Patent ID: 9077345
Filing Date: 2015-07-07
Classification: G02B,H03K

Abstract:
1. A capacitive sensing apparatus comprising: a capacitive sensor located on a first surface of a substrate, the capacitive sensor providing a means for generating a capacitive sensing field from a capacitive sensing area; a light source; and a light guide comprising a light scattering means and arranged so as to locate the capacitive sensor between the substrate and the light guide, wherein the light source is spaced apart from the capacitive sensing area and the light guide is arranged to guide light from the light source to the light scattering means, the light scattering means being positioned substantially at the capacitive sensing area, and wherein the light guide and the substrate are arranged to form an air gap that separates the light guide from the substrate and the capacitive sensor, the air gap being continuous between the spaced apart light source and the capacitive sensing area.