| 摘要 |
PURPOSE:To print a picture in a correct position by obtaining the length from the part, where a photosensitive body and a recording form are brought into contact with each other, to the front end of the recording form and the length from said contacting part to the front end of a toner image on the photosensitive body and controlling the carrying speed of the recording form in accordance with the difference between these lengths. CONSTITUTION:The length from the position, where the front end of a form 2 passes a gate 4, to a point P where a front end 2A of the form 2 and a photosensitive drum 1 are brought into contact with each other is obtained as a digital value by a form position sensor 6 and is subjected to D/A conversion by a D/A converter 12 and is inputted to the negative terminal of an adder 9. Meanwhile, the length from a front end 5A of a toner image 5 on the photosensitive drum 1 to the point P is obtained by a toner image position detecting sensor 7B and is subjected to D/A conversion and is inputted to the positive terminal of the adder 9. The addition result is inputted to a differential amplifier 10 to drive a driving motor 11A, and the rotative speed of a form carrying roll 3 is controlled to be accelerated or decelerated so that the output of the adder 9 is zero. Thus, printing is always started from a carrect position of the form 2 automatically. |
