COMPOSITE DIFFUSION PLATE

摘要

The present invention provides a composite diffusion plate that can suppress occurrences of local variations in brightness. A composite diffusion plate (100, 200, 300) is configured by a first diffusion plate (10) and a second diffusion plate (20, 30) being arranged in order from the incident side. At least one of the first diffusion plate (10) and the second diffusion plate (20, 30) is formed from a random microlens array (10) having a plurality of microlenses (12). The plurality of microlenses (12) has a plurality of parameters that characterize the lens properties. At least one of the plurality of parameters is distributed randomly. The random microlens array (10) generates a phase shift in the light that is transmitted.