Average Co-Inventor Count = 4.21
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. Hitachi, Ltd. (3 from 42,485 patents)
2. Tokyo Rope Mfg. Co., Ltd. (1 from 43 patents)
3. Hitachi Building Systems Co., Ltd. (1 from 10 patents)
4 patents:
1. 11953317 - Reference core position calculation device for elevator and reference core position calculation method
2. 11708242 - Control system for elevator
3. 8418433 - Elevator wire rope
4. 7097000 - Elevator apparatus