Is there a damages threshold below which a US judge would not accept a patent litigation case? Let's say defendant demonstrates that plaintiff would at most get 10k $ in damages in questionable patent confrontation. Would judge accet such case? Knowng in advance that this would result in overlitigated case. If so is it the same for all states?
No. There is no threshold.
For example, a patent case can even be accepted if requested damages are $0, but the plaintiff simply requests that the alleged infringer stops making, using, sell, offering to sell, OR importing into the United States.
Jurisdiction is likely Federal which is applied the same in all states.
Talk with a patent litigation attorney about this before doing anything.
Damages are capped at $100,000 for "small cases" by federal patent law. Therefore it applies to all 50 states. A judge can chose weither to accept a case or not (Ref: http://www.invention-protection.com/ip/publications/docs/Damage_Relief_for_Patent_Infringement.html)