BRIGHTNESS CONTROL DEVICE AND BRIGHTNESS CONTROL METHOD

摘要

Provided are a brightness control device and a brightness control method allowing the brightness of a light-emitting element to be controlled in such a manner that a user does not feel discomfort readily, while restricting the amount of information to be stored. A CPU (21) subtracts reference duty ratio (Dn) from reference duty ratio (Dn + 1), divides the resulting value by an interpolation division number (Nd) to calculate an interpolation variation width (Dn'), and continues to accumulate the interpolation variation width (Dn') on a reference duty ratio each time an interpolation interval (ΔT) elapses, thereby reducing the brightness variation width of LED (4). This allows a user to not feel discomfort readily, and can restrict the amount of information to be memorized.