Real World Toner Testing
Cartridge New Product Introduction
Recharger Magazine Expo 2005
S 86
Eastport Engineering Ω Eastport, Maine [email protected]
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Toner Testing Objectives
o Basic EP principles
o Basic image formation
o Human visual response to images
o Test target selection
o Image analysis tools
o Subjective measurement
o Statistical image measurement
o Test Plan and Data Base
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• Constant Improvement2Understand limitations of the printer and
process 2Governs product development2Corrective action 2Standards are here .. And will continue
2ASTM 1856, 1531 … ISO 13660 … ISO 19751
Evaluation Development
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Basic Cartridge
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Basic Cartridge
** Color toner hopper / catridge
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EP Process
Key Component
• Clean• Cleaning Blade ~ Toner ~ OPC ~ Process
• Charge• OPC ~ PCR ~ Process
• Writing• OPC ~ Laser ~ Process
• Developing• OPC ~ Toner ~ Developer Sleeve ~ Process
• Transferring• OPC ~ Toner ~ Media ~ Process
• Fixing• Toner ~ Media ~ Fuser ~ Process
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Critical Components
o Image is cleaned from the OPCo Image is formed in/on the OPC o Image is developed onto the OPCo Image is transferred from the OPC
Much of the electrophotography science is happening here !!! ON a high commodity component ( << $10) DO NOT Overlook this components contribution to overall image performance
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Cleaning
• Preparation for new latent image• wiper blade Care and cleaning/handling
• recovery blade
PCR (charge roller technology)
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Cleaning Problems
• Vertical streaking• smearing• ghosting (double imaging)• background haze• peppering of loose toner
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Conditioning
Primary charge roller applies a uniform negative charge(-600V to -720 V DC)
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Writing
• Laser beam used to discharge the conditioned charge on drum surface
• aluminum substrate is connected to an electrical ground
Gears & Ground path
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Writing
• Photo conductive material becomes electrically conductive when exposed to light
• The negative charges moves onto the surface of the drum conduct to the aluminum base when exposed to light creating the latent image
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Writing
• Image area will attract toner in the later development stage
• Ground contacts• DEVELOPMENT Spacing
Contact development – NON Magnetic toner
Zone Development – HP – Magnetic toner
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Developing
• Latent image becomes visible image• process contains four major components
Metering blade
OPC
Toner
Mag
Cleaning Blade
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Developing
• Toner• developer roll assembly• metering blade• AC/DC charge
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Developing
• Toner attracted to developer roll by internal magnet or electro-static charge
• Roller carries toner particles to the metering blade and creates tribo-electric charge (friction) on surface of toner particles
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Developing
• Metering blade(doctor blade) allows even distribution of toner to drum
• developer roller then charged with an AC/DC charge from high voltage power supply
• allows toner to jump from developer roller to the opc and is attracted to latent image
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Developing …………….. Toner
Interaction• Light print • Blasting• Backgrounding• Leaking or spilling• Excess waste toner• Toner build-up on the fuser assembly
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Transferring
• Transfer of image on the drum to a piece of paper• As paper passes under drum it passes over a corotron assembly• The assembly places a positive charge on the back of the page
TRANSFER Eff % -KEY for yield and density
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Fusing
• Toner is attracted off the drum• Poor transfer of toner creates more waste• Toner is permanently affixed to the paper
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Fusing
Fuser Assembly• Heated roller• Pressure roller• Heating element• Thermistor• Thermal fuse• Cleaning pad
• Time …. Duty Cycle … Print Job length
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Fusing
• Heating element placed inside of aluminum roller coated with teflon• Roller heated to 355°F (180 °C)• Pressure roller is rigid foamed silicon roller• Pressure is applied to heated roller
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Fusing
• The paper passes between the rollers• The heated roller melts the toner particles while the
pressure roller presses the toner into the fiber weave of the paper
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Transferring/Fusing
Problems• Raised print• Toner flaking• Light print• Ghosting• Offset
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Image Formation
• OPC response forms a proper image• OPC active layer responds proportional to the resolution of
the printer.
• Toner is charged properly and is formulated such that the latent image is correct.
