Friday, March 10, 2006

Independent Invention: The Light Bulb

Who invented the light bulb? Thomas Edison? Are you sure? From willitsell (via IPBiz):
An English gentleman (Joseph Swan) patented a similar light bulb in England a few months before Edison and other light bulb development considerably predated that. In fact, on October 8, 1883 the US Patent Office ruled that Edison’s US Patent was invalid due to prior art by William Sawyer. To summarize the story so far, the “light bulb” idea was not Edison’s, successful development took considerable resources, and Edison’s patent was worthless well before it had a chance to expire.
Edison, Sawyer, and Swan were not the only ones pursuing improvements on the light bulb idea. But even with Edison eventually winning the U.S. patent, it didn't do him a whole lot of good:
But Edison’s light bulb must have been a smashing success right? After all, it cost him over $10,000–in 1879 dollars when cheap labor cost 7 cents an hour–and everybody must have wanted electric light bulbs right? Some $200,000 plus later the light bulb was commercialized and 3,144 light bulbs had been sold to 203 customers by sometime in 1882. By 1889, 10 years after the patent, there were only 710 customers. The problem was that electricity and its support infrastructure cost too much and, of course, had to be installed. Ten more years later, after electricity costs had come down, there were 3 million customers and all the basic light bulb patents had expired. In fact it took 46 years for electric lighting to reach just 25% of the US population.

Seven years, and more than $100,000 in litigation expenses after Edison’s patent was invalidated by the US Patent Office, on October 6, 1889, a judge ruled that the electric light improvement claim for "a filament of carbon of high resistance" was valid. Unfortunately further research exposed in A Streak of Luck by Robert Conot (1979), also shows that Edison and his attorneys hid significant information from the judge. They cut out the October 7-21, 1879 section of a notebook that the judge might have determined showed that they were simply extending Sawyer’s (or Swan’s) work with carbon "burners" or "rods" in an evacuated glass bulb.

The reality probably is that all Edison and his team did was change their terminology to "filament" and there is a high probability they got that from a presentation Mr. Swan made in the US after filing for his patent in England. In fact, Edison and his team did not find a commercially workable filament (bamboo) until more than 6 months after Edison filed the patent application. The weak and short lived (40-150 hours) carbon filament was laid to rest for good by the coming of the tungsten filament in 1906.
We love to beat a dead horse here at Right to Create, and our current system of ignoring the independent invention defense is certainly a rotten, stinking corpse.

Previous Independent Invention Coverage:


Anonymous Anonymous said...

Yes, it's a dead corpse because it's not going to happen.

For one thing, who's going to compete for a patent (and pay for it) if they know all their competitors are going to be immune for independent invention once the patent issues?

Although Edison was no angel, he was an innovative, hard-working, and effective engineer. If you read about the technology and the players in this case, you'll see that his contribution was significantly different than those who came before. Whether his patent was valid - that's a different story. But part of the whole idea of the patent system is to incentivize more than one person to develop the next step in technology.

10:48 PM  
Anonymous kenny said...


I'll ask two equivalent questions: Who would compete for a patent if they knew all their competitors could be immune by inventing around the patent once the patent issues? Who would invent anything and keep it as trade secret knowing that their competitors could independently invent it and bring it to market?

We have plenty of examples of answers to the last two questions: it just isn't a problem. Lots of companies and individuals are busy innovating using both methods, and their competitors are answering with their own innovation. It doesn't hurt anything that these two loopholes exist.

Why should it be any different for the first?

The only reason we don't have examples of the first, is that we don't have an exemption for independent invention, so there is obviously no data to support the argument on either side.

BUT, the evidence we do have for similar situations is compelling; it argues that the independent invention defense would be beneficial.

8:00 PM  
Blogger Lawrence B. Ebert said...

Of Edison, he created longer-lived bulbs by carbonizing certain bamboo fibers to make a high resistance filament. The Sawyer/Man patents were indeed about something else, and they ultimately lost in court. Some other issues: carbonized bamboo filaments had been tried before, and, more importantly, Edison didn't disclose bamboo in his patent application. Figuring out "who" to reward can be a tricky issue, and will be a problem coming up in spades in embryonic stem cells. I discuss some of the details in "Edison's Light Bulb and Stem Cells" in a coming issue of Intellectual Property Today.

8:52 AM  
Blogger Ralleh said...

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4:02 PM  

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