Most people prefer the unsplit design. A fresnel is a terrible quality lens. Edmunds claims 5% FL variance on their fresnels. Their fresnels are probably better than most. This translates to a muddy, poorly focusable image.
What about a microlens film for the field fresnel? If each microlens is the diameter of the pixels and designed to focus that pixel's light at a set FL it might make a very nice split design.
http://www.ntu.edu.sg/home/yqfu/PDF paper/031104-JVSTB.pdf
http://rogers.mse.uiuc.edu/files\2003\APL_82_1152.pdf
Thoughts?
What about a microlens film for the field fresnel? If each microlens is the diameter of the pixels and designed to focus that pixel's light at a set FL it might make a very nice split design.
http://www.ntu.edu.sg/home/yqfu/PDF paper/031104-JVSTB.pdf
http://rogers.mse.uiuc.edu/files\2003\APL_82_1152.pdf
Thoughts?
projecting without lens
They're already used in newer 3LCD commercial projectors. They increase brightness and reduce the grille effect. I understood their optical axes are parallel. But to replace a field Fresnel each microlens must be aimed to a common point, in a converging cone. And if that is manageable, why not point each microlens the opposite, in a diverging pattern. Then you'd have the ultimate projector, just an ordinary LCD monitor with a foil over it, no other lenses or light sources whatsoever.
In reality such cheap optical foil lenses, the Fresnels being an example, lack the necessary precision, at least for now. The manufacturing process needs elaboration.
They're already used in newer 3LCD commercial projectors. They increase brightness and reduce the grille effect. I understood their optical axes are parallel. But to replace a field Fresnel each microlens must be aimed to a common point, in a converging cone. And if that is manageable, why not point each microlens the opposite, in a diverging pattern. Then you'd have the ultimate projector, just an ordinary LCD monitor with a foil over it, no other lenses or light sources whatsoever.
In reality such cheap optical foil lenses, the Fresnels being an example, lack the necessary precision, at least for now. The manufacturing process needs elaboration.
Hey,
Some applications where a single micro optical element is not enough. For example, CCD/CMOS sensors usually require microlenses in front of each photodetector; we need design microlens arrays. When designing a microlens array is necessary to define the configuration in which we will fabricate the lenses. Some common packing configurations are: square, hexagonal, circular and random configurations. Two additional parameters are the pitch and the fill factor of importance when designing microlenses for CMOS sensors with a high density of photodetectors. Also, a wide variety of substrates that we can use. The choice of substrate is related to the polymer that we will use for our microlens, but also on the application, whether we require a rigid or flexible substrate will limit our options. Regardless of the choice of substrate we need to keep in mind its thickness and optical properties because they will affect the optical performance of our system.
Some applications where a single micro optical element is not enough. For example, CCD/CMOS sensors usually require microlenses in front of each photodetector; we need design microlens arrays. When designing a microlens array is necessary to define the configuration in which we will fabricate the lenses. Some common packing configurations are: square, hexagonal, circular and random configurations. Two additional parameters are the pitch and the fill factor of importance when designing microlenses for CMOS sensors with a high density of photodetectors. Also, a wide variety of substrates that we can use. The choice of substrate is related to the polymer that we will use for our microlens, but also on the application, whether we require a rigid or flexible substrate will limit our options. Regardless of the choice of substrate we need to keep in mind its thickness and optical properties because they will affect the optical performance of our system.
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