OPTICAL SHEET FOR HIGH UNIFORMITY RATIO OF ILLUMINATION

摘要

PURPOSE: A high uniformity optical sheet is provided to increase a uniformity ratio by emitting the light of an LED through hemispherical protrusions which are formed on a sheet body unit. CONSTITUTION: A sheet body unit (10) is configured to be attachable to an LED. A protrusion unit (20) comprises multiple protrusions (21) which are protruded with a hemispherical shape from the surface of the sheet body unit faced with the LED. The multiple protrusions are arranged with a space from each other. The protrusion unit has a micro-lens array structure which is faced with a light source. The ratio of a protrusion height (a) of a protrusion to a diameter (b) of a part which is contacted with the sheet body unit is 0.9-1.1.