Vehicle lighting device

A vehicle lighting device comprising:

• a light source unit including a plurality of light-emitting elements connected in series;
• and
• a power supply unit to turn on the plurality of light-emitting elements, wherein
• in the light source unit, the plurality of light-emitting elements connected in series are divided into a first light-emitting element group and a second light-emitting element group,
• the light source unit includes:
• a pair of comparison resistors connected in series, the pair of comparison resistors being connected to a high potential side and a low potential side of the first light-emitting element group and the second light-emitting element group to generate a voltage equivalent to a voltage at a connecting point between the first light-emitting element group and the second light-emitting element group;
• and
• a transistor having a base connected to one of connecting points including:
• a connecting point between the first light-emitting element group and the second light-emitting element group;
• and a connecting point between the pair of comparison resistors, and having an emitter connected to another one of the connecting points,
• the first light-emitting element group, the second light-emitting element group, and the pair of comparison resistors form at least one bridge circuit, and
• when one or more light-emitting elements included in the first light-emitting element group or the second light-emitting element group are short-circuited, the transistor operates.