Signal device and collision avoidance system

A turn signal device comprising:

• a right turn signal, provided on a right side of a rear part of a host vehicle, the right turn signal having a plurality of light-emitting units arranged in a vehicle width direction of the host vehicle;
• a left turn signal, provided on a left side of the rear part of the host vehicle, the left turn signal having a plurality of light-emitting units arranged in the vehicle width direction of the host vehicle;
• an operation device, provided in a driver cab of the host vehicle, the operation device being capable of generating an operation signal for causing one or both of the right turn signal and the left turn signal to operate in response to an operation made by a driver;
• an acquisition unit that acquires a determination signal indicating a determination result of whether or not there is a risk of a collision between the host vehicle and a following vehicle traveling behind the host vehicle;
• a normal situation control unit that, on the basis of the operation signal, outputs a normal situation control signal such that the plurality of light-emitting units in one or both of the right turn signal and the left turn signal light up sequentially from an inner side to an outer side with respect to the vehicle width direction at constant time intervals, wherein the normal situation control unit outputs the normal situation control signal such that after a first light-emitting unit of the plurality of light-emitting units lights up, a second light-emitting unit of the plurality of light-emitting units lights up while the first light-emitting unit lights up;
• and
• a dangerous situation control unit that, upon the determination signal indicating a determination result that there is a risk of the collision being acquired, outputs a dangerous situation control signal such that the plurality of light-emitting units in both of the right turn signal and the left turn signal light up sequentially from the outer side to the inner side with respect to the vehicle width direction at constant time intervals, wherein the dangerous situation control unit outputs the dangerous situation control signal such that after the first light-emitting unit of plurality of light-emitting units lights up, the second light-emitting unit lights up while the first light-emitting unit lights up.