Sogou V. Baidu Input Method Software Invention Patent Infringement Dispute Case

China IP,[Patent]

 

In the comparison of the technical features of this case, Sogou Company first proved through experiments that Baidu Input Method software could record the user’s input of sentences and the selection of words on the screen during user input, so as to prove that Baidu Input Method and the patent in question have same technical effects, Baidu was forced to provide counter-evidence, and finally realized that the case will be judged on the basis of fact-finding.
First trial case number: (2015) Shanghai Intellectual Property Civil Judgement No. 747
 
Second-instance case number: (2018) Shanghai Final Civil Judgement No. 134
 
【The main takeaway of the trial】
 
Regarding the distribution of the burden of proof in invention patent infringement cases of computer software, the patentee must not only provide evidence to prove that the alleged infringing software has the same technical effect, but also prove that it has a great possibility of infringement. After the patentee has completed the preliminary proof obligation, the accused infringer has an obligation to prove that the two technical means are different.
 
Regarding the comparison of invention patent infringement of computer software, the same technical effect is not equal to the same as the entire technical solution. A technical solution is composed of several technical characteristics. When analyzing technical characteristics, it needs to be analyzed from the perspective of the overall technical solution. It is necessary to consider the literal meaning of the technical characteristics and the internal connection between the technical characteristics. Technical features that have been clearly distinguished in patent claims and related patent examination documents should no longer be considered as equivalents.
 
【Case Introduction】
 
Appellant (plaintiff in the original trial): Beijing Sogou Technology Development Co., Ltd. (referred to as Sogou Company)
 
Appellee (defendant in the original trial): Shanghai Tianxi Trading Co., Ltd. (referred to as Tianxi Company), Baidu Online Network Technology (Beijing) Co., Ltd. (referred to as Baidu Company), Beijing Baidu Netcom Science Technology Co., Ltd. (referred to as Baidu Netcom Company)
 
Sogou Company has an invention patent named " A method for users to participate in intelligent group word input and an input method system", the patent number is ZL200810113984.9 (referred to as the patent involved), and the patent is valid so far. Sogou Company believed that the technical solution of "implicit self-made words" in the "Baidu Input Method" software jointly produced by Baidu Company and Baidu Netcom Company fell into the protection scope of 16 claims including claim 1 of the patent involved. Sogou Company sued the Shanghai Intellectual Property Court, requesting an order for Baidu Company, Baidu Netcom Company, and Tianxi Company to stop infringement, and Baidu Company and Baidu Netcom Company to compensate Sogou Company for economic losses and reasonable expenses of RMB10 million (of which RMB 50,000 yuan shall be jointly compensated by Tianxi Company).
 
The first instance of the court held that the binary pairs of the patents involved need to participate in the calculation of the probability, so the technical characteristics of the patents involved not only record the "two adjacent words", but also record the "adjacent relationship between the two words." Comparing the binary pair technical features of the alleged infringing software and the patent in question, the two are similar in that they both record adjacent input words. The difference between the two is that the alleged infringing software does not distinguish between different combinations of the same self-made words; that is, it does not record the adjacent relationship of adjacent words. In addition, according to the patent specification and the review decision of the request for invalidation of the involved patent, it can be seen that there are differences and connections between "word frequency" and "probability". Word frequency refers to the frequency with which a user enters a specific word. The "probability" in the patent involved refers to the probability that a certain adjacent word pair entered by the user will appear in all adjacent word pairs entered by the user. The impact of the number of times the specific word is entered is not simply equal to the number of times the user has entered. The difference between the two is that the probability T(A,B)/(SUMBI) is affected by the total number of times the user enters the binary word pair (SUMBI), while the word frequency is not affected by the total number of times the user enters the binary word pair (SUMBI). After testing the accused infringing software and inspecting the source program, the accused infringing software gave the user the corresponding word frequency information for the user's self-made words according to the total number of times the user entered the self-made words, and did not count the probability of user-made words accounted for all users' self-made words. The patent claims and related patent examination documents involved have clearly distinguished the different meanings of “frequency” and “probability”. Therefore, in the judgment of patent infringement, the two should be directly identified as different technical features, and no longer consider whether the two constitute equivalent. Based on this, the alleged infringing software and claim 1 of the invention patents involved are neither identical nor equivalent to technical solutions, which do not fall into the protection scope of claim 1 of the involved patent.
 
In summary, the court's first-instance judgment: Dismissed all claims of Sogou Company.
 
Sogou Company refused to accept the judgment of the first instance and appealed to the Shanghai Higher People's Court. The court ruled in the second instance: Dismissed the appeal and upheld the original judgment.
 
【Typical meaning】
 
This case is the country's first software invention patent infringement dispute. It is difficult to ascertain the facts of software patents. Because the plaintiff does not have the code information of the alleged infringing software, which can only prove that the appearance is the same, and then transfer the burden of proof to the defendant. However, if the defendant can prove that its technical solution is different from the patent involved, the burden of proof was again transferred to the plaintiff. In the comparison of the technical features of this case, Sogou Company first proved through experiments that Baidu Input Method software could record the user’s input of sentences and the selection of words on the screen during user input, so as to prove that Baidu Input Method and the patent in question have same technical effects, Baidu was forced to provide counter-evidence, and finally realized that the case will be judged on the basis of fact-finding. The burden of proof, in this case is continuously transferred and allocated between the plaintiff and the defendant, which has reference value for the trial of similar cases.
 
Software patents are essentially methodological inventions. When understanding and analyzing technical features, it is necessary to analyze from the perspective of the overall technical solution. It is necessary to consider the literal meaning of the technical features and the internal connection between the technical features. The comparison of "word frequency" and "probability" is not limited to conceptual comparisons but should also be combined with related records in patent claims and related patent examination documents. The clearly distinguished technical features should no longer be considered as equivalent. This case provides a trial idea for reference in the determination of technical facts in similar cases.

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