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. Color Monitor Color Space RGB Human Eye Color Space CMYK Printer Color Space 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. Black Yellow Cyan Magenta Process Direction 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. OPC Unit / Cleaning Blade Carousel M K C Y 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 4500’s is Huge • Durability- The hallmark of HP’s laser printer series has been the excellent serviceability and reliability. • Four Pass to inline (One pass) • Development -- process speed --- Perceived quality DPI’s 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 • TM’rd 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 isn’t 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. Figure 7 Figure 3

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 RM’s 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