Electrostatic copying apparatus

An electrostatic copying apparatus including a photoconductive belt, charging means for forming an electrostatic charge on the belt, imaging means for performing a scanning operation by scanning an original document and radiating a light image of the document on the belt to form an electrostatic image while the belt is held stationary and developing means for applying toner to the belt to develop the electrostatic image into a toner image, characterized by comprising:

• sensor means movable integrally with the imaging means for sensing an optical density pattern of the document and producing electrical signals corresponding thereto;
• computing means for computing a predetermined operating parameter of a unit of the apparatus which is to be controlled after completion of the scanning operation in response to the electrical signals;
• and
• control means for controlling the unit to operate in accordance with the computed parameter;
• the unit being an illumination means for radiating light onto non-image portions of the belt between the scanning and developing operations, the parameter being a timing of operation of the illumination means;
• and
• first and second rollers, the belt being trained around the first and second rollers, the electrostatic image on the belt moving around the first roller before moving around the second roller, the first roller being transparent, the illumination means being disposed inside the first roller.