摘要 |
A light-based input device may be based on a wedge-shaped light-guide structure. Light may be introduced into the interior of the light-guide structure from a light source and corresponding reflected light exiting the light-guide structure may be measured using a light detector such as an image sensor. The location at which a user places an object in contact with an upper surface of the light-guide structure may be detected by analyzing the pattern of reflected light that exits the light-guide structure. Multiple layers of light-guide structures may be separated from each other by opaque material such as plastic so that the device can determine the direction in which the object is traversing the light-guide layers. A light-based input device may be implemented using free-space light beams that are interrupted by the user. Keys may be provided in a light-based input device by movably mounting contact pads to a light-guide structure.
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