Average Co-Inventor Count = 4.00
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. Sumitomo Electric Industries, Limited (1 from 10,264 patents)
2. Nippon Telegraph and Telephone Corporation (1 from 5,290 patents)
1 patent:
1. 5422975 - Optical filter doped with rare earth elements and used with optical