Patent ID: 8830216

Claim:
An illuminance detection method comprising: detecting an open operation of a flip-type electronic device including: a first housing having user interface located at an inner side in a closed state; a second housing engaged with the first housing so that the second housing may oppose the user interface and freely open and close; and an illuminance sensor installed at an outside of the flip-type electronic device when the second housing is in a closed state; measuring illuminance level in a vicinity of an area when an open operation of the flip-type electronic device is detected at a start of the open operation being performed, such that the flip-type electronic device was previously closed immediately prior to detection of the open operation being started, and such that the illuminance level is measured before the open operation has been completed, in that the illuminance level is measured as the flip-type electronic device is beginning to be opened but has not yet been completely opened; and controlling a backlight of the user interface based on the illuminance level measured in the measuring by comparing the illuminance level to a threshold, and turning on the backlight when the illuminance level is less than the threshold.