There is a significant demand for systems using laser beams to create light shows for nightclubs and the like. One type of system used for this purpose consists of a laser generating device in combination with a plurality of motor actuated mirrors which are carefully aligned with each other and with the laser beam and timed to deflect the laser beam through several apertures as separate spots or beams of light which are deflected in many directions. Each mirror is fastened to a shaft which is attached to the motor output shaft. To achieve the desired light effect, the mirror support must be exactly perpendicular to the motor output shaft. The desired deflection of the mirror requires only a limited rotation of the motor and the mirror support operates between two spaced stops. Such light show systems have been in use for a number of years but have represented a fairly significant investment. They also have been somewhat heavy and cumbersome so that, while they can be moved from place to place, moving them requires a substantial effort.
Applicant""s U.S. Pat. No, 5,576,901, describes how reductions in the weight and cost of such systems have been attained by reducing the size, weight and cost of the motors. There have, however, been disadvantages in even the latest such systems because the motor-driven mirror actuators are relatively delicate and can be knocked out of adjustment if subjected to careless handling. Also, there is a significant labor cost in initial assembly and adjustment of the motor-driven mirror actuators.
Because of the substantial labor cost in getting the mirror actuators mounted and properly adjusted, applicant began to consider alternative ways of producing the desired light shows. Existing systems used one laser diode and driver to create a single. laser beam, which was deflected in various directions by causing mirrors to move in and out of the beam to deflect the beam through several apertures. This necessarily limits the display to one beam at a time, although the actuators move the mirrors quite rapidly to create a visual effect of many beams. Even with the use of a beam splitter to make more beams available, the power output per aperture is reduced, so this option is not always satisfactory.
In analyzing all cost factors, applicant concluded that although using one laser diode and driver per aperture would be expensive, it would be only slightly more expensive and probably less expensive in volume to make the system with, for example, eight laser diodes and drivers as compared with using one laser diode and driver with eight electromechanical mirror actuators, once the higher labor costs were factored in. The separate lasers and drivers can each be driven by the same commercially available DMX controller which was used to drive the mirror actuators in the prior art device described in U.S. Pat. No. 5,576,901. By using a separate laser diode and driver for each of the desired number of apertures, greater flexibility is afforded because more than one laser diode can be operating at a time and lasers of varying colors can be turned on at the same time. In addition to using lasers of different colors, other optical devices, such as color filters and diffraction grating means, can be used with any or any number of the laser beams. This makes it possible to display colors, which are a mix of the colors directly available from the individual laser diodes.