Alps Electric Exhibits Lens Array That Gives LED Light Directionality

At the recent "CEATEC JAPAN 2011," Alps Electric exhibited a reference transparent plastic lens array for LED lighting that can direct light to a narrow range. The exhibited array consists of an integrated molded unit of 10 lenses horizontally × 6 lenses vertically. From directly above, the light emitted by the LED beneath the lens array can be seen, but when viewed from a slight angle, no light is visible.

Plastic lens array for LED lighting exhibited by Alps Electric. Left is viewed from directly above, right is viewed from a position slightly in front.

The exhibited array is made of acrylic resin, but if the material is a transparent plastic that can be injection-molded, there are no particular restrictions. The surface is spherical, while the inner side is a tapered prism shape. The operating temperature range is 0 to +65°C, and the storage temperature range is -30 to +80°C.

Side view of the plastic array. Light passes upward through it.

The array was realized by adopting micro-cutting processing technology to manufacture high-precision molds. "Homogeneous flow of the molten plastic during molding is extremely important. Uneven flow affects optical properties and prevents achieving full directivity" (Alps Electric).