Patent attributes
A head-mounted display device includes one or more infrared light sources configured to emit infrared light toward one or more eyes of a wearer, a first mirror configured to transmit the infrared light reflected from the one or more eyes of the wearer toward the first mirror, that reaches the first mirror at a first incident angle, the second mirror configured to reflect the infrared light transmitted through the first mirror, toward the first mirror so that the first mirror is configured to reflect the infrared light reflected by the second mirror, and incident on the first mirror at a second incident angle that is greater than the first incident angle, one or more sensors configured to detect the infrared light reflected by the first mirror and the second mirror for determining a gaze direction of the one or more eyes of the wearer.