Average Co-Inventor Count = 4.57
ph-index = 4
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. (5 from 42,485 patents)
5 patents:
1. 6708183 - Spatial information search system
2. 6381612 - Link information maintenance and management method
3. 6266676 - Link information management method
4. 6208935 - Map application system
5. 6169995 - Link information maintenance management method