32.0. LIQUID CRYSTAL 2.1. Three major characteristics of Liquid Crystal The Thermal NatureSolid State(Crystal)Liquid CrystalineStateLiquidStateLow TempHigh TempMelting PointClearing PointThe Optical Nature of a LC moleculeXXXNO light passing throughLightLight passing throughThe Electrical Nature of the LC moleculesElectrodesAC potentialNo potential fieldP.2.
42.2. COMMON STRUCTURAL PHASES in the Liquid Crystal State Smectic Phase Nematic Phase Cholesteric phase2.3. Two other components to make a Liquid Crystal Display PanelTransparent Electrodes ---- Glass with conductive ITO layer which isetched to form a pattern.The Polarizer FilmOutgoing light& its axisLight wave& its axisPolarizer &its light axisP.3.
52.4. A TYPICAL TN TYPE LCD CELL Polarizer(Axis 0 degree)Glass with electrodesNO powersupplyWith AC VoltsconnectedGlass with electrodesPolarizer(Axis 90 degrees)Cell Gap =The separationbetween two glassesPositive Mode =Black digit on the grey backgroundNegative Mode =Clear digits on the dark backgroundLightP.4.
62.5. THREE COMMON TYPES OF LCD TRANSMISSIVE TYPELCDLight(Back Light)EyesPOLARIZER ON BOTH SIDESREFLECTIVE TYPELCDIncident LightPOLARIZER ON THE FRONT SIDEREFLECTOR ON THE BACK SIDETRANSFLECTIVE TYPELCDDay LightNight Light(Back Light)POLARIZER ON THE FRONT SIDETRANSFLECTOR ON THE BACK SIDEP.5.
72.6. CHARACTERISTIC CURVES Vs (Saturation Voltage)% LIGHTABSORPTION(or TRANSMISSION)Vth of LC90% changesAt higherTemp.5 v4 v10% changeVOLTS0 volt-40 deg C+80 deg CVth (Threshold Voltage)LC FluidViscosity% LightAbsorptionmm2/sec10,000At a lowerTemp.100TimeTon 5ms to 100msToff 20ms to 300ms-40 deg C+80 deg CDepending on how the LCD fluid is formulated.The smaller the cell gap, the faster response.P.6.
82.7. TN & STN (Super Twisted Nematic) The LC moleculemid-plane tilt angleVthVs% Light Absorption% Light Absorption% Light Absorption90 degTwisted180 deg240 degTwistedTwistedVVVoltsWide View AngleNarrow View AngleTN LCDSTN LCDGrey Backgroundin the positive modeYellow Green background colorIn the positive modeP.7.
92.8. HTN (Highly Twisted Nematic) & FSTN (Film STN) 180 deg or higher degTwistedTN90 deg TwistedWide View Angle BUT withDarker Color Background &Blue or dark blue patterns.Narrow View AngleHTN110 degTwistedFSTN240 deg or higher degTwisted1st Minimum TNLittle wider ViewAngle than TN(see later pages)Wider View Angle than TNbut narrower than STNView angle same as 240 deg STNBUT in Grey Background Color& Black patterns.PolarizerDSTN (Double STN Cells)1st Cell with patternsSame as usual STNOld waywhen NORetardationfilmLCD Cell2nd Cell without patternBut in reverse twistingRetardation Films on Polarizersto correct the color phaseP.8.
102. 9. COMPARISON AMONG TN, HTN, STN & FSTN 2. 9. 1 2.9. COMPARISON AMONG TN, HTN, STN & FSTN Positive Mode (Pattern on a Clear Background)EitherTNHTNSTNFSTNDeg Twisted90110180240BackgroundColorGreyYellow Greenor GreyGrey orPattern ColorBlackDark Blueor BlueBlue orTemp Range-40C to +85C-20C to +40C-20C to +70CMultiplex Ratio=< 1/8 duty=<1/16 duty=<1/32 duty=<1/240 dutyView Angle60 deg80 deg120 deg110 degView DirectionAt 6 or 12 O’clock ONLYAt 6 or12 O’clock ONLYMay specify6 or 12 O’clockAllVoltage2.5v min5v typical3v min5v typical, (higher duty, higher volts)P.9.
