Average Co-Inventor Count = 3.00
ph-index = 1
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. (1 from 42,517 patents)
2. Hitachi Engineering Co., Ltd. (1 from 162 patents)
1 patent:
1. 4517644 - Symmetry type loop communication system