When it comes to lenses for digital pico projectors, there’s currently something of a trade-off. Traditional lenses, where multiple glass magnifiers are placed one in front of the other, are long and bulky. Microlens arrays, in which many tiny lenses are assembled together on one flat surface, are a much more compact, lightweight alternative. However, so far such arrays have mostly been made out of plastic, which the bulbs in some projectors are capable of melting. Now, researchers from Germany’s Fraunhofer Institute for Machine Tools and Forming Technology have come up with what they say is a solution: microlens arrays made from glass, using a hot embossing technique.
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