新しい発明をした場合、特許を取っておかないと、すぐにその アイデア を使われてしまう

Question

新しい発明をした場合、特許を取っておかないと、すぐにその アイデア を使われてしまう。

The problem stems from the fact that I can't handle some elements in this sentence and therefore also have issues determining the exact meaning of the conditional phrase. First, my attempt at translation:

"When you've made a new invention, if you don't patent it, this idea will be used immediately."

First, in the conditional clause, おかない is an issue for me. I've learnt that て-form + おきます expresses:

1. A necessary action is performed until a certain point in time
   旅行の前に、切符を買っておきます。
2. A necessary action is performed so you can use X the next time.
   鋏を使ったら、もとのところに戻しておいてください。
3. You let something remain in its current state:
   明日会議がありますから、いすはこのままにしておいてください。

I think that in this case, it should be in the function of 1).
However, I always feel a bit unsure about this, so I wanted to confirmation

Second, しまう.
て-form しまいました was introduced as indicating regret.

試験は失敗してしまいました。

However, if I remember correctly it can also express that something was finished.
Still, I just don't really know what it adds to this sentence, especially since it isn't in past tense, which makes it harder for me to coax the "finished" meaning into it.

Third, the overall mood of the sentence.
The sentence as it stands strongly suggests an unreal meaning in my opinion.
In English, this would be expressed the conjunctive mood. However, I learned some constructions for unreal expressions, but these aren't here.

"If you make a new invention, if you don't patent it, the idea would/could immediately be used."

I guess it's mostly because I don't feel very sure about my interpretation of the elements I mentioned before, that I feel like something is lacking.

Answer 1

You've basically got it right. The sentence presents a counterfactual, and there are a couple of words/constructions that are there simply to denote a regretful situation.

特許を取っておかない is simply the negative of 特許を取っておく、which means "get a patent." The ておく construction is there to imply "get a patent in advance to prevent misuse of your invention." おかない just means to fail to do that. The following と is the conditional と, meaning the following clause represents an inevitable result.

Finally, 使われてしまう。This is a combination of the "suffering passive" (使われる), implying "will be used, to my disappointment/disadvantage," and しまう just intensifies that. So overall, in colloquial English:

"If you don't patent your invention, someone's going to steal your idea right away and you'll be screwed."

Answer 2

I'm an amateur myself, but I think you are more or less right. Don't beat yourself up too hard :)

ておく (6㋓) あとに起こる事柄を予想して、前もって…する意を表す。 (Predicting something happening in the future, and doing something in advance to prepare for that)

When it comes to 使われてしまう it simply means it will regretably be used as you said, so my interpretation is "If you make an invention and don't patent it immediately, other people will unfortunately use it (the idea)."