Average Co-Inventor Count = 1.23
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 (4 from 5,451 patents)
4 patents:
1. 7678981 - Keyboard structure of electronic keyboard instrument
2. 7544876 - Keyboard apparatus of electronic keyboard instrument
3. 7476795 - Keyboard device for electronic musical keyboard instrument
4. 6980432 - Electronic apparatus