On a drive ring, a first cam and a second cam are formed. The first cam engages with a slider when a light emitting unit is in a stored state. The second cam releases engagement between the slider and the first cam to engage with the slider when the light emitting unit in the stored state is brought into the in-use state by a manual operation. When the light emitting unit is moved from the stored state to the in-use state by the manual operation, a gap is formed between the light emitting unit that becomes the stored state and the slider so that the light emitting unit moves from the stored state to the first state with a state in which the slider is in engagement with the first cam without moving.