BLOG: Laser Video Projector Safety
As an increasing number of video projectors start to use lasers as their light source, more people have been asking us about the safety implications in using these devices.
Projecting video imagery using lasers has been in use to a limited extent for many years, employing a range of techniques to scan or deflect a beam in order to produce raster-type content as is typically used to show video-type content. Even Pangolin’s laser control software, intended for vector-based artwork, has a feature to generate low-resolution raster images using standard x-y light show galvanometers. Other solutions use combinations of polygon, and resonant scanners, or micro-mirrors to achieve better resolution. In each case, the resulting product is a laser product that must be classified under the IEC 60825-1 Laser Product Safety Standard. The resulting classification determines what safety controls (precautions), should be employed when using the product. In some instances, these could be the same as the precautions used for typical laser show safety applications, such as outlined in IEC/TR 60825-3:2008, that describes laser show safety practice.
There is however a growing number of laser video projectors that use lasers as the source, but using a technique completely different to the methods described so far. These are called referred to as Laser Illuminated Projector Systems (LIPS), which, as indicated by the descriptive title, are video projectors that are illuminated by a laser source. The key difference between laser video projectors (LVP), and laser illuminated projectors (LIPS), is that the latter do not emit any direct laser light, unlike the former, which do manipulate laser light to form an image. In the case of LIPS, the laser light source is used internally in the video projector as a highly efficient source that, in turn, illuminates a phosphor surface inside the video projector, (known as the homogeniser. The intense light emitted from the phosphor is the light that makes its way through the projector’s imaging system and is emitted from the product.
The exposure risk to light emitted from the LIPS device is similar to that of similar intensity light emitted from a traditional video projector. i.e. precautions should be taken to avoid direct exposure, but it doesn’t normally require the same level of precaution as when working near direct laser light. This is because no direct laser light is ever emitted from the video projector. Instead the laser light remains inside the video projector during normal use, and the light generated by the phosphor does not have the harmful properties that are present in laser beams.
It is for this reason that the laser product safety standard, IEC 60825-1:2014, now has an exemption clause for devices such as LIPS to be considered as Class 1 laser products, if they meet a number of criteria related to radiance. If they do meet the criteria, they can be classified under the lamp safety standard IEC 62471-5:2015, which is part of the 62471 series of standards. You can read more about lamp safety in this article.
So in summary, older style laser video projectors (LVP) still need to be treated as laser systems, while newer laser illuminated projector systems (LIPS), can normally be used the same way as conventional video projectors, if they meet the radiance criteria in IEC 60825-1:2014.
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