The invention Adler is best known for is the wireless
remote control for
televisions. While not the first remote control, its underlying
technology was a vast improvement over previous remote control systems. The "
Zenith Flash-Matic" remote control, invented by
Eugene Polley, another
engineer at
Zenith, was the first wireless remote control, replacing the signal cable–based remote control devices, which never were a success. The Flash-Matic used directional
flashlight in the transmitter device, and photocells in the television set itself. One of the major shortcomings of this technology was that if the television set was exposed to direct sunlight, it could inadvertently trigger one of the remote control functions. The company president sent the engineers back to the drawing board to come up with a better solution. A system based on
radio waves was briefly considered but rejected because the signals could easily travel through walls and could inadvertently change the channel on a neighbor's television. Furthermore, the marketing people at Zenith desired a remote control which did not require batteries, as it was perceived at the time that if the battery died, the customer might think something was wrong with the television set itself. Adler's solution was to use sound waves to transmit signals to the TV. The first remote control he developed, the "Space Commander", used
aluminum rods, analogous to
tuning forks, struck by hammers toggled by the buttons on the device, to produce high-frequency tones that would be interpreted to control functions on the television set. In the 1960s, Adler modified the remote control to use
ultrasonic signals, a technology which went on to be used in television sets manufactured for the next 25 years, until replaced by infrared systems which could transmit more complex commands but required batteries to run. ==Professional accomplishments==