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 42,517 patents)
2 patents:
1. 4000945 - Information recording apparatus
2. 3989364 - Electrophotographic copying apparatus