A light emitting element comprising at least a light emitting layer containing a light emitting material and a host material and having a light emission maximum wavelength of 500 nm or less wherein the minimum excitation triplet energy level of the host material is higher than the minimum excitation triplet energy level of the light emitting material. The second member is relatively movable in a first direction with respect to the first member. As a result of the use of an ion beam assist method in the formation of any one of the intermediate film, bottom electrode, ferroelectric film or piezoelectric film, a piezoelectric device or ferroelectric device which has a piezoelectric film or ferroelectric film with an in-plane orientation can be manufactured with good efficiency. A host device obtains authentication information from the accessory in accordance with a protocol associated with the master interface.