Average Co-Inventor Count = 2.25
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 (3 from 58,129 patents)
3 patents:
1. 4757490 - Modulation abnormality detector for optical sound-recording system
2. 4734903 - Level control circuit for light beam recording apparatus
3. 4442461 - Signal recording and/or reproducing technique