is almost three orders of magnitude lower than the limit value, and at a distance of 0.5 m, LR is also significantly lower than the limit values. For the closest distance of 0.2 m, the LR level is below the LR limit values for the average risk group RG2 and the level of thermal hazard created by optical radiation with wavelengths of 380‒1400 nm does not exceed the norm for the studied projectors. Conclusions are drawn about the compliance of the studied low‒ power image projectors with the blue light safety conditions established by the international standard