This study focuses on the potential of expired patents, that is, patents freely available in the public domain, to become new technology opportunities. These technologies can create a new value, if they are well utilized and combined with other technologies, or go through further commercialization processes. Furthermore, such value can be obtained effectively, given their initial usability, proven by a patent system and high accessibility. Despite the numerous studies aimed at seeking technological opportunities from patents, however, little attention in academia has been given to those expired patents as a source of such opportunities; accordingly, the distinguishing features of expired patents as opportunities have been largely overlooked in the existing studies. To fill this research gap, we propose a novel approach to identify technology opportunities using the expired patents, where two types of opportunities are investigated: 1) opportunities within the target technological field named as promising technology; and 2) opportunities from other technological fields named as convergence technology. After key technological topics, either in the target field or in the reference field, are identified using LDA topic modelling, a target topic of interest is chosen, and its corresponding patents are evaluated from their patent quality and risk of implementation. Finally, the patents with high patent quality and low risk of implementation are identified as technology opportunities. The proposed approach is applied to biocosmetics products, and the research findings indicate that the expired patents can have as much importance as the valid patents as sources of new technology opportunities. Hence, by guiding the use of expired patents, the proposed approach is expected to reduce the costs and risks of adopting those patents for a firm's own business.

这项研究的重点是过期专利（即在公共领域免费提供的专利）成为新技术机会的潜力。如果这些技术得到充分利用并与其他技术结合，或者经过进一步的商业化过程，它们可以创造新的价值。此外，考虑到其最初的可用性，可以通过专利制度证明其具有很高的实用价值，并且具有很高的可及性。尽管进行了大量旨在从专利中寻求技术机会的研究，但是，学术界很少关注那些已过期的专利作为此类机会的来源。因此，在现有的研究中，过期专利作为机会的显着特征在很大程度上被忽视了。为了填补这一研究空白，我们提出了一种使用过期专利来识别技术机会的新颖方法，其中对两种机会进行了调查：1）目标技术领域中被称为有前途技术的机会；2）来自其他技术领域的机会，这些技术被称为融合技术。在使用LDA主题模型确定了目标领域或参考领域中的关键技术主题之后，选择了感兴趣的目标主题，并根据其专利质量和实施风险对相应的专利进行了评估。最后，具有较高专利质量和较低实施风险的专利被确定为技术机会。提议的方法适用于生物化妆品产品，研究结果表明，过期专利与有效专利一样具有作为新技术机会来源的重要性。因此，通过指导过期专利的使用，预计所提出的方法将减少为企业自身业务采用这些专利的成本和风险。