Plateau-based control of the transmission of a variable transmission lens

Patent metadata

Field	Value
Publication number	US-11226499-B2
Application number	US-201615743166-A
Country	US
Kind code	B2
Filing date	Jul 7, 2016
Priority date	Jul 10, 2015
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

The invention relates to a variable transmittance device including at least one variable transmittance lens and a control circuit comprising at least one sensor suitable for measuring an illuminance (E), the control circuit being suitable for automatically controlling the value of the transmittance of the variable transmittance lens depending on the illuminance (E) measured by the sensor, wherein the control circuit defines a plurality of successive illuminance ranges (P) each illuminance range (P) being bounded by a minimum illuminance value (Emin) and a maximum illuminance value (Emax), and wherein the control circuit is suitable for controlling the transmittance of the lens to a plurality of setpoint transmittance values (Tv) respectively corresponding to said plurality of illuminance ranges (P).

First claim

The invention claimed is:

1. A variable-transmittance device comprising:
one variable-transmittance lens;
one control circuit comprising at least one sensor configured to measure a light level (E), the control circuit being configured to automatically set a transmittance value of the variable-transmittance lens depending on the light level (E) measured by the sensor; and
a memory, wherein:
the control circuit is configured to define and store in the memory at least three successive light-level plateaus (P) and two threshold values, each light-level plateau (P) being bounded by a minimum light-level value (Emin) and a maximum light-level value (Emax), each threshold value being a maximum light-level value of a first light-level plateau and a minimum light-level value of a second light-level plateau of the at least three successive light-level plateaus (P),
the control circuit is configured to set transmittance of the lens to at least three setpoint values (Tv) corresponding to the at least three successive light-level plateaus (P), respectively, based on a defined merit function using a plurality of criteria,
the control circuit is configured to determine a state of a battery and to use the merit function to define the at least three successive light-level plateaus (P) and to set the transmittance of the lens to the at least three setpoint values (Tv) based on at least one of the plurality of criteria to decrease an electrical power consumption of the device, the at least one of the plurality of criteria comprising the state of the battery, and
when the battery discharges, the control circuit is configured to define a lower number of light-level plateaus to decrease the electrical power consumption of the device.

2. The device as claimed in claim 1 , wherein the sensor is configured to measure the light level (E) periodically, the measurement period (Tmes) of the sensor being comprised between 5 milliseconds and 1 second.

3. The device as claimed in claim 1 , wherein a variation between two successive setpoint values (Tv) of the lens is comprised between 0.05 and 0.6.

4. The device as claimed in claim 1 , further comprising an adjusting mechanism configured to allow a wearer of the device to modify the at least three setpoint values (Tv) and/or the minimum values (Emin) and/or the maximum values (Emax) of the at least three light-level plateaus (P).

5. The device as claimed in claim 1 , wherein each of the at least three setpoint values (Tv) of the lens is comprised in one of the following intervals:
between 0.80 and 1;
between 0.43 and 0.80;
between 0.18 and 0.43; and
between 0.08 and 0.18.

6. The device as claimed in claim 1 , wherein the at least three setpoint values (Tv) of the lens are comprised in different intervals, respectively.

7. An ophthalmic system comprising at least one variable-transmittance device as claimed in claim 1 .

8. A method for controlling transmittance of a variable-transmittance lens of a variable-transmittance device comprising a control circuit including at least one sensor configured to measure a light level (E), the control circuit being configured to automatically set a transmittance value of the variable-transmittance lens depending on the light level (E) measured by the sensor, the method comprising:
defining, by the control circuit, and storing in a memory at least three successive light-level plateaus (P) and two threshold values, each light-level plateau (P) being bounded by a minimum light-level value (Emin) and a maximum light-level value (Emax), each threshold value being a maximum light-level value of a first light-level plateau and a minimum light-level value of a second light-level plateau of the at least three successive light-level plateaus (P);
depending on the current light level (E) measured by the sensor, setting, by the control circuit, transmittance of the lens to one setpoint value (Tv) from at least three setpoint values (Tv) corresponding to the at least three successive light-level plateaus (P), respectively, based on a defined merit function using a plurality of criteria;
determining, by the control circuit, a state of a battery and using the merit function to define the at least three successive light-level plateaus (P) and to set the transmittance of the lens to the at least three setpoint values (Tv) based on at least one of the plurality of criteria to decrease an electrical power consumption of the device, the at least one of the plurality of criteria comprising the state of the battery; and
when the battery discharges, defining, by the control circuit, a lower number of light-level plateaus to decrease the electrical power consumption of the device.

9. The method as claimed in claim 8 , further comprising:
storing in the memory at least the minimum light-level value (Emin) and the maximum light-level value (Emax) of a current plateau (P 0 ) corresponding to a current transmittance of the variable-transmittance lens; and
acting, by the control circuit, on a current light-level value (E) measured by the sensor only once the sensor has measured a current light-level value (E) lower than the minimum light-level value (Emin) or higher than the maximum light-level value (Emax) of the current plateau (P 0 ) for a length of time longer than a triggering time (Δt).

10. The method as claimed in claim 9 , further comprising:
after the current light-level value (E) measured by the sensor has been received, determining, by the control circuit, a new current plateau (P 1 ) in which the measured light-level value (E) is located; and
automatically setting the transmittance of the lens to the setpoint value corresponding to the new current plateau (P 1 ).

11. The method as claimed in claim 10 , further comprising, after a new setpoint value (Tv) of the lens corresponding to a new current plateau (P 1 ) has been applied, transmitting, by the control circuit to the sensor, the minimum light-level value (Emin,hyst) and the maximum light-level value (Emax,hyst) of the new current plateau (P 1 ), for storage in the memory.

12. The method as claimed in claim 9 , further comprising:
defining, by the control circuit, for each plateau (P), a secondary minimum value (Emin) and a secondary maximum value (Emax), the minimum value (Emin) of a current plateau (P 0 ), stored in the memory, being lower than or equal to the secondary minimum value (Emin) of this current plateau (P 0 ), and the maximum value (Emin) of a current plateau (P 0 ), stored in the memory, being higher than or equal to the secondary maximum value (Emax) of the current plateau (P 0 );
after the current light-level value (E) measured by the sensor has been received, determining, by the control circuit, a new current plateau (P 1 ) in which the measured light-level value (E) is comprised between the secondary minimum value (Emin) and the secondary maximum value (Emax) of the new current plateau (P 1 ); and
automatically setting the transmittance of the lens to the setpoint value (Tv) corresponding to the new current plateau (P 1 ).

13. The method as claimed in claim 9 , wherein the triggering time (Δt) of the sensor is comprised between 1 second and 2 seconds.

14. The method as claimed in claim 8 , further comprising obtaining the light level-dependent setpoint values (Tv) of the lens via transmittance values of a photochromic lens.

15. A non-transitory computer readable storage medium, with a program stored thereon, said program comprising instructions for implementing the method of claim 8 .

Assignees

• Essilor Int

Inventors

• Peloux Marius
• Gilbert Cedric
• Archambeau Samuel

Classifications

• G02C11/10 Primary

  Electronic devices other than hearing aids · CPC title

• G02C7/101 Primary

  having an electro-optical light valve (electro-optical elements per se G02F) · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02F2203/48

  Variable attenuator · CPC title

• G02F2201/58

  Arrangements comprising a monitoring photodetector · CPC title