FIELD: physics.
SUBSTANCE: control section controls alternately switching the control period, during which the backlight emits light, and the pause period, during which the backlight does not emit light, with a predetermined period. The control section controls the ratio of the control period and the pause period and controls the amount of the backlight control current during the control period. The control section sets the pause period as a predetermined period and controls the control current for the range, where the set point value is less than the set value, sets the control current to the predetermined value, and reduces the pause period duration less than the predetermined period for the range, where the set point exceeds the predetermined value.
EFFECT: increasing the brightness adjustment range.
9 cl, 10 dwg
