Average Co-Inventor Count = 2.00
ph-index = 3
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. (3 from 42,517 patents)
3 patents:
1. 6728686 - Electronic money holding device and electronic money automatic payment method
2. 6502078 - Electronic money holding device and electronic money automatic payment method
3. 6058382 - Electronic money holding device utilizing an automatic payment method