employer and employee filed a joint patent, employer is threatening legal action what are my rights under WA state fedeal laws

Federal patent law provides the rules to determine whether a person is a joint inventor of whatever invention(s) are described in the claims that are filed as part of a patent application. Very oversimplified, "[a] joint invention is the product of collaboration of the inventive endeavors of two or more persons working toward the same end and producing an invention by their aggregate efforts." If a person is a joint inventor, then he must not only be named as an inventor in the application, he is required to make and sign certain declarations about the invention sought to be patented. With some exceptions, if all the inventors are known but one or more are not named in the application, then any patent that matures from that application could be invalidated.

Assuming the person is a joint inventor, the rule under federal patent law is that once the patent application matures into a patent (if it ever matures -- many do not because they do not qualify) then the person has the right to make, use, sell, and otherwise exploit (via licensing, etc.) every one of the inventions claimed in the patent. That is, each named inventor owns the right to all the claimed inventions and none of the inventors are obligated to account to any of the others for the profits they each make by exploiting those inventions.

The wrinkle is that the ownership of patent rights can be altered by contract and by state statutory law. Which is why good employment agreements include a provision that assigns to the employer essentially all of the inventions made by its employees. This effectively transfers to the employer all the rights that the employee inventor is afforded under the inventorship provisions of federal patent law. Those transfer provisions in employment agreements are often limited, however, by state laws. For example, in California transfer provisions that purport to transfer rights in inventions from employees to employers are void if the employee developed the invention "entirely on his or her own time without using the employer's equipment, supplies, facilities, or trade secret information" and the invention does not relate to the employer's business or its research and development efforts and it was not the result of work that the employee performed for his employer. Some states have, however, "shop right" provisions that grant employers the right to use all employee inventions made while the employee was working within the scope of his or her employment even if that employees is not contractually obligated to assign the invention to the employers.

In short, you need a competent Washington state employment lawyer (with litigation experience) to take a look at whatever employment agreement you signed while at your former employer -- or if there is no employment agreement, then at the employee handbook -- in order to determine what rights you contracted away to your former employer and to determine what rights and limitations Washington state law imposes.

You could start the process by politely asking, in writing, for a copy of the signed employment agreement and/or employee handbook that allegedly obligates you to assign your inventorship rights to your former employer. If no documents are forthcoming, then ask (again in writing) for the basis for your former employer's claims that you must assign away those rights.

Note also that if your former employer has threatened to file suit against you for not cooperating you may have the right to file your own "declaratory judgment" lawsuit (in the court closest to your own home) against your former employer which seeks from the court a declaration as to what rights you and your former employer have vis a vis the inventions claimed in the patent application.

Mr. Ballard's response is spot on and I concur. Additionally, I would like to clarify how ownership or "title" to a patent works.

Any person who contributes to the invention of subject matter in at least one claim in a patent application MUST be named as an inventor in the application. By default, each inventor owns a proportional share; however, each inventor would have a right to license, sell, enforce or otherwise use any patent rights without consent of any of the other inventors.

Many times, as Mr. Ballard notes, an employment agreement will include a clause that states an inventor must assign any inventions to the employer that were made during the course of employment AND that the inventor will reasonably cooperate with the employer in filing for and obtaining a patent. Specifically, this would include sighing various declaration forms and likely a formal assignment agreement, which would be recorded at the USPTO.

Accordingly, it is important to review your employment agreement to determine whether you agreed to assign this invention to the employer and whether you have a duty to cooperate with them during the process. Most importantly, depending on the circumstances under which you invented and developed this invention, you may have valuable patent rights remaining. Have the situation analyzed by an attorney before you sign anything.