Average Co-Inventor Count = 2.40
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. Hitachi Software Engineering Company, Ltd. (2 from 228 patents)
2 patents:
1. 5490135 - Method and system for arranging common channel signal network through
2. 5333187 - Switching system for electronic switcher