摘要 |
An image display apparatus comprising a rotatable member carrying an array of light emitting devices; a drive for rotating the member, and a control for selectively energizing each of the light emitting devices in a predetermined sequence as the member rotates so as to present a visible image. The image display device is incorporated in a fan cooling unit having a plurality of blades, the rotatable member being one of the blades of the fan cooling unit. The fan cooling unit includes a sensing arrangement responsive to rotation of the blades, for triggering the control for the energization of the light emitting devices in dependence on the speed of rotation of the blades. |