HP LaserJet 5000 Service Manual - Page 129

Duplexer This function is to reverse the one side printed paper from the printer and refeed it into the printer. The Duplexer operation sequence is controlled by the duplex driver PCA. The duplex driver PCA has the 8-bit microcomputer, which controls the serial communications between the operation sequence control of the duplexing unit and the DC controller PCA of the printer. The duplex driver PCA drives motors and solenoids with various commands from the DC controller PCA. The duplex driver PCA also sends the status of the Duplexer back to the printer. Reversing/Refeed System The paper is first fed into the Duplexer with the duplex deflector in the printer. In the Duplexer, the reversing roller switches the feeding direction of the paper. After the side registration guide adjusts the side registration, the paper is sent back into the printer with the feed and refeed rollers. The reversing motor (PM1701), the side registration guide drive motor (PM1702), and the refeed motor are all stepping motors. They are controlled both in straight and reverse rotation by the microcomputer (CPU) on the duplexing driver PCA. The reversing roller is driven by the reversing motor (PM1701). The feed and refeed rollers are driven by the refeed motor (PM1703). The side registration guide is driven by the side registration guide drive motor (PM1702), and is adjusted according to the size of the paper. 5-38 Functional Information EN