One hundred ten years ago, a British inventor created the first ever light-emitting diode (LED). To mark the anniversary of this discovery, we are running a series highlighting the evolution and everyday uses of LEDs. This week, in the third of four posts, we examine the many consumer applications for LEDs
After the expansion of the LED spectrum, applications for LED lights blossomed. No longer confined to a dim glow or invisible infrareds, LEDs infiltrated all manner of electronics. They even appeared in unconventional, unexpected places. By the time three Japanese scientists discovered the blue LED in the early 1990s, the efficient bulbs were already visible throughout the country. With the blue LED and improvements in efficiency and cost, they were omnipresent.
Film director Stanley Kubrick inspired the first popular consumer applications for LEDs. Kubrick famously sweated the details for his 1968 science-fiction epic 2001: A Space Odyssey. In addition to consulting dozens of experts to help depict the science for his fictional future, Kubrick wanted a futuristic clock for his set. He reached out to the Hamilton Watch Company to create a clock with a digital display. Hamilton produced a clock with red LED digits, wowing keen-eyed audiences. The groundbreaking display inspired the watchmakers to explore other opportunities to use the LED display. The resulting watch, named the Pulsar, revolutionized time-keeping. The Pulsar was the first watch with a digital display and the first to use LEDs. Hamilton called it a “time computer” and counted President Gerald Ford, comedian Jerry Lewis, and even the fictional James Bond as admirers.
LEDs invaded many small electronics, in addition to the Pulsar, in the 1970s. The inexpensive, low power lights drove down prices, making once-expensive products into affordable consumer items. New digital wristwatches, designed to compete with the Pulsar, flooded the market. While the Pulsar cost over $1,000, by 1975 Texas Instruments sold digital watches for as little as $20. LEDs also revolutionized calculators. A Japanese company created a digital LED display for a calculator in 1971. Not only did the LEDs help reduce the price, but they also helped manufacturers reduce the calculator’s size, leading to the first pocket calculator. Capitalizing on this creation and fighting off competition, Pulsar combined the two technologies into the calculator watch, which the company introduced in 1975. Smaller, cheaper, and more reliable than incandescent lights, LEDs became the go-to light source for small electronics in the 1970s.
After engineers transformed watches and calculators with LEDs, they set their sights on everything else that glowed. Within two decades, nearly every light-producing part of daily life had been improved with light-emitting diodes. Today we take for granted the improvements in size, price, and efficiency afforded by these everyday innovations. The expansion of LEDs across our late 20th century landscape, however, was equal parts incremental and transformative. Here is an abbreviated list of items that transitioned to LEDs:
1977 – First LED television. According to an intrepid Wikipedia author, the first LED television was built by an Iowa student named James Mitchell in 1977. The single-color model reportedly won local and national recognition on the student science circuit. Mitchell toured Iowa and then the country with his TV. Though digital confirmation of Mitchell’s achievement is scarce, the Wikipedia citations do include several print sources that suggest Mitchell deserves honors for this breakthrough. Further innovation on his LED TV took decades. It wasn’t until 2007 when Samsung introduced the first LED television, replacing the traditional fluorescent lights with LEDs to backlight a liquid crystal display. Today, LED TV’s dominate the market, in the form of both inexpensive models and top-of-the-line OLED technology.
1985 – First mass-produced LED exit signs. Exit signs are less glamorous than televisions but equally prevalent. Their evolution to LED was also much faster. Gilbert Industries produced the first LED exit signs in 1985 and by 2001, 75% of all exit signs sold in the US used LEDs.
1989 – LED traffic lights. Raymond Deese introduced the first LED traffic lights in 1989. He then watched his product, and his competitors’, gradually dominate our streets. Supported by state departments of transportation, cities first replaced the red lights, then green, then entire signals with LEDs. The City of Philadelphia was a leader throughout the transition. It was one of the first cities to introduce red LEDs to intersections and also one of the first to replace entire signals with LED lights.
1998 – LED holiday lights. Like in exit signs and traffic lights, LEDs provide a huge efficiency boost to holiday lights, but it wasn’t until the late 1990s that LEDs flourished in December. The biggest transformation took place in the mid-2000s however. In 2005, the Christmas tree at the Capitol in Washington, DC was adorned with 10% LEDs and 90% incandescents. Just one year later, the tree had 100% LEDs. The year after that, the Christmas tree in Rockefeller Center in Manhattan held 100% LEDs for the first time.
In addition to making existing products more efficient, LED lights helped researchers develop new products that dramatically improved on their predecessors. The LED, for example, enabled the creation of the digital/optical mouse, which rapidly replaced mechanical/roller mice. The LED was necessary for the invention and advancement of digital video players, first with DVDs and then Blu-ray. These are just the obvious places where LEDs have intervened. Invisibly improving thousands (millions even?) of electronic devices, the light-emitting diode made technologies smaller and more efficient, enabling our head-over-heels rush toward smaller and smaller gadgets.
LEDs entered our homes, our streets, our jobs, and our vacations; it was only a matter of time before they entered our closets. Credit for pioneering LED-adorned apparel belongs to the American shoe company LA Gear. Marketing their light-up LA Lights shoes to children, LA Gear sold millions of pairs every year. At the height of the craze in the 1990s, the LA Gear founder (and eventual co-founder of Sketchers), exclaimed, ”They’re like little red wagons — every kid has to have them.” The LED takeover of our wardrobe never did occur though. On occasion, LED clothing highlights celebrity attire at a gala (Katy Perry, 2010) or an opening (Nicole Scherzinger, 2012). Attempts to penetrate the clothing market with LEDs continue, but the next breakthrough on the scale of LA Lights remains elusive.
Next week, for our final post, we will examine the LEDs most impactful disruption: the replacement of traditional incandescent and fluorescent bulbs for everyday use.