Average Co-Inventor Count = 3.00
ph-index = 2
The patent ph-index is calculated by counting the number of publications for which an author has been cited by other authors at least that same number of times.
Company Filing History:
1. Hitachi, Ltd. (2 from 42,508 patents)
2 patents:
1. 6604679 - Payment management method and system using an IC card
2. 6488204 - Payment management method and system using an IC card