112.9.2. Negative Mode (Clear Pattern on a Color Background) TNHTNSTNFSTNDegree Twisted90 deg110 deg180 deg240 degBackgroundColorBlack(Seldom used)Dark BluePattern ColorClearOther natures same as the Positive Mode.2.10. Gooch-Tarry Curve --- The 1st Minimum TN LCD% Transmissionn : Birefringence (reflective indices ofLight transmitted in parallel & perpendicularTo the director of LC molecules.12%8%d : the cell gap4%0%d n0.48 (1st Min* )1.05 (2nd Min)1.64 (3rd Min)(um)P.10.*The 1st Min process is patented by E. Merck.
122.11. THE STATIC & MULTIPLEX DESIGN OF ELECTRODES 4 pairs of electrodes8 connectors needed.No time sharing forthe input signals –The STATIC Design5 electrodes5 connectors needed.1/4 time sharing forthe input signals toeach of the top electrode.No time sharing forthe bottom glass.We call the top electrodesthe SEGMENT whilethe bottom electrodesthe COMMON.4 electrodes in matrix4 connectors needed.1/2 time sharing forthe input signals toboth the top andbottom electrodes----The MULTIPLEX Design.We call it 1/2 duty if the1/2 time sharing is usedon the Common.PROBLEM:The higher the duty ratio, the shorter time the power signal goes into each electrode pair.Finally the power rms value may NOT be enough to fully drive the LC twisting properly.P.11.
132.12. THE PASSIVE AND ACTIVE LCD Y1Y2SignalX1TimeX2SignalAn ACTIVE Component ;MIM (metal insulator metal) DiodeOrTFT (thin film transistor)TimeThe LCD PixelThe TFT method is commonly used today on the large DOT MATRIX LCD,we call it the ACTIVE MATRIX LCD, or AMLCDThe LCD built together with the Active Component is not only the TFT LCD. The LCOSis also an LCD built on a silicon wafer with active components to control the LCD.In general, the duty ratio over 1/256 may not give a good contrast in the Passive design.But there are still some special design to work in the Passive way, such as;Dual Scan STN (DSTN), High Performance Addressing (HPA), …. etcP.12.
142.13. THE HISTORY OF LC & LCD Application Approx Year Major DevelopmentLiquid Crystalline initially described by an Austrian Scientist,Mr. Friedrich Reinitzer.18881904E. Merck sold the first Liquid Crystal substrates to the research market.1960Westinghouse used the cholesteric LC as a temperature indicator.Thermometer1965RCA demonstrated a dynamic scattering LCD to show numeric symbols.Kent State Univ. in Ohio USA presented an LCD operated at room temp.1970Rockwell (USA) and Sharp (Japan) made LCD Calculators.Hull Univ. in England synthesised new biphenyls with excellent physicalproperties for display use.Higher Contrast Twisted Nematic Mode in use.OCLI (USA) coated ITO on glass as electrodes.BDH (UK) sold LC to LCD manufacturers.CalculatorTime pieces1975Hamlin Inc (USA) in TN LCD mass production.E. Merck introduced Biphenylcyclohexanes LC for higher multiplex.InstrumentsMotorola built LCD on 4 ½”x 4 ½” glass substratesMicroma (USA) further improved the mass production technique andFairchild Semiconductor Inc. moved LCD production to Hong Kong.Timex (USA) bought RCA LCD facility and merged with Fairchild.The Japanese developed a Chemical Sealing process for cost reduction.Data bank & PDAP.13.
152.13. THE HISTORY (continued) ApplicationApprox YearMajor DevelopmentThe first LCD scriber made by Villa Precision Inc. (USA)Roche, BDH, E.Merck improve LC mixtures for TN, STN19805x7 CharacterDot Matrix GraphicWord ProcessorFairchild scaled up to 14x14” substratesClover Display Ltd established in May 1983MIM & TFT AMLCD inventedFull Dot Matrix &TV PanelsBrewer Science Inc. & OIS of Troy, USA developed colourAMLCD for space shuttle use.1985PDA, Laptop &Notebook PCFull color TFT panel for Notebook PC1990Mobile phones1995Bi-stable Cholesteric LCDE Books2000New Display to replace LCD ?---- OLED, PLEDP.14.
