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. Ngk Spark Plug Company, Limited (1 from 2,606 patents)
2. Aica Kogyo Company, Limited (1 from 26 patents)
2 patents:
1. 4871596 - Artificial marble
2. 4238425 - Ultrasonic humidifier