Average Co-Inventor Count = 2.00
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 5,451 patents)
2. Nippon Gakki Seizo Kabushiki Kaisha (2 from 841 patents)
4 patents:
1. 4957032 - Apparatus for realizing variable key scaling in electronic musical
2. 4947724 - Electric music instrument with the capability of memorizing and
3. 4711148 - Fractional range selectable musical tone generating apparatus
4. 4483231 - Preset apparatus of electronic musical instrument