Renesas Electronics America Inc. © 2010 Renesas Electronics America Inc. All rights reserved. ID C22C: Flat Panel Displays Beyond the Basics Robert Dunhouse,

Renesas Electronics America Inc. © 2010 Renesas Electronics America Inc. All rights reserved. ID C22C: Flat Panel Displays Beyond the Basics Robert Dunhouse, Display BU Version: 1.1 12 October 2010 Engineering Manager

2 © 2010 Renesas Electronics America Inc. All rights reserved. Robert F. Dunhouse, Jr. Displays Applications Engineering Manager Application Engineering support for North America Electrical & mechanical consultation. Customer equipment debugging. Direct communication with NEC LCD Technologies in Japan to resolve technical issues and advise direction for future designs. Design demonstration computers and display housings for field demo program. Includes circuit design & circuit board layout of LCD video interfaces and mechanical design of equipment housings. 14 years engineering experience with NEC LCD Displays. Over 25 years experience in the electronics industry Research & development at Cincinnati Microwave (founders of ESCORT radar detectors) – Opened a branch office in Sydney Australia Founded US design and manufacturing company – Creative Circuits

3 © 2010 Renesas Electronics America Inc. All rights reserved. 3 Sophisticated solutions Sustainable support Display Module Solutions Industrial Mobile Displays LED Backlight LCDs Emerging Technologies Super-Fine TFT (SFT)  Robust feature sets  Long-term product support  Amorphous silicon (A-Si) displays  Low-temperature polysilicon (LTPS) displays  High luminance and wide color gamut  Superior image quality  Ultra-wide viewing angles  2D/3D displays  Color enhancement  E-paper  On-cell touch  Low power consumption  Long life LEDs  Thin profile and light weight design  Replaceable LED light source unit Wide Format LCDs  More data on a single screen  16:9 aspect ratio Natural Light TFT (NLT)  Suited for a variety of ambient-light environments  Proprietary transflective LCD technologies  Super Reflective NLT (SR-NLT)  Super Transmissive NLT (ST-NLT)

4 © 2010 Renesas Electronics America Inc. All rights reserved. 4 Sophisticated solutions Sustainable support Display Module Solutions Industrial Mobile Displays LED Backlight LCDs Emerging Technologies Super-Fine TFT (SFT)  Robust feature sets  Long-term product support  Amorphous silicon (A-Si) displays  Low-temperature polysilicon (LTPS) displays  High luminance and wide color gamut  Superior image quality  Ultra-wide viewing angles  2D/3D displays  Color enhancement  E-paper  On-cell touch  Low power consumption  Long life LEDs  Thin profile and light weight design  Replaceable LED light source unit Wide Format LCDs  More data on a single screen  16:9 aspect ratio Natural Light TFT (NLT)  Suited for a variety of ambient-light environments  Proprietary transflective LCD technologies  Super Reflective NLT (SR-NLT)  Super Transmissive NLT (ST-NLT) Emerging Technologies New 2/3 dimensional displays Color enhancement e-Paper On-cell Touch Long Term Support/Production

6 © 2010 Renesas Electronics America Inc. All rights reserved. Our High Performance Liquid Crystal Displays Renesas has an extensive lineup of “Industrial” grade Liquid Crystal Displays. Our products are designed with extended shock, vibration & temperature standards, enhanced front of screen performance and long product cycles. We demonstrate industry leading technologies in transflective, high resolution, high color, 3D, e-Paper and low power portable displays all to help solve many of today’s design challenges.

8 © 2010 Renesas Electronics America Inc. All rights reserved. Key Take aways This lecture is a continuation of the “Flat Panel Display Basics” and will focus on common integration issues. You will learn general LCD topics including panel interfaces, video timing, image retention, viewing angle technologies, outdoor viewing and defect specifications.

11 © 2010 Renesas Electronics America Inc. All rights reserved. 18-bit Parallel Digital CMOS R0 R1 R2 R3 R4 R5 G0 G1 G2 G3 G4 G5 B0 B1 B2 B3 B4 B5 HSYNC VSYNC DE CLK 6 color bits for each “primary” color (RGB) Minimum of 22 conductors not including power & grounds. 12” maximum cable length. Resolution up to SVGA (800 x 600).

