(FR2758039-A1)      The detector includes a matrix (20) of photosensitive points (p1,p2,p3), located on a support (40), exposed to incident radiation (Ri) with an additional light source (6), producing additional radiation (Rd) formed on a face (7) of the support opposite to the face (3) on which the matrix is formed.     The radiation from the additional light source is in a narrow waveband within the waveband of the incident radiation (Ri), centred on a different wavelength. Transmission of the additional radiation is favoured by a transparent dichroic layer and by a coloured layer (9) in varnish, polymer or glass plate.    ADVANTAGE -   Improves contrast without altering power of additional radiation, particularly at low spatial frequencies.    (JP10206552-A)      The detector includes a matrix (20) of photosensitive points (p1,p2,p3), located on a support (40), exposed to incident radiation (Ri) with an additional light source (6), producing additional radiation (Rd) formed on a face (7) of the support opposite to the face (3) on which the matrix is formed.     The radiation from the additional light source is in a narrow waveband within the waveband of the incident radiation (Ri), centred on a different wavelength. Transmission of the additional radiation is favoured by a transparent dichroic layer and by a coloured layer (9) in varnish, polymer or glass plate.    ADVANTAGE -   Improves contrast without altering power of additional radiation, particularly at low spatial frequencies.    (US5973327-A)      The detector includes a matrix (20) of photosensitive points (p1,p2,p3), located on a support (40), exposed to incident radiation (Ri) with an additional light source (6), producing additional radiation (Rd) formed on a face (7) of the support opposite to the face (3) on which the matrix is formed.     The radiation from the additional light source is in a narrow waveband within the waveband of the incident radiation (Ri), centred on a different wavelength. Transmission of the additional radiation is favoured by a transparent dichroic layer and by a coloured layer (9) in varnish, polymer or glass plate.    ADVANTAGE -   Improves contrast without altering power of additional radiation, particularly at low spatial frequencies.