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 42,485 patents)
2 patents:
1. 6975227 - Method for controlling coming and going personnel, and a system thereof
2. 6621414 - Method of controlling coming and going personnel, and a system thereof