Last week American Eugene Polley died at the age of 96. Eugene invented “Flash-Matic” the first TV remote control in 1955. This was an early example of visible light communication (VLC) in action.
Eugene’s passing prompted me to think about some of the VLC inventions in history. I am not really thinking about the core technology, but more the early products that lay legitimate claim to being VLC applications. History will teach us how current VLC inventions might be recorded so let’s ignore these and rewind to another age.
Way back in 1971 when I was in short trousers and solid state electronics was in its infancy, the Japanese toy manufacturer Nintendo released the Light Telephone. It was developed by their #1 inventor, Gunpei Yokoi, long before their fame for Game Boys and the like. The Light Telephone was expensive, perhaps before it’s time and a bit of a novelty, but nevertheless really cool and if anyone has an original still in the box I would happily make you an offer!
The Light Telephone was capable of transmitting speech 10-30m in free space using simple incandescent torch bulbs. While the practicalities of such a device are limited, as a novelty toy there would have been a huge wow factor in 1971.
Rewinding back to 1955 and Eugene Polley’s remote control. The Zenith Flash-Matic TV was able to change channels up and down or mute and unmute the volume. These four functions were controlled by pointing the remote control’s light beam at one of the four photo-sensors located at each corner of the TV. It seems that the functions were occasionally triggered by sunlight hitting a sensor, but a TV remote control in the mid-50s was a great invention. In terms of the evolution it took a while for TV remotes to become widespread, but by the 1980’s ultrasonic devices were used. I recall our own could occasionally be triggered by opening a fizzy juice can. My brother also told me I could mute the TV by standing on the cat’s tail but I never replicated this despite repeated experiments! Remote control technology then reverted to optical technology, this time invisible light in the form of the infra-red remote controls we are all familiar with today.
To my mind the first real VLC invention was the Photophone created by Alexander Graham Bell in 1880. Patented just 4 years after the telephone, the Photophone was used to make the very first cordless phone call. This was long before radio was used for this purpose. I posted a blog on this back in February 2011 if you want a little more detail.
It will be interesting to see how VLC will be reported in the history books of the future. I am convinced that solid state lighting will be seen as the enabler for mass market adoption of VLC which improves our lives. Bell stated that the Photophone was his greatest invention – bigger even than the telephone. History may yet prove him correct. History will hopefully prove me right too!