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. Yamaha Corporation (2 from 5,450 patents)
2 patents:
1. 5147969 - Musical tone control apparatus
2. 5125313 - Musical tone control apparatus