Operation method of electronic device

An operation method of an electronic device comprising a first display element, a second display element, a first circuit, and an optical sensor, comprising:

• measuring an illuminance of external light by the optical sensor;
• transmitting an illuminance data including the illuminance of external light to the first circuit;
• obtaining a first data and a second data by the first circuit;
• setting a first gain value to 0 by the first circuit and determining a second gain value with use of a first function and the illuminance of external light by the first circuit when the illuminance of external light in the first circuit is lower than a first illuminance;
• determining the first gain value with use of a second function and the illuminance of external light by the first circuit and determining the second gain value with use of a third function and the illuminance of external light by the first circuit when the illuminance of external light in the first circuit is higher than or equal to the first illuminance and lower than a second illuminance;
• determining the first gain value with use of a fourth function and the illuminance of external light by the first circuit and setting the second gain value to 0 by the first circuit when the illuminance of external light in the first circuit is higher than or equal to the second illuminance;
• multiplying the first data by the first gain value or a value corresponding to the first gain value to generate a third data in the first circuit and multiplying the second data by the second gain value or a value corresponding to the second gain value to generate a fourth data in the first circuit after the first gain value and the second gain value are determined;
• and
• displaying an image based on the third data using the first display element and an image based on the fourth data using the second display element.