Motors See “Timing Diagram” on page 5-50 for specific timing details for the printer motors. The Main Motor, MT1, is controlled by the Engine Controller Board. The Main Motor drives the Main Gear Assembly and rotates during the initial rotation period (following power-on), the print period, the last rotation period, or whenever the printer’s Top Cover is opened and closed. Figure 5-8 Main Motor Control The Main Motor is a DC brushless motor and is unified with the motor drive circuit. The CPU (IC501) sets the Main Motor Drive signal (/MON) to “L” and rotates the Main Motor.
When the HP LaserJet 4000 series printer is printing at 1200 dpi, the CPU sets the main motor rotation switching signal (/HALF) to “L” and decreases the rotation speed of the Main Motor to half. The HP LaserJet 4050 prints 1200 dpi at engine speed. Engine Controller System 5-13