1. A driving device configured to change a quantity of light emitted from a backlight based on a predetermined BL-drive value,
comprising:
a drive normalization part configured to calculate a reference light quantity measurement representing a light quantity measurement
which is estimated and obtained from an optical sensor when the backlight is driven using a predetermined reference BL-drive
value at a current time based on a current BL-drive value, representing a BL-drive value at the current time, and a light
quantity measurement, representing a numerical value of a light quantity of the backlight driven by the current BL-drive value,
which is obtained from the optical sensor;

a low-pass filter configured to calculate a moving average among a plurality of reference light quantity measurements being
temporarily held, thus outputting a smoothed reference light quantity measurement precluding noise; and

a BL-drive value calculation part configured to calculate a target BL-drive value representing a BL-drive value which allows
the smoothed reference light quantity measurement to match a target light quantity based on the smoothed reference light quantity
measurement and the target light quantity based on a user's setting of luminance.