Patent ID: 7804478

Claim:
An electronic feedback device for feedback control of photometric or colorimetric characteristics for a light box which illuminates optical-valve images, comprising: an electronic control circuit which controls at least a first and a second array of light-emitting diodes disposed in the light box, the first array of light emitting diodes emitting light in a first spectral band, the second array of light emitting diodes emitting light in a second spectral band; an electronic processing/computing unit driving the electronic control circuit; and optoelectronic devices for measuring photometric and colorimetric characteristics of the light-emitting diodes connected to the electronic processing/computing unit, said optoelectronic devices comprising a first optoelectronic assembly including: a first optoelectronic light-emitting diode identical to one light emitting diode of the first and second arrays of light emitting diodes in the light box; and a photosensitive sensor placed facing said first optoelectronic light-emitting diode, said first optoelectronic light emitting diode being controlled by the electronic control circuit, said first optoelectronic assembly comprising a structure which isolates the first optoelectronic assembly from external light said first optoelectronic assembly being placed in an environment close to that of the light box, and said electronic processing/computing unit comprising: a storage unit for storing setpoint values of the photometric and colorimetric parameters; a processing unit for processing the data coming from the photosensitive sensor, said processing unit being connected to the optoelectronic measurement devices; an electronic comparator for comparing the data coming from the processing unit with the setpoint values; and a control unit connected, on one side, to the electronic comparator and, on the other side, to the electronic control circuit for the arrays of light-emitting diodes, thereby making it possible to maintain the setpoint values of the photometric and colorimetric parameters.