Patent ID: 8235606

Claim:
A mirror unit comprising: a first mirror that reflects and passes incident light from a subject side; a second mirror that reflects the incident light passed by the first mirror; a first mirror holder that holds the first mirror, is rotatable on a rotational axis arranged above an optical path of the incident light, is lowered to a first mirror-down position in which the first mirror is inserted into the optical path of the incident light, and is raised to a first mirror-up position in which the first mirror is removed from the optical path of the incident light; and a second mirror holder that includes an auxiliary component and a mirror holding component holding the second mirror, is lowered to a second mirror-down position in which the second mirror is inserted into the optical path of the incident light, and is raised to a second mirror-up position in which the second mirror is removed from the optical path of the incident light, wherein the auxiliary component is provided below the first mirror holder in the direction of the lowering, is rotatable on a rotational axis that is the same as or parallel to the rotational axis of the first mirror holder, and can be lowered independently of the first mirror holder, the mirror holding component is engaged with the auxiliary component to be relatively rotatable around a rotational axis that is parallel to the rotational axis of the auxiliary component, and the second mirror holder is lowered from the second mirror-up position to the second mirror-down position prior to the first mirror holder being lowered from the first mirror-up position to the first mirror-down position.