Average Co-Inventor Count = 4.09
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. Hitachi, Ltd. (3 from 42,485 patents)
3 patents:
1. 4578787 - Record disc reproducing apparatus
2. 4476556 - Apparatus for reproducing information from a record disc
3. 4101878 - Self-cut-off power switch for a remote controlled electronic equipment