DLP Cubes vs. Flat-screen Displays
Contents
1. brightness adjustment Service Interval 1 2 per year 1 2 per year Availability of spare units sizes and 10 years resolutions change quite quickly Operation in 24 7 Max 0 5 1 year 10 years Total 9 2 A modular matrix of screens made up of LCD monitors or DLP cubes is generally controlled by a so called split controller which provides special graphic boards for incoming and outgoing signal sources RGB DVI LAN analog Video or IP Video With these graphics controller units it is possible to display all connected signals and sources on the large screen wall These signals can be PCs connected via RGB or DVi inputs applications running directly on the controller network sources and video signals for example The split controller should support real time display of the sources Further streaming video or video over IP should be decoded by hardware decoding cards inside the controller With a comfortable software solution like eyevis eyecon software it is possible to control and administer the complete system and all connected signal sources As mentioned before eyevis is one of only few manufacturers which can provide complete one stop solutions for any kind of professional large screen system eyevis is also famous for providing customised solutions and specially designed products for sophisticated projects eyevis GmbH www eyevis de Hundsschleestr 23 Seite 27 info eyevis de D2. For monitor wall applications a central IR sensor is used that the matrix of displays can be controlled by one single remote control No disturbing front control LED s for the displays Internal splitcontroller for a matrix of 10 x 10 displays with 2 x DVI 2 x RGB 2x video 1x RS 232 inputs and 1 x RS 232 output Excellent viewing angle without overhang of display housing Data based control software over RS 232 IR remote or on panel control Stable metal housing Stackable for monitor wall applications with an quick and easy mounting concept 2 1 New LED backlight LCDs One of the latest products in the eyevis LCD family is the LED backlit LCD Unlike conventional LCDs in previous years the LED LCD makes use of different technology in its backlight structure Its backlight structure is composed of LED light bulbs which are more efficient than CCFL Cold Cathode Florescent Lamps bulbs in terms of delivering a realistic graphic display It has many advantages compared to the traditionally used CCFL bulbs and increases the quality of the viewing experience eyevis GmbH www eyevis de Hundsschleestr 23 Seite 15 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays The LED backlit LCDs have a better color gamut giving way to a fine color display This feature of LED LCDs results in a realistic graphic output which is easy to
3. eyevis GmbH www eyevis de Hundsschleestr 23 Seite 25 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays 3 2 LCD DLP Comparison table eyevis Feature LCD Monitors Valuation DLP Cubes Valuation Image retention of Yes No static pictures MTBF Main parts Panel 50 000 h DMD 150 000 h Lamps UHP 10 000 h Lamps LED gt 65 000 h Aspect Ratio 16 9 4 3 5 4 16 9 16 10 Resolutions 1366x768 1024x768 1920x1080 1280x1024 1400x1050 1600x1200 1920x1080 1920x1200 Gap between Narrow bezel 14 0 3 mm 0 68 mm adjacent modules mm 28 mm Super narrow bezel 7 3 mm Image size per 40 46 52 with 50 56 65 67 70 display in inch narrow bezel 80 84 100 46 55 60 with super narrow bezel 65 70 82 only with broad bezel Installation depth 25 40 cm 1 00 1 60 m with room for technical eyevis GmbH www eyevis de Hundsschleestr 23 Seite 26 info eyevis de D 72766 Reutlingen Germany Tel 49 0 7121 43303 0 Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays installation behind the cube wall Control External or internal External or Controller internal Controller Installation Wall mount display Integrated or free rack or integrated standing Autom colour and available
4. of benefiting from your LED backlit screen The LCD LED backlight has small power consumption This is important for applications where the electrical power consumption has to be monitored and you can save a lot of money from this LCD s low voltage requirement Although it has smaller power requirement it is still efficient in delivering quality display outputs An LED backlit display can consume up to 45 less power than CCFL bulbs Also in terms of design the LED backlight LCDs offer various advantages they have a slim design with only 46 mm depth and a bezel of only 25 mm to meet space limitations for integration and installation This design is much deeper and offers a slimmer bezel than traditional CCFL backlit LCDs eyevis GmbH www eyevis de Hundsschleestr 23 Seite 16 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays EVEN IS 2 2 24 7 LCDs There are also LCDs available for 24 7 operation even with static image content But there are requirements and instructions that have to be taken into account Required measures Generally TFT panels are subject to different ageing processes This requires special countermeasures to minimize the early appearance of effects disturbing the quality of the displayed images uneven picture image sticking boundary line Besides certain software functions these are simple instructi
