What should you do if you are unable to obtain the source code in a software patent infringement dispute? The guiding case of the Supreme People's Court clarifies the rules for technical fact ascertainment and burden of proof.
This article analyzes the adjudication essentials of the Intellectual Property Court of the Supreme People's Court on the identification of software technical facts in patent infringement litigation by combining a related key case published by the Supreme People's Court represented by the author — the patent infringement dispute case of Wuhan Company A v. Suzhou Company B, and attempts to summarize the rules for proving/identifying software and algorithm-related technical facts in similar cases.
Introduction
With the rapid development of information technology, software-based patents are playing an increasingly important role in scientific and technological innovation and industrial development. Compared with hardware-based patents, such patents are usually embodied in program operation logic, and the specification and even the claims mostly adopt functional descriptions, while the specific technical solutions are often invisible to the naked eye. In the patent infringement link, technical comparison is convenient only when software codes and algorithm processes are combined with application scenarios, but key evidences such as software codes and operation logs are usually held by the alleged infringer. Therefore, the core difficulty of software-based patent infringement cases lies not only in the complexity of the technical problem itself, but also in how the plaintiff can reasonably and effectively restore the alleged technical solution and complete the infringement comparison accordingly under the condition that the defendant's source code cannot be obtained. In practice, if the traditional proof rule of "he who asserts shall prove" is strictly followed, the plaintiff often fails to win the case because he cannot obtain the alleged infringer's technical solution and thus cannot directly conduct technical comparison. Combining a related key case published by the Supreme People's Court represented by the author — the patent infringement dispute case of Wuhan Company A v. Suzhou Company B[1], this article analyzes the adjudication essentials of the Intellectual Property Court of the Supreme People's Court on the identification of software technical facts in patent infringement litigation, and attempts to summarize the rules for proving/identifying software and algorithm-related technical facts in similar cases.
I. Objects of Software Patent Protection
(1) Claims of Software-based Patents
The Patent Examination Guidelines[2] stipulates that for invention patent applications involving computer programs, the claims may be drafted as product claims including apparatus claims. If the apparatus claim is drafted based on the flow of the computer program in a manner completely consistent with each step of the program flow, each component therein shall be construed as a program module that must be established to implement each step of the program flow. The apparatus claim defined by the program modules shall be construed as a program module architecture that implements the solution mainly through the computer program recorded in the specification, rather than a physical apparatus that implements the solution mainly through hardware means.
The patent in question involves a signal processing method and apparatus, which detects the picture quality of the display module through static picture point screen. Its technical contribution lies in the program operation steps of the signal processing apparatus and the processing flow formed by the cooperation of various program modules. The components in the apparatus claims in the claims of the patent in question are drafted according to each step in the program flow. Combined with the provisions of the aforementioned Patent Examination Guidelines, their technical features should be understood as program modules that implement the corresponding program steps. As an abstraction of the functions and logical organization mode of computer programs, the program module does not naturally correspond to a physical structure with an independent appearance, and its operation process and internal processing logic are also difficult to be directly identified by observing the external form of the product.
(2) The Physical Product Is Not the Only Way to Fix the Alleged Infringing Technical Solution
In practice, the products corresponding to software-based patents may be To B (for commercial users) dedicated products, which are difficult for the right holder to obtain through public channels. Even if the relevant products are obtained, under the condition that the key procedures and operating conditions are controlled by the alleged infringer, if the right holder is required to submit the physical product and complete all technical comparisons accordingly, the actual operation characteristics of the software technical solution and the objective obstacles to evidence acquisition will be ignored.
In this case, to solve the above dilemma, Company A conducted experiments at the user site of Company B and preserved evidence through notarization. However, Company B argued that Company A's comparison opinion was a unilateral speculation and Company A should bear the consequence of inability to adduce evidence on the grounds that Company A did not submit the physical product for technical detection. At the same time, Company B submitted the on-site experimental evidence designed by itself, claiming that its technical solution is different from the patent in question. The court held in the trial that in patent infringement cases, the right holder will submit the physical alleged infringing product for technical comparison, but the physical product is not the only way to fix the alleged technical solution. For the right holder, its proof only needs to reach the level required for comparison with the patent in question. Company A has fixed the alleged infringing technical solution through various channels, and also submitted the patent documents applied for by Company B for the same model product involved in this case. The above evidences can mutually corroborate to determine the complete alleged infringing technical solution, which can be compared with all the technical features recorded in the claims.
II. Accurately Defining the Protection Scope of Software Patents
(1) Accurately Defining the Connotation and Extension of Technical Features According to Technical Logic
In software-based patent infringement cases, the interpretation of claims shall be based on their literal meaning, combined with the specification and the common understanding of those skilled in the art to accurately grasp the connotation of technical features, avoid improperly introducing unnecessary details in the specific embodiments into the claims, resulting in unreasonable narrowing of the protection scope of the claims.
