Abstract: An LED display device for displaying a pattern on a rotatable object by light-scanning; wherein when the rotating object rotates with a high speed, the pattern will display; the device comprising: a display device for displaying at least one pattern; the display device being fixed without rotation in operation; the display device including a screen, a processor and a memory; the processor serving to control displaying of patterns on the display device; the memory serving to store patterns to be displayed and other processing programs; a rotating printed circuit board having at least one bank of LEDs; a control circuit board controlling electric conduction of each LED; and an image scanner connected to the control circuit board; the image scanner can scan through the screen of the display device so as to sense the pattern on the screen.

Abstract: A projector includes a lighting device, a first image forming unit including first through third light modulation elements, a second image forming unit including fourth through sixth light modulation elements, a polarization combining optical system, a projection optical system, and an image correction device, wherein the image correction device, based on one of combined transmittance and combined reflectance obtained by combining one of transmittances and reflectances corresponding to gray-scale values of two of the first through sixth light modulation elements for modulating the same colored light beam, outputs the drive value corresponding to the input image data for driving the two light modulation elements corresponding to the predetermined colored light beam.