Brightness enhancement film for backlit image displays

A brightness enhancement film for mounting on an outward side of a light source of a backlit display, the film comprising:

• (a) a transparent sheet formed of a solid transparent dielectric material;
• (b) a first plurality of approximately hemispherical solid transparent dielectric hemi-beads substantially covering and protruding outwardly from an outward surface of the sheet, at least some of the hemi-beads having a minimum diameter of 2 microns;
• (c) a gap between adjacent ones of the first plurality of hemi-beads;
• and
• (d) at least some of the gaps containing at least one of a second plurality of approximately hemispherical solid transparent dielectric hemi-beads, each one of the second plurality of hemi-beads having a second average diameter less than the first average diameter.

A method of enhancing the brightness of a backlit display, the method comprising:

• (a) providing an outward surface on an outward side of a light source of the display with a first sheet formed of a solid transparent dielectric material;
• (b) substantially covering an outward surface of the first sheet with a first plurality of outwardly protruding, hemispherical solid transparent hemi-beads;
• and
• (c) guiding light rays emitted by the display through the first sheet and hemi-beads.

A method of enhancing the brightness of a backlit display, the method comprising:

• (a) providing an outward surface on an outward side of a light source of the display with a first sheet formed of a solid transparent dielectric material;
• (b) substantially covering an outward surface of the first sheet with a first plurality of outwardly protruding, hemispherical solid transparent hemi-beads;
• and
• (c) guiding light rays emitted by the display through the first sheet and hemi-beads;
• wherein a gap remains between adjacent ones of the first plurality of hemi-beads and wherein the first plurality of hemi-beads have a first average diameter, the method further comprising providing, in at least some of the gaps, at least one of a second plurality of approximately hemispherical transparent high refractive index hemi-beads, each one of the second plurality of hemi-beads having an second average diameter less than the first average diameter.