A single liquid-crystal display can be used to be either of direct-vision or projection type, if required. Separate display devices for monitor and OHP are not required. Further, power consumption can be reduced, with the service life of the display being prolonged to improve economy.The liquid-crystal display includes a display housing which receives a liquid-crystal panel, a driver circuit unit and a cooling fan, the display housing being detachably mountable in a back light stand. When the display housing is mounted or dismounted in the back light stand, the fan and back light can automatically be turned on or off to reduce the power consumption. The liquid-crystal panel can be prevented from being degraded by cooling it by way of the fan.