Average Co-Inventor Count = 3.20
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. Sony Corporation (2 from 58,130 patents)
2 patents:
1. 4786255 - Group education system
2. 4310317 - Educational apparatus with automatic terminal identification