Hi All,
I’m looking for practical guidance on using a micro-prismatic BEF film (3M BEF3-T-155n) to increase on-axis luminance for a transparent LCD storefront display where the backlight is made from COB LED strips mounted only around the perimeter (edge-lit, no LGP).
It is anybody with experience in using this film for LCD displays ?!
Thank you
Greetings,
It might be helpful if you could describe the application in a bit more detail, and provide some more specific questions to follow up on.
A search term like “3M BEF application note” should surface a variety of resources that describe the operational concepts behind the material, including the one below. Basic idea is that the stuff uses a combination of reflection & refraction to concentrate transmitted light in the normal direction, to achieve higher brightness at the cost of a narrower viewing angle.
Typical display applications would put the stuff between the backlight source (whatever it may be) and the image panel. In that case the goal is to spread out a concentrated light source into a nice, even illuminant to backlight the image-forming part of the screen. That allows the film to stay well-protected against dust, condensation, etc. as it needs to be since the micro-prisms that let it do what it does are quite small and easily interfered with by such things.
It’s not immediately obvious to me how one might think of using the stuff in a transparent display, but I wouldn’t expect it to remain transparent with the addition of the film. Translucent yes, but not transparent.
Thank you for your answer. This was also my concern regarding the transparency after applying the film behind the display. It doesn’t seem logical to keep the same transparency !