5. ventilation ducts to dissipate the heat produced by the displays of a monitor wall So if we make a direct comparison of the different technologies we can exclude the use of plasma displays from control room applications due to their sensibility for burn in effects their minor resolution and the wide gaps between the displays when used in a combined video wall Common projectors for office applications should also not be taken into account What is left for professional video wall applications are DLP cubes of professional LC displays Besides the display solution sophisticated large screen systems generally comprise a so called split controller including appropriate control management software To avoid problems of interoperability the preferable solution should be to receive all of these components from one provider One of the only manufacturers who are able to provide complete one stop solution is eyevis With its EC DLP rear projection cube series its EYE LCD series the Netpix graphics controllers and the eyecon wall management software eyevis is able to provide complete systems for any kind of control room application LCD monitors are already available with a relatively thin bezel which is especially important for modular video wall applications Eyevis offers these systems in 40 46 in WXGA resolution and from May onwards in native HD resolution and 52 in native HD resolution these are the EYE LCD4000M W EYE LCD4600m W o
6. 4 1400x1050 and 1920x1080 pixels Cubes with resolutions up to 1920x1200 pixels are already under development A disadvantage of the DLP cubes is the high performance lamp used for illumination These lamps have an MTBF of approx 10 000 hours To guarantee higher reliability of the systems they can be equipped with automatic double lamp systems i e the system automatically switches within seconds to a second spare lamp if the operating lamp breaks Cubes using alternative light sources for illumination LED provide a higher MTBF of gt 55 000 hours for the LED lamps and gt 100 000 hours for the power supply are already offered by the German manufacturer eyevis If you compare LED light DLP cubes to normal UHP lamp DLP cubes you have much lower operating costs as well as a more eco friendly solution as in the UHP lamps mercury is used eyevis GmbH www eyevis de Hundsschleestr 23 Seite 23 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays EVEN IS 3 1 Go Green Go LED eyevis is always ahead with their new developments so also with their new DLP rear projection cubes with LED light source These systems are available in 60 and 67 full HD resolution EC 60 LHD EC 67 LHD 50 70 and 80 SXGA resolution EC 50 LSXT EC 70 LSXT EC 80 LSXT and 70 WUXGA EC 70 LWXT Advantages of these systems High lifetime MTBF of g
7. 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays 3 3 Comparison of total cost of ownership This comparison takes an operation of 10 years into account the compared large screen technologies are LCD DLP Cube with UHP lamp and DLP Cube with LED light source The eyevis products for this comparison are e EYE LCD 6500 HD e EC 67 HD e EC 67 LHD These products were chosen because they have almost the same screen size and HD resolution The values that were taken into account for the comparison are e LED light source e UHP lamp e colour wheel e high voltage power supply e low voltage power supply e LCD Display e Energy e service technician e purchase costs DLP cubes with LED light source e purchase costs DLP cubes with UHP lamps e purchase costs LCD Displays Based on these values the following graph shows the differences in TCO eyevis GmbH www eyevis de Hundsschleestr 23 Seite 28 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays eyevis TCO in Euro TCO without purchase costs 35 000 00 30 000 00 Cubes with LED light 25 000 00 rn Cubes with 20 000 00 UHP lamps 15 000 00 LCD Displays 10 000 00 5 000 00 0 00 operation time years 4 2 3 4 5 6 7 8 9 10 Re
8. Comparison table 0 240snnnnnnnnnnnnnennnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nenn 26 3 3 Comparison of total cost of ownership 222u022004nnnnnennnnnnnnnnnnnnennnnnnnnnnnnnnnnnnnnnnnnnnn ran 28 eyevis GmbH www eyevis de Hundsschleestr 23 Seite 2 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays 1 Displays for professional applications 1 1 Flat panel displays LCD monitors The technologies used for large screen systems in professional applications are various nowadays flat panel displays are becoming more and more popular and available in the market Also the flat panel displays like LCD or Plasma displays are becoming more and more big so that they become more and more attractive for professional applications These professional applications could be control rooms digital signage advertising flight information displays visitor guidance systems But displays for professional applications cannot be purchased off the shelf from any electronic store because the Large screen systems for such applications should be ready for 24 7 operation i e they have to match the requirements of continuous long term operation and should comprise appropriate features As we already know the old CRT monitors suffered from a burn in effect when displaying static pictures This resulted in an imprint of a permanent im
