2. Moving the Lensa. Moving the Lens in Y (vertical) DirectionThe machine’s lens is mounted on a lens stage, which is moved in Y (verticaldirection) when the lens Y motor (M5) is rotated.b. Moving the Lens in the X (horizontal) DirectionThe lens X motor (M4) mounted behind the lens stage is used to move the lens in X(horizontal) direction.3. Lens Motor Control CircuitThe lens X motor (M4) and the lens Y motor (M5) are 4-phase stepping motors. Bothmotors are controlled in the same way, and the lens X motor is discussed here.The motor is controlled by the four types of motor drive signals from the DC controllerPCB: M4A, M4A*, M4B, M4B*. The direction of the motor is changed by changing thetiming at which these motor drive signals are sent.To keep the lens X motor stationary, the lens X motor hold signal (X-HOLD) isgenerated, thereby applying brakes in the form of a voltage lower than when rotating themotor.Figure 3-203DC controller PCBQ156Micro-processor24V24VLens XmotordrivecircuitLens YmotordrivecircuitJ110A-3-6-1-2-4-5X-HOLDM4AM4A*M4BM4B*J736J736J739M4M5Lens (X) motorLens (Y) motorJ110A-12-15-10-11-13-14Y-HOLDM5AM5A*M5BM5B*COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)CHAPTER 3 EXPOSURE SYSTEM3-3
