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

Patent metadata

Field	Value
Publication number	US-2018210236-A1
Application number	US-201615743166-A
Country	US
Kind code	A1
Filing date	Jul 7, 2016
Priority date	Jul 10, 2015
Publication date	Jul 26, 2018
Grant date	—

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

1 . A variable-transmittance device comprising:
one variable-transmittance lens; and one control circuit comprising at least one sensor suitable for measuring a light level (E), the control circuit being suitable for automatically setting the transmittance value of the variable-transmittance lens depending on the light level (E) measured by the sensor, wherein: the control circuit defines a plurality of successive light-level plateaus (P), each light-level plateau (P) being bounded by a minimum light-level value (Emin) and a maximum light-level value (Emax), and the control circuit is suitable for setting the transmittance of the lens to a plurality of setpoint values (Tv) corresponding to said plurality of light-level plateaus (P), respectively.

2 . The device as claimed in claim 1 , wherein the sensor is suitable for measuring 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 the variation between two successive transmittance setpoint values (Tv) of the lens is comprised between 0.05 and 0.6.

4 . The device as claimed in claim 1 , comprising an adjusting mechanism suitable for allowing a wearer of the device to modify the transmittance setpoint values (Tv) and/or the minimum values (Emin) and/or the maximum values (Emax) of the light-level plateaus (P).

5 . The device as claimed in claim 1 , wherein each of the transmittance 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 transmittance setpoint values (Tv) of the lens are comprised in different intervals, respectively.

7 . The device as claimed in claim 1 , wherein the control circuit comprises a memory for storing the minimum and maximum light-level values (Emin, Emax) of the light-level plateaus (P).

8 . The device as claimed in claim 1 , wherein the control circuit defines at least three successive light-level plateaus (P), the control circuit being suitable for setting the transmittance of the lens to at least three setpoint values (Tv) corresponding to said three light-level plateaus (P), respectively.

9 . A method for controlling the transmittance of a variable-transmittance lens of a variable-transmittance device comprising a control circuit including at least one sensor suitable for measuring a light level (E), the control circuit being suitable for automatically setting the transmittance value of the variable-transmittance lens depending on the light level (E) measured by the sensor, the method including the steps, implemented by the control circuit, of:
defining a plurality of successive light-level plateaus (P), each light-level plateau (P) being bounded by a minimum light-level value (Emin) and a maximum light-level value (Emax); and depending on the current light level (E) measured by the sensor, setting the transmittance of the lens to one transmittance setpoint value (Tv) from at least a plurality of transmittance setpoint values (Tv) corresponding to said plurality of light-level plateaus (P), respectively.

10 . The method as claimed in claim 9 , furthermore comprising steps in which:
the sensor stores in memory at least the minimum light-level value (Emin,hyst) and the maximum light-level value (Emax,hyst) of a current plateau (P 0 ) corresponding to a current transmittance of the variable-transmittance lens, and the control circuit acts 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,hyst) or higher than the maximum light-level value (Emax,hyst) of the current plateau (P 0 ) for a length of time longer than a triggering time (Δt).

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

12 . The control method as claimed in claim 10 , wherein:
the control circuit furthermore defines, for each plateau (P), a secondary minimum value (Emin) and a secondary maximum value (Emax), the minimum value (Emin,hyst) of a current plateau (P 0 ), stored by the sensor, being lower than or equal to the secondary minimum value (Emin) of this current plateau (P 0 ), and the maximum value (Emin,hyst) of a current plateau (P 0 ), stored by the sensor, being higher than or equal to the secondary maximum value (Emax) of this current plateau (P 0 ), after the current light-level value (E) measured by the sensor has been received, the control circuit determines 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 sets 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 11 , wherein, after a new transmittance setpoint value (Tv) of the lens corresponding to a new current plateau (P 1 ) has been applied, the control circuit transmits 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 of the sensor.

14 . The method as claimed in claim 9 , wherein the light level-dependent transmittance setpoint values (Tv) of the lens are obtained via transmittance values of a photochromic lens.

15 . The method as claimed in claim 10 , wherein the triggering time (Δt) of the sensor is comprised between 1 second and 2 seconds.

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

17 . A non-transitory computer readable storage medium, with a program stored thereon, said program comprising instructions for implementing the method of claim 9 .

Assignees

• Essilor Int

Inventors

• Peloux Marius
• Gilbert Cedric
• Archambeau Samuel

Classifications

• G02F1/163

  Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor · CPC title

• G02C11/10 Primary

  Electronic devices other than hearing aids · CPC title

• G02F2001/13312

  Physics · mapped topic

• G02F2203/48

  Variable attenuator · CPC title

• G02C7/101 Primary

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