Average Co-Inventor Count = 2.67
ph-index = 4
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. Tomy Kogyo Co., Ltd. (2 from 376 patents)
2. Nittetsu Mining Co., Ltd. (2 from 43 patents)
4 patents:
1. 5607490 - Filter having chemical resistance, antistatic property and water vapor
2. 5558689 - Reinforced filter element
3. 4864607 - Animated annunciator apparatus
4. 4721437 - Animated annunciator apparatus