Average Co-Inventor Count = 1.71
ph-index = 3
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. Nippon Gakki Seizo Kabushiki Kaisha (3 from 841 patents)
3 patents:
1. 4892023 - Electronic keyboard percussion instrument
2. 4741240 - Recorder
3. 4127050 - Brass wind musical instrument