Oki IP-6620 Maintenance Manual page 525

The media feed unit can feed roll media and can be operated from the rear.
- The pressure roller lever is a mechanism used to remove the pressure from the roller when
setting a media roll. The lever sensor is a photo sensor installed near the pressure roller
lever on the right side of the frame. It detects the position of the lever. When the grip is
removed, the media cannot be fed. Thus the printer operations are stopped when the lever
sensor detects that no grip is applied to the media. In addition, when the grip is detected
again, the media may have been reinstalled. In such a case the lever sensor detection is as a
signal for executing the media detection.
- The media type is specified on the operation panel.
- The media feeding sensor is a reflection-type photo sensor installed in the media feed unit
that lets the engine controller firmware recognizes the media status via detecting the media
existence by reflection on the media back surface.
(2) Driving block
The driving block comprises an x motor (media feed motor), grit roller, pressure roller, and lever.
The media feed motor is a stepping motor for feeding the media, which is controlled by the
engine controller firmware. When this motor is operated, the grit roller rotates, and feeds the
media that is gripped by the pressure roller. The pressure roller is set to grip or canceled by the
lever.
(3) Platen and suction fan
When the media is fed to the platen, air is sucked through the holes on the platen to stick the
media onto the platen and prevent it from floating and coming in contact with the print heads.
Four suction fans are installed. These four fans can be operated independently to match the
media width. The air that has been sucked is released from the lower parts on the capping unit
side and maintenance area side of the printer.
(4) Paper guide and media output sensor
The paper guide is a guiding plate with a curb used for media output to prevent folding of the
media printed on the platen unit. The media output sensor is a reflection-type photo sensor
installed in the media outlet that lets the engine controller firmware recognize the media status
via detecting the media presence by reflection on the media back surface.
(5) Cover switdh and Interlock switch
8-4
OKI Data Infotech Corporation CONFIDENTIAL
Chapter 8 Operation Mechanism