Average Co-Inventor Count = 1.55
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 (2 from 5,450 patents)
2. Nippon Gakki Seizo Kabushiki Kaisha (2 from 841 patents)
4 patents:
1. 5641930 - Electronic musical apparatus for controlling musical tone using initial
2. 5552561 - Playing-style detecting apparatus and electronic musical instrument
3. 4111091 - Touch response sensor for an electronic musical instrument
4. 3979990 - Keyboard arrangement in electronic musical instrument