A system for scanning a surface, comprising: - illumination means configured and arranged for projecting on a surface to be scanned at least one light beam (Be) with a determined divergence for illuminating a sub-area (Si) of the area forming said surface to be scanned, which is at least partially reflective; - light direction means associated with said illumination means, configured for directing said light beam (Be) so that it illuminates different sub-areas (Si) of the surface to be scanned in an alternating manner; and - reception and detection means configured and arranged for receiving and detecting, in an alternating manner, corresponding portions of light (Br) of said light beam (Be) reflected on each of said different sub-areas (Si) of the surface to be scanned, where said reception and detection means comprise at least one light detector; wherein, said reception and detection means comprise light redirection means including a plurality of light redirection elements arranged according to a determined spatial distribution model (Qr), in a number greater than the number of said at least one light detector, and configured for receiving portions of reflected light (Br), each of them in at least one part of a respective sub-model (SQr) of said determined spatial distribution model (Qr); and said light redirection means are configured and arranged for sequentially redirecting each of the portions of reflected light (Br) received in at least said part of each of said sub-models (SQr) towards said at least one light detector; characterized in that the light direction means comprise at least one reflective device (Me) arranged between the light beam (Be) and the surface to be scanned, and which has elements configured to carry out the alternating direction of the light beam (Be) without the entire reflective device (Me) having to be moved, wherein said reflective device (Me) is implemented by means of a microelectromechanical system. - illumination means configured and arranged for projecting on a surface to be scanned at least one light beam (Be) with a determined divergence for illuminating a sub-area (Si) of the area forming said surface to be scanned, which is at least partially reflective; - light direction means associated with said illumination means, configured for directing said light beam (Be) so that it illuminates different sub-areas (Si) of the surface to be scanned in an alternating manner; and - reception and detection means configured and arranged for receiving and detecting, in an alternating manner, corresponding portions of light (Br) of said light beam (Be) reflected on each of said different sub-areas (Si) of the surface to be scanned, where said reception and detection means comprise at least one light detector; wherein, said reception and detection means comprise light redirection means including a plurality of light redirection elements arranged according to a determined spatial distribution model (Qr), in a number greater than the number of said at least one light detector, and configured for receiving portions of reflected light (Br), each of them in at least one part of a respective sub-model (SQr) of said determined spatial distribution model (Qr); and said light redirection means are configured and arranged for sequentially redirecting each of the portions of reflected light (Br) received in at least said part of each of said sub-models (SQr) towards said at least one light detector; characterized in that the light direction means comprise at least one reflective device (Me) arranged between the light beam (Be) and the surface to be scanned, and which has elements configured to carry out the alternating direction of the light beam (Be) without the entire reflective device (Me) having to be moved, wherein said reflective device (Me) is implemented by means of a microelectromechanical system. wherein, said reception and detection means comprise light redirection means including a plurality of light redirection elements arranged according to a determined spatial distribution model (Qr), in a number greater than the number of said at least one light detector, and configured for receiving portions of reflected light (Br), each of them in at least one part of a respective sub-model (SQr) of said determined spatial distribution model (Qr); and said light redirection means are configured and arranged for sequentially redirecting each of the portions of reflected light (Br) received in at least said part of each of said sub-models (SQr) towards said at least one light detector; characterized in that the light direction means comprise at least one reflective device (Me) arranged between the light beam (Be) and the surface to be scanned, and which has elements configured to carry out the alternating direction of the light beam (Be) without the entire reflective device (Me) having to be moved, wherein said reflective device (Me) is implemented by means of a microelectromechanical system.