Patent ID: 7911412

Claim:
A method of controlling beam power of an X-Y vector scanning light beam provided by a projector forming an image viewable in mid-air and being projected into a projection area including a viewing audience, the method comprising the steps of: projecting a scanning light beam into the projection area including a viewing audience, wherein at least some members of the audience are looking directly toward the projector projecting the scanning light beam; accessing a data table, the data table including: a spatial grid representing at least a portion of the projection area over which the scanning light beam is to be projected, the spatial grid comprising a plurality of regions having spatial coordinates correlated to the projection area; and a maximum permissible light level for at least some of the regions correlated to a portion of the projection area available to the viewing audience; receiving the spatial coordinates of an instantaneous X-Y beam position on the spatial grid; correlating the received spatial coordinates with a respective region in the data table; receiving a beam power of the scanning light beam; comparing the received beam power with the maximum permissible light level at the respective region; and if the received beam power exceeds the maximum permissible light level at the respective region, issuing a signal indicative thereof.