Average Co-Inventor Count = 5.54
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. Hitachi, Ltd. (3 from 42,496 patents)
3 patents:
1. 4486482 - Vacuum heat insulator
2. 4366856 - Apparatus for storing heat
3. 4130997 - Refrigerator