9. December 2010 DLP vs Flatscreen Displays ey EVIS DLP Cubes VS Flat screen Displays eyevis GmbH www eyevis de Hundsschleestr 23 Seite 1 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays Content 1 Displays for professional applications uuruesnnnesnnnnnnnnnnnnnnnnnnnnnnnnnnannnnnnnnnnnnnnnnnnnnnannnnnannn 3 1 1 Flat panel displays LCD monitors 44srs00unnnennnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn 3 1 2 What is Image Retention Image Sticking Image Persistence Memory Effect Ghost mage sees ses ete AS A a a aa Mee densi eed ane eid aca 4 1 3 Is image retention permanent nsnseensnnnnsnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nn 5 1 4 Operating your GisplAay cc cece eeecceceeeeeeeaeeeesaeeseneecaeeeeaaeseeaeeseaeeeseaesseaaeeseeeeeseaeeseaaesseneeeeaes 9 1 5 Gonclusion a u re een nnd rnit 12 2 Professional LCDs made in Germany uunssessnnnnnansnnnnnnnannnnnannnnnnnnnnannnnnannnnnnnnnnnnnnnannnnnannn 14 2 1 NeWILED backlidht LCDs unsn nn 15 2 2 24 7 LODS erei r a ai an ann a an nenn 17 2 3 Measures to prevent premature damage to the display ersnsenrsennnnnnnnnnnnnnn nn 18 3 Comparing different display technologies DLP cubes and LCD monitors 21 3 1 Go Greeti Go LED a seen ee nennen 24 3 2 LCD DLP
10. GmbH www eyevis de Hundsschleestr 23 Seite 19 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays EVENS The display of image content with extreme contrast transitions should be avoided e g black white white black transitions Care for sufficient ventilation of the device please see the user manual for acceptable operating conditions Keep the device free from dust Especially the ventilation holes have to be checked every three months and cleaned if necessary eyevis GmbH www eyevis de Hundsschleestr 23 Seite 20 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays 3 Comparing different display technologies DLP cubes and LCD monitors Which technology to choose We have seen the advantages of the flat panel displays which are availability price and less space requirements But we have also seen that there are some disadvantages especially when displaying relatively still images If you respect the different precautions for the LCD monitors they could be an alternative for continuous operation like in control rooms The technologies most often used in control rooms of today and tomorrow are rear projection cubes based on DLP technology and LC displays Rear projection cubes are available with various screen sizes and resolution s
11. age in the display It was caused from the continuous display of a particular image content in the display for an extended period of time This causes a breakdown in the phosphors on the CRT and would result in the image being burned into the screen the burn in phenomenon What about this phenomenon at flat panel displays In fact Plasma displays also suffer from this effect and could not be used for continuous operation or for displaying static pictures What about LCD monitors As Plasma displays are not suitable for continuous operation especially when displaying static pictures we don t handle this technology in this paper eyevis GmbH www eyevis de Hundsschleestr 23 Seite 3 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays Burn in on PDP T Uneven light emission Light emission E g Damaged pn ee as Glass Fluorescent layer Separator _ Electrode __ Glass Sul Undamaged fluorescent Off cell On cell On cell On cell 1 2 What is Image Retention Image Sticking Image Persistence Memory Effect Ghost Image Like burn in on CRTs or Plasmas image retention image sticking image persistence memory effect ghost images is caused by displaying continuously static images on the screens over an extended period of time days weeks months For one phenomenon different terms are used but h
12. ave the same effect Continuous displaying static graphics could be for example a windows desktop of a PC label of a video window network overviews etc If you change the static content with a new one the previous one content could have been memorized in the background these images are sticked in or occur like a ghost image For example at airports this can be seen very often the logo of the airline remain as a ghost image in the background while the content in the foreground is already changed The image persistence or however you want to call it can also be recognized by dark lines following the original edges of the previous content This phenomenon occurs because the LCD crystals have a memory for their location to generate the colours of graphics If a different colour will be displayed in that location the colour will be off from what it should be and instead have a memorized image from what was previously displayed This problem affects the image content which does not change position colours or shape like e g displayed logos taskbars desktop icons or background images To explain it more technically When a fix image or repetitive sequence is shown over a sufficiently long period the electrically charged ions that are always present in the liquid crystal material can collect at the LCDs panel electrodes These ions cause a parasite electric field that affects the normal LCD behavior eyevis GmbH www eyevis de Hundsschleestr 23 Sei