• Transfer to the media is correct, mechanically• Fusing, toner formulation minimizes spread• Repetitive defects (component related)
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Toner Manufacturing- Understanding performance and $$Design Criteria
Raw MaterialsRaw Materials
CompoundingGrindingClassifying
Particle Size & DistributionClassifying EfficiencyContamination
Chemical Toners
- Their shape can be almost spherical
- Their size can be smaller (about 5 microns) and much more regular.
- Their electrostatic characteristics make them easier to mix together to get custom colors.
- Their transfer efficiency from photoreceptor to paper is almost 100%.
- Cheaper to produce, they put less strain on printing engines.
This new process requires less energy to make, generate less waste, contribute to printer reliability.
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Raw Materials
• Magnetic Toner• Resin system (melt point,grindability,wetting,cross-linked)• Iron oxide (coercivity,shape,wetting,purity)• Carbon Black (wetting,particle size,purity)• Post additives (Fumed Si, Ti, Polyproplene wax)
• Non Magnetic Toner• Resin system (melt point,grindability,wetting,crosslinked)• Carbon Black (wetting,particle size,purity)• Post additives (Fumed Si, Ti, Polypropylene wax)
• Chemically Prepared Toner• Resin system• Pigment• Post-adds
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Toner Requirements
• Provide desirable output image on a given media
• Stable in different environmental conditions
• Economical considerations• Health risks• Careful control of materials
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Dry Toner Manufacturing ProcessSimplified
Raw Material
Mixers
FineClassification
AdditiveMixing
TheFines
FinishedProduct
DustCompounding
CoarseClasification
Fine Mixing
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Compounding Technique
• MeltMixing• Distributive mixing• Batch or continuous • Must control of flux point• Layered additions (technique)• Wear protection• $$$$ electricity• Secondary mixing on Roll Mill• Cleanouts $$$$ time
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Toner “Finishing” Process Control
• Coulter , Lasentec• Measurement technique• Accuracy• Meaningful results• Forensics
• Q/M• Prepared / Actual samples• Temp & rh%• CCA
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Particle Size
• 5-10 microns Typical laser product• Cut is important : not Average PSD• Sub 5u why ?• Additive issues• Health hazard warning
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Melt Mix Dry Toner Resin Systems
Physical Properties Specific Gravity
Mechanical Properties Strength (Tensile and Flexural)
Modulus (Tensile and Flexural) Elongation Hardness Impact Resistance
Thermal Properties Heat Deflection Temperature Glass Transition Temp Heat Capacity Thermal Conductivity Thermal Expansion Coefficient
Processing Characteristics Melt Flow Index Melt Strength Melting Point, No-flow Temp Shear Rate/Viscosity Relation Compressibility (Pressure/Volume/Temperature
Relation)
Optical Properties Light Transmission Haze Refractive Index
Electrical Properties Surface and Volume Resistivity
Dielectric Constant Dielectric Strength Dissipation Factor Breakdown Voltage
Environmental Properties Chemical Resistance UV Resistance Flame Resistance (UL Rating) Oxygen Index Water Absorption
Morphology CrystallinityOrientation Composition (Neat, Blended,
Filled)
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Toner Handling and Filling Product and Process
• Contamination• Oils• Water• Other toners• Dry Lubes
• Flow-ability• OPC Cleaning Properties• Filling Systems
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Human Response to Imaging
Light response is logarithmicEdge definition and shade difference is keyHalftones (Gray Scales) 0-15 % are keyImproper line formation is easily detectedGhosting or shade variance is easily detected
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Test Target SelectionFWhite FGray (25%)FBlack FGhost FHalftonesFFine LinesFSolid FillF5% Character Coverage
Cartridge Life500 pages of 5% coverage and then a sequence of imaging targets:White , Halftone, Solid fill Blocks
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BID and Solid Fill Areas http://www.qea.com/pdf/QEA%20Test%20Target%20rev%204f.pdfhttp://www.imagexpert.com/site-new/docs/toner_test_targets_720dpi.pdf
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Fine Lines and Halftones
•Gray scales …. Are very critical with the 1200 dpi printers
•Watermarks and GS values under 15% are hard to develop
•Postscript from Adobe pushes the envelop of halftone cell development
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Ghosting
Ghost images are formed in solid areas as lighter shaded artifacts or as dark artifacts in light shaded objects. The developer sleeve and opc can cause ghost formations.
