Patent ID: 8370026

Claim:
An activation device for detecting a collision of a vehicle and activating a protection apparatus for protecting an occupant, the activation device comprising: a front collision detection unit configured to detect a front collision of the vehicle and output a front-collision-state activation signal to a protection apparatus related to the front collision so as to activate the protection apparatus related to the front collision when detecting the front collision; and a rear collision detection unit configured to detect a rear collision of the vehicle, output a rear-collision-state activation signal to a protection apparatus related to the rear collision so as to activate the protection apparatus related to the rear collision when detecting the rear collision, prohibit output of the rear-collision-state activation signal to the protection apparatus related to rear collision for a first predetermined period when the front collision detection unit detects the front collision, and set a first rear collision threshold and a second rear collision threshold, which are for determining whether the vehicle causes the rear collision, respectively to a third rear collision threshold and a fourth rear collision threshold, which are less than the first rear collision threshold and the second rear collision threshold respectively, in a second predetermined period subsequent to elapse of the first predetermined period; wherein the first and second predetermined periods are shorter than a time period between the front collision and an expected subsequent rear collision.