The Transfer System is one of the most important components in a Konica Minolta bizhub photocopier. After the toner image has been developed on the OPC (Organic Photoconductor) Drum, it must be transferred accurately to the paper. This task is performed by the Intermediate Transfer Belt (ITB) and the Primary and Secondary Transfer Rollers, which use carefully controlled electrostatic fields to move toner without physically scraping it from the drum.

Unlike older monochrome copiers that transferred toner directly from the drum to the paper, most modern Konica Minolta color bizhub machines first transfer each color image to an Intermediate Transfer Belt. The belt collects the Cyan, Magenta, Yellow, and Black toner images into a perfectly aligned full-color image before transferring them to the paper in a single step.

A properly functioning transfer system provides:

Accurate color registration
Efficient toner transfer
Sharp text and graphics
High image density
Clean backgrounds
Reliable duplex printing

When the transfer system develops faults, technicians may observe:

Faded prints
Color misregistration
Missing colors
Toner not transferring completely
Background contamination
Repeating belt defects
Image distortion

Understanding how the Transfer Belt and Transfer Rollers work is essential for diagnosing many print-quality problems in Konica Minolta bizhub machines.

The Transfer System in the Imaging Process

The complete electrophotographic process is:

Primary Charge Roller charges the OPC drum.
Laser Scanner Unit writes the latent image.
Developer Unit applies toner to the drum.
Primary Transfer Roller transfers the toner image from the drum to the Intermediate Transfer Belt (ITB).
The process repeats for each color (Cyan, Magenta, Yellow, and Black).
Secondary Transfer Roller transfers the combined image from the ITB to the paper.
The Fusing Unit permanently bonds the toner to the paper.
Cleaning systems remove residual toner from the drum and transfer belt.

The transfer system is the bridge between image formation and image fixing.

What Is the Intermediate Transfer Belt (ITB)?

The Intermediate Transfer Belt (ITB) is a continuous conductive belt that temporarily holds the toner image before it is transferred to paper.

Its main functions are:

Collect toner from all four drum units.
Maintain precise color alignment.
Transport the complete image to the secondary transfer position.
Release the toner image onto the paper.

The ITB allows all four colors to be combined into one perfectly registered image before printing.

Main Components of the Transfer System

Component	Function
Intermediate Transfer Belt (ITB)	Carries the combined toner image
Primary Transfer Rollers	Transfer toner from each drum to the ITB
Secondary Transfer Roller	Transfers toner from the ITB to the paper
Belt Drive Roller	Rotates the transfer belt
Belt Tension Roller	Maintains proper belt tension
Belt Cleaning Blade	Removes residual toner from the ITB
Waste Toner Auger	Moves removed toner to the waste toner bottle
High Voltage Power Supply (HVPS)	Supplies transfer voltages

How Electrostatic Transfer Works

The transfer process depends entirely on electrostatic attraction.

The toner is not pushed mechanically.

Instead:

The toner particles carry an electrical charge.
Transfer rollers create stronger electrical fields.
Toner naturally moves toward the stronger attraction.

This non-contact transfer preserves image quality while minimizing wear.

Stage 1: Toner Image on the OPC Drum

After development:

The toner image sits on the OPC drum.

The toner remains attached because of electrostatic attraction.

At this point:

The image is fully developed.
Nothing has yet reached the paper.

Stage 2: Primary Transfer to the ITB

Each drum contacts the Intermediate Transfer Belt.

A Primary Transfer Roller positioned behind the belt applies the appropriate transfer voltage.

This creates an electrostatic field that:

Pulls toner away from the drum.
Attracts toner onto the ITB.
Leaves only a small amount of residual toner on the drum.

The drum cleaning blade removes this remaining toner.

Why an Intermediate Belt Is Used

Without an ITB:

Each color would have to be transferred directly onto paper.

This would require:

Extremely precise paper positioning.
Multiple passes through the machine.
Greater risk of color registration errors.