Measure shade differences
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Repetitive Defects
•Repetitive-Defect Rulers are available from HP Manual & FG,SCC,Oasis
•Engine Specific ( Process Orientation )
•Develop good forensics
•Offset (Cold - Hot) OPC, DS, Transfer roller
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Image Analysis Tools
• Create a toner cartridge print specification sheet • Have samples of acceptable and unacceptable
prints• Always have a good cartridge available for
comparison• Have samples of OEM prints
• Gold Cartridge/System (trace, baseline)
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Solution Samples
• Document solutions to print defects on the Process Notes Log.
• Make a defect book from all the different defects that you find, both common and unusual.
• Example: If you have a test sheet that shows one dark band line on the top and you fixed it by scraping the grounding surface on the drum, write it down and keep it on file. If it happens again, you can identify the problem immediately.
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Statistical Measurements
• Make a run chart and list different defects
• Look for trends in your process• Plan out what you can do to prevent common defects
• Training• Task Rotation• Tools … loupes, light, etc.
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Character Formation
Characters that are hollow or contain voids have improper formation. The occurrence of voids also is toner related. Opc sensitivity can play a part when character formation problems exist. GUIDE is ISO13660
B B B
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Repetitive Defects Key
•Defect Rulers are available from HP & others
•Engine Specific ( Process Orientation )
•Develop good forensics
•Engine charts and knowledge base
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Moving Forward• Canon WX (HP-8000) Defect Ruler Inches MM
• Registration Roller 1-3/4 44 mm• Primary Charge Roller 1-3/4 44 mm• Developer Roller 2-1/8 54 mm• Delivery Roller (B) 1-7/8 48 mm• Transfer Roller (B) 2-1/4 58 mm
• Lower Fuser Roller (B) 3-11/16 94 mm• OPC Drum 3-11/16 94 mm• Upper Fusing Roller 4-7/8 125 mm
• Hewlett Packard HP-4000 Defect Ruler Inches MM
• Primary Charge Roller 1-1/2 38 mm• Transfer Roller (B) 1-7/8 47 mm• Feed Roller 2 51 mm• Pre-Transfer Roller (B) 2 51 mm• Developer Roller 2 51 mm• Lower Fuser Roller (B) 2-1/2 63 mm• Tray Feed Roller 2-15/16 75 mm• Separation Roller 2-15/16 75 mm• Upper Fuser Roller 2-15/16 75 mm• OPC Drum 3-11/16 94 mm
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Image Analysis Tools
• Create a toner cartridge print specification designed around you customers key requirements
• Have samples of acceptable and unacceptable prints for your techs to use as baseline
• Always retain a gold standard cartridge available for comparison testing between printers
• Have samples of OEM prints to refresh engine designed performance.
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Image Analysis Tools
• Clean well lit table space for observing prints• Eye loupe visual aids (Graticule)• Reflectance Densitometer (Tobias, MacBeth)• Training
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Problem & Product - Solution Samples
ù Document solutions to print defects on the Process sheet. ù Make a defect book from all the different defects
that you find, both common and unusual.
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Statistical Measurements
• Make a run chart and list different defectsé When you get a defect, mark the chart
• Look for trends in your process• Plan out what you can do to prevent
common defects• Training• Task Rotation• Tools … loupes, light, etc.
