A plano concave lens is an optical lens with one concave surface and one flat surface. It has a negative focal length, and can be used for light projection, beam expansion, or to increase focal length ...

LEDtronics built its latest high-intensity discrete LED with a concave lens, so the 5-mm-wide T1-¾ device delivers light that is even from the center to the edge. This lens spreads the inherently ...

The double convex lens/mirror is symmetrical across both its horizontal and vertical axis. Each of the lens's two faces can be thought of as originally being part of a sphere. The fact that a double ...