I have an LCD display I'd like to use in a collimated HUD display, however it seems that I can't get the light (image) from it to collimate properly. I'm trying to use a lens with the focal distance of 4.5 cm. When I place the display 4.5 cm away from the lens' center I expected to achieve the collimation however the only thing I can see in the lens is a blurry mess. Questions is: Maybe I'm putting the lens in the wrong side of the display - in order to get a collimated image from it do I actually have to pass already collimated light through the display (replace the display backlight with a collimated light source) or is it somehow possible to collimate the image coming out from it (it's shown this way on all schematics of collimated displays/collimators i've been able to find)? Optionally, are there other means of collimating an image from an LCD display?