| 摘要 |
A LED symbol signal with LEDs arrayed to correspond to a desired symbol. A mask defines the desired symbol. A diffusion surface on the cover diffuses the display aspect, obscuring the individual LEDs. The mask is spaced a distance from the diffusing surface. The more aggressive the diffusion pattern the closer the mask is spaced to the diffusion pattern. Preferably, the ratio of the pitch of the optical elements to the width of the symbol at the diffusion surface is less than 1:2, preferably less than 1:4, more preferably less than 1:6 and most preferably approximately 1:10. |
