Average Co-Inventor Count = 2.86
ph-index = 1
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 5,452 patents)
2 patents:
1. 12300206 - Keyboard apparatus and proximity sensor
2. 9472175 - Drum head and drum