Average Co-Inventor Count = 5.00
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. (1 from 42,494 patents)
2. Hitachi Unisia Automotive, Ltd. (1 from 49 patents)
2 patents:
1. 7409937 - Hydraulic control system for internal combustion engine
2. 6802289 - Valve timing control system for internal combustion engine