The claims of the patent in question record two technical features of software programs, one is "shearing the image data to obtain valid image data, and storing the valid image data to obtain stored data", and the other is "encoding the read stored data according to the recovery clock in accordance with the V-BY-ONE protocol to obtain a V-BY-ONE image signal". During the comparison of technical features, the focus of dispute between the two parties is on how to interpret "shearing" and "according to the recovery clock" in the above two technical features. The court analyzed in combination with the common meaning of relevant technical terms and the customary technical means in the field, found that the alleged infringing technical solution has the above two technical features, and pointed out that in the absence of clear basis, the technical features should not be limited to a specific implementation mode. When interpreting the claims, it is necessary to avoid improperly converting the specific implementation modes in the embodiments of the specification into restrictions on the protection scope of the claims.
(2) Determining Whether Technical Features Are Provided in Combination with the Actual Operation State of the Alleged Product
Although the external functions and technical effects of software-based products are observable, their internal algorithms and program logic are often difficult to obtain directly. If the alleged infringer claims that there is a difference in the technical solution based on the experimental results, it shall not only prove the authenticity of the experimental results, but also prove that the experimental environment and conditions are consistent with the actual operation state of the alleged product. The experimental conclusion, product operation performance and other evidence on record shall be comprehensively reviewed to judge whether the experimental results can truly reflect the technical solution of the alleged product.
In this case, the experiment of changing the output frequency designed by the defendant is inconsistent with the fact that the output clock frequency of the product cannot be modified in practice, indicating that the technical solution used in the defendant's simulation experiment is not the technical solution actually used by the alleged product, which is insufficient to prove that the alleged technical solution is different from the patent in question. After comprehensively reviewing the evidence on record, analyzing relevant facts and excluding other possible situations, the Supreme People's Court finally found that the alleged technical solution has all the technical features recorded in the claims of the patent in question, and falls into the protection scope of the patent right.
It should be noted that the source code is usually the best basis for interpreting program algorithms and defining software technical features. If the source code of the software used in the defendant's product can be obtained through evidence preservation, there is actually no need to make the fact-finding of this case so complicated. Unfortunately, the application for evidence preservation in this case was not approved by the court of first instance, which caused both the plaintiff and the defendant to go to great lengths to continuously submit their respective simulation experiments in the second instance, and also forced the Supreme People's Court to conduct two on-site inspections in Guangdong and Hunan before reaching a conclusion. In contrast to extraterritorial judicial practice, the United States not only presumes that the alleged product is manufactured by the patented method under specific circumstances, but also relies on pre-trial evidence discovery and confidentiality orders to allow parties to access technical materials including source code in confidence when conditions are met. Japan balances the identification of infringement facts and trade secret protection through the systems of specific explanation obligation, document submission order and secrecy preservation order. In contrast, Chinese courts currently can only basically rely on the burden of proof transfer system. For cases involving highly sensitive technical information such as source code, China lacks sufficient compulsory measures and institutional guarantees comparable to those of the United States, Japan and other countries. In the future, the improvement and implementation of the Special Procedure Law on Intellectual Property Litigation is expected to better protect the interests of intellectual property right holders and better protect innovation.
III. Rules for Identifying Technical Facts of Software Patents
(1) The Plaintiff's Evidence Is Sufficient to Prove That the Alleged Technical Solution Falls into the Patent Protection Scope with a High Possibility
Article 66 of the Patent Law stipulates the inversion rule of burden of proof for patents of manufacturing methods for new products, while method patents for non-new products have long lacked special provisions on the burden of proof. However, the phenomenon of "evidence asymmetry" is widespread in method patent infringement cases. The manufacturing/process/processing methods are usually implemented in the production site controlled by the defendant, and it is difficult for the right holder to directly obtain evidence, which is particularly typical for software patents. The alleged technical solution in this case exists in the form of codes and algorithms and is controlled by the defendant in the background, so it is difficult for the right holder to obtain the source code through the product itself for comparison.
To this end, the Supreme People's Court introduced the transfer of burden of proof on the condition of "relatively high possibility" in Article 15 of the Opinions on Giving Full Play to the Function of Intellectual Property Trial to Promote the Great Development and Prosperity of Socialist Culture and Promote the Independent and Coordinated Economic Development in 2011. In 2020, Article 3 of the Provisions of the Supreme People's Court on Several Issues Concerning Evidence in Civil Intellectual Property Litigation clarified the burden transfer rule for non-new product manufacturing methods after meeting the "three elements" of "same product - high possibility - reasonable efforts have been made", which well solves the problem of difficulty in adducing evidence for holders of method invention patents. The Supreme People's Court applied the above rule in the "dibasic acid" method patent infringement case (2021) Zui Gao Fa Zhi Min Zhong No. 1305 (50 typical intellectual property cases of Chinese courts in 2021), and held that the alleged infringer failed to prove that its manufacturing method is different from the patented method in question, and shall bear the adverse consequences.
