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New Logitech Dark Field Mice Operate On Glass
Slatterz writes "Logitech has introduced new mice that use two lasers rather than one to work on a variety of previously unusable surfaces. The first laser picks out imperfections in the surface of a tabletop while the second laser focuses on microscopic imperfections highlighted and uses those to direct the cursor. The technique, dubbed dark field microscopy, allows mice to be used on almost any surface, including glass (as long as it is more than 4mm thick)."
Didn't Logitech make a mouse that worked on "any surface" about five fucking years ago?
*puzzle*
Kid-proof tablet..
Any time I have ever encountered anything resembling a glass table, it has always been a freaking slab of glass, not 4mm of it.
Nerd rage is the funniest rage.
In case anyone cares, "dark field" refers to an imaging technique which uses a light beam to illuminate a surface, but positions the sensor such that specular reflections (i.e., direct reflections which occur when light strikes a fairly smooth surface) are not picked up by the sensor. Instead, scattered (diffuse) reflections are picked up by the sensor, which highlights bumps and nicks in the surface.
Compare this to "bright field" which refers to a technique where the specular reflection is received directly by the image sensor. The specular reflection is typically much brighter than any diffuse components which also happen to strike the sensor, so a simple threshold is able to filter out the diffuse components.
Both techniques are used in, e.g., inspection of objects for defects, such as integrated circuits and masks, PCB soldering, etc.