4. Moving the Lensa. At Power-OnWhen the power switch is turned on, the lens X motor (M4) starts to rotate, and thelens moves in the direction of the lens X home position sensor (PS6). Then the lens Ymotor (M5) rotates to move the lens in the direction of the lens Y home position sensor(PS7). When the signal plate on the lens housing blocks the lens X home position sensor(PS6), the X motor starts to rotate in reverse; when the signal plate on the lens stageblocks the Y home position sensor (PS7), the lens Y motor (M5) starts to rotate inreverse.The motors stop to rotate when the lens has reached Direct/A4 width position. (Seeperiod I of Figure 3-204.)b. While Making CopiesThe microprocessor slave (Q140) remembers the location of the lens in Direct/A4position. When a different ratio is selected, it immediately applies drive pulses to the lensX motor (M4)/Y motor (M5) to change the position of the lens. (See period II of Figure 3-204.)The lens Y motor (M5) starts to rotate to move the lens when the Copy Start key hasbeen pressed and the sizes of the original and the copy paper have been determined.(See period III of Figure 3-204.)• Sequence of OperationsFigure 3-204Power switchONLens Y motor (M5)Lens X motor (M4)WMUP/WMUPRRatio change(Reduce)Lens X homeposition (PS6)Lens Y homeposition sensor (PS7)Motor CW/sensor ONMotor CCWMotor ON (direction depends on conditions)STBY INTRRatio change(Enlarge)Copy Start keyONI II IIIIICOPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 3 EXPOSURE SYSTEM3-4
