Fig 1.
Process for establishing the classification system of IVV.
Table 1.
Classification system of IVV technology.
Table 2.
Countries ranked by the number of EPO-granted patents.
Table 3.
The number of patents of IVV fields and its subfields.
Fig 2.
Number of granted patents of IVV by application year.
Fig 3.
Number of granted patents in four subfields of IVV by application year.
Table 4.
Target countries or organizations of IVV patents from main origin countries.
Fig 4.
Topic distribution of IVV subfields technology by IPC.
Table 5.
Major topic distribution of IVV patents.
Table 6.
Top 20 core patents and high-value patents for IVV patents.
Fig 5.
The number of patents and core patents of typical countries.
Table 7.
Summary of data statistics for all patents, core patents, and high-value patents of IVV.
Fig 6.
Numbers of patents and high-value patents in representative countries.
Table 8.
Summary data statistics for IVV subfields patents.
Fig 7.
Numbers of patents, core patents, and high-value patents of IVV subfields.