An airbag cushion has two chambers to permit the front chamber to inflate less rapidly than the back chamber for cushioning the head of an occupant in a vehicle with less force than the chest of an occupant is cushioned by the back chamber. More particularly, hydrogen from a store is provided to pre-cool helium contained within a closed loop refrigeration circuit. When the micro lens array is applied to a display device, a high contrast ratio can be obtained, and the light can be transmitted in a single direction.