This is a concept question for my and hopefully others' benefit.

I have recently developed a working prototype for a medical application. It is based on a principle that was developed in the 1960's and is an area of active research in universities around the world. Since my prototype is now functional, I plan to make a commercial product out of this.

For the sake of this discussion, let us assume that I am building a thermometer that transmits the sensed temperature to the cloud so the user can trend his temperature changes on his smartphone.

I did a patent search a found a few patents that are recently awarded that are very broad. My questions are:

  1. In this case, measuring the temperature using a temperature sensor is a basic principle in science. So if I build a thermometer, do I have to pay royalties to existing patent holders of such a basic application?
  2. The existing patents also claim sending the measured data to the cloud for trending and later viewing. Does it mean that I cannot build similar functionality without paying royalties?
  3. If the existing patents claim N sensing units for measuring the temperature, does it mean that they have a patent on 2,3,4,..to..infinity sensors? Can I make a product with 3 sensing units without infringing?

These are general questions that will help a novice get started. I plan to get professional help, I am just trying to understand what to expect.


  • Which patents have you found, specifically? Dec 18, 2012 at 21:35

4 Answers 4


Generally claims cover structures. Two very different structures can have the same function. Patents do not monopolize all ways of carrying out a function.


In addition to Jeremy Thompson's answer, remember that royalties only have to be paid if the patent owner demands them. There is no automatic legal requirement for you to offer to pay royalties; in fact, you may never have to pay anything if the patent owner either never finds out about you or does not care. It may turn out that you don't even actually infringe.

However, if the owner does eventually decide to assert his patent, you may be liable. Prior knowledge of the patent may make you liable for enhanced damages if a lawsuit does occur and willful infringement is successfully proven. (This is statistically somewhat unlikely though, and most patent suits end in settlements.)

You may wish to head off your liabilities ahead of time by proactively seeking licensing. Or, more typically, you could focus on getting a successful product on the market out first before worrying about potential infringement. After all, if your product doesn't become a competitive threat, you're probably not worth suing.

  • Or cite the prior art and show how you have improved on it...?
    – Krista K
    Dec 30, 2013 at 4:03

First, make sure you are asking the right questions.

  1. Yes, you may have to pay royalities to a patent holder with a broad patent. Consider how much money TI made licensing the initial patent on an integrated circuit.

  2. No one can properly answer your question without seeing the entire claim. If you admit that you will infringe all of the other elements of the claim and this element as well, then yes.

  3. Again, no one can properly answer your question without seeing the entire claim. If you admit that you will infringe all of the other elements of the claim and this element as well, then yes. For this question, you must evaluate what the patentee meant by N. What does the specification say about N? What did the patentee say about N during prosecution? Is N limited by prior art? Is N inherently limited by the specification? In the end, will it matter? No-if N can be 2 and you use 2 or more, then you will infringe.


It is based on a principle that was developed in the 1960's

This is good news. This probably means that any really broad patents on the principle and basic applications thereof have long since expired. But you say you found recent broad patents.

One possibility is that these seemingly broad patents are not as broad as they seem (or are invalid). It is the patent attorney's job to make patent claims seem scary. Looks like it worked.

Another possibility is that the focus of your analysis is incorrect. Taking your example, since thermometers are known since the 1960's, any recent broad patent to N sensors would/should be patentable only if there is some particular effect of having N sensors, such as noise reduction (or a particular structure). Are you using these novel things? Do you need to, in order to make actual use of the original principle? How did people manage before?

Finally, the patents could well be invalid. You have 50+ years of prior art and publications in this field that could be useful. Most small businesses, however, will not go forward even if they believe that a patent is invalid, due to risk of legal costs.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .