A low profile touch display can be provided, namely one including an optical detection system with the bulk of the electronics and optics positioned partially or completely below the detecting plane surface. The light source and optical detection system components can be configured so that the exit and entry apertures for light being directed to and/or received from the detection plane are the only members above the touch surface. For instance, a reflective or refractive member at the edge of the touch surface can direct light to detection optics and/or from illumination sources via a pinhole aperture, with the light moving between the detection optics and illumination sources in one or more detection planes above the touch surface. Consequently, the touch screen can have a thin cross section that is more suitable for devices such as mobile phones, PDAs, and other portable computing devices for which minimal device thickness is a priority.