13. d and the image retention will last forever Image retention occurs slowly but it will also disappear slowly Memory effect image persistence image sticking image retention affects every LCD monitor in the world because it is the nature of this technology when showing still images Of course there are professional manufacturers who integrate optimizing features into their monitors for continuous operation like special screen savers special cooling eyevis GmbH www eyevis de Hundsschleestr 23 Seite 5 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays systems regeneration modes etc but in order to be sure you have to take precautions it is like when you go in the sun you will use sun cream otherwise you will get a sunburn How fast you will get a sunburn depends on your complexion and if you are in direct sunlight or in the shadow etc It is similar to the image retention Which precautions can we take display a scheduled content if you have a matrix of displays in a video wall move the images around the different displays from time to time Means rotate your contents use screen savers At your desk you use screen savers for your PC or laptop monitor why don t you use screen savers for your large LCDs If you operate the system 24 hours and you have static pictures turn it off for at least 6 hours switch off backgrou
14. e display electronics since 6 years in 24 7 operation Experience and references in continuous operations with the display diagonals of 40 52 since 2 years in 24 7 operation LCD Display in diagonals of 40 64 with identical technology electronics available Modular configuration of the displays At failures the according assemblies can be changed by the user therefore a high availability is achieved LCD Control Software which prevents from memory effects with the possibility to schedule this function in time intervals Scheduler Function Screen Saver Running Line Heat is the major reason for the memory effect therefore the M version has integrated cooling channels to evacuate the heat from the displays to prevent from memory effects Also the displays are not designed fan less for this reason Panel regeneration mode and inverting of images for prevention of memory effects eyevis GmbH www eyevis de Hundsschleestr 23 Seite 14 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays The LCD Displays are available in the long term with the same design Manufacturing and R amp D of the devices in Germany Numerous mounting accessories are available therefore multifunctionally deployable Wall mounted in display rack as stand alone base stands for integration in interior design special constructions
15. er but keep in mind that there are only 4 raw LCD panel manufacturer for large size LCDs in the world and every display manufacturer has to buy from one of these 4 For every big screen diagonals not every of these 4 manufacturers offer size of bigger than 65 For professional applications never chose a fan less LCD as we have heard above heat is the major factor for image retention by reducing the noise you increase the risk of image sticking eyevis GmbH www eyevis de Hundsschleestr 23 Seite 9 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays evevis Test patterns for image retention Color Win Black White Window Pattern eyevis GmbH www eyevis de Hundsschleestr 23 Seite 10 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays ey EVIS Evaluation of Image Retention Full Display Grey Scale Image Area Type Line Type Typically at 50 Gray Examples of image retention Heat caused image retention eyevis GmbH www eyevis de Hundsschleestr 23 Seite 11 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis VISUAL SOLUTIONS December 2010 DLP vs Flatscreen Displays Daa ci Image retention because of static image 1 5 Conclusion Never use plasma displays for conti
16. general TFT displays are subject to various aging processes Image Sticking Boundary Line Therefore it is necessary to take appropriate counter measures in order to optimize the display quality of devices in continuous operation The activation of the hereinafter described actions is highly recommended and is a prerequisite for compliance with the warranty conditions Pixel shifting Continuous shifting of the entire image in different directions prevents image sticking At normal viewing distance this is almost not visible It is recommended to keep the factory set value of 4 pixels In this case the image is shifted by 4 pixels to the top bottom left and right The shifting of the image is performed in a 1 minute interval in steps of 1 pixel See the user manual for more information on the adjustment Dynamic pixel refreshing With dynamic pixel refreshing thanks to the intrusion of an artificial noise pattern image sticking is reduced This is done by a selective switching on off pulsation of the TFT cells The procedure is virtually invisible to the viewer a and increases display lifetime considerably when static image content is displayed We recommend to keep the factory set value Level 1 See the user manual for more information on the adjustment eyevis GmbH www eyevis de Hundsschleestr 23 Seite 18 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis Dece
17. hleestr 23 Seite 7 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays eyevis ons Line Type Image Retention Line type image retention is caused by aggregation of ionic impurity Aggregation of ionic impurity is caused by The moving speed of ions changes with each gray level The move direction is decided by internal electrical fields Line type image retention can result in actual damage to the LC display White area Black area White area Black area Glass LC Grass oF Same image is displayed for Se ