Average Co-Inventor Count = 5.46
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 42,488 patents)
2. Hitachi Engineering Ltd (1 from 7 patents)
2 patents:
1. D339123 - Video tape recorder
2. D332258 - Combined facsimile transceiver and copying machine