In this case, although the relevant technical means in the alleged technical solution cannot be directly learned by observing the alleged product, Company A conducted on-site inspection of the alleged product, took pictures and videos, submitted the operation manual and quality system document specification of the alleged infringing product for demonstration and comparison, and also submitted the patent documents applied for by Company B for the same model product involved. When it has reasonably shown that the alleged product can achieve the functions and effects that the patent in question is intended to achieve, the patent holder shall be deemed to have completed the preliminary burden of proof. This case confirms and continues the above rules in the most difficult scenario where the plaintiff "cannot submit the physical product or source code", which reflects the flexible and reasonable distribution of the burden of proof in software patent infringement cases. In the second instance of this case, the Supreme People's Court, based on the alleged technical solution fixed by Company A through various channels and the completed simulation experiment, held that it has reasonably shown that the alleged product can achieve the functions and effects that the patent in question is intended to achieve. In view of the fact that the software technical solution in question is an electrical signal processing method, and the background program is controlled by Company B, Company A has made reasonable efforts to prove that Company B uses the patented technical solution in question. In this case, if Company B claims that the alleged technical solution does not have the corresponding technical features in the patent in question, it shall submit counter-evidence to prove it.
(2) The Defendant Who Only Makes Negative Defense without Submitting Counter Evidence Such as Software Programs Shall Bear Adverse Consequences
In software-based patent infringement cases, when the right holder proves that the external functions, operation performance and technical effects of the product are highly consistent with the patented technical solution, forming a reasonable possibility of infringement, he can complete the preliminary burden of proof and transfer the burden of proof accordingly, which is a necessary measure to achieve procedural justice and promote fact-finding under the condition of asymmetric technical information. In practice, the alleged infringer may select specific technical conditions and simulation scenarios to claim differences on the grounds of different experimental results, and then deny infringement. In this regard, the right holder shall fully note that when the alleged infringer proves that the software operation method is different through simulation experiments, it shall also prove that the experimental software has a real and sufficient connection with the alleged product, in particular, it shall prove that the experimental object is indeed the software actually running in the alleged product, and its version, configuration, operating environment and parameters can reasonably reflect the real state of the alleged product. If the alleged infringer has disputes over the technical features including the relevant software programs, but only makes negative defense without submitting corresponding counter evidence such as software programs, and fails to fulfill the burden of proof resulting in the uncertainty of facts, it shall bear the corresponding adverse consequences.
In this case, the evidence submitted by Company A and the court's on-site inspection show that there is a relatively high possibility of the basic fact that Company B commits the infringement. Although Company B defended that the alleged product is only the same as the patented solution in external effect, but actually adopts a different method, and proved it with simulation experiments, claiming that the software version has not been upgraded and iterated during this period, the defendant failed to provide the complete solution of its technical method, only claimed that individual features are different through technical experiments, and the authenticity of the experiment and its relevance to the complete technical method are in doubt. In addition, Company B has continuously and massively upgraded and transformed the alleged products for customers, and stated in another case[3] that the relevant software version will be sent by email, which shows that Company B, under the circumstance that it actually holds and has the ability to submit the relevant software, failed to submit the software materials that can reflect the actual operation state of the alleged product, and only made negative defense based on individual experiments, which is insufficient to prove that the alleged technical solution is different from the patented solution. The Supreme People's Court held that Company B's explanations for relevant technical features are contradictory, and it had the ability but did not submit the drive software source code of the product corresponding to the notarial certificate, found that Company B's defense is insufficient to prove that the alleged technical solution is different from the patent in question, and finally found that the alleged solution falls into the patent protection scope.
IV. Conclusion
With the increase of software and algorithm-based patent disputes, the identification of technical facts has become a key link in the infringement judgment of such patent litigation cases. Since the software operation logic is difficult to be directly identified from the outside, and the key evidence is mostly held by the alleged infringer, the right holder faces great difficulties in adducing evidence. In this regard, the Intellectual Property Court of the Supreme People's Court has pointed out in the aforementioned key case that it adheres to the claim-centered and evidence-based principle, comprehensively considers the evidence control situation, the proof capacity of both parties and the efforts made to obtain evidence, and reasonably distributes the burden of proof. For the alleged infringer's technical defense, the authenticity and completeness of the evidence and its relevance to the actual operation state of the alleged product shall be reviewed. If the plaintiff has adduced evidence sufficient to prove that the alleged infringing technical solution falls into the patent protection scope with a high possibility, and the defendant has disputes over the technical features including the relevant software programs but only makes negative defense without submitting corresponding counter evidence such as program codes, it shall bear the adverse consequences. This adjudication essential reflects the organic combination of procedural fairness and fact-finding, provides clear guidance for lower courts to identify technical facts in cases involving software and algorithm-based patent disputes, effectively solves the problem of difficulty in adducing evidence in software patent cases, and fully protects the innovation of right holders.
Notes
[1] This case is a series of cases, with two related cases, namely (2022) Zui Gao Fa Zhi Min Zhong No. 1226 and (2023) Zui Gao Fa Zhi Min Zhong No. 3114. This case was also selected into the "10 Typical Intellectual Property Cases of Jiangsu Courts in 2024 Serving and Ensuring the Development of New Quality Productive Forces".
[2] Chapter IX, Part II, Patent Examination Guidelines (2023).
[3] (2021) Su 05 Min Chu No. 129, see the civil judgment (2022) Zui Gao Fa Zhi Min Zhong No. 1226 for details.