Average Co-Inventor Count = 2.67
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. 4731777 - Optical disk player
2. 4592039 - Disc player