Average Co-Inventor Count = 7.78
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. (3 from 42,508 patents)
3 patents:
1. 6108165 - Rotary drum equipment and recording/reproducing equipment using the same
2. 5978185 - Rotary head and recording/reading apparatus provided with rotary head
3. 5661622 - Rotary magnetic head cylinder device for reduced vibration and proper