Abstract: An optical diffusing element includes a light emitting surface. The light emitting surface has microstructures, each microstructure has a border, the border of each microstructure is completely connected with the borders of the adjacent microstructures, each microstructure has a surface profile, and a functional formula of the surface profile is: s ? ( x ) = x 2 R + R 2 - ( ? + 1 ) ? x 2 ; s(x) represents the surface profile of each microstructure on an x-axis. The value x represents a vertical projection position of the surface profile on the x-axis. The value R represents a curvature radius of a vertex of each microstructure. The value ? represents a conic coefficient of each microstructure. The microstructures have the same value R and value ?. A light emitting assembly for three-dimension sensing includes the optical diffusing element and a light source.

Abstract: A backlight module includes a back plate, light sources, protrusive pieces and a reflective sheet. The light sources are disposed on the back plate. The protrusive pieces protrude from the back plate. Each of the protrusive pieces is located between at least two adjacent light sources. The reflective sheet is disposed on the back plate and has through holes. Each of the light sources passes through a corresponding through hole. The reflective sheet further has cutting line groups. Each of the cutting line groups includes two cutting lines intersected at an intersection point. Each of the intersection points is substantially aligned with a corresponding protrusive piece. Portions of the reflective sheet adjacent to the cutting line groups are warped upwards from the back plate, and respectively resist the protrusive pieces.

Abstract: A backlight module includes a back plate, light sources, protrusive pieces and a reflective sheet. The light sources are disposed on the back plate. The protrusive pieces protrude from the back plate. Each of the protrusive pieces is located between at least two adjacent light sources. The reflective sheet is disposed on the back plate and has through holes. Each of the light sources passes through a corresponding through hole. The reflective sheet further has cutting line groups. Each of the cutting line groups includes two cutting lines intersected at an intersection point. Each of the intersection points is substantially aligned with a corresponding protrusive piece. Portions of the reflective sheet adjacent to the cutting line groups are warped upwards from the back plate, and respectively resist the protrusive pieces.