Here’s a fun patent from Canon – a lens that sucks. And I mean this quite literally. This lens incorporates a mini vacuum cleaner that cleans your camera sensor from dust.
This funky little “lens” is actually not a lens, but a specialty camera vacuum called the Fujin Mark II. The device uses an electric fan which the manufacturer says, “can easily remove the type of dust, dirt, and sand that could not be removed before.” All you have to do is mount the lens on your camera, flip on the power switch and let the device extract the dust from inside your camera.
Fujin suggests you use the vacuum in conjunction with certain camera functions (they specifically mention sensor cleaning, mirror-lockup, and continuous shooting) for an even more effective cleaning.