In some embodiments, the position information of the face (i.e., the face position information) may be a position of the face relative to the electronic device 100. For example, when the face is in the left front of the electronic device 100, the face position information includes the left front, and thus the infrared light source 12 with the corresponding illumination range may be the infrared light source 12 on the left side of the electronic device 100, so that the infrared light source 12 on the left side of the electronic device 100 may be turned on to provide infrared light to the face. In addition, other infrared light sources 12 may be turned off or remain turned off to avoid unnecessary power consumption of the electronic device 100 and severe heat generation caused by the operation of the multiple infrared light sources 12 together. Since other infrared light sources 12 other than the infrared light source 12 with the corresponding illumination range may be in an on state or an off state, other infrared light sources 12 are turned off or remain turned off may include that the infrared light source(s) 12 in an on state among other infrared light sources 12 is/are turned off, and the infrared light source(s) 12 in an off state among other infrared light sources 12 remain(s) turned off.

In some embodiments, the face position information includes eye position information, nose position information, ear position information, or the like. That is, the face position information may be determined by position information of a part such as an eye, a nose, or an ear.