HP M5025 Service Manual - Page 136

Print engine Figure 4-2 Device function block diagram Basic sequence of operation The microprocessor (CPU) on the DC controller controls the operation sequence of the device. The following events take place during typical device operation. Table 4-3 Sequence of operation (engine) Period WAIT period STBY (Standby period) INTR (Initial rotation) PRINT LSTR (Last rotation) Duration Purpose Remarks From the time the power is turned on until the initial drive for the main motor is complete Removes the charge that creates a potential difference from the drum surface, and adjusts the drum phase Detects cartridge presence From the end of the WAIT or LSTR period until either the print command is received from the formatter or the power is turned off Maintains the printer in readiness for a print command and maintains the heater at a targeted temperature From the time the print Prepares the photosensitive command is received until the drum for printing and cleans pickup solenoid is turned on the transfer charging roller From the end of INTR period until the fuser paper sensor detects the trailing edge of paper Forms the images on the photosensitive drum and transfers the toner image to the print media From the end of the PRINT period until the fuser motor stops rotating Moves the last printed sheet out of the printer The printer enters the INTR period as soon as the formatter sends another print command 106 Chapter 4 Theory of operation ENWW