OPINION
American Medical Electronics (AME) appeals the summary judgment granted in favor of appellees. AME brings four points of error contending that the trial court erred in determining that AME’s suit for attorney malpractice was time-barred under the applicable two-year and four-year statutes of limitations. We overrule AME’s points and affirm the trial court’s judgment.
FACTUAL BACKGROUND
In 1982, AME hired Sheldon Thaler as a consultant to assist it in developing a device to stimulate the healing of broken bones. AME and Thaler completed development of the device in 1983, and a dispute arose concerning the ownership of the invention. AME hired the law firm of Richards, Harris & Medlock, Inc., to represent it in the dispute with Thaler, and Martin Korn was the main attorney on the case. Thaler suggested that he be allowed sole ownership rights in the patent application. AME consulted with Korn on this proposal, and Korn told AME: (1) that the patent probably would not issue, and (2) that even if the patent did issue, AME could practice the invention nonexclusively under the shop-right doctrine. 1 Based on this advice, AME assigned its rights in the patent application to Thaler.
On March 31, 1987, Thaler was issued a patent for the device. AME then consulted the law firm of Howson & Howson to obtain a second opinion concerning its right to continue to practice the patented device. In a letter dated July 21,1987, Howson told AME that, although a reasonable argument could be made that the assignment transferred ownership only and not the shop right to practice the invention, “if the issue were litigated, there is a substantial likelihood that the court would conclude that the shop right was released by the ... assignment.”
On January 26, 1990, Thaler sued AME for patent infringement, and on February 23, 1990, AME sued Korn and the other appellees for malpractice. Thaler’s patent-infringement suit against AME was settled on June 6, 1990. In its suit against appel-lees, AME alleged that appellees “were negligent in failing to advise AME of the possibility that it might not have non-exclusive rights to practice the invention in the event the patent application were granted.” AME further alleged that if appellees had advised it “that there was a possibility it might lose the right to practice the invention, it would not have conveyed rights in the patent application to Thaler.” AME alleged that this negligence proximately caused the Thaler litigation.
STANDARD OF REVIEW
The function of a summary judgment is not to deprive a litigant of his right to a full hearing on the merits of any real issue of fact but to eliminate patently un-meritorious claims and untenable defenses.
Gulbenkian v. Penn,
1. The movant for summary judgment has the burden of showing that there is no genuine issue of material fact and that it is entitled to judgment as a matter of law.
2. In deciding whether there is a disputed material fact issue precluding summary judgment, evidence favorable to the non-movant will be taken as true.
3. Every reasonable inference must be indulged in favor of the non-movant and any doubts resolved in its favor.
*576
Nixon v. Mr. Property Management Co.,
When the defendant is the mov-ant, summary judgment is proper only if the plaintiff cannot, as a matter of law, succeed upon any theory pleaded.
Peirce v. Sheldon Petroleum Co.,
A defendant seeking summary judgment on the basis of limitations must prove as a matter of law when the cause of action accrued. When the plaintiff has pleaded the discovery rule,
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the defendant must negate the rule by proving as a matter of law that there is no genuine issue of fact about when the plaintiff discovered or should have discovered the nature of the injury.
Burns v. Thomas,
APPLICABILITY OF A FOUR-YEAR STATUTE OF LIMITATIONS
In the third and fourth points, AME contends that the trial court erred in granting the summary judgment because a suit for attorney malpractice is subject to a four-year limitations period. AME argues that an attorney malpractice claim structured as a “breach of implied warranty based upon an oral contract” is subject to the limitations period for breach of an oral contract. Earlier, the statute of limitations for breach of an oral contract had been two years. It was later changed to four years. AME directs us to two cases in support of this argument:
Woodburn v. Turley,
*577 TIME OF ACCRUAL OF AME’S CAUSE OF ACTION
In the first and second points, AME contends that the trial court erred in holding that AME knew or should have known that its cause of action against appellees accrued more than two years before it filed suit. The main dispute on this issue is the determination of when AME knew or should have known that it suffered injury due to the negligence of appellees.
A cause of action for negligence accrues at the moment that the plaintiff is entitled to sue the defendant for damages
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caused by the negligent acts or omissions of the defendant.
Willis,
In its petition, AME alleged that appel-lees “were negligent in failing to advise AME of the possibility that it might not have non-exclusive rights to practice the invention in the event the patent application were granted.” AME further alleged that if appellees had “advised AME that there was a possibility it might lose the right to practice the invention, it would not have conveyed rights in the patent application to Thaler.” Finally, AME states that the damages it sustained as a result of Thaler’s suit against it resulted from appel-lees’ negligence. In the summary judgment proceedings, appellees contended that AME suffered injury due to the alleged negligence at the time that the patent issued and that it should have become aware of the injury due to the negligence when Thaler’s attorney denied that AME had a shop right or, at the latest, at the time that Howson & Howson advised it that there was a possibility that a judge could find that AME had waived its shop right. AME contends that it did not suffer any injury due to the negligence until Thaler filed suit against it, and because it filed suit against appellees within a month after being sued by Thaler, it was well within the two-year statute of limitations.
The negligence alleged in this case is one of omission: the failure to warn of the possibility that a judge could hold that no shop right exists. As AME’s president states in his affidavit, AME would never have given up its rights in the patent application if it had “known there was any risk it might be charged with infringement for use of the invention.” In a legal malpractice, negligent advice case, the invasion of the plaintiff’s legally protected interest occurs at the time that the plaintiff receives the incomplete or otherwise improper advice. Here, then, AME’s legally protected interest in receiving complete, professional advice from its attorneys was invaded at the time that it received the incomplete advice. The remaining issue, then, is the time at which AME discovered or should have discovered that the advice it received was incomplete and that it could sue for damages.
When the patent issued on March 31, 1987, AME was immediately put on notice that appellees’ prediction that the patent probably would not issue was wrong. AME then went to the law firm of Howson & Howson to obtain a second opinion. The Howson firm told AME in July 1987 that it was subject to a suit for patent infringement and that a court probably would not hold that a shop right existed. At this *578 point, AME was put on notice that there was at least a difference of opinion among lawyers concerning AME’s rights under the shop-right doctrine. Thus, AME then knew or should have known that there existed “the possibility that it might not have non-exclusive rights to practice the invention in the event the patent application were granted,” which was the negligence AME alleged in its petition.
AME maintains that it could not have known that it had been damaged until Thaler sued it. We disagree. The initial damage to AME, although perhaps nominal, occurred when its right to receive professional and complete advice from its attorneys was violated. AME knew or should have known that it had been damaged at the time that Howson told it that a court would probably hold that it had no shop right. Thus, under the discovery rule, AME’s cause of action against appellees accrued when it received the letter from Howson in July 1987. The fact that AME did not know the full extent of its damages at that time did not prevent the statute of limitations from running.
Black,
Notes
. The shop-right doctrine is an equitable defense to an action for patent infringement. The doctrine permits an employer whose property is used in the development of an invention patented by its employee to practice the invention nonexclusively without having to pay royalties or obtain an express license from the inventor-employee.
See
Annotation,
Application and Effect of “Shop Right Rule” or License Giving Employer Limited Rights in Employees’ Inventions and Discoveries,
. Under the discovery rule, the statute of limitations does not begin to run until the claimant discovers or in the exercise of reasonable diligence should have discovered the facts establishing a cause of action.
Willis v. Maverick,
. "Damages” may be defined as “legal injuries,” which are any invasions of the plaintiffs legally protected interest.
Zidell v. Bird,