12 © 2010 Renesas Electronics America Inc. All rights reserved. 18-bit Single Channel LVDS Achieves 64 shades of gray and 262,144 colors. Reduced to 8 conductors not including power & grounds. Lower power differential signaling. Less susceptible to noise. Cable should be 100 Ohm twisted pair. Up to 10 meters. R0 R1 R2 R3 R4 R5 G0 G1 G2 G3 G4 G5 B0 B1 B2 B3 B4 B5 HS VS DE CLK LVDS Transmitter Low Voltage Differential Signal R0 R1R2R3 R4 R5G0 G1 G2 G3 G4G5B0 B1 B2 B3 B4 HS B5 VSDE CLK

13 © 2010 Renesas Electronics America Inc. All rights reserved. 24-bit Single Channel LVDS Adds two more color bits/color to achieve 256 shades of gray, 16.7M colors. 10 conductors not including power & grounds. LVDS was originally used for XGA and above resolutions but is now found in VGA and above. R0 R1 R2 R3 R4 R5 G0 G1 G2 G3 G4 G5 B0 B1 B2 B3 B4 B5 HS VS DE CLK LVDS Transmitter R6 R7 G6 G7 B6 B7 Low Voltage Differential Signal R0 R1R2R3 R4 R5G0 G1 G2 G3 G4G5B0 B1 B2 B3 B4 HS B5 VSDE CLK R6R7G6B6 G7 B7NC

14 © 2010 Renesas Electronics America Inc. All rights reserved. 24-bit 2 Channel LVDS Even and odd pixel data is sent through separate channels. Reduces the demands on cable bandwidth. Typically used for SXGA (1280 x 1024) & UXGA (1600 x 1200) resolutions. Four channel LVDS is used for QXGA (3M pixel) and QSXGA (5M pixel). Odd Pixels Even Pixels R0 R1R2R3 R4 R5G0 G1 G2 G3 G4G5B0 B1 B2 B3 B4 HS B5 VSDE CLK R6R7G6B6 G7 B7NC R0 R1R2R3 R4 R5G0 G1 G2 G3 G4G5B0 B1 B2 B3 B4 HS B5 VSDE CLK R6R7G6B6 G7 B7NC

15 © 2010 Renesas Electronics America Inc. All rights reserved. LVDS Color Bit Mapping Standards VESA  Video Electronics Standard Association  Open LVDS Display Interface (Open LDI)  MSB color bits are mapped to the upper differential data pair. JEIDA  Japan Electronic Industries Development Association  LSB color bits are mapped to the upper differential data pair.

18 © 2010 Renesas Electronics America Inc. All rights reserved. 0ms < t < 35ms Power Sequencing ON OFF ON Toff > 50ms VALID Period VCC Display Signals 10us ≤ Tr < 30ms 3.0V 0ms < t < 35ms Min & Max VCC-to-active video times must be met at startup Minimum VCC cycle time Once video is established there can be NO interruption of the control signals or VCC must be power cycled

19 © 2010 Renesas Electronics America Inc. All rights reserved. Defining Timing Signals Four control signals CLK - Clock – Also called “Dot clock” DE – Data Enable – When video data is actively written to the display HSYNC – Horizontal Sync – Resets the line scan VSYNC – Vertical Sync – Resets the frame scan Data signals – 24-bit color RED0 – RED7 GRN0 – GRN7 BLU0 – BLU7

20 © 2010 Renesas Electronics America Inc. All rights reserved. Hsync pulse width Defining Timing Signals Hsync Data Enable Hsync cycle Hsync back porchHsync front porch Vsync pulse width Vsync Data Enable Vertical display period Vsync back porchVsync front porch Vsync cycle Horizontal display period 1234 N

23 © 2010 Renesas Electronics America Inc. All rights reserved. Image Retention Both positive and negative charged ionic contaminants exist in liquid crystal material. A DC voltage applied across the LC cell causes ionic alignment. AC drive disperses ionic concentrations. Over time a static image will create a DC component. Removal of the drive voltage leaves a weak residual field. Cross Section of LCD Glass

24 © 2010 Renesas Electronics America Inc. All rights reserved. Image Retention & Countermeasures Image retention exists in all Liquid Crystal Displays but to varying degrees. Newer panels use purified LC material, better alignment layer materials and have improved the “wiping” process during manufacturing. Ways to counteract image retention Use screensavers. Move image several pixels at a pre-determined period. Drive with full white or black image. Extreme image retention conditions drive the display as above and at high temperature (50C). – High temperature improves mobility of the ionic contaminants.

