Device for illuminating an object with a controlled light intensity and associated method

Abstract

The invention concerns a device 10 for illuminating an object 12 with a controlled light intensity, the light intensity being controlled when the light intensity fulfills a plurality of conditions to be fulfilled, the plurality of conditions comprising a condition relative to the intensity at a given time and a condition relative to the dose during a period of time.

1 . A device for illuminating an object with a controlled light intensity, the light intensity being controlled when the light intensity fulfills a plurality of conditions to be fulfilled, the plurality of conditions comprising a condition relative to the intensity at a given time and a condition relative to the dose during a period of time, the device comprising:
 a light source adapted to produce a beam whose intensity does not fulfill at least one of the conditions to be fulfilled,   a photodiode adapted to measure the intensity of an incident beam,   an optical system adapted to convey the light from an entrance to at least one exit, the light source, the photodiode and the optical system being arranged so that the device has two distinct configurations, an operating configuration in which a first portion of the light emitted by the light source is conveyed to the object, and a second portion of the light emitted by the light source is conveyed to the photodiode and a control configuration in which, in normal operating, no light produced by the light source is sent to object nor to the photodiode,   a controller adapted to control the value of the first portion based on the intensity measured on the photodiode when the device is in the control configuration and based on the conditions to be fulfilled.   
     
     
         2 . The device according to  claim 1 , wherein one condition to be fulfilled is that the light intensity at any given time be inferior or equal to a maximum intensity. 
     
     
         3 . The device according to  claim 1 , wherein one condition to be fulfilled is that the light intensity at any given time be superior or equal to a minimum intensity. 
     
     
         4 . The device according to  claim 1 , wherein one condition to be fulfilled is that the dose during the period of time be inferior or equal to a maximum value. 
     
     
         5 . The device according to  claim 1 , wherein the optical system comprises a plurality of reflectors, each reflector having three positions, a first position in which the reflector reflects the incident beam towards the object, a second position in which the reflector reflects the incident beam towards a photodiode and a third position in which the reflector reflects the incident beam neither to the object nor to the photodiode, the controller being adapted to command the position of each reflector, the device being in the operating configuration when the controller commands each reflector to be in the first position or in the second position and the device being in the control configuration when each reflector is commanded to be in the third position. 
     
     
         6 . The device according to  claim 1 , wherein the controller is further adapted to deduce the number of reflectors to be moved in the first position based on the intensity measured on the photodiode when the device is in the control configuration and based on the conditions to be fulfilled and commanding the deduced number of mirrors to move in the first position. 
     
     
         7 . The device according to  claim 1 , wherein the light source is a matrix of light sources, each light source having two states, an unfed state in which the light source emits no light and a fed state in which the light source emits light, the controller being adapted to control the state of each light source. 
     
     
         8 . The device according to  claim 1 , wherein a plane to be illuminated is defined for the object and wherein at least one of the light source and the optical system is such that the several independent spatial areas illuminated by different levels of intensity of light can be defined in the plane to be illuminated when the device is in the operating configuration. 
     
     
         9 . The device according to  claim 8 , wherein the optical system comprises optical components ensuring that the point spread function be inferior to 25 μm at the system output. 
     
     
         10 . The device according to  claim 9 , wherein the optical system comprises a system adapted for correcting optical aberrations, the system adapted for correcting optical aberrations being adjustable. 
     
     
         11 . The device according to  claim 10 , wherein the system adapted for correcting optical aberrations is a liquid lens. 
     
     
         12 . A method for illuminating an object with a controlled light intensity, the light intensity being controlled when the light intensity fulfills a plurality of conditions to be fulfilled, the plurality of conditions comprising a condition relative to the intensity at a given time and a condition relative to the dose during a period of time, the method comprising:
 providing a device for illuminating an object with a controlled light intensity, the device comprising:
 a light source adapted to produce a beam whose intensity does not fulfill at least one of the conditions to be fulfilled, 
 a photodiode adapted to measure the intensity of an incident beam, 
 an optical system adapted to convey the light from an entrance to at least one exit, the light source, the photodiode and the optical system being arranged so that the device has two distinct configurations, an operating configuration in which a first portion of the light emitted by the light source is conveyed to the object, and a second portion of the light emitted by the light source is conveyed to the photodiode and a control configuration in which, in normal operating, no light produced by the light source is sent to object nor to the photodiode, 
 a controller adapted to control the value of the first portion, 
   commanding the device to operate in the control configuration,   measuring the intensity on the photodiode,   determining an intensity illuminating the object due to an abnormal operating of the device in the control configuration based on the measured intensity,   deducing the first portion of light to be emitted in the operating configuration based on the determined light intensity and on the conditions to be fulfilled, and   commanding the device to be in the operating configuration with the value of the first portion being equal to the deduced first portion.   
     
     
         13 . The method according to  claim 12 , wherein the object is an object which restores or improves the eyesight of a user of the device. 
     
     
         14 . The method according to  claim 12 , wherein the object comprises at least one cell expressing photoreactive proteins. 
     
     
         15 . The method according to  claim 12 , wherein photoreactive protein is chosen in the group consisting of light-gated ion channel.