Average Co-Inventor Count = 2.86
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. At&t Bell Laboratories (1 from 3,345 patents)
2. American Telephone and Telegraph, Co. (1 from 386 patents)
3. At&t Information Systems Inc. (1 from 243 patents)
2 patents:
1. D304726 - Telephone dialing apparatus
2. D289155 - Telephone answering device