The Colloidal Metamorphosis: Time Division Multiplexing of the Reflectance State

Specular reflection plays an important role in an image's appearance. However, LCDs don't have sufficient contrast to express specular reflection, and ordinary projector screens only have diffuse-reflection surfaces. A new display system projects ultrasound waves to dynamically change the reflection state of a screen made of a colloidal substance--soap film. The system uses time division multiplexing of the diffuse and specular states to produce realistic appearances. It employs an optical illusion that exploits the characteristics of human sight. Optical measurements and a user study validated this approach's effectiveness.