163.0. HOW LCDs ARE MADE 3.1. THE FRONT END PROCESS ITO = Indium Tin Oxide, a transparent conductive layer coated on theSodium Lime Glass. Its resistance is from 10 Ohms to 120 Ohms/square.Glass area usually in 14x16”. Thickness in 1.1, 0.7, 0.5, 0.4, 0.3mmITO GlassClean Glasswith DI waterArtwork & Mask DesignPatterning theElectrodes on ITOMethods: Photo Masking, Resist Ink Printing,ITO Ink direct Printing, Laser Cutting.Alignment LayerTo form a rough surface to hold the LC molecule chainsTo form the cell and the inter-connections between the top and bottom glassesSealing Frame &Silver Dot PrintingTop/bottom GlassAlignment and SealThe Laminated pairsP.15.
173.2. THE BACK END PROCESS Laminated Pair Cutting into cells Liquid Crystal MixtureFormulationLiquid Crystal FillingEnd Sealing& CleaningTesting & InspectionPolarizer CuttingPolarizer FixingMetal Pin or Heat Seal Connector fixingCosmetic CheckLCD Module Assembly (COB, TAB, COG, COF)Optional ProcessShipmentsP.16.
184.0. THE COLOR LCD 4.1. THE FULL COLOR LCD Black and White LCD Slice ITOinto narrowsectionsSegmentsRGBColorFilterCommonCommonIn order to give a better color mixing,the RGB line widths are usually lessthan 30 micron in width per color.Hence the same for the ITO electrodes.The color LCD can be built as a Passive LCD.But most large size Dot Matrix Color LCDsare built in the Active design.P.17.
194.0. THE COLOR LCD (continued) 4.2. THE ECB (ELECTRICALLY CONTROLLEDBIREFRINGENCE) COLOR LCD% LightAbsorptionVarious ECB Types;1) Homogeneous TypeRed->Yellow->Green->Blue2) Deformation of Vert AlignedPlane (DAP) TypeBlue->Green->Yellow->Red3) Hybrid Aligned Nematic(HAN) TypeGreen->Red->Blue4) Vertical Aligned Nematic(VAN) TypeVClearDarkGreyY O R P B GColor around2.4v to 3.7vDarkVNo pure color,50% Green + 25% Red + 25% Blue at this pointP.18.
204.4. GUEST HOST LCD (Single fixed color) 4.3. DOUBLE CELL COLOR LCDThere are two kinds of double cell can generate colors;A) With Color Polarizer B) With usual Polarizers at certain angles(Only working in Transmissive Mode) (Reflective Mode is also possible)4.4. GUEST HOST LCD (Single fixed color)Mixing color dye in the LC fluid and build LCD in Negative Mode.It will show clear pattern on a color background.Such method was used in the early date.4.5. LCD WITH COLOR POLARIZER, COLOR FILM ORCOLOR REFLECTOR IN CERTAIN AREA (fixed color)Pre-printed color polarizer is expensive.4.6. COLOR INK PRINTING ON THE BOTTOM GLASS SURFACE(fixed color)This is the cheapest way to make LCD with fixed colors.The LC image & color area may not coincide well due to the glass thickness.P.19.
215.0. TODAY’S LCD Active LCD Passive LCD STN TN Duty Ratio LCD TV & MonitorsPassive LCD1/256Projector Portable TVNotebook Panels1/128Digital CameraOffice Equipment1M+ Pixels1/64PDA100K Pixels1/32Mobile Phone Digital InstrumentsSTN1/1610K PixelsTNData Bank1/81/4Film Camera1K PixelsCalculator1/3100 Pixels1/2Time piecesHand Held GamesPanelSize1/1Static10 mm21001,00010,000100,000 mm2P.20.
226.0. CUSTOM DESIGN LCD & LCM --- The factors to consider 6.1. LCD PANEL DIMENSIONSOuter Dimensions (Be economical size)View Area (normally 2mm from the edges)End Seal (0.5mm thick)Active Area (Area with patterns)Pinout or Connection Area (2 to 2.5mm)Glass Thickness (1.1, 0.7, 0.5, 0.4 or 0.3mm/one side)( Glass Material: Sodium Lime Glass with SiO2 barrier, surface polished for STN use )Economical Panel Size: The outer dimension may use up most the raw glass sheet area.For small order size or pilot run,7x8 inches sheets are used to boostup the yield and save the tool cost.orRaw Glass Sheet7x8 inches(178x203mm)14x16 inches(355x406 mm)(The usable area is 7mm off the edge)P.21.
