Microsoft has developed a micro injection molding technology to make light guides for handheld and other electronic devices. The micro light guide receives light from an illuminator and reflects it to a display surface.
Wedge features in the guides are separated by less than 10 micrometers. Lengths of the light-guiding wedges are less than 50 micrometers.
In some embodiments, the mold that defines the microstructure light guide uses pixelated areas to enable selective temperature adjustment.
Micro guides are needed to provide displays as computing devices decrease in size. Conventional techniques for manufacturing light guides cannot achieve required tolerances for the tiny sizes, according to Microsoft. The micro molding process is an attempt to produce tight tolerances as net shapes that do not require expensive secondary machining.
The plastics that will be used for the light guides are polycarbonate or acrylic.
The inventors are Kurt Jenkins, manufacturing research engineer at Microsoft who specializes in development of new injection molding processes for optics, back-lights and micro-structure replication, and Lincoln Ghioni, also a mechanical engineering researcher at Microsoft, Redmond, Washington.