[JackC]

This wikipedia section is a good place to start seeing how it works: https://en.wikipedia.org/wiki/Patent_claim#Basic_types_and_c...

What I remember from law school is: let's say you're drafting a patent, and you want it to cover as much as possible without getting invalidated by prior art. So you're going to write some claims, and each claim can stand or fall on its own (each claim could be rejected by the patent office, or invalidated later because of prior art, without invalidating the more specific claims). So first you'll write a series of independent claims, and those will each be as broad as you hope you can get away with ("it's HTML on a computer!"). Having the broad independent claims stand is your best case scenario, because that makes it hard for competitors to work around your patent. But then for each independent claim you'll add dependent claims, which narrow down what you're claiming ("OK, it's HTML on a computer with foo," "OK, it's HTML on a computer with foo and bar"). That's your fallback scenario: maybe "HTML on a computer" gets rejected, and "HTML on a computer with foo" gets rejected, but "HTML on a computer with foo and bar" is original enough to make it through, so you still end up owning something of value. But maybe now that your broad claims are gone, your competitors can avoid your patent by doing "HTML with foo and baz" to accomplish the same thing.

So that's how the game theory works: you're basically leaving money on the table if you don't include some super broad claims at the top. Doesn't cost you anything if those ones don't stick. So we can't just read a patent and assume it actually protects every single broad claim -- but we can't assume it doesn't, either. We won't find out for sure which (if any) claims are actually valid unless there's a lawsuit and a judge or jury has to pick through the prior art and decide whether there are claims in there that are narrow enough to be original.

[dathinab]

> "HTML on a computer with foo and bar"

But here it's where the patent system is broken. Doing conceptually trivial combinations of on itself non patentable thinks should _never_ be patentable, at lest for software but probably for anything. Sure patenting a specific complex mechanism for combining two thinks might be patentable but in case of software this is hardly ever the case, most times its more or less trivial glue code.

So e.g. Face recognition + smartphone + unlock screen might all be patentable by itself. Especially a faceregocnition algorithm which works especially good for smartphone usecase might be patentable. Bu using existing face recognition on a smartphone to unlock the screen shouldn't be patentable. They are all existing components and combining them is conceptually trivial. In the end patents where meant to protect research investments, not random ideas.

[adrianN]

Every invention is just a combination of existing things with maybe a new twist somewhere. James Watt wasn't the first person to build a steam engine, he just introduced a separate condenser to an existing design.

It's really hard to find a good line of what should constitute a patentable invention. Personally I think that no software should be patentable, ultimately because I don't think that Mathematics should belong to anybody. But I understand that other people see this differently.

[bdowling]

> existing things with maybe a new twist somewhere.

To be valid, a claim must be novel (new) and non-obvious over the prior art. So there absolutely must be a new twist somewhere.

[adrianN]

I can still build a machine entirely from off-the shelf parts, connecting them exactly in the ways they're built to connect to each other, and claim to have invented it.

[bdowling]

If the resulting combination is a machine that is useful, new, and non-obvious, then I'd call that an invention.

[pnw_hazor]

The claims in the issued patent define exactly and only what the patent protects.

During the prosecution of the patent (the back and forth with the USPTO) the claims may be amended as long as there is support for the amendment in the description. The description (generally speaking) cannot be amended without refiling and losing the priority date.

These amendments are usually narrowing the independant claims to avoid prior art - similar to your example. Additional details from the descriptions are added to the claims until the examiner agrees that the prior is overcome.

The independent claims are the broadest, and the dependent claims add additional limitations (more or less) that are often directed optional features.

In this patent, which is pretty good for an old-time software patent, this element:

"(c) substituting the data entered by the user into the HTML input form into a dynamic SQL query using a common name space, wherein the common name space comprises variables found in both the dynamic SQL query and the HTML input form;"

is probably what convinced the examiner to allow the patent.

[_bxg1]

> Doesn't cost you anything if those ones don't stick.

This sounds like the central problem, to me.