HP P3015 Service Manual

Image formation process
Each of the following process function independently and must be coordinated with the other product
processes. Image formation consists of the following processes:
●Latent-image formation block
◦Step 1: primary charging
◦ Step 2: laser-beam exposure
● Developing block
◦Step 3: developing
● Transfer block
◦Step 4: transfer
◦ Step 5: separation
● Fusing block
◦Step 6: fusing
● Drum cleaning block
◦Step 7: drum cleaning
Figure 1-17   Image formation process
Drum cleaning Developing...

Latent-image formation stage
During the latent-image formation stage, the laser/scanner forms an invisible image on the
photosensitive drum in the print cartridge.
Primary charging Step 1: DC and AC biases are applied to the primary charging roller, which transfers a uniform negative
potential to the photosensitive drum.
Figure 1-18   Primary charging
Primary charging bias
Photosensitive drum
Primary charging roller
Laser beam exposure
Step 2: The laser beam scans the photosensitive drum to neutralize...

Developing stage
Print cartridgeStep 3: In the print cartridge, the developing cylinder comes in contact with the photosensitive drum to
deposit toner onto the electrostatic latent image.
Figure 1-20   Print cartridge
Blade
Photosensitive drum
Unexposed area
Exposed area Unexposed area
Exposed area
Developing roller
Developing bias
Toner acquires a negative charge from the friction that occurs when the developing roller rotatesagainst
the developing blade. The developing bias is applied to the developing...

Transfer stage
Step 4: The transfer charging roller, to which a DC positive bias is applied, imparts a positive charge
on the print media. When the print media comes in contact with the photosensitive drum, the toner is
transferred to the print media.
Figure 1-21   Transfer
Media
Transfer roller Photosensitive
drum
Transfer bias
Step 5 : The elasticity of the print media causes its separation from the photosensitive drum. A static
charge eliminator aids separation by weakening any electrostatic...

The product uses an on-demand fuser method. The toner image is permanently affixed to the printing
paper by heat and pressure.
Figure 1-23  Fusing
Media
Toner
Fuser film Fuser heater
Pressure rollerBrush
Fuser bias
Cleaning stageStep 7: The cleaning blade scrapes the residual toner off of the photosensitive drum and deposits it into
the waste toner case.
Figure 1-24   Drum cleaning
Toner collection box Photosensitive
drum
Cleaning blade
ENWW
Image-formation system 31 

Toner detection
The product uses a nonvolatile memory tag built into the print cartridge. Print-cartridge detection
happens when the engine controller detects the presence of a genuine HP print-cartridge that contains
a memory tag. Toner detection happens as the engine controller reads or writes the data that is stored
on the memory tag. The engine controller renews the information in the prescribed timing and reads or
writes it from or to the memory tag.
The engine controller commands the memory tag to...

Pickup, feed, and delivery system
The pickup/feed/delivery system consists of several types of feed rollers and sensors. The ECU uses
a motor and two solenoids to drive the rollers. Three media-detection sensors detect paper as it passes
through the product. If media does not reach or pass each sensor within a specified time, the ECU
determines that a jam has occurred and alerts the formatter.
Paper trays
The product has the following paper trays:
●Tray 1 (multipurpose tray; all models)
● Tray 2...

Photo sensors and switches
Figure 1-26  Photo sensors and switches (product)
SW235
M8001
M8002PS3
PS215PS205
PS502
PS8001
PS4
PS1
PS2PS225 SW501
SL1
SL2
Table 1-10   Photo sensors and switches (product)
ItemDescriptionItemDescription
PS1Face-up sensorPS215Top-of-Page (TOP) sensor
PS2Fuser delivery sensorPS225Media width sensor
PS3Cassette media-presence sensorPS502Duplex media-feed sensor (duplex models only)
PS4Face-down tray media-full sensorPS8001Rear door sensor
PS205Tray 1 (MP tray) media-presence...

Figure 1-27  Photo sensors and switches (Tray 3 and Tray 4)
PS451
PS8008
SL3
M8001
SW461
CL1
Table 1-11
  Photo sensors and switches (Tray 3 and Tray 4)
ItemDescription
PS451Paper feeder cassette-media presence sensor
PS8008Paper feeder media-feed sensor
SW461Paper feeder cassette presence switch
1Tray 3 and Tray 4 are identical 500-sheet input trays.
ENWW Pickup, feed, and delivery system 35 

Solenoids and clutches
Figure 1-28  Solenoids and clutches (product)
SL1
SW235
SL2
M8001
M8002PS3
PS215PS205
PS502
PS8001
PS4
PS1
PS2PS225
SW501
Table 1-12   Solenoids and clutches (product)
ItemDescription
SL1Tray 1 (multipurpose tray) pickup solenoid
SL2Cassette (Tray 2) pickup solenoid
36 Chapter 1   Theory of operation ENWW