HP Color LaserJet CP2020 Service Manual - Page 80

Sequence of operation Table 5-1 Sequence of operation Period Duration Purpose Remarks WAIT From the time the power is turned on, the door is closed, or the Sleep mode is released until the printer gets ready for a print job Brings the printer to printing readiness Detects the pressurization status of the pressure roller, presence of the cartridges, and home position of the development unit; cleans the ITB; and completes any required calibration (color registration control and image stability) STBY (Standby period) 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 The printer enters Sleep mode when the formatter sends a sleep command and performs color registration and image stability control when the formatter sends those commands INTR (Initial rotation period) From the time the print command is received from the formatter during STBY until the temperature of the fuser reaches the target temperature Prepares the photosensitive drum for printing Starts up each high-voltage bias, laser/scanner unit, and fuser unit PRINT From the end of INTR period until the last media completes the fusing operation Forms the images on the photosensitive drum and transfers the toner image to the print media Performs color misregistration control and image stabilization at a specified print interval LSTR (Last rotation period) From the end of the PRINT period until the delivery motor stops rotating Moves the printed sheet out of the printer and stops operation of the laser/scanner unit and high-voltage biases The printer enters the INTR period when the formatter sends another print command. 60 Chapter 5 Theory of operation ENWW