HP LaserJet 4100 Service Manual download pdf (Page 129)

EN Chapter 5 Theory of operation 127

Envelope feeder

The operation sequences of the envelope feeder are controlled by the envelope-feeder driver. A 4-bit

microprocessor is used in the envelope feeder driver, which controls the envelope-feeder sequence

and the communication with the engine controller board of the printer.

The engine controller board sends the pickup command to the envelope-feeder driver with the

necessary timing. The envelope-feeder driver activates the solenoid in response to the command.

The envelope feeder driver also sends the envelope-feeder status to the engine controller board.

A charge of +24 VDC is supplied to the envelope feeder from the printer, and +3.3 V for the ICs is

generated from the +24 VDC inside the envelope-feeder driver.

Pickup and feeding

In the envelope feeder, the envelope sensor (PS901) detects the presence of envelopes and the

envelope-size sensor (PS903) detects if the envelope size is wide or narrow. All of the rollers in the

envelope feeder are driven by the envelope pickup motor (M901).

When a print command is sent to the printer from the formatter, the printer starts the main motor

(M101). When the initial rotation phase is completed, the scanner motor starts rotating. As the

scanner motor rotates, the envelope pick-up motor starts rotating to drive the pickup roller, feed roller,

and separation roller, and an envelope is picked up.

Then, any unnecessary envelopes are stopped by the separation roller, and the envelope is fed to

the printer. The envelope then reaches the registration assembly, where its skew is corrected. Then it

goes through transfer, separation, and fusing stages; passes through the delivery unit; and is

delivered to the output bin. See figure 104 on page 252.

Duplexer

The operation sequences of the duplexer are controlled by the duplexer driver. A 4-bit

microprocessor is used in the duplexer driver, which controls the duplexer sequence and the

communication with the engine controller board.

The duplexer driver drives the solenoid, motors, and fan according to commands sent from the

engine controller board to the duplexer and duplex pickup command via serial communication. The

duplexer also returns its status to the engine controller board.

A charge of +24 VDC is supplied to the duplexer from the printer, and +5 V for the ICs is generated

from the +24 VDC inside the duplexer driver.

Reversing and duplexer pickup

The duplexer has two stepping motors, the reversing motor (M701) and the duplex feed motor

(M702). Normal and reverse rotations are controlled by the duplexer driver.

Print media is fed to the duplexer from the face-up output tray divertor, which is controlled by the

duplexer solenoid.

Note If the face-up tray is open, the duplexer cannot be used.

When the trailing edge of the media passes the reverse sensor (PS703), the reversing motor

changes direction. The media is then transported by the oblique roller and feed roller so that its edge

makes contact with the left panel to correct its skew.

1 2 ... 124 125 126 127 128 129 130 131 132 133 134 ... 335 336

No comments

HP LaserJet 4100 Service Manual Page 129