Ricoh PRO C7200X User manual

Operating Instructions
Advanced Settings for Custom Paper Adjustment
For safe and correct use, be sure to read Safety Information before using
the machine.

TABLE OF CONTENTS
1. Introduction
Basic Procedure.................................................................................................................................................. 3
Advanced Settings..............................................................................................................................................4
2. Mechanism
Xerographic process - Overview...................................................................................................................... 5
Xerographic Process-Laser Exposure................................................................................................................7
Laser Unit (Exposure)..................................................................................................................................... 7
Xerographic Process – Development................................................................................................................8
Development...................................................................................................................................................8
Xerographic Process – Drum-to-Belt Transfer................................................................................................ 10
Drum-to-Belt Transfer...................................................................................................................................10
Xerographic Process – Belt-to-Paper Transfer............................................................................................... 11
Belt-to-Paper Transfer..................................................................................................................................11
PTR Rotation Speed......................................................................................................................................14
Paper Separation.........................................................................................................................................14
Xerographic Process - Fusing.......................................................................................................................... 16
Fusing Unit.................................................................................................................................................... 16
Fusing Nip width Adjustment...................................................................................................................... 17
Fusing Cleaning Unit....................................................................................................................................17
Fusing Belt Smoothing Roller.......................................................................................................................18
Paper Delivery..................................................................................................................................................20
Mainframe....................................................................................................................................................20
Decurl Unit....................................................................................................................................................23
3-Tray LCIT................................................................................................................................................... 24
2-Tray LCIT................................................................................................................................................... 24
3. Details of Advanced Settings
Overview.......................................................................................................................................................... 27
Print Mode....................................................................................................................................................27
Registration....................................................................................................................................................... 28
Image Position/Magnification....................................................................................................................28
Image Quality...................................................................................................................................................29
Maximum Image Density............................................................................................................................ 29
Image Transfer Current................................................................................................................................29
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Paper Transfer.............................................................................................................................................. 30
Fusing............................................................................................................................................................32
Paper Feed/Delivery from Mainframe Trays................................................................................................ 39
2-Tray LCIT................................................................................................................................................... 39
3-Tray LCIT................................................................................................................................................... 43
Decurler Unit................................................................................................................................................ 44
Mainframe Trays..........................................................................................................................................44
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1. Introduction
This chapter provides an overview of the Media Library.
Basic Procedure
This machine is capable of printing on a wide variety of media using the latest technologies in digital
printing such as the AC transfer and elastic fusing belt.
Also, the introduction of the Clear/White toner - available in the 5-color model - is capable of adding
further value to print products.
In addition to the above new technologies and features, support of various media is also made possible
by the Media Library database, which is registered with tested and proved media and programmed
with optimized print parameters by media type/weight.
How to use the Media Library:
1. Select a media from the library and associate the media to a tray.
2. Set the media on the associated tray.
3. Specify the media in Job Properties of the color controller.
3

Advanced Settings
As described in the previous slide, printing from the Media Library is possible with a simple procedure,
however, precise adjustments (such as the transfer and fusing conditions) may be required depending
upon the media attributes, which differ by each and every media.
Such precise adjustments can be made from [Tray Paper Settings] [Advanced Settings].
DZH201
In this menu, the followings can be adjusted:
• Machine: Image Position
• Machine: Image Quality
• Machine: Paper Feed / Output
To effectively adjust the above, it is important to have a basic understanding of how the printer works.
1. Introduction
4

2. Mechanism
This chapter provides explanation on the basic Xerographic process of the engine by referring to the
items of the Advanced Settings.
Xerographic process - Overview
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KCMYS
687
321
4
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1. OPC drum
2. Charger roller
3. Laser unit
4. Development roller
5. Image transfer roller
6. Intermediary transfer belt(ITB)
7. Paper transfer roller(PTR)
8. Fusing unit
The electrophotography process consists of the following steps:
Drum charge Laser exposure Development Transfer Fusing
• Drum charge …… The charge roller [2] gives an equal charge across the surface of the OPC drum
[1].
• Laser exposure …… Laser beam [3] creates an electrostatic latent image on the OPC drum [1].
• Development …… The development roller [4] carries toner to the latent image on the OPC drum
[1].
• Image transfer
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Drum-to-belt transfer …… Toner images created on each OPC drum [1] are transferred sequentially
to the ITB [6].
Belt-to-paper transfer …… Toner image on the ITB [6] is transferred onto the paper when the paper
passes through the PTR [7].
• Fusing …… The fusing unit [8] applies heat and pressure to fuse the toner image onto the paper.
2. Mechanism
6

Xerographic Process-Laser Exposure
Laser Unit (Exposure)
The laser unit is equipped with the Vertical Cavity Surface Emitting Laser (VCSEL) technology.
40 laser beams are emitted to produce 2400dpi×4800dpi.
Laser beams are reflected on the polygon mirror and lenses to create a latent image on each of the
photoconductive drums by imparting static electricity on the surface of the drum.
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2
3
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1. VCSEL
2. Polygon mirror
3. OPC drum
4. Laser beam
Adjusting the start timing and frequency of this latent image creation process in both main and sub scan
directions enables registration, masking and scaling of the image.
Related Advanced Settings
page 28 "Image Position/Magnification"
page 36 "Erase margin: leading/trailing edge"
Xerographic Process-Laser Exposure
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Xerographic Process – Development
Development
The development system employs the dual-component*1 development method.
The developer is pre-mixed*2 to prevent image quality degradation caused by deterioration of the
developer that occurs over time.
Electrostatic latent image areas of the drum attract negatively charged toner particles from the
development roller [4].
To maintain consistent amount of toner attraction from the development roller [4] to the drum [1] and
stable image quality(toner density), image quality adjustment process runs automatically when turning
on the machine power and at optimum timings.
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During the image quality adjustment process, toner patterns in 5 gradients are created on the ITB for
each toner color, which are read by the toner mark sensors. Xerographic conditions are adjusted
according to the sensor readings, maintaining consistent development (maximum image density).
[1]
[2]
[3]
DZH006
*1 The developer consists of positively charged carrier (+) and negatively charged toner (-).
*2 The carrier is pre-mixed with the toner in the toner bottle and the mixture is supplied to the
development unit to constantly refresh old developer in the development unit with new developer.
2. Mechanism
8

Related Advanced Settings
page 29 "Maximum Image Density"
Xerographic Process – Development
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Xerographic Process – Drum-to-Belt Transfer
Drum-to-Belt Transfer
To enable printing in all five toner colors as well as printing using only special color, the mechanism to
contact/separate the ITB and ITB rollers was modified in the drum-to-belt transfer process for the
machine. Among the following four print modes, the correct mode is selected according to the print data
sent from the printer controller.
• BW mode: Job contains only black data.
• FC mode: Job contains color data.
• FCS mode: Job contains color and special color data.
• S mode: Job contains only special color data.
S Y M C K
S Y M C K
S Y M
Paper
C K
S Y M C K
15 6
BW
Print
mode
Engine status
(Stations greyed out are inactive.)
FC
FCS
S
Paper
Paper
Paper
DZH207
1. OPC drum
5. Image transfer roller
6. Intermediary transfer belt(ITB)
By applying a positive (+) bias (transfer current) to the image transfer roller, negatively charged toner (-)
on the drum is attracted to the ITB that positions between the roller and the belt. Any remaining toner on
the drum is cleaned by the drum cleaning unit.
Related Advanced Settings
page 29 "Image Transfer Current"
2. Mechanism
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Xerographic Process – Belt-to-Paper Transfer
Belt-to-Paper Transfer
Applied voltage
The AC transfer technology is used for the belt-to-paper transfer, to support printing on textured media.
Negatively charged toner image (-) on the ITB [6] is transferred to the paper by applying a negative
bias (-) to the paper transfer bias roller [7].
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DZH031
Following are the two types of negative bias applied to the paper transfer bias roller:
• DC bias: For all media types
• AC bias: When 1218: [Paper Transfer Output: Textured Paper Mode] is enabled
Bias is adjustable by print mode because the optimum bias level is dependent on the amount of toner
transfer.
(Bias is higher for FC than for BW/Special due to the greater amount of transferred toner.)
The illustration below describes how AC transfer transfers toner to textured media.
By nature of AC, in which the current flows in an alternating up-and-down movement, toner particles
sync with this movement. Toner transferred to the media is pulled back to the ITB to gain further
transferability, enabling toner particles to fall into the indentations on the rough surfaced media.
Xerographic Process – Belt-to-Paper Transfer
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Textured paper mode
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1. ITB
2. Textured paper
3. Toner is partially transferred.
4. Toner transferred to the paper returns to the belt and combines with toner remaining on the belt.
5. Toner is transferred to the indentations on the surface of the paper.
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1. AC transfer inactive
2. AC transfer active
Bias correction can be adjusted for each imaging mode, because the optimum bias correction value
varies depending on the transferred toner. (More bias correction is required for printing in FC/FCS
mode, which consumes more toner than printing in BW/S mode.)
Related Advanced Settings
• DC bias
page 30 "Paper transfer current"
• AC bias
page 30 "Textured paper mode"
2. Mechanism
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Leading/Trailing edge correction
To prevent image quality problems caused by the unstable condition of the paper when it enters the nip
of the PTR, the belt-to-paper transfer bias is adjusted for the leading/trailing edges.
The following are the three bias correction settings that adjust the bias level and duration.
• Belt-to-paper transfer: Constant voltage
• Belt-to-paper transfer: Leading edge correction
• Belt-to-paper transfer: Trailing edge correction
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• Current vs. Voltage
• Bias is applied using 'constant current' for drum-to-belt and belt-to-paper transfer, as this
method is resilient to changes in operational environment and thickness of the media.
• On the other hand, 'constant voltage' is used for AC bias and as this method does not require
adjustments according to paper width.
Related Advanced Settings
page 30 "Paper transfer current: TE"
Shock-jitter canceller
The shock generated and the change in speed when the leading edge enters and the trailing edge exits
the nip between the PTR [9] and ITB bias roller [7] may cause image quality problems where unwanted
lines appear perpendicular to the paper feed direction (shock-jitter).
To ease the shock, the PTR unit is equipped with the "shock-jitter canceller" function, in which the PTR [9]
moves up when the paper enters the nip and moves down when the paper exits the nip.
Xerographic Process – Belt-to-Paper Transfer
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9
P. P
P. P
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Related Advanced Settings
page 31 "Paper transfer gap"
PTR Rotation Speed
The PTR [9] has the function to deliver the paper from the paper transfer timing roller.
Since the paper transport speed is controlled by the PTR, if the PTR rotation speed is slower than the
target the image will shrink, if faster the target the image will stretch.
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9
P. P
P. P
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Since the paper is simultaneously gripped by the PTR and the paper transfer timing roller, uneven density
and banding problems may occur, if the speed differs between these rollers. PTR rotation speed (and
paper transfer timing roller speed) is made adjustable for this reason.
Related Advanced Settings
page 47 "Paper transfer roller feed speed"
Paper Separation
Paper is applied with charge when it passes through the PTR.
To discharge this charge, AC bias is applied to the discharge brush [10].
2. Mechanism
14

10 P. P
P. P
DZH032
Feeding black or metallic media without selecting the correct media from the library will stop the
machine.
This is because the constant voltage control used for separating the media from the ITB causes a ground
fault due to the conductive carbon substance contained in the media.
If "Black" or "Metallic/Pearl" is selected as the paper type in [Advanced Settings] for the custom paper,
the paper transfer separation voltage is automatically to set to zero. Accordingly, this setting does not
need to be adjusted if the paper type setting is specified properly.
Xerographic Process – Belt-to-Paper Transfer
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Xerographic Process - Fusing
Fusing Unit
The fusing belt has a thick elastic layer, as with the previous model, to allow the belt to reach farther into
the surface indentations of textured media.
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Base layer
Base layer
Elastic layer
Elastic layer
Surface layer
Surface layer
Textured paper
Textured paper
Fusing belt
Ton e r
Conventional fusing belt
New fusing belt
DZH211
Fusing roller
Pressure roller
A total of four heaters are used in the fusing unit: three in the heating roller [11], one in the pressure
roller [13].
Toner is fused onto the media by applying heat to the fusing belt [12] via the heating roller [11],
maintaining consistent temperature and pressure on the media.
The heater in the pressure roller [13] functions as a supplementary heater, to maintain consistent
temperature at the nip between the fusing and pressure rollers.
The fusing temperature can be adjusted by print mode(BW/FC/FCS/S), as the optimum fusing
temperature is dependent on the amount of toner.
(The more there is toner, the more heat needed for fusing. Clear toner also requires high fusing
temperature to yield the gloss effect.)
The fusing temperature is momentarily increased one notch immediately before the paper passes
through the nip, to compensate for the slight temperature drop of the fusing belt [12] due to the heat
absorption by the paper.
In addition, the target fusing temperature is momentarily increased another notch immediately before the
pressure roller [13] contacts the fusing belt, to compensate for the slight temperature drop due to the
contact.
2. Mechanism
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Printing starts when the fusing belt temperature reaches the prescribed temperature range against the
target.
Image quality issues originating in the fusing unit, for example, residual gloss images, river marks, can
be prevented by adjusting the target fusing temperature.
Related Advanced Settings
page 32 "Fusing temperature" / page 33 "Fusing temperature correction"
Fusing Nip width Adjustment
The width of the fusing nip (or nip pressure) is made adjustable to prevent wrinkles.
This adjustment can be performed with precision when selecting [Envelope] from the media library.
Even for paper other than envelopes, the nip width can be narrowed to any of 4 levels including the
initial value.
DZH013
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4
5
2
1. Fusing roller
2. Envelope
3. Heating roller
4. Paper transfer belt
5. Pressure roller
Related Advanced Settings
page 37 "Fusing nip width adjustment: envelope"
Fusing Cleaning Unit
The cleaning web [15] is pressed against the pressure roller [14], to rub off toner and paper dust
adhered to the fusing belt.
The web is soaked with silicone oil, which is supplied to the pressure roller and the fusing belt in very
small amounts.
Xerographic Process - Fusing
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The interval between each cleaning operation can be adjusted to any of 4 levels.
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Related Advanced Settings
page 35 "Fusing cleaning"
Fusing Belt Smoothing Roller
Printing continuously on a particular paper size causes the paper edges to nick the fusing belt, and when
switched to a job printed on a larger size, the nicked fusing belt produces unwanted gloss streaks on the
prints.
Also, continuous printing of high image coverage pages causes the wax content of toner to gradually
adhere to the fusing belt, affecting the gloss consistency of the prints.
Paper edge
Scratched fusing belt
caused by paper edge
Fusing belt
Fusing belt surface condition
Scratches
Scratches are polished
by the belt smoothing
operation
DZH214
Image quality issues such as gloss streaks and uneven gloss can be resolved by polishing the surface of
the fusing belt with the fusing belt smoothing roller [16].
The belt smoothing operation can be run manually or automatically. The setting can be selected in the
Advanced Settings.
2. Mechanism
18