26 © 2010 Renesas Electronics America Inc. All rights reserved. Viewing Angle Technologies Twisted Nematic Fast response, limited viewing angles, most common, less expensive In Plane Switching Widest viewing angles, highest color stability, w/ overdrive comparable to TN response, black not as good as VA, most used in color critical applications. Vertical Alignment / Patterned VA Black better than TN, response slower, viewing angles inferior to IPS, contrast/color shift off angle viewing, vibration error. Multi-Domain Vertical Alignment Multiple LC alignment, better color stability than VA, viewing angles inferior to IPS, less transmissive. Optically Compensated Bend Fast 2ms response

28 © 2010 Renesas Electronics America Inc. All rights reserved. Counteracting the Effects of Bright Light Preserving contrast not peak luminance is key. Most shop “peak luminance” what they buy is “contrast”. Correction methods: Transmissive panels – 2 methods – Active – “Brute force” adds many backlight elements to overpower the effects of sunlight. – Passive – Film or glass based enhancements. Transflective panels: – Renesas offers 2 technologies – SR-NLT - A reflective layer is added to the TFT layer. Using a patterned surface wide viewing angles are achieved. – ST-NLT - A standard transmissive panel that adds a proprietary AR film and backlight recycling to create transflective properties.

29 © 2010 Renesas Electronics America Inc. All rights reserved. SR-NLT – Super Reflective NLT Backlight ON or OFF – Highly reflective surface, great for direct sunlight applications where backlight is normally off for maximum power savings

32 © 2010 Renesas Electronics America Inc. All rights reserved. Advantages of ST-NLT & SR-NLT ST-NLT & SR-NLT products carry full manufacturer’s warranty. NEC uses “passive” enhancements and avoids the reliability issues of “brute force” method. Most shop luminance what they buy is contrast. An NEC ST-NLT panel @ 375 nits equals a standard panel @ 810 nits. Overdriving backlights is not needed. By increasing the peak (white) luminance, black level also rises making the panel no better in contrast. It may actually cause “wash out”.

34 © 2010 Renesas Electronics America Inc. All rights reserved. General LED Notes LED lifetime = 50% of the original luminance Lifetime figures are provided by the LED manufacturers and are for only the LED device itself. Actual panel lifetimes will be lower. High temperature is the enemy of LEDs. Some manufacturers use common anode and cathode LED strings. LEDs fail open or shorted In this configuration an open LED in a series string will result in higher current flow through the remaining LED strings. With individual string connections select LED driver with independent branch regulation. Better maintaining luminance uniformity.

35 © 2010 Renesas Electronics America Inc. All rights reserved. General LED Notes - continued Additional LED controller features: Open & short circuit protection Programmable configuration – Dimming and current settings An automatic efficiency optimizer – Reduces the LED forward voltage to minimize power Fault condition notification – Dedicated output that sets a “flag” when an open or short condition is sensed

37 © 2010 Renesas Electronics America Inc. All rights reserved. -40-20020406080 Ambient temperature (C) Relative luminance (%) *100% at 25C ℃ LED vs. CCFL Temperature Performance 12.1XGA (CCFL) 6.5XGA (LED) 12.1XGA (LED) LED luminance is better over temperature

38 © 2010 Renesas Electronics America Inc. All rights reserved. X LED vs. CCFL Color Performance 12.1XGA (CCFL) 6.5XGA (LED) 12.1XGA(LED) -20 ℃ 70 ℃ LED color stability worse than CCFL over temperature Y

41 © 2010 Renesas Electronics America Inc. All rights reserved. Defect Specifications All manufacturers have defect specifications that define the maximum allowable pixel, mechanical and cosmetic defects. Many manufacturers do not include defect specs in their data sheets so ask. Include defect specs when comparing LCD displays from different manufacturers. Actual defect yields will be less.

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59 Appendix – LCD Defect Specification

61 © 2010 Renesas Electronics America Inc. All rights reserved. What’s found in a Defect Specification? Bright Dot Category Dark Dot Category Bright and Dark Dot Combination Category Line Defect Category Inspection Condition This presentation will show an example of a 6.5” NL6448BC20-08E defect specification. All other Defect Specifications from other sizes can be followed similarly.

62 © 2010 Renesas Electronics America Inc. All rights reserved. Bright Dot Category Highlighted is a Bright Dot Category from a 6.5” NL6448BC20-08E defect specification Note: One Dot refers to one Sub- pixel of a pixel. A pixel contains 3 sub-pixels of Red, Green and Blue. Dot and Sub-pixel are used interchangeably.

