Why is Founder Font of Peking University a patent?

Microsoft Yahei is a patented font work designed and developed by Peking University Founder Electronics Co., Ltd.

Founder of Peking University generally refers to Founder Group Co., Ltd. Founder Group was founded by Peking University 1986. Academician Wang Xuan is the technical decision-maker and founder of Founder Group, and his invention of Chinese character laser phototypesetting technology laid the foundation of Founder Group.