Abstract: A backlight module including at least one light emitting element and a brightness enhancement diffuser is provided. The light emitting element is capable of emitting a light beam. The brightness enhancement diffuser is disposed in the transmission path of the light beam and has a first surface and a second surface opposite to the first surface. The light beam passes through the first surface and the second surface. The brightness enhancement diffuser includes a plurality of protrusions and a plurality of recesses. The protrusions are disposed on the first surface, and each of the protrusions has a curved surface. The recesses are disposed on the first surface, and each of the recesses has at least one plane surface. Each of the recesses is surrounded by several of the protrusions.

Abstract: A backlight module disposed under a display panel and close to a polarizer on a lower surface of the display panel is provided. The backlight module has an illumination module and an optical film disposed above the illumination module. The optical film has a lower layer and an upper layer attached to the lower layer. The upper layer is close to the polarizer and has a plurality of first micro-protrusion structures formed on an upper surface thereof. The lower layer has a plurality of second micro-protrusion structures with various heights formed on an upper surface thereof. The higher second micro-protrusion structures support the upper layer, so as to form a gap with various dimensions between the upper layer and the lower layer.

Abstract: An optical film is applied to a side-emitting backlight module. The side-emitting backlight module has a light guide plate for guiding a chief light beam. The light guide plate has a light emitting surface to define a normal direction thereof. The optical film includes a lower prism structure, an intermedium layer, and an upper prism structure. The lower prism structure is disposed on the light emitting surface. The intermedium layer is connected between the lower prism structure and the upper prism structure. When the chief light beam exits from the light emitting surface of the light guide plate, and then goes through the lower prism structure, it goes through the intermedium layer along a changed traveling direction. When the chief light beam exits from the intermedium layer, and goes through the upper prism structure, it turns from the changed traveling direction to the normal direction.

Abstract: A light guide plate has a bottom surface including flat surfaces (FSs) and a plurality of prism patterns (PPs) disposed alternately with the FSs, a light emitting surface (LES) and a light incident surface (LIS). Each FS is at a first distance respectively from the LES and the first distances gradually decrease along a direction away from the LIS. Each PP has a first slanted surface (FSS) and at least a groove having a second slanted surface (SSS) and a third slanted surface (TSS). The two opposite sides of the FSS are spaced out a second distance apart. The two opposite sides of the SSS are spaced out a third distance apart. The specific value of dividing a first orthogonal projection of the second distance on an axis perpendicular to the FSs by a second orthogonal projection of the third distance on the axis is between 0.5 and 1.5.

Abstract: A light guide plate has a bottom surface including flat surfaces (FSs) and a plurality of prism patterns (PPs) disposed alternately with the FSs, a light emitting surface (LES) and a light incident surface (LIS). Each FS is at a first distance respectively from the LES and the first distances gradually decrease along a direction away from the LIS. Each PP has a first slanted surface (FSS) and at least a groove having a second slanted surface (SSS) and a third slanted surface (TSS). The two opposite sides of the FSS are spaced out a second distance apart. The two opposite sides of the SSS are spaced out a third distance apart. The specific value of dividing a first orthogonal projection of the second distance on an axis perpendicular to the FSs by a second orthogonal projection of the third distance on the axis is between 0.5 and 1.5.

Abstract: A light guide plate (LGP) adapted to a backlight module having a light emitting surface, a bottom surface opposite to the light emitting surface, and at least one light incident surface contacting with the light emitting surface and the bottom surface is provided. The bottom surface has a plurality of flat surfaces and a plurality of groove groups. The groove groups and the flat surfaces are arranged in an alternating fashion. Each of the groove groups has at least two grooves. Each of the grooves has a first slanted surface, a peak, and a second slanted surface intersecting with the first slanted surface at the peak. In each of the grooves, a first side of the first slanted surface away from the peak is at a first distance from a second side of the second slanted surface away from the peak. The luminance efficiency of the LGP is better.