Average Co-Inventor Count = 3.27
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. Hoya Corporation (3 from 2,529 patents)
3 patents:
1. 7781125 - Lithography mask blank
2. 7611808 - Halftone type phase shift mask blank and halftone type phase shift mask
3. 7166392 - Halftone type phase shift mask blank and halftone type phase shift mask