Originally Posted by SolipsismX
But is not being required to submit a working prototype the same as using a concept that in no way could be a real product?
As shown above, the patent office no longer requires working prototypes - mostly due to practical reasons. There are around 8 million patents currently, so how could they store 8 million prototypes - with multiple examples of some of them. In addition, many patents are only useful if they are part of a larger device. For example, a patent might involve an improvement to the control rods of a nuclear plant. To show a working prototype, you'd need a full nuclear plant to be submitted with the application.
The patent office has the right to ask for a working prototype, but they do so only in unusual cases. However, that does not absolve you of the requirement to provide enough detail in your disclosure that a working prototype COULD be built. If you simply provide a concept, there's not enough detail to build a working product, so it should be rejected.
That's one of the key factors to be considered in filing for patents. If you don't apply for a patent, you can keep secrets for yourself. You're not protected, but if the technology is difficult enough that you think the competitors can't find it on their own, it may make sense not to file for a patent. OTOH, if you file for a patent, you have legal protection (albeit protection that costs you a lot of money to enforce), but you have to explain your invention in enough detail that it's possible for a competitor to duplicate it. It's not surprising that a lot of companies are foregoing the patent system entirely because they don't have the money to fight a larger competitor, so why disclose enough information to get a patent?
Of course, that's the way it's supposed to work and the way it should work under the law. There are certainly cases where the patent examiner allows a patent where there's not enough detail to duplicate the invention and create a working prototype. If that's the case, the patent can be challenged because of vagueness.