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Develop Test Plan for YOUR Process
Incoming Inspection:
•Visual
•Sift/retain
•Print Test
Final Inspection
•Print Test
•Build in SPC and Process Control
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Toner Basics
• Density• Compound technique and PSD
• Resolution• PSD/Shape (CPT)
• Charge rate
• Background• Classifying cut
• Fusing• High speed / permanent
• Gloss
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Imaging Materials Science – Where defects are organic
• Toner Resins• Charging ,Fusing, Processing, Permanence
• Ink Pigments• Black or color, compound-ability, Magnetic properties
• Toner Charge control• Charging rate• Saturation
• Toner Modifiers• Fusing release agents (pe, Polyolefin)• OPC Cleaning
• Coated Media Cost has dropped HUGE since paper manufacturers start to coat at the source
• Character formation• Archivability• UV Stability
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Tribo electric : “charging”
• Controlling charge rate is critical for image performance over the life of the cartridge
• Detailed science of combining toner componentry has won attention in polymetric science circles
• The last few years many high tech companies have looked at polymer science for imaging consumables as a viable business
• Many resin companies have found the lucrative toner resin market
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Development Physics
• Link toner net charge with particle size distribution• Smaller particles have a higher charge rate• Higher charge particles accumulate on developer
components
• Physics are simple charge rate vs residence time
• Toner particles are subject to incredible force .. Bring in the ME• Strain, Temperature, elastic yield
• Environmental stability
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Consumption per Thousand pages
0.00
10.00
20.00
30.00
40.00
50.00
60.00
1000
2000
3000
4000
5000
6000
7000
8000
9000
1000
0
Pages printed
Gra
ms
of T
oner OEM
OPC1/T1
OPC2/T2
OPC1/T2
OPC2/T1
Toner Consumption HP 4250
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Charge Distribution
• Perfect toner distributions …• The compounding process is perfectly
homogenous • All particles exactly the same diameter and
mass
• Current polyester resins allow for excellent compounding … Mostly for fusing in hi speed printers, runs a little cleaner
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Toner Development
Q/M for Canon Engines
-50.00
-45.00
-40.00
-35.00
-30.00
-25.00
-20.00
-15.00
-10.00
-5.00
0.0020s 2m 20m 2hr
Charge time
uCou
lom
bs/g
ram
HP8100
HP4000
WX
Std.
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Fused Image Formation
Process Velocity and Fusing
0
50
100
150
200
250
0 20 40 60 80 100 120 140
Process mm/s
Tem
p
deg
rees
C
Cold Offset Region
Hot Offset Region
FusingRegion
Glossy
Matte
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Safety Requirements
• Ames Testing• Low Odor• Particle size ( Less than 5 um)
• Inhalant hazard (volume in air space)• Long term effects• OEM 4000 is ~17% “fines”
• EUROPEAN Concerns --- law suit has
found in favor of plaintiff “toner in an officeenvironment
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Commitment to laser printing
• Major OPC chemistry advancements by Hitachi, Mitsubishi, Kodak, Xerox
• Strong polymeric science advancement from resin manufacturers for imaging • Improved fusing• Consistent controlled compounding of
formulations• Consistent Grinding and Classification• LOWER COST
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Demands on Toner
• PSD - Particles now have controlled shape and size distribution CPT & MMT
• Materials design will help with charge rate and compounding, classification,fusing
• Small changes in materials & PSD will enhance image performance at current digital density
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Remanufacturing Success Metrics ------------------ CPT• Image Performance
• Halftone reproduction• Line art
• Yield• Solid fill uniformity• Printer maintenance reduced
• Fuser performance• cleanliness
• Standards and industry uniformity
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CPT …………………….. Mono & Color
• Timing• Color thinkers produce documents that demand color printing• Ink Jet will defeat some barriers but will lose because of ppm,
in business imaging for NOW … watch HP IJ new system
• CPT dominates color market
A soft wax core in each particle melts as the toner is fused to the paper, ensuring fast, even fusing. Improved, patented pigments are another key ingredient in HP toner.
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CPT Comparison
Unique chargeability
Yield is wonderful in a balanced system
Image performance is more controllable
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CPT Pixel Magic
ë Dots within a cellâ Dithering - is the art of placing single pixels of Mono or CMY adjacent to
one another to create the illusion of shading or color. This is a “single level” process common to most laser printers.
â 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.
â Level address ability is costly in memory and/or formatting time.
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Standards and Current Work …. ASTM
• Business Imaging F-05 (04 EP) (07 IJ)• Committee of industry representatives• Approx. 20 active members
• Charter• Outline imaging standards for consumer• Develop methods, accept proposals from within industry
• Timeliness• Year 1989 was start of process for 1531 … finished in 1994• Year 1991 was start of 1856 …. Completed 1998
• Process• Industry dependent “What’s at stake”• Marketing Quality …………. ISO ??
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Standard Practice for Determining Toner Usage in Printer Cartridges F-1856-98
• Evaluation of OEM and RM’d Cartridges• METHOD of extrapolating actual consumption
• Mass Balance• Toner movement from hopper• Toner transfer to the OPC• Toner transfer to the media
• Metrics• Eff %• PPM• GPP• G/1000
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Standard Practice for Determining Toner Usage in Printer Cartridges F-1856-98
• Coverage estimates and printer development variation• Method Variance
• Test Masters (5%)• RH% and Temperature• Relative comparison for your customer & for internal development
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Standard Practice for Comparing Printer or Copier Cartridges Cartridges F-1531-94
• Summary• Packaging & Marking• Leakage• Component Condition• Copy/Print Quality• Yield• Noise & Odor• Operational conditions• Mass Balance
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Standard Practice for Comparing Printer or Copier Cartridges Cartridges F-1531-94
• Baseline method for reference total performance of remanufactured product.
