Average Co-Inventor Count = 3.75
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 42,485 patents)
2. Hitachi Engineering Co., Ltd. (1 from 162 patents)
3. Hitachi Keiyo Engineering Co., Ltd. (1 from 34 patents)
2 patents:
1. 5481664 - Method of controlling information in multimedia system
2. 4588488 - Method of removing oxide on metal surface