Hello, I am interested in making modifications to the LightCrafter4500 iView Engine so that I can generate diffraction patterns from a point light source.
There is a lot of information about the iView Engine at the following page but it appears to be missing a description of some of the internal lens/windows and the role they play.
"Each LED has an optical collimator to collect the wide beam of light from the LED and produce a narrower beam. This narrow beam of light passes through a set of dichroic mirrors that reflect a specific color of light while letting other colors of light pass through it. The dichroic mirrors recombine the different colors of light into one co-linear beam. The recombined light passes through a fly-eye and condenser lens that provides uniform light intensity. The light bounces of a mirror and passes through a total internal reflection (TIR) prism. The light is directed towards the DLP4500 DMD and goes through the focus optics."
Between the dichroic mirrors there is an additional lens that no mention is made of, and immediately after the fly eye lens but before the prism there are two lens' but only one condenser lens is mentioned.
I'm trying to understand the role of these extra lens' given that the light beam should be collimated after the first collimator for each led. (Perhaps they are simply to deal with the fact the light is not truely collimated as the LED is not a point source and thus needs intermediary lens to prevent too much divergence of the light?)
If I understand correctly in order to generate diffraction patterns assuming the light is collimated passing from the led collimators to the condenser, it should be sufficient to turn one LED into a point source LED (by masking with a pinhole for example) and remove the fly-eye lens and I should be able to shine coherent light on the DMD and generate diffraction patterns. However I'm uncertain what if any effect the above lens' have on my ability to do this. If they are refocusing the light multiple times and the light is not truely collimated then removing those lens as well as removing the fly-eye lens may interfere with the condensers ability to focus the light onto the DMD if it were truely collimated from a point source.
Any input or guidance further detailing what the role of these additional lens' are and/or the feasibility of modifying the light engine as I desire, would be very much appreciated.
I expect the distances between the various lens' distances may have been precisely tuned to deal with the imperfect collimation of the current LED light sources, in which case I'm just hoping that using a true point light source will simplify things to the point where I don't need to worry too much about things and it may just work. (call me an optimist :))
