Patent ID: 8013845
Filing Date: 2011-09-06
Classification: G06F

Abstract:
1. An optical touch pad for determining a position of an object with respect to an external surface of the optical touch pad, the optical touch pad comprising: a multilayer waveguide comprising: wherein the first waveguide layer comprises a rigid layer that comprises the external surface of the optical touch pad and a pliable layer that is directly adjacent to the external layer, wherein the rigid layer is more rigid than the pliable layer and the pliable layer is more pliable than the rigid layer, and wherein when an external force is applied to the external layer that deforms the external layer into the pliable layer, the pliable layer compresses without substantially stressing any other layers within the multilayer waveguide; wherein the multilayer waveguide is configured to direct electromagnetic radiation by total internal reflection to at least one detector to enable the detector to determine the position of the object with respect to the external surface; and wherein the rigid layer and the pliable layer are index of refraction matched.