Optical touch sensor

摘要

An optically transmissive element of a computing device can be used to enable touch input. One or more light sources, such as infrared (IR) light emitting diodes (LEDs), can direct radiation into an edge of the transmissive element and direct light to reflect from at least one other side or edge using total internal reflection (TIR). The transmissive element can have one or more curved or shaped regions, the extent of which can affect the amount of light lost from the element due to less than TIR at those regions. If a user places a finger at a position where the light internally reflects, a portion of the light will be transmitted out of the element causing a reduction in the amount of light received to one or more light sensors. By monitoring patterns of intensity loss, the locations of user inputs can be determined.

主权项

1. A computing device, comprising:
a display element; a cover glass element covering the display element and having a lip region around a periphery of the cover glass element; an infrared (IR) emitter positioned to direct IR radiation into a first location of the lip region such that at least a portion of the IR radiation, incident on an internal surface of the cover glass element, undergoes internal reflection and is transmitted across a portion of the cover glass element; an IR detector positioned to detect the IR radiation transmitted across the portion of the cover glass element and emitted from a second location of the lip region; a processor; and a memory element including instructions that, upon being executed by the processor, cause the computing device to:
determine that the computing device is being held;determine a baseline intensity pattern of detected IR radiation corresponding to a portion of the lip region at a time that the computing device is being held;monitor an intensity pattern of detected IR radiation corresponding to the portion of the lip region;determine that one or more differences between the intensity pattern and the baseline intensity pattern corresponds to a known user input received via the portion of the lip region; andperform an action corresponding to the known user input.