The ITB solves these problems by building the complete color image before it reaches the paper.

Stage 3: Building the Full-Color Image

The process repeats four times.

First Rotation

Cyan transfers to the ITB.

Second Rotation

Magenta aligns precisely over Cyan.

Third Rotation

Yellow is added.

Fourth Rotation

Black completes the image.

The result is a fully registered CMYK toner image on the transfer belt.

Stage 4: Paper Registration

While the ITB carries the completed image:

The paper transport system positions the sheet with precise timing.

The leading edge of the paper must arrive at the secondary transfer point at exactly the right moment.

Even small timing errors can produce image misalignment.

Stage 5: Secondary Transfer

The paper passes between:

Intermediate Transfer Belt
Secondary Transfer Roller

The Secondary Transfer Roller applies an opposite electrical charge.

Its electrical field is stronger than the attraction between the toner and the ITB.

As a result:

Toner leaves the transfer belt.
Toner transfers onto the paper.
The complete image moves in one operation.

Stage 6: Belt Cleaning

After image transfer:

A small amount of toner remains on the ITB.

The Belt Cleaning Blade:

Scrapes residual toner from the belt.
Directs toner into the waste toner chamber.

A waste toner auger transports the toner to the waste toner bottle.

The cleaned belt is then ready for the next print cycle.

The Role of the High Voltage Power Supply (HVPS)

The High Voltage Power Supply controls:

Primary transfer voltage
Secondary transfer voltage
Charging voltage
Developer bias voltage

Stable transfer voltages are essential for:

High transfer efficiency
Uniform image density
Reliable color reproduction

Even slight voltage variations can affect print quality.

Factors That Affect Transfer Efficiency

Several factors influence how effectively toner moves from the drum to the ITB and then to the paper.

Transfer Roller Condition

A worn or contaminated transfer roller may cause:

Light prints
Missing colors
Uneven transfer

Transfer Belt Condition

The ITB must remain:

Clean
Smooth
Properly tensioned
Free of scratches

A damaged belt cannot maintain uniform electrostatic characteristics.

Environmental Conditions

High humidity can:

Reduce electrostatic attraction.
Lower transfer efficiency.

Low humidity can:

Increase static electricity.
Affect toner charging.

Konica Minolta bizhub machines automatically compensate for many environmental changes through Image Stabilization and engine control.

Paper Type

Heavy, coated, or textured papers require different transfer conditions than plain paper.

The machine adjusts transfer voltage based on the selected paper type to optimize image quality.

Common Transfer Belt and Transfer Roller Problems

1. Light Prints

Possible Causes

Weak transfer voltage
Dirty transfer roller
Worn transfer belt
High humidity
Incorrect media settings

2. Missing One Color

Possible Causes

Failed primary transfer roller
Poor drum-to-belt contact
Damaged transfer belt
High-voltage fault

3. Color Misregistration

Possible Causes

ITB drive issues
Incorrect belt tension
Belt slippage
Registration sensor problems

4. Repeating Marks

Possible Causes

Toner buildup on the ITB
Belt scratches
Damaged cleaning blade
Foreign material on the belt

The spacing between repeated defects often matches the circumference of the transfer belt or one of its rollers.

5. Background Contamination

Possible Causes

Dirty transfer belt
Contaminated transfer roller
Excess toner on the ITB
Belt cleaning failure

6. Incomplete Toner Transfer

Appearance

Residual toner remains on the belt.
Images appear faded.
Toner may smear.

Possible Causes

Low transfer voltage
Worn secondary transfer roller
Belt contamination
Incorrect paper settings

Transfer Belt Problems vs. Drum Problems

Print Symptom	Transfer System	OPC Drum
Missing colors	✓
Color misregistration	✓
Incomplete transfer	✓
Belt-related repeating marks	✓
Drum circumference defects		✓
Ghost images		✓
Vertical drum scratches		✓

Diagnostic Procedure for Technicians

Step 1: Print Internal Test Pages

Print:

Solid CMYK pages
Registration patterns
Gradation charts

Evaluate:

Color alignment
Density
Missing colors
Transfer efficiency

Step 2: Inspect the Transfer Belt

Check for:

Scratches
Toner buildup
Surface damage
Wrinkles
Contamination

Step 3: Inspect the Transfer Rollers

Look for:

Toner contamination
Surface wear
Flat spots
Physical damage

Replace rollers that no longer provide uniform pressure or electrical characteristics.

