THEORY OF OPERATION
4-5. Detectors
(1) Home Position Detector A photo-interrupter is used in the home position detector, which is set at the left side of the frame unit. ON/OFF signals are generated according to the position of the shield plate mounted at the base of the carriage, and the printing position is determined by these signals. Paper Out Detector Paper out detector is located at the paper insertion slit. When paper is present, the photo transistor with the reflecting type photo sensor goes on. As soon as paper runs out, this transistor goes off, outputting a paper empty signal.
(2)
Fig. 2-29 Home Position Detector (3)
Fig. 2-30 Paper Out Detector
Bail Lever Position Detector The leaf switch is open when the bail roller is in contact with the platen roller, and it is closed when the bail roller is separated from the platen roller. Release Lever Position Detector The leaf switch is closed when the release lever is in the Friction position, and is open in the Tractor position.
