This will not "block the sun from any angle". Not unless you make it block all light from any angle. If I'm understanding your proposal, what it will do if it w

This will not "block the sun from any angle". Not unless you make it block all light from any angle. If I'm understanding your proposal, what it will do if it works is to block all light that enters the window perpendicularly (and at certain other angles), whether it comes from the sun or not; but if you happen not to be looking straight at the window, there's no guarantee that the sun will be blocked. And if you are looking straight at the window, you won't see anything. There's nothing magical about sunlight that will enable you to block it while letting in other light from the same direction. And light from the sun could reach the window at a wide range of different directions. (If you somehow contrive to have the sun always in the same direction -- say you're in a spaceship and it keeps a consistent orientation relative to the sun -- then this kind of thing could work. Not so feasible here on earth, though.)