The utility model discloses a projecting lamp and controller to and has a display system of this projecting lamp. The projecting lamp is used for installing to display device, and the display device rear has the background face, and background bread is drawn together the central zone who lies in the display device dead astern and lie in the central zone outlying peripherally regional. The projecting lamp includes a housing. The light source subassembly is including installing to the luminescence unit of casing, polarisation optical element covers in the luminescence unit to a peripheral regional biasing that is used for installing to display device's rear side or when peripheral at the casing, sends at least partial light towards the background face with the luminescence unit the utility model provides a projecting lamp sent shines wide part and shines peripheral regional at display device rear background face, and the light source of make full use of projecting lamp reduces the lightand shade contrast when watching media.