236.2. PANEL CONFIGURATIONS The thick lines representing the pinout areas.ABCDEyesConnectors suitable:Zebra (Silicone Rubber) – A, B,Heat Seal or TAB – A, B, C, D,Metal Pins – C, D,All the above 4 models required Ag (silver) connections inside the LCD cell.If such Ag connection not to be used or unable to be used, the configurations will be as follows;GEFModels E, F & G are good for combination use of Zebra and Heat Seal connectors together.Most TAB connections are also applying on such models.40+deg40+degFor TN LCD, don’t forget tospecify the View Direction15+deg45+deg15+deg45+deg6 O’clockP.22.12 O’clock
246.3. PATTERN LAYOUT Too Long Trace Cross Over Narrow down trace Good BadLayoutC S1 S2 S3 S4 S5 S6S6 S3 C S1 S2 S4 S5+P.23.
256.4. ZEBRA CONNECTORS Three kinds of Rubber 1. Sponge Rubber 2. Silicon Rubber3. Super Soft RubberSide Wall InsulatorsConductive LayersInsulation LayersMetal Mounting BezelPitch: (Conductor/Insulator Layers)Low Cost Type mmGeneral Type mmDot Matrix Type – mmGraphic Type mmLCDAssemblyZebraPCBContact Resistance:1000 –1500 ohms at 10%-15% compressionPrecautions in AssemblyPre-clean ZebraThree or more conductors in contactPCB wraping <0.375mm / 50 mmBezel has opening gaps with PCB0.3mm or 10%-15% compressionDummy zebra use with single sidecontact LCD.Insulation side wall quality.LCDZebraGoodMis-alignedA safer way(wider contact on PCB)P.24.
266.5. HEAT SEAL CONNECTORS Choose proper LCD configuration: Conductors (~20 um particles) printed on a Polyester (PET) Film of umContact Resistance & PitchGraphite Type to 100 ohms/sq , 0.60, mmSilver Graphite Type ohm/sq , 0.35, mmSilver Type ohm/sq mmChoose proper LCD configuration:Hot PressPET filmLCDConductor sideWeldedPET sidePCBPCBPrecautions in AssemblyThe Hot Press head temperature deg C at joint32 Kg/sq cm pressure is recommendedLeveling the press for even pressure along the joint.Properly select the sealing time to prevent uneven flow orwash away the conductor particles.100pcs/mm2 particles at contact area is suggested.Peeling off strength be >200gm (Vertical)& >500gm (Horizontal)LCDPET sidePCBPET sideP.25.
276.6. METAL PIN CONNECTORS ( for 0.7 & 1.1mm glass ) Standard Pitch: 1.27mm, 1.8mm, 2.0mm, 2.54mmPin Length: mm, 30mm, & 45mm maxLCDClip Depth mm to 2.4mm maxContact Resistance: <0.05 ohmPrecautions in Assembly:Prolong soldering may damage the Pin contact to glass---- A good LCD will add carbon cushion between pinclip and glass contact area.Care on bending the pins ---- LCD maker provides pinlead forming.Pin length under 4.0mm is not recommended.Wave solder is not recommended ---- Polarizer is weakMechanical stress on pin or temperature changes maycause LCD background color changed.Epoxy enforcementWider seal area isrequired.All the above connections may have IC on PCB by SMT, Wire Bonding (COB) or Insert & Solder.6.7. TAB (TCP IC BONDING)LCDIC on a flexible filmwith conductors.The Film is heat sealedonto the LCD pinout areaTAB = Tape Automation BondingTCP = Tape Carrier PackageP.26.
286.8. CHIP ON FILM (COF) 6.9. CHIP ON GLASS (COG) LCD Same as TAB, but with morecomponents on the film likea circuitry on PCB6.9. CHIP ON GLASS (COG)The IC Chipfor COG isdifferent fromthose for usualwire bondingon PCB.Same as anusual LCDLCDGlass withFine tracesFan-in &Fan-outACF* film is used to fix theCOG chip onto the glass.The ACF film is similar toHeat Seal but with much finerPitch and conductive particles.Most panels withMetal PinsIC Chip* ACF=Anisotropic Conductive FilmP.27.
296.10. TRICKS ON THE LCD PANEL DESIGN Recommended Driving Freq60 Hz to 120 HzTHE BIAS VOLTAGETheoretical Driving Waveform% LIGHTABSORPTIONApplied toSegment90%Applied toCommon10%ResultingWaveformto LCDVolts0 voltVthVoltsOffOnPractical Design Waveform(Example: Waveform to LCD at 1/3 Bias)VOn2/3VOffOff1/3VThe BiasVoltageThe drivingVoltage-1/3V-2/3VTime-VP.28.
