Thermal pattern sensor comprising: - a support (S); - a matrix of pixels arranged on the support (S); - an integrated circuit disposed under the support (S), the matrix of pixels comprising a plurality of rows and a plurality of columns of pixels, said matrix comprising: - an active thermal element formed by a thermosensitive material disposed between a lower layer (10, c 1 , c 2 , c 3 , c 4 , c N ) and an upper layer (30, Es), the lower layer (10, c 1 , c, c 23 , c 4 , c N ) consisting of a plurality of first tracks made of electrically conductive material and extending in a first direction, the said first tracks forming columns of pixels; - a heating element disposed on the active thermal element and forming a serpentine path, said heating element being constituted by a plurality of second tracks (L1, L2, L3, L4, L5, L6) of electrically conductive material and is also constituted by connection sections (w1, w2, w3, w4, w5, w6) of electrically conductive material connected to the ends of the second tracks (L1, L2, L3, L4, L5, L6), the connection sections connecting second tracks (L1, L2, L3, L4, L5, L6) to one another, said second tracks (L1, L2, L3, L4, L5, L6) extending in a second direction different from the first direction and forming lines of pixels, the second tracks being connected, with the exception of the first and last second tracks (L1, L2, L3, L4, L5, L6), by their respective ends to one of the ends of a preceding second track and a following second track via said connecting sections (w1, w2, w3, w4, w5, w6), the first and last second tracks having a free end connected to a connection section, said integrated circuit being connected to the matrix of pixels by routing lines (Ir, zm) of electrically conductive material extending from each of the sections. - a support (S); - a matrix of pixels arranged on the support (S); - an integrated circuit disposed under the support (S), the matrix of pixels comprising a plurality of rows and a plurality of columns of pixels, said matrix comprising: - an active thermal element formed by a thermosensitive material disposed between a lower layer (10, c 1 , c 2 , c 3 , c 4 , c N ) and an upper layer (30, Es), the lower layer (10, c 1 , c, c 23 , c 4 , c N ) consisting of a plurality of first tracks made of electrically conductive material and extending in a first direction, the said first tracks forming columns of pixels; - an active thermal element formed by a thermosensitive material disposed between a lower layer (10, c 1 , c 2 , c 3 , c 4 , c N ) and an upper layer (30, Es), the lower layer (10, c 1 , c, c 23 , c 4 , c N ) consisting of a plurality of first tracks made of electrically conductive material and extending in a first direction, the said first tracks forming columns of pixels; - a heating element disposed on the active thermal element and forming a serpentine path, said heating element being constituted by a plurality of second tracks (L1, L2, L3, L4, L5, L6) of electrically conductive material and is also constituted by connection sections (w1, w2, w3, w4, w5, w6) of electrically conductive material connected to the ends of the second tracks (L1, L2, L3, L4, L5, L6), the connection sections connecting second tracks (L1, L2, L3, L4, L5, L6) to one another, said second tracks (L1, L2, L3, L4, L5, L6) extending in a second direction different from the first direction and forming lines of pixels, the second tracks being connected, with the exception of the first and last second tracks (L1, L2, L3, L4, L5, L6), by their respective ends to one of the ends of a preceding second track and a following second track via said connecting sections (w1, w2, w3, w4, w5, w6), the first and last second tracks having a free end connected to a connection section, said integrated circuit being connected to the matrix of pixels by routing lines (Ir, zm) of electrically conductive material extending from each of the sections. <EOS>