Step 4: Check Belt Cleaning

Inspect:

Belt cleaning blade
Waste toner chamber
Waste toner auger
Waste toner bottle

A blocked waste toner path can reduce cleaning efficiency.

Step 5: Verify High-Voltage Operation

Following the service manual:

Verify:

Primary transfer voltage
Secondary transfer voltage
Electrical contacts
HVPS connections

Step 6: Check Belt Drive and Tension

Inspect:

Belt drive motor
Drive gears
Tension mechanism
Belt tracking

Mechanical problems often appear as registration defects.

Common Technician Mistakes

Replacing the Drum Instead of the Transfer Belt

If all drum units produce good images individually but the final print shows missing colors or poor transfer, inspect the transfer system before replacing drums.

Touching the Transfer Belt Surface

Fingerprints, oils, and scratches can alter the belt’s electrical properties and lead to print-quality defects.

Handle the ITB only by approved contact points.

Ignoring the Belt Cleaning System

Residual toner on the ITB can cause repeating defects, background contamination, and color contamination.

Always inspect the cleaning blade and waste toner transport whenever servicing the transfer belt.

Using Incorrect Paper Settings

Selecting the wrong media type can prevent the machine from applying the correct transfer voltage, resulting in poor toner transfer or image defects.

Always verify that the paper type selected in the printer matches the media being used.

Preventive Maintenance

To maximize transfer system performance:

Keep the transfer belt clean and free of damage.
Avoid touching the belt surface.
Replace the transfer belt and transfer rollers at the maintenance intervals specified in the service manual.
Keep the waste toner path clear.
Use genuine Konica Minolta toner.
Perform Image Stabilization and Gradation Adjustment after replacing transfer components when required.

Typical Transfer System Symptoms

Print Symptom	Likely Cause
Light overall image	Low transfer efficiency or transfer voltage issue
Missing one color	Primary transfer roller or ITB problem
Color misregistration	Belt drive, tracking, or registration fault
Repeating belt marks	ITB contamination or surface damage
Background contamination	Belt cleaning failure
Toner left on the ITB	Secondary transfer problem
Toner smearing	Incomplete secondary transfer or improper media settings

Why Understanding the Transfer System Matters

The Intermediate Transfer Belt and Transfer Rollers form the critical link between image creation and final printing. Even when the charging system, laser scanner, developer units, and OPC drums are functioning correctly, a fault in the transfer system can prevent toner from reaching the paper accurately. Because transfer-related defects often resemble problems with the drums or developer units, technicians must evaluate the entire transfer path before replacing imaging components.

By understanding how electrostatic forces move toner from the drum to the ITB and finally to the paper, Konica Minolta service technicians can diagnose missing colors, density loss, color registration errors, and transfer inefficiencies with greater accuracy and confidence.

Conclusion

The Intermediate Transfer Belt (ITB) and Primary and Secondary Transfer Rollers are essential components of the Konica Minolta bizhub electrophotographic system. Using carefully controlled electrostatic fields generated by the High Voltage Power Supply, they transfer toner first from each OPC drum to the ITB and then from the completed full-color image to the paper with exceptional precision.

Working together with the drum units, developer system, paper transport, and belt cleaning assembly, the transfer system ensures accurate color registration, high transfer efficiency, and consistent print quality. A thorough understanding of its operation enables Konica Minolta service technicians to diagnose transfer-related image defects effectively, reduce unnecessary parts replacement, and maintain the reliable performance expected from modern bizhub multifunction systems.