Dual LED usage for glint detection

摘要

A wearable computing system may include an eye-tracking system configured to track the position of an eye of a wearer of the wearable computing system. In particular, an infrared light source illuminating the eye of a wearer at a relatively high intensity may generate specular reflections off the wearer's cornea, also called ‘glints’. The glints can be imaged with an infrared camera. When the infrared light sources are illuminated at a relatively lower intensity, determination of the pupil location is possible. Glints, in combination with the pupil location, may be used to accurately determine the gaze direction and eye rotation. The determined gaze direction could be used in various eye-tracking applications. By controlling the light sources to change intensity levels and by combining multiple images of the eye to incorporate multiple glint locations with the pupil location, eye tracking can be performed with better accuracy and with fewer light sources.

主权项

1. A method, comprising:
illuminating a viewing location during a first period of time with at least a first light source and a second light source, such that during the first period of time the first and second light sources both illuminate the viewing location and the first light source illuminates the viewing location with a higher intensity than the second light source; acquiring a first image from light reflected from the viewing location during the first period of time using a camera, wherein the first and second light sources are located off-axis with respect to an optical axis of the camera; illuminating the viewing location during a second period of time with at least the first light source and the second light source, such that during the second period of time the first and second light sources both illuminate the viewing location and the second light source illuminates the viewing location with a higher intensity than the first light source; acquiring a second image from light reflected from the viewing location during the second period of time using the camera; obtaining combined data from at least the first and the second images, wherein the combined data comprises a reference location, a first glint location, and a second glint location; and determining a gaze direction based on the combined data.