Disaster recovery category does not include

Does the subject want to ask "which types do not belong to the dr category"? Laser emission type. DR system, that is, direct digital X-ray photography system, has no laser emission system. DR system, that is, direct digital X-ray photography system, consists of electronic cassette, scanning controller, system controller, image monitor and so on. It directly converts X-ray photons into digital images through electronic cassette, which is a generalized direct digital X-ray photography.