A double-function correcting memory reacts to an incremented meter rate synchronised with the input of an image's data, in order to form an image of a data recording medium through scalable turning movements of a reading head (4), fitted with numerous luminous dots (14). The double-function correcting memory stores data for correcting brightness corresponding to the tone of each luminous dot. Data stored in the double-function correcting memory is read according to each image's data entered through a data input bus and according to the meter rate of the meter, synchronised with the image's data. A tone regulating device regulates the period of luminosity for each luminous dot, applying a time apportioning mode. This is driven by a device relying on data read by the double-function correcting memory.
