Average Co-Inventor Count = 2.40
ph-index = 4
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 (4 from 5,452 patents)
4 patents:
1. D718809 - Digital piano
2. D718375 - Digital piano
3. D696715 - Electronic keyboard
4. D668710 - Electronic keyboard