Abstract: A light-emitting diode display device includes a support unit, a display body that is mounted movably on the support unit, light-emitting diodes that are mounted on the display body, a drive unit that is coupled to the display body and that is capable of driving periodic movement of the display body relative to the support unit, a controller unit that is coupled to the light-emitting diodes and that is operable so as to actuate the light-emitting diodes for presenting images while the display body is driven by the drive unit to move relative to the support unit, and a photo-detector that is mounted on the display body, that generates an output signal in response to an incident light beam, and that is coupled to the controller unit such that the controller unit operates in accordance with the output signal generated by the photo-detector.

Abstract: An LED display apparatus includes an LED display module, an inner frame member, and a supporting unit. The LED display module has an array of light emitting diodes mounted thereon, and a longitudinal axis. The inner frame member is disposed to confine the LED display module therein, and has a size sufficient to permit movement of the LED display module in opposite directions of the longitudinal axis. The supporting unit mounts the LED display module in the inner frame member such that the LED display module is movable back and forth in the inner frame member along the longitudinal axis.

Abstract: A method for compensating for the non-uniform color appearance of a color display is disclosed. Since there are variations of the chromaticity coordinates for each primary of every pixel in a display, the color appearance is not uniform. From the distribution of the chromaticity coordinates of the original primaries, we can choose a set of virtual primaries so that the chromaticity coordinates of each virtual primary can be produced by the original primaries in every pixel. The virtual primaries are used as the primaries of the display in stead of the original primaries. Because the chromaticity coordinates of the virtual primaries are the same for all pixels, the color appearance can be made to be uniform. This method is called the virtual primary method. LED displays are taken as an example to show this method.