Average Co-Inventor Count = 5.29
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 42,517 patents)
3 patents:
1. 5057944 - Multiplex rotating magnetic head system for multiply recording and
2. 4959743 - Jitter reducing tapered rotary drum for magnetic head apparatus
3. 4924329 - Rotary drum apparatus for a magnetic recording and reproducing device