US 12,407,191 B2
Closed-space sensor system and method for operating closed-space sensor system
Yoshiaki Yamagishi, Tokyo (JP)
Assigned to AZBIL CORPORATION, Tokyo (JP)
Appl. No. 18/025,438
Filed by Azbil Corporation, Tokyo (JP)
PCT Filed Sep. 15, 2021, PCT No. PCT/JP2021/033829
§ 371(c)(1), (2) Date Mar. 9, 2023,
PCT Pub. No. WO2022/075020, PCT Pub. Date Apr. 14, 2022.
Claims priority of application No. 2020-168858 (JP), filed on Oct. 6, 2020.
Prior Publication US 2023/0334978 A1, Oct. 19, 2023
Int. Cl. H02J 50/20 (2016.01); H02J 50/40 (2016.01)
CPC H02J 50/20 (2016.02) [H02J 50/40 (2016.02)] 11 Claims
OG exemplary drawing
 
1. A closed-space sensor system comprising:
an electromagnetic wave irradiator including a power transmitter that emits an electromagnetic wave; and
a plurality of sensors, each of which includes an antenna, converts the electromagnetic wave received via the antenna into electric power, and is thereby driven;
wherein
each of the plurality of sensors further includes a power storage unit, and each of the plurality of sensors starts to be driven when a power storage amount in the power storage unit reaches a drive start threshold value that is common to the plurality of sensors,
the power transmitter of the electromagnetic wave irradiator emits the electromagnetic wave in at least one of a plurality of power transmission frequency channels within a power transmission frequency range, and
in a relationship of reception sensitivity of the antenna to a power transmission frequency, an interval between the power transmission frequency channels is narrower than an interval between two power transmission frequencies, each of which gives the reception sensitivity of a sensitivity threshold value with which each of the plurality of sensors can be driven.