HP Pro 4300 C9H70UT C9H70UT#ABA manual Paper pickup and feed block

The paper pickup and feed system is divided into two blocks. The paper pickup/feed block, and the fuser/delivery block.

Fuser/delivery block

Paper pickup/feed block

Figure 15. Paper pickup/feed and fuser/delivery block diagram

Paper pickup and feed block

The printer functions that take place in the pickup/feed block are cassette media size and presence detection, media entering the paper path from tray 1 or tray 2, Lifting of the tray 2 paper plate, multiple feed prevention, and page skew correction. For information about the locations of switches, sensors, and motors in the pickup/feed block, see “Printer switches and sensors” on page 336 and “Printer motors and fans” on page 337.

When the print command is received from the host computer by the DC controller PCA it turns the main motor (M101) power on. This motor will drive the tray 2 pickup, feed, and separation rollers to rotate. For the HP LaserJet 4300, the print cartridge motor power also is turned on. The laser/scanner motor power is turned on.

The DC controller PCA then activates the feed clutch (CL101) to rotate the feed roller. The tray 2 pickup solenoid is activated (SL101) and the pickup arm descends. The pickup roller touches the media and a sheet is fed into the printer. The separation roller prevents multi-sheets of media from being fed all at one time.

As the pre-feed sensor (PS102) detects the media, the DC controller PCA turns off the clutch which stops the media. When the DC controller PCA detects that the laser/scanner is ready it activates the feed clutch again. The feed roller moves the media further into the printer. Page skew is corrected by the registration shutter and the media is transported to the fuser/delivery block (feed belt, fuser, and delivery output bin).

For information about the timing of these operations, see “HP LaserJet 4200 general timing diagram” on page 357 and “HP LaserJet 4300 general timing diagram” on page 358.

Q2431-90912 Chapter 5 Theory of operation 79