Average Co-Inventor Count = 3.60
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. Iwatsu Electric Company Ltd. (3 from 190 patents)
2. Nippon Telegraph and Telephone Corporation (2 from 5,290 patents)
3 patents:
1. D557676 - Conference telephone
2. D529894 - Telephone set
3. D515063 - Telephone set