Abstract: An optical diffusion plate and a light source module are provided. The optical diffusion plate includes a light incident surface, a light emitting surface, at least one pattern region, and a reflection layer. The pattern region is located on at least one of the light incident surface and the light emitting surface. The reflection layer covers a portion of the pattern region. The pattern region includes a central region located at a central position, a plurality of first circular regions, and at least one second circular region. The central region is surrounded by the first circular regions and the second circular region alternatively, and perimeter of the central region is adjacent to one of the first circular regions. Coverage rates of the reflection layer at the second circular region and the central region are higher than coverage rates of the reflection layer at the first circular regions.

Abstract: A light source module including at least one optical film and a light source unit is provided. The light source unit is disposed under the at least one optical film, and a space is formed between the light source unit and the at least one optical film. The light source unit includes a plurality of light emitting elements and a plurality of secondary lenses. The light emitting elements are arranged along a direction parallel to the at least one optical film. The secondary lenses are correspondingly disposed on the light emitting elements and each of the secondary lenses has a patterned reflective layer.

Abstract: A light source module including at least one optical film and a light source unit is provided. The light source unit is disposed under the at least one optical film, and a space is formed between the light source unit and the at least one optical film. The light source unit includes a plurality of light emitting elements and a plurality of secondary lenses. The light emitting elements are arranged along a direction parallel to the at least one optical film. The secondary lenses are correspondingly disposed on the light emitting elements and each of the secondary lenses has a patterned reflective layer.

Abstract: An optical diffusion plate and a light source module are provided. The optical diffusion plate includes a light incident surface, a light emitting surface, at least one pattern region, and a reflection layer. The pattern region is located on at least one of the light incident surface and the light emitting surface. The reflection layer covers a portion of the pattern region. The pattern region includes a central region located at a central position, a plurality of first circular regions, and at least one second circular region. The central region is surrounded by the first circular regions and the second circular region alternatively, and perimeter of the central region is adjacent to one of the first circular regions. Coverage rates of the reflection layer at the second circular region and the central region are higher than coverage rates of the reflection layer at the first circular regions.

Abstract: A light source module including at least one optical film and a light source unit is provided. The light source unit is disposed under the at least one optical film, and a space is formed between the light source unit and the at least one optical film. The light source unit includes a plurality of light emitting elements and a plurality of secondary lenses. The light emitting elements are arranged along a direction parallel to the at least one optical film. The secondary lenses are correspondingly disposed on the light emitting elements and each of the secondary lenses has a patterned reflective layer. Each of the secondary lenses has a light hole radius R, a distance between a distribution range of the patterned reflective layer and a bottom of the corresponding secondary lenses is H, and the distribution range of the patterned reflective layer satisfies 1/R<H<3/2R.