Canon Designed a Lens That Sucks petapixel.com

Canon engineers have designed a lens that quite literally and intentionally sucks.
In a newly published patent filing over in Japan (2019-191432), first reported on by CanonWatch, Canon describes a clever solution it came up with for removing sensor dust.
This air is channeled back into the mirror box of the DSLR while the mirror is up and sensor exposed.
The dusty air stirred up is then channeled through the internal areas of the lens until it’s expelled out the front of the lens through channels surrounding the front element.
Canon’s idea would go a step further by getting dust out of the mirror box and camera.