A Legal Analysis of the Apportionment Rule in Patent Infringement Cases in U.S. Law and Its Applicability in Iranian Law

Introduction
The Apportionment Rule is a key principle in determining damages arising from patent infringement in the legal system of the United States. This rule is particularly significant in cases where only a portion of a product or process is covered by a patent, as it helps to distinguish the real contribution of the patent to the overall product. The purpose of this rule is to prevent the issuance of unfair damages and to create a balance between the rights of patent holders and the public interest. In recent years, the application of this rule in key cases has been challenged because, in some instances, incorrect or incomplete implementation of this rule has resulted in excessive damages and the emergence of phenomena like patent trolls, which, instead of promoting innovation, have created significant barriers for inventors. This issue highlights the crucial role of how the rule is applied in maintaining fairness and transparency in legal processes. In contrast, in the Iranian legal system, due to the absence of clear rules and procedures for determining damages in patent infringement cases, this matter has received less attention. This article aims to examine the Apportionment Rule in U.S. law and its potential adaptation to Iranian law, providing a practical and fair model for determining damages in patent infringement cases. The main research question of this study is: How has the Apportionment Rule been applied in patent infringement cases in the United States, and can this rule be adapted and implemented in Iranian law? The author's hypothesis is that the correct application of the Apportionment Rule in the United States can serve as a model for determining fair damages in Iranian law, provided that complementary laws and specialized training are developed and implemented in the Iranian legal system. To answer this question, the research analyzes key cases in the United States, such as the Garretson case, and evaluates the influence of the Georgia-Pacific factors and Panduit factors. The theoretical framework of this research is based on the balance between the intellectual property rights of inventors and the public interest. To maintain this balance, while protecting the rights of Patent Holders and preventing their rights from being infringed upon, increasing transparency in the damage calculation process and ensuring the interests of other economic actors are also considered on the other side of the justice scale. This theoretical framework is based on the assumption that the balance between these two principles can strengthen innovation and create incentives for investment in new technologies.
Method
This research employs descriptive, analytical, and comparative methods. Key U.S. cases, including the Garretson case, are analyzed alongside influential legal standards such as the Georgia-Pacific and Panduit factors. The study examines judicial approaches to the Apportionment Rule and assesses its implementation challenges and impacts.
Sampling Procedures
The study selects landmark legal cases and doctrinal materials related to patent infringement damages in the U.S., alongside comparative legislative documents from Iran. Selection criteria focus on cases that explicitly address the application of the Apportionment Rule and its effects on damage calculation.
Sample Size, Power, and Precision Although this is a legal-analytical study without empirical data collection, it ensures comprehensive coverage by reviewing a representative sample of influential U.S. cases and Iranian legal materials to provide accurate and well-rounded conclusions.
Mixed Methods Research By combining qualitative legal analysis with comparative study, this research integrates insights from judicial opinions, statutory frameworks, and academic literature to develop a holistic understanding of the Apportionment Rule's functioning and applicability.
 
Conclusions
It is suggested that the Iranian legislator, by studying the successful experiences of the U.S. legal system, develop clear rules for determining patent infringement damages and design mechanisms for ensuring the precise implementation of these rules. The proper application of these rules can lead to a reduction in unfair litigation and prevent the issuance of unjust rulings in the country. This research concludes that the correct application of the Apportionment Rule in the United States can serve as a model for determining fair damages in Iranian law. This will not only support inventors and reduce lawsuits but also strengthen innovation incentives by creating transparency and fairness in the calculation of damages. Given the importance of this issue, it is necessary for Iranian legislative and judicial bodies to seriously examine and develop regulations related to the Apportionment Rule.