Illumination device, especially for an automotive vehicle, comprising LEDs, mounted on a printed circuit board or PCB, comprising a combination of means essentially composed of: (a) • in front of the illuminating face of the LEDs, a system comprising opaque parallel plates (1, 2) at least one of the faces of which is a light colour, preferably a white colour, whereas the opaque plates (1, 2) define an annular channel or passage having a circular, quadrangular, polygonal shape, regular or not, or a linear or sinuous channel, and advantageously a set of concentric tubes, and whereas the LEDs or the PCB bearing the LEDs are placed at an angle of up to approximately 20°, and preferably approximately 15°, relative to the transverse section plane of said plates forming a channel for the light from said LEDs, • at least two of said parallel plates bearing on the PCB and/or on the periphery thereof, respectively on either side of at least one LED borne by said PCB, so as to define a channel at the bottom of which said LEDs are distributed, and • said plates forming a wall being arranged to channel the light emitted by said LEDs, which escapes from said device via the side of said plates opposite the side mentioned above bearing on or around the PCB, and • the at least one light- or white-coloured face of said plates being turned towards the interior of said channel, and (b) near the front end of said channel, level with said end or preferably upstream thereof in the direction of light emission output in operation, a substantially planar reflector and, downstream thereof in the direction of light emission/scattering in operation, a semi-transparent screen, substantially parallel to said reflector and comprising, on at least one of the two main faces thereof, elements promoting the dispersion of the incident light, whereas said reflector is mounted and only extends inside the surface defined by the profile of the inner periphery of the output end of said channel, and whereas said semi-transparent screen has a profile facing said reflector, at a distance therefrom and is of a larger size such that it further substantially covers the output end of said channel. (a) • in front of the illuminating face of the LEDs, a system comprising opaque parallel plates (1, 2) at least one of the faces of which is a light colour, preferably a white colour, whereas the opaque plates (1, 2) define an annular channel or passage having a circular, quadrangular, polygonal shape, regular or not, or a linear or sinuous channel, and advantageously a set of concentric tubes, and whereas the LEDs or the PCB bearing the LEDs are placed at an angle of up to approximately 20°, and preferably approximately 15°, relative to the transverse section plane of said plates forming a channel for the light from said LEDs, • at least two of said parallel plates bearing on the PCB and/or on the periphery thereof, respectively on either side of at least one LED borne by said PCB, so as to define a channel at the bottom of which said LEDs are distributed, and • said plates forming a wall being arranged to channel the light emitted by said LEDs, which escapes from said device via the side of said plates opposite the side mentioned above bearing on or around the PCB, and • the at least one light- or white-coloured face of said plates being turned towards the interior of said channel, and • at least two of said parallel plates bearing on the PCB and/or on the periphery thereof, respectively on either side of at least one LED borne by said PCB, so as to define a channel at the bottom of which said LEDs are distributed, and • said plates forming a wall being arranged to channel the light emitted by said LEDs, which escapes from said device via the side of said plates opposite the side mentioned above bearing on or around the PCB, and • the at least one light- or white-coloured face of said plates being turned towards the interior of said channel, (b) near the front end of said channel, level with said end or preferably upstream thereof in the direction of light emission output in operation, a substantially planar reflector and, downstream thereof in the direction of light emission/scattering in operation, a semi-transparent screen, substantially parallel to said reflector and comprising, on at least one of the two main faces thereof, elements promoting the dispersion of the incident light, whereas said reflector is mounted and only extends inside the surface defined by the profile of the inner periphery of the output end of said channel, and whereas said semi-transparent screen has a profile facing said reflector, at a distance therefrom and is of a larger size such that it further substantially covers the output end of said channel.