Loading patent…
AssigneeArkema France
InventorsMichael T. Burchill, Steven W. Gaskey, Robert A. Wanat, Jiaxin Ge, Mark A. Aubart
Estimating the term…
The invention relates to optical light diffusers for use with point light sources, such as LED lighting. The optical diffusers achieve an optimum balance of light transmission and hiding power. The optical light diffuser is a transparent plastic matrix, such as Plexiglas® resin from Arkema Inc., having organic particles dispersed within the matrix. The particles are crosslinked beads having specific particle sizes and loading. Different beads can be combined to provide added properties such as a textured surface, and to optimize hiding power and light transmission. The invention also relates to a luminous device containing at least one light-emitting diode and a cover made of the optical light diffuser. The invention further relates to a method for assessing hiding power.
A cover for a point light source having a composition comprising a transparent thermoplastic or thermoset plastic matrix having dispersed therein a blend of from 1 to 10 equivalent loading weight percent of small cross-linked diffusing particles having a mean particle size of from 2 to 20 microns, and from 2 to 10 equivalent loading percent by weight of large cross-linked diffusing particles having a mean particle size of from 40 to 80 microns, the weight percent based on the polymer matrix, and wherein the optical transmission is greater than 75 percent and the hiding power is greater than 40 percent, and wherein said cover has a surface roughness of from 0.5 to 4 microns.
Dependencies are inferred from the claim text.