A discharge lamp driving device comprising: a discharge lamp driving unit configured to supply a driving current (Id) to a discharge lamp provided with electrodes (92, 93); and a controller configured to control the discharge lamp driving unit, wherein the controller is configured to control the discharge lamp driving unit to provide a plurality of periods, characterised by the plurality of periods comprising: a hybrid period in which a first period for supplying an AC current with a first frequency to the discharge lamp and a second period for supplying a DC current to the discharge lamp are alternately repeated, a third period in which an AC current with a second frequency lower than the first frequency is supplied to the discharge lamp, and a fourth period alternately including a fifth period in which a DC current is supplied to the discharge lamp, and a sixth period in which a DC current with a polarity opposite to a polarity of the DC current supplied to the discharge lamp in the fifth period is supplied to the discharge lamp, wherein a length of the fifth period is longer than a length of the sixth period, wherein the length of the sixth period is less than 0.5 ms, and wherein a total of lengths of the fifth periods in the fourth period is longer than a length of the second period, and is longer than a length of half a cycle of the AC current with the second frequency in the third period. a discharge lamp driving unit configured to supply a driving current (Id) to a discharge lamp provided with electrodes (92, 93); and a controller configured to control the discharge lamp driving unit, wherein the controller is configured to control the discharge lamp driving unit to provide a plurality of periods, characterised by the plurality of periods comprising: a hybrid period in which a first period for supplying an AC current with a first frequency to the discharge lamp and a second period for supplying a DC current to the discharge lamp are alternately repeated, a third period in which an AC current with a second frequency lower than the first frequency is supplied to the discharge lamp, and a fourth period alternately including a fifth period in which a DC current is supplied to the discharge lamp, and a sixth period in which a DC current with a polarity opposite to a polarity of the DC current supplied to the discharge lamp in the fifth period is supplied to the discharge lamp, a hybrid period in which a first period for supplying an AC current with a first frequency to the discharge lamp and a second period for supplying a DC current to the discharge lamp are alternately repeated, a third period in which an AC current with a second frequency lower than the first frequency is supplied to the discharge lamp, and a fourth period alternately including a fifth period in which a DC current is supplied to the discharge lamp, and a sixth period in which a DC current with a polarity opposite to a polarity of the DC current supplied to the discharge lamp in the fifth period is supplied to the discharge lamp, wherein a length of the fifth period is longer than a length of the sixth period, wherein the length of the sixth period is less than 0.5 ms, and wherein a total of lengths of the fifth periods in the fourth period is longer than a length of the second period, and is longer than a length of half a cycle of the AC current with the second frequency in the third period.