| 摘要 |
PURPOSE:To position easily and accurately a print density detecting head on a basis of the center position of a positioning mark, by forming a continuous positioning mark narrower than a mark for print density detection and reading the positioning mark by the print density detecting head. CONSTITUTION:An electrostatic latent image is formed by a laser light or electrostatic recording, and a toner image is transferred to a transfer paper 9 after development due to a developer. When the electrostatic latent image is formed, a latent image for print density control is formed also, and its toner image is transferred to form a print density control mark 17 on the transfer paper. In case that a print density detecting head 18 is positioned for assembling in a factory or maintenance and inspection, a continuous positioning mark narrower than the print density control mark is generated from a positioning mark generating circuit, and the density of its transferred toner image 21 in the breadthwise direction is read by the detecting head, and the detecting head is fixed to the peak value of a detection signal S2. |