64 © 2010 Renesas Electronics America Inc. All rights reserved. Bright and Dark Dot Combinations Highlighted is a Bright Dot and Dark Dot Combination Category from a 6.5” NL6448BC20-08E defect specification

67 © 2010 Renesas Electronics America Inc. All rights reserved. Inspection Conditions Panel inspection should be at a room temperature of about 25 degrees Celsius. The panel should be at a distance of about 8 in or 20cm from your eyes and is viewed from its front center perpendicular surface. Inspection angles can vary from 20 degrees left/right and/or 20 degrees up when measured from front center perpendicular. The ambient room illumination measured on the front panel surface should be about 60 lx, which is about equivalent to 6 burning candles one foot away from the panel. Basically this is a low light condition.

68 © 2010 Renesas Electronics America Inc. All rights reserved. What Are You Looking For? You Are Looking For: Bright Dots (sub-pixels) explained under the “Bright Dots Category” Dark Dots (sub-pixels) explained under "Dark Dot Category” Bright and Dark Dots combinations (sub-pixels) explained under the "Bright and Dark Dots combination Category” Line Defects under "Line Defect Category"

71 © 2010 Renesas Electronics America Inc. All rights reserved. Best Image for Bright and Dark Dot Combination If you feel you've seen both (Dark and Bright Dots) and you're questioning the Allowable combination of both Dark and Bright dots, then the best image to view these are on a gray image where the dark and bright dots can be seen together.

73 © 2010 Renesas Electronics America Inc. All rights reserved. Bright Dot Category and Other Categories The Bright Dot defect category will be reviewed here. The other categories will not be reviewed as they are similar to the Bright Dot defect category. The Line Defect category is self-explanatory. If either a bright or dark line defect is observed the panel is considered defective and should be returned.

79 © 2010 Renesas Electronics America Inc. All rights reserved. Linked Defects of 2 dots of same color When 2 bright dots of the same color are linked, the panel is defective. Further details are explained on following slides.

81 © 2010 Renesas Electronics America Inc. All rights reserved. Two Linked Bright Dots of Same Color 1 set of bright dots single color (red) are shown as an example. There are 3 possible color combinations. Patterns of this type are NOT allowed

82 © 2010 Renesas Electronics America Inc. All rights reserved. Two Linked Bright Dots of Different Colors When 2 bright defect dots of different colors are linked, the panel is not considered defective. Further details are explained in the next slide.

83 © 2010 Renesas Electronics America Inc. All rights reserved. Two Linked Bright Dots of Different colors 3 sets of bright dot defects each with two colors of red and green are shown as examples. There are 9 sets of any two color patterns possible. Patterns of this type are allowed until Red, Green or Blue conditions are exceeded.

84 © 2010 Renesas Electronics America Inc. All rights reserved. Linked Bright Dot Defects of 3 or More When 3 or more bright defect dots of different or same colors are linked, the panel is considered defective. Further details are explained in the next few slides.

85 © 2010 Renesas Electronics America Inc. All rights reserved. Three Bright Dots or More (Single Color) 1 set of bright defect dots in a single color of red are shown as an example. There are three possible combinations (3 red or 3 blue or 3 green). Patterns of this type are NOT allowed.

86 © 2010 Renesas Electronics America Inc. All rights reserved. Three Bright Dots or More (Dual Color) 10 sets of 3 linked bright dot defects each with 2 colors of red and green are shown as examples. There are 30 possible combinations. Patterns of this type are NOT allowed.

87 © 2010 Renesas Electronics America Inc. All rights reserved. Three Bright Dots or More (Triple Color) 9 sets of 3 linked different color bright dot defects are shown as examples. There are 27 possible combinations. Patterns of this type are NOT allowed.

