Capacitive sensing apparatus,申请号US200912990087-传众专利搜索

Capacitive sensing apparatus

申请公布号：US9077345(B2)

申请号：US200912990087

申请日期：2009.05.08

申请公布日期：2015.07.07

申请人：

DESIGN LED PRODUCTS LIMITED

发明人：Gourlay James

分类号：G06F3/044;H03K17/96;F21V8/00

主分类号：G06F3/044

代理机构：

Nixon & Vanderhye P.C.

代理人：Nixon & Vanderhye P.C.

地址：Livingston GB

摘要：A capacitive sensing apparatus is described that incorporates a light guide having a light scattering means for illumination of the apparatus. The apparatus has a capacitive sensor mounted on a substrate that provides a capacitive sensing area for generating an electric field that emanates from the apparatus. A light source is arranged in optical communication with the light scattering means via the light guide. This arrangement acts to mitigate the effects of interference between the capacitive sensor and the light source. When an opaque substrate is employed an air gap is located between the substrate and the light guide so as to provide a substantially uniform illumination across the light guide. Appropriate selection of the refractive indices of the light guide, ng, and a transparent substrate, ns, provides the same desired uniform illumination in alternative embodiments. The capacitive sensing apparatus finds particular application within a touch sensitive display.

主权项：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.