Abstract: A recording system for driving heating elements of a thermal printing head such that the recording intensity is substantially the same at two different recording speeds. One of at least two given recording character modes is selectively set, each of the recording character modes setting a given different recording speed. At least the pulse amplitude of a driving electric power signal, which is selectively applied to the heating elements of the thermal head, is varied in accordance with the set recording character mode while keeping the pulse cycle of the driving electric power signal at a predetermined substantially constant period. The pulse amplitude of the driving electric power signal has a higher value when recording at a higher speed and a lower value when recording at a lower speed. In addition to controlling the amplitude of the driving electric power signal, it is possible to further control the pulse widths of the pulses forming the driving electric power signal.

Abstract: In electrostatic recording apparatus recording head such as an optical fiber tube (OFT) is closely spaced from the image forming member, such as a drum covered with a photosensitive substance. The electrostatic latent image is generally formed with the use of a toner applied to the drum. Despite the use of various cleaning devices, toner particles are carried by the drum into the narrow gap between the OFT and the drum and adhere to the scanning face of the OFT, interfering with the projected image. The present invention provides a manual or automatic cleaning device positioned in the narrow gap for removing adherent toner or other interfering material from the scanning face of the OFT.