• Reliability is determined through a designed trial using OEM or other reference metric
• Reporting format • Operational• Mass Balance• Leakage• Visual• Packaging & Marking
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ISO 13660
• ISO-13660 - international standard for print quality evaluation• The standard defines fourteen PQ attributes and specifies techniques
for measuring them• Provides a framework for communication industry-wide• ISO-13660 requires that measurement instruments be calibrated to
physical units. This is critical for ensuring reproducible results.
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ISO 13660
• Baseline method for reference total performance of remanufactured product.• ISO 19751 “Appearance based image quality standards for printers” includes
standardizing color reproduction quality (scheduled for review 2005)
Imaging Artifact/Comparison Artifact
Halftone Dot/Dot shapeHalftone Dot/Dot gainHalftone Dot/Dot locationHalftone Dot/Dot surround/satellitesHalftone Dot/Dot edgeLine/Line densityLine/Edge sharpnessLine/Resolution/line modulationLine/Line widthLine/Edge raggednessSolid Fill Area/DensitySolid Fill Area/ColorSolid Fill Area/Halftone noiseSolid Fill Area/Gloss
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Moving Forward
• Standards laboratory• Cartridge certification
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Small/Medium/Large Testing Plan
• NPI development• Vendor data and print results (cartridge
BoM)
• Gold Cartridge – Silver test• Initial Life Tests• Graphics data / Text • Digital imaging data (Photoshop)• Test Targets• SPC / Control parametrics• Link to engine and Cartridge
componetry• DataBase
• Production• Sampling Life• EOL testing …. NPI (AQL to zero)
(Audit)• SPC on key variables • Realtime ---- Shift
REAL world
• Driving out cost
•Component Change
•Process Change
•Multi-function toners
•Filling systems
•Temp / Rh
•Storage
•Humidity limits testing
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Bibliography
• http://www.zeon.co.jp/business_e/enterprise/toner/toner5.html• http://www.qea.com/pdf/Paper_1999%20ISJ-JH%20Applications%20of%20ISO-13660.pdf
Applications of ISO-13660, A New InternationalStandard for Objective Print Quality Evaluation• ISO and Standards – http://www.iso.ch/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=22145• http://www.iso.org/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=22145&ICS1=37&ICS2=100&ICS
3=10• Halftone and color science – http://www.adobe.com/support/techguides/color/colortheory/variables.html• http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html• http://gretagmacbeth.com/Source/Gm.asp?part=Products&page=ProductsDisplay&id=6878&code=c&typ=prod
uct• http://www.loglight.com/• Avedon, Don M. and Courtot, Marilyn E., Glossary of Imaging Technology. AIIM TR2-1992. Silver Spring, MD:
Association for Information and Image Management; 1992.• A comprehensive glossary of technical terms; Electro-Optics Handbook, Waynant, R.W. and Ediger, M.N.,
Editors, Optical and Electro-Optical Engineering Series, McGraw-Hill, 1994• Fortner, Brand and Meyer, Theodore E., Number by Colors, Springer-Verlag, 199• Halliday & Resnick, Fundamentals of Physics, 3E, Wiley 1988• Halliday, Resnick, Walker, Fundamentals of Physics Extended, 5th Ed, Wiley 1997• Hecht, Eugene, Optics, Schaum’s Outline Series, McGraw-Hill, 1975• Light and Color, General Electric Company Publication TP-119• Minnaert, M. G. J., Light and Color in the Outdoors, Springer-Verlag, 1993• Waldman, Gary, Introduction to Light, The Physics of Light, Vision and Color, Prentice-Hall, 1983• Williamson, S J and Cummins, H Z, Light and Color in Nature and Art, Wiley 1983• Young, Hugh, University Physics, 8th Edition, Addison-Wesley, 1992. • http://www.wide-format-printers.org/autodownloads_FLAAR_reports/QEA_analisys.pdf