88 © 2010 Renesas Electronics America Inc. All rights reserved. “D” denotes the distance between two defective dots. Panels with same color bright dots which are 6.5 mm or less apart are considered defective. Close Defect Dots of Same Color D ≤ 6.5mm

89 © 2010 Renesas Electronics America Inc. All rights reserved. Using the 6.5”-08 as an example, if Da is less than or equal to 6.5 mm the panel is defective. An easy way to measure 6.5 mm is in pixels. The panel’s pixel width is 0.20 mm. Dividing 6.5mm by the pixel width of 0.20mm yields 32.5 pixels. If two defects dots are 33 pixels or less distance then the panel is defective. Close Defect Dots of Same Color D ≤ 6.5mm

90 © 2010 Renesas Electronics America Inc. All rights reserved. Panels with different color bright dot defects which are 6.5 mm or less but greater than zero are allowed. Panels with bright dot defects greater than 6.5 mm apart are allowed. Close Defect Dots of Different Colors D ≥ 6.5mm

91 © 2010 Renesas Electronics America Inc. All rights reserved. Close Defect Dots of Different Colors Db ≥ 6.5mm (2) Da ≤ 6.5mm, Db ≥ 6.5mm If two or three defective pixels of same color are greater than 6.5mm apart then the panel is still considered good and allowable. If defective pixels are either greater or lesser than 6.5mm apart and different colors from either other, the panel is still considered good and allowable.

98 © 2010 Renesas Electronics America Inc. All rights reserved. Inspection Condition Panel inspection should be at a room temperature of about 25 degrees Celsius. The panel should be at a distance of about 8 in or 20cm from your eyes and is viewed from its front center perpendicular surface. Inspection angles can vary from 45 degrees left/right and/or 45 degrees up/down when measured from front center perpendicular. The ambient room illumination measured at the inspection table should be about 700 lx, which is about equivalent to 70 burning candles one foot away from the panel. Basically this is a bright office lighting condition.

103 © 2010 Renesas Electronics America Inc. All rights reserved. General Handling Procedures 1.The LCD module should be removed from the shipping box by holding the panel frame at the sides. Be careful to not grasp the circuit boards or cable connections. 2.Do not use any connector or cable to aid in removing the panel from the packaging. Also, be careful not to allow these to snag during removal. 3.To move the panel temporarily, the panel should always be placed on a flat, clean surface with the display side down and with the clear protective film in place. 4.Do not press or rub the display surface as damage may result. If it is necessary to clean the surface always use a clean, soft & lint free cloth with a ethanol based LCD screen cleaner. 5.Take all necessary pre-cautions to prevent Electro Static Discharge (ESD) as damage may result. 6.When handling, it is advisable to use the clear protective film provided with each display to protect against scratches to the outer surface polarizer. Use of adhesive type protection films is not recommended. 7.Remember, the panel is made of glass. Do not attempt to handle if broken.

104 © 2010 Renesas Electronics America Inc. All rights reserved. 1.Incorrect operation of this component may result in personal physical injury. Review & understand the following precautionary symbols: Do not remove or disturb any connection during operation as this would result in incorrect power sequencing and damage may result. Do not bend the lamp cables as breakage may occur resulting in failure of the lamps and possible exposure to high voltage electrical shock. Do not touch a working backlight as burn injuries may result. Do not subject the panel to shock exceeding 539m/s² for 11ms or pressure exceeding 19.6N as glass breakage may result. Incorrect operation will result in damage to the LCD or personal injury. Incorrect operation will result in electrical shock. Incorrect operation will result in personal physical injury. General Operating Precautions Caution symbols found in the LCD specification Examples:

105 © 2010 Renesas Electronics America Inc. All rights reserved. Environmental Precautions 1.Do not store or operate in high temperature, high humidity environments or where condensation is likely to occur. 2.When preparing to use a LCD panel stored in low temperatures, it is recommended to allow the LCD to warm in it’s original packing box for a period of time that insures slow warming. This is necessary to avoid condensation from occurring. NEC recommends 6 hours or more in the original packaging. 3.Do no store or operate in corrosive environments. 4.For long term storage use the provided anti-static bag and avoid exposure to sunlight & dust. Store at room temperature. 5.Do not operate in high magnetic fields as circuits may fail. 6.This product is not designed to be free from Radio Frequency Interference (RFI)

106 © 2010 Renesas Electronics America Inc. All rights reserved. General Mechanical Considerations 1.Install the LCD module using the provided mounting holes. Care should be taken to insure the mounting locations are in a true flat plane and that the hole centers are correctly located. Any undue stress to the LCD frame will cause problems with video uniformity and in worst cases may break the glass. 2.The torque for the mounting locations should never exceed 0.249Nm as distortion of the frame bezel may result. 3.Do not disassemble or adjust variable resistors as this will alter operation and void warranty.

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Renesas Electronics America Inc. © 2010 Renesas Electronics America Inc. All rights reserved. ID C22C: Flat Panel Displays Beyond the Basics Robert Dunhouse,

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