Oki Pacemark 4410 Service Handbook

Also see for PACEMARK 4410: User guide Specifications Maintenance manual Service manual

Contents

40496501TH Draft Version 372.2.3 Head gap adjustingThe auto gap adjusting mechanism automatically adjusts the space between the platen and printhead according to the thickness of papers. This mechanism does this driving the platen back andforth with the AG motor (pulse motor), and effects the auto gap motion after the reverse motion ofthe platen. The platen is reversed at power on or off line when cover open or paper end is detected,and the auto gap adjusting motion is performed when the printer returns to on line.When the printer is shifted to off line at power on or detection of paper end, the platen reverses tothe position that the space to the print head becomes wider than the thickness of paper (gap openposition).As the off line mode is released, shifted to on line after platen reverses, the AG motor drives theplaten to the direction that the space between the print head and platen becomes narrower.The rotational force of tha AG motor moves the platen to the print head (in the direction that thespace becomes narrower) through various idle gears and adjusting cam.After that, the AG plate impinges on the paper, and the AG frame is deflected, changing the coregap of the auto gap sensor located on the AG frame. When the change of the core gap is detected,the AG motor stops rotating.Next, the AG motor reverse-rotates only a fixed step and stops. This allows the platen movebackward, obtaining an proper space with the print head.The forward an backward motion of the platen is driven by the adjusting cam being rotated, andthe platen is always pulled to the reart of the unit by the spring.