Average Co-Inventor Count = 2.73
ph-index = 5
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 (4 from 2,606 patents)
2. 501 Ngk Spark Plug Co. Ltd. (1 from 2 patents)
5 patents:
1. 4883643 - Oxygen sensor protected against contaminants
2. 4741816 - Oxygen sensor
3. 4672933 - Precombustion chamber with insulating means
4. 4668477 - Gas sensor
5. 4507191 - Oxygen sensor with heater