Mobile x-ray device with telescopic column comprising: - A chassis which supports the telescopic column, - A telescopic column comprising a lower fixed portion which rotates with respect to a vertical axis, and at least one upper mobile portion. - A telescopic arm which moves vertically along the telescopic column and which supports at its end a head assembly which contains the x-ray emitter. This arm on extending or retracting allows the x-ray emitter to be moved further away or brought closer horizontally. - The arm-head assembly which comprises the telescopic arm and the head assembly, can move from a minimum height at the lower position of the at least one upper mobile portion in the retracted position of the telescopic column to a maximum height at the upper position of the mobile portion in the extended position of the telescopic column. - Also all movements of the column are manual and have a mechanical balancing mechanism. Wherein The mechanical balancing mechanism comprises: - A first mechanism that balances the weight of the two suspended bodies with vertical movement (the at least one upper mobile portion on the one hand, and the telescopic arm with the head assembly on the other hand). This first mechanism is housed in the fixed portion. - A second mechanism that balances the weight of the assembly consisting of the telescopic arm and the head assembly and which is housed in each of the at least one upper mobile portions that the telescopic column comprises. Characterized in that: the first balancing mechanism comprises: - A tension spring which can use any type of traction technology, and which is fixed to a support (11.1) at its lower end - A block and tackle consisting of one group of lower pulleys (12.1) and one group of upper pulleys (12.2). The lower pulleys (12.1) of the block and tackle are joined to the tension spring. - A variable radius pulley wherein the cable that comes from the block and tackle and is coiled in the grooves of the pulley whose radii vary throughout the run of the cable, thereby achieving that the cable at the output of the pulley has a constant tension. This force will be the sum of the two weights to be balanced (that of the at least one upper mobile portion and that of the telescopic arm with the head assembly. - A chassis which supports the telescopic column, - A telescopic column comprising a lower fixed portion which rotates with respect to a vertical axis, and at least one upper mobile portion. - A telescopic arm which moves vertically along the telescopic column and which supports at its end a head assembly which contains the x-ray emitter. This arm on extending or retracting allows the x-ray emitter to be moved further away or brought closer horizontally. - The arm-head assembly which comprises the telescopic arm and the head assembly, can move from a minimum height at the lower position of the at least one upper mobile portion in the retracted position of the telescopic column to a maximum height at the upper position of the mobile portion in the extended position of the telescopic column. - Also all movements of the column are manual and have a mechanical balancing mechanism. - A first mechanism that balances the weight of the two suspended bodies with vertical movement (the at least one upper mobile portion on the one hand, and the telescopic arm with the head assembly on the other hand). This first mechanism is housed in the fixed portion. - A second mechanism that balances the weight of the assembly consisting of the telescopic arm and the head assembly and which is housed in each of the at least one upper mobile portions that the telescopic column comprises. the first balancing mechanism comprises: - A tension spring which can use any type of traction technology, and which is fixed to a support (11.1) at its lower end - A block and tackle consisting of one group of lower pulleys (12.1) and one group of upper pulleys (12.2). The lower pulleys (12.1) of the block and tackle are joined to the tension spring. - A variable radius pulley wherein the cable that comes from the block and tackle and is coiled in the grooves of the pulley whose radii vary throughout the run of the cable, thereby achieving that the cable at the output of the pulley has a constant tension. This force will be the sum of the two weights to be balanced (that of the at least one upper mobile portion and that of the telescopic arm with the head assembly. - A tension spring which can use any type of traction technology, and which is fixed to a support (11.1) at its lower end - A block and tackle consisting of one group of lower pulleys (12.1) and one group of upper pulleys (12.2). The lower pulleys (12.1) of the block and tackle are joined to the tension spring. - A variable radius pulley wherein the cable that comes from the block and tackle and is coiled in the grooves of the pulley whose radii vary throughout the run of the cable, thereby achieving that the cable at the output of the pulley has a constant tension. This force will be the sum of the two weights to be balanced (that of the at least one upper mobile portion and that of the telescopic arm with the head assembly.