Average Co-Inventor Count = 2.40
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 patents:
1. 5801931 - DC power source apparatus that suppresses harmonics
2. 4935897 - Semiconductor memory device suitable for use as a dot image buffer for a