The company was granted four patents that cover several aspects of the technology this week alone. Four patent applications were filed as early as July 2011, confirming that Google has been playing with this idea for quite some time.
One week ago, Google was granted several design patents that show detailed illustrations of the glasses and hint to their construction:
Besides the plain design patents (viewing of the TIFF images provided by the USPTO require a TIFF plugin such as AlternaTIFF, which is only available for IE), the nose bridge sensor may be the most interesting patent that has been granted so far. The document describes that the glasses will use a sensor on a nose bridge that will determine the power state of the glasses and will communicate to the system whether the glasses are actually in use or not.