306.10.1. THE BIAS VOLTAGE (continued) The formula and design facts;N: Multiplex Rate. Example: N=3 for 1/3 dutyS: Bias The ideal design S= NVd: The supply voltage to the panel.Von = ( Vd / S ) x ( N-1+S ) / NVoff = ( Vd / S ) x [ N – 1 + ( S – 2 ) ] / N22N234816S5Vd3 volts5 voltsVoff1.06 v1.22 v1.00 v0.88 vVon2.37 v2.12 v1.73 v1.27 v1.58 vVon – Voff1.31 v0.90 v0.73 v0.39 v0.36 vLess than 1 volt !Beware the drifting under temp changesP.29.
316.10.3. THE POLARIZER SELECTION CROSS OVER LAYOUTEpoxy Sealing FrameS S S S4Ag DotConnectionC1Hided under FrameC2C12 cross over pointsTHE POLARIZER SELECTIONThe Glue Type or Non-glue Type polarizer.The Polarizer with the UV Barrier may extend the LCD Life under strong UV exposure.The Anti Glare Polarizer may improve the contrast.The high durability polarizer may stand for wider temperature environment.The slightly orientation of Polarizer axis may change the background color.6.11. THE THERMAL COMPENSATIONIt is recommended to use the thermal compensation circuit when a LCD will be operated undera wide temperature range.P.30.
326.12. TEMPERATURE RANGE Wide Temp Type Clearing point Melting point Low Temp TypeGeneral purposeTempDeg COperatingTemp.-30-200 deg+50+60+75 degStorageTemp10 deg C lower10 deg C higherThe STN temp is 10 deg narrower than TNBackground blackenedCross TalkProblemwhen exceedsrated temp.Black SpotsSlow responseAll the above defects are reversible at room tempPossible designSpecific for High TempSpecific for Low TempTemp+100-40 deg+10+30 degP.31.
336.13. BACK LIGHTS - Choice of Back Light Descriptions Common Color Side LED Type( Fig. 1 )Wedge diffuser (Light Guide) and reflector are needed.Poor illumination for large panelYellow Green,Blue, WhiteArray LED Type( Fig. 2 )Consuming more power and generating more heat.Beware the difference in supply voltages of each model. Easy assemblyRed.EL (Electro-Luminescent)The best in even brightness and light weight. But less brighter than LED Backlight. High voltage and EMC consideration.Green, Blue,White.CCFL (Cold Cathode Fluorescent Lamp)The strongest illumination.High voltage and EMC consideration.Important: The Transmissive and the Transflective Type LCD absorb the different light intensity.LightLight-Diffuser PaperLight GuideLED wiringLEDs+Reflector domesFig. 1.Reflector PaperFig. 2.P. 32.
347.0. BI-STABLE LCD Bi-stable Cholesteric Display, or SSCT – Surface Stabilised Cholestric Texture Display, orMulti-stable Chiral Nematic Display, orE-Book DisplayThis is a new technology in LCD making use of the Cholesteric Liquid Crystal. Mr. John Westand Mr. D. K. Yang of Kent State University, Ohio, USA filed the patent in 1995.The display image is retentive in the absence of an electric field. It has a excellent readabilityand wide view angle under the daylight or strong ambient light.No Polarizer is required on this kind of display panels.The Liquid Crystal is switchable and stable in two kinds of texture.The Twisted Planar Texture, which has the LC layers parallel to the display surface,reflects the incident light.(b) The Focal Conic Texture, whose LC is in fragmentary, scatters the incident light.Switch-able(a)(b)The above two textures are switch-able under 30V to 180V pulse of 10ms to 100ms,and stable in zero electric field.By properly adjust the pitch of the Twisted Planar Texture, it can reflect R, G, B lights.P.33.
358.2. THE DIFFERENCE BETWEEN LCD & OLED 8.0. ORGANIC LEDThe Organic Electro Luminescent Displays (OELD) , or The Organic Light Emitting Devices (OLED)The EL ( Electro-luminescence ) Back Light for LCD has been used for many years. It operatesat high voltage (>100V). In 1987, Tang and Van Slyke in Kodak, USA reported a low voltage (<10V)Organic EL. It comes a new display ---- the OELD.8.1. THE BASIC STRUCTUREMetal CathodeElectron Transport LayerDCvoltRe-combination and Emission LayerHole Transport LayerITO Layer (Anode)Glass SubstrateLight emits8.2. THE DIFFERENCE BETWEEN LCD & OLEDLCD OLEDNo Light emission Emits light in colours (100cd/sqm)Narrow view angle Wide view angle (>150 degrees)Slow response Fast response (<10 microsec)OLED has most the advantage of LCD such as;Easy patterningLow operating voltage but at high current ( 20ma/cm2)Low manufacturing costThin and light weightP.34.
368.0. ORGANIC LED (continued) 8.3. THE OLED & PLEDThere are two major ways to build the OLED;The small molecule process ---- by spluttering the organic materials onto the ITO patterns.Kodak uses such way.The large molecule process, or the polymer process ---- by spin coating, dip coating or screenprinting the organic pastes layer by layer. Cavendish Lab in Cambridge, UK and DowCorning, USA developed such process and materials in ’90s.Some people now call the OLED made under polymer process the PLED.The small molecule process is also applying to making the ACTIVE OLED.Pioneer, Japan seems the first one in mass production for the OLED.It is expected the OLED will replace the LCD step by step from 2005.CLOVER DISPLAY GROUP has started a joint venture with the University of Hong Kong to researchand develop the materials and process for OLED.The newly formed joint venture company is named COLED DISPLAY LTD., established Sept 2002.P.35.
379.0. TOUCH PANELS 9.1. ANALOG TYPE 9.2. DIGITAL TYPE PE Film With ITO RaRbSilverConductorsA PE film with ITO layer is sealedonto an ITO Glass with epoxy dots asSpacer to maintain a gap.When the external pressure oftouching makes contact of two ITOlayers, the sensing IC circuit with givean analog reading corresponding to thetouch position.Epoxy dotsAs SpacerGlass withITORdPin outAreaRc9.2. DIGITAL TYPEThe ITO on the PE Film and theITO Glass are etched out into sectors.When touched, the correspondingsectors are shorted circuit and reflectedto the pins concerned.PE FilmWith ITOEpoxy dotsAs SpacerGlass withITOPin outAreaP.36.
3810.0. CUSTOM LCD/LCM DEVELOPMENT GUIDE. Enquiry from CustomerFeasibility Study & NRECharge / Unit Price QuotedFree quote in 2-4 working daysNRE payment in advanceNRE Order Confirmation** normally LCDor 3-5 LCM sampleswill be free. For more qty,please notice us in advancewhen confirm the NRE order.LCD PanelPCB & CircuitExternal Casing1 week1 week1-3 weeksPanel Drawingfor ApprovalCircuit diagram& PCB LayoutCase Drawing3-6 weeks3-4 weeks3-10 weeksMask Design& Samples**for ApprovalPCB Tool Design& Samples** forApprovalHand mould up sampleFinal CaseMould3-9 weeksPrimary SampleFinal SampleTotal development time;LCD Panels weeks, LCM Modules weeks; With External Case 7-18 weeksP.37.
3911.0. ACKNOWLEDGEMENT & DECLAIMER We have tried our best to present up-to-date and correct information here. Some of them to beexplained together with photographs and demonstration samples to form a complete part of theIntroduction.We wish that the information discussed in this seminar may help the design engineers to makea cost effective and quality custom design in an easier and logical way.However, this is not an academic seminar that we have used a simply way in the presentation.All information here is provided in good faith without any expressed or implied warranty. The readershould seek for more detail advice from the industry.The information in above are partly referring to the following documents;Proceedings of the Liquid Crystal Seminar HK by E. Merck, Darmstadt, Germany.Various articles in the SID International Symposium and Information Display by the Society forInformation Display, Inc. USALCD Displays, the leading edge in flat panel displays, by Sharp Technical Library, Vol. 1, ofSharp Corporation, Osaka, Japan.Editions:7th edition Sept 29, 20056th edition Mar 13, 2003.5th edition Sept 19, 2001.4th edition Apr 16, 2000.3rd edition Sept 6, 1999.2nd edition Sept 1, 1998.1st edition May 19,1997.All copy rights reservedClover Display Ltd. H.K.Prepared by;Johnny C. L. Chou,Clover Display Ltd.Room 1006, 26 Hung To Road, 10/F, Kwun Tong, Hong KongTel: ,Fax: ,URL: (in English)(in Japanese)(in Chinese)P.38.