The Technology of Color Laser Printers

1
The Technology of Color Laser Printers

• Mark Hibbard Washington County Community College
• Recharger Magazine World EXPO
• 27 September 2004
• Session S19

2
Overview

• Market Watch
• Color for Free
• Color Application
• Current Printer Configurations (Networking)
• Remanufacturing Options
• (still risk management)

• Image Dynamics
• Cartridge Components
• Cartridge Complexity

3
Color Market Watch

• Color-Timeline
• 1993 QMS (10k) 1996 QMS (4K) 1997 TEK
  (2.2K) 1998 HP (1.8K) 1999 QMS (1.2K)
  2000(4550) 2002 (4600)
• ( 0.80 0.6
  0.30 0.20
  0.12 0.09
• Business Imaging Pressure to Go Color
• Communication with color NOT a novelty (WWW)
• Cost per page fallen rapidly
• Image quality
• Device independent document creation
• Process speed increased
• Competition fierce
• Corporate MIS Purchasing see value

4
North American Color Laser Placements
HP claims 59 market share all laser
printers 70 Color Market 62 Color Laser
Market
5
The Ink Jet Crossroads
Paper media is the differential photo printing
6
Imaging Decision Makers

• MIS Directors ? Connectivity / Flexibility
• Purchasing Agent ? Comparison Shopping
• Owner Operators ? Features
• PC Resellers ? Cost / Features
• Government ? Varied directives
• Education ? Cost / Features

7
Color vs Mono

• Mono Color
• 1993 1,700.00 HP-LJ4
• 1996 850.00 HP-LJ5
• 1997 1,000.00 HP-LJ4000 4,000 HP-LJC5
• 1998 1,000.00 HP-LJ4000 4,000 HP-LJC5
• 1999 1,000.00 HP-LJ4000 2,200 HP-LJ4500
• 2000 1,100.00 HP-LJ4100 1,900 HP-LJ4550
• 2001 1,100.00 HP-LJ4300 1,900 HP-LJ4550
• 2002 1,000.00 HP-LJ4200 1,790 HP-LJC4600
• 2003 500.00 HP-LJ2300 699 HP-LJC2500
• 2004 399.00 HP-LJ1300 500 HP-LJC2500

8
Mixed Graphic NT/Desktop
9
Color Imaging Primer

• Dots on a page - forget what you learned
• Subtractive color synthesis - White light
  contains all the wavelengths of the visible
  spectrum
• Primary colors are used in computer monitors -
  RGB
• Complementary colors are the control colors of
  printing technology. Single complementary colors
  reflect there own wavelength and absorb the rest
  of the spectra. M C Y
• Two complementary colors in equal intensities
  will produce a primary color.
• Magenta and Yellow Red
• Magenta and Cyan Blue
• Yellow and Cyan Green

10

• Vary complementary intensities (toner)
• Produce gamut of color
• Screen effect and the human eye !!!
• Photo mechanical process tricks the eye
• Dot size, viewing distance, lighting
• Perceived image quality
• Visual Color Image Characteristics
• Color Reproduction memory color gamut ..
  accuracy
• Tone Scale . Rendering density , depth ,
  texture
• Sharpness . High definition detail
• Uniformity Grain, banding, streaks
• Psychometric Scale
• Is it real ? Or Roger Rabbit
• Subjective targets viewed at fixed distance and
  proper light
• Perceived image quality

11
Pixel Magic

• Dots within a cell
• Dithering - is the art of placing single pixels
  of CMY adjacent to one another to create the
  illusion of color. This is a single level
  process common to most laser printers.
• Latest technology that HP uses on the 4500 places
  dots on top of one another in varying amounts.
  This is the multi level approach used in
  lithography. ImageRET2400 is exclusive to HP.
• Level address ability is costly in memory and/or
  formatting time.
• Toner development dot gain can alter color
  perception
• Humans can perceive shading gradients very well
• Core-Shell CP toners have better fusing, best
  color images are perceived to be glossy

12
The Color World

• Color Systems and Real World
• RGB monitors using 256 levels of primary color
  can reproduce 16.77 million colors
• The print media world is severely limited. Since
  perfect dyes do not exist CMY usually creates a
  muddy brown color. So a key color of pure black
  is included.
• Gamut Color Space

13
Real World Color Printing

• Materials - Paper, inks and toners are imperfect
  producing imperfect colors
• Developing dots - The dot needs to be uniform in
  size, shape and translucency. To correctly absorb
  or reflect the light.
• Development (interlace/overlay)
• Transfer
• Fusing
• Color formatting - Color picture information that
  is digitally represented in a WYSIWYG format is
  in RGB data form. The process of converting bit
  by bit the RGB data into CMY is not trivial. RIP
  systems are hot software projects in digital
  imaging.

14
Color complexity

• Linear color development
• This color process uses four complete e-p systems
  that will transfer color pigment onto the media
  in one-pass. Used in low cost Optra 1200 to high
  cost Xiekon printers. Where the 1200 prints 4 ppm
  one side and the Xiekon prints 75 ppm both sides.

Fuser assembly
Media lies on a transfer belt, each development
station places toner onto the media. Each
cartridge has a hopper, toner delivery mechanism,
sweeper strips, cleaning blade, OPC, PCR and
developer cylinder.
15
Color print engine design

• Carousel development system
• To reduce the complexity of the printer a
  carousel array that can rotate onto a single
  development zone is implemented within the Optra
  C.
• Having four discrete toner vessels that can use a
  single contact development cylinder and single
  drum unit reduces the number of critical e-p
  components.

Transfer Cylinder
16

Color print engine design

• Four pass color processing
• Direct transfer . Intermediate transfer - The
  four stage process can develop the sequential
  color masks onto the OPC surface or onto a
  transfer device in the form of a belt or drum..
• Registration is super critical. Paper slippage
  upon transfer cylinder is common. The laser
  write process occurs each pass as the carousel
  aligns the staged color. The media is then
  separated from the transfer cylinder and fused.
• Rotational speed and toner adhesion can effect
  color registration and definition.
• Cleaning the OPC in the four pass process is
  critical. The OPC and transfer systems will need
  robust cleaning components.

17
HP Color Systems

• The installed base of 4500s is Huge
• Durability- The hallmark of HPs laser printer
  series has been the excellent serviceability and
  reliability.
• Four Pass to inline (One pass)
• Development -- process speed ---
• Perceived quality

DPIs CM technology http//www.dpisolutions.co.kr/

18
Toners for Color Systems

• Color - non-magnetic toners
• The polyester binder resins are more expensive
  than monochrome binders.
• Color pigments that are color correct
  expensive.
• Processing is expensive (getting cheaper)
• Direct Polymerization has arrived
• Canon color toner is a DP toner with a PE wax
  core. (CPT)
• Several CP toner processes in IP
• Emulsion aggregate (FujiXerox)
• Chemical Milling (DPI)
• Suspension polymerization (Ricoh, Nippon)

19
CPI Toner Development

• Still a dynamic technology
• Only 2 of all toner produced in 2000
• Forecasted to represent 10 by 2010
• Many chemical companies have CPT manufacturing
  skills but have not participated in the business
  imaging market
• Recognized suppliers, MCA, FX, Minolta/Konica,
  DIC, DPI, ICMI, Coates Repro some others have
  vested interest
• Cost and scale-up are barriers .. But being
  overcome

20
Value added to image performance !!

• Smaller and more uniform PS
• Lower grams per page without density sacrifice
• Better fusing (lower I2R)
• Better transparency and better intra-color
  visual appearance
• Core-shell integration

21
Image Dynamics

• Complete charge control
• Balance between opc sensitivity, development
  zone,
• opc design, toner charge process speed
• Cleaning is paramount for color balance

Backgrounding
400 v
Smooth Color Gradient
125 v
Over-developed
22
CPT replacements Traditional manufacture

• TMrd Color toner major issues
• Fusing requirement is difficult to match with
  pulverized clone
• Particle size control is difficult with classic
  manufacturing
• Post blending a additives for CC and fusing being
  used in some color toner systems
• Toner design gets much more complicated with
  increased PPM

23
Color Science
24
Color Test Methods and Standards

• Visual inspection
• Image Performance
• Cartridge line statistics
• Print testing
• Defect analysis . Corrective action
• ASTM
• ISO 13660

25
Managing Color

• What you see isnt always what you get
• Printers have different printing schema
• Monitors have a wide range of color variation
• Print output is VERY different
• from screen output

26
(No Transcript)
27
Figure 4
28
Color Influences

• Light in the viewing room
• Natural day light
• Florescent light
• Ultraviolet light
• Amount of light or shadow

29
Figure 10
30
Figure 11
CMY Subtractive colorants
31
Color development
32
Test patterns
33
Integrated Test Targets
34
Color interference
35
QEA Personal IAS -- Figure 12
36
Setting up a Cell

• Breakdown - Cleanliness will be critical.
  Cross-toner contamination must be controlled.
• Filling - Start up process while production
  demand is low will be done with bottles.
  (Kitting)
• Filling systems will require triplication or
  extremely aggressive cleanout. Some existing
  fillers will not handle color toner.
• Sealing systems .

37
Suppliers

• Some major shift to buy direct on some high
  volume componetry
• RM Suppliers Imaging Materials Manufacturers
• Testing differentials OEM v Market fitness for
  use
• Initial cost and RD Efforts
• Partnerships possible depending on commitment
• SCC, FG, Oasis, TP vested and committed

38
Working with Vendors

• Provide RMs with as much information as
  possible on color performance
• Resolution standards
• Spatial resolution
• File formats
• File size
• Possible printer options
• File format (TIFF,JPEG,PDF,)
• Future Print Image Formats
• PNG
• JPEG 2000