US 12,451,734 B2
Photovoltaic cell for laser beam power detection
Ortal Alpert, Ness Ziona (IL); Ori Refael Mor, Tel Aviv (IL); Lior Golan, Ramat Gan (IL); Ran Sagi, Tel Aviv (IL); and Eyal Conforti, Tel Aviv (IL)
Assigned to Wi-Charge Ltd., Rehovot (IL)
Filed by Wi-Charge Ltd., Rehovot (IL)
Filed on Jan. 24, 2024, as Appl. No. 18/421,079.
Application 18/421,079 is a continuation of application No. 17/440,809, granted, now 11,909,224, previously published as PCT/IL2020/050336, filed on Mar. 20, 2020.
Claims priority of provisional application 62/821,143, filed on Mar. 20, 2019.
Prior Publication US 2024/0195225 A1, Jun. 13, 2024
Int. Cl. H02J 50/30 (2016.01); H02S 40/30 (2014.01); H10F 77/30 (2025.01); H10F 77/42 (2025.01)
CPC H02J 50/30 (2016.02) [H02S 40/30 (2014.12); H10F 77/315 (2025.01); H10F 77/488 (2025.01); Y02E 10/52 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A safety system for a wireless optical power transmission system comprising a transmitter, a receiver and a control unit, wherein:
(i) said transmitter comprises:
a laser adapted to emit a beam; and
a scanning mirror adapted for steering said beam towards said receiver;
(ii) said receiver comprises:
a photovoltaic cell having a plurality of conductors on a surface adapted to receive said laser beam, said photovoltaic cell having at least one junction having a bandgap energy between 0.75 eV and 1.2 eV; and
a cover layer disposed upon said photovoltaic cell, said cover layer comprising a material adapted to restrict by either absorption or reflection, illumination having wavelengths outside of the range of the wavelength of said laser beam, and to transmit said laser beam towards said photovoltaic cell; and
(iii) said control unit is adapted to receive first data representing the position of said scanning mirror, and to receive second data from said transmitter representing the power of said beam emitted by said laser, and to determine from said first and second data, an expected power incident on said photovoltaic cell, and to compare said expected power with said power of said laser beam impinging upon said receiver, as measured by said photovoltaic cell, and to indicate a potential safety problem if said expected power deviates from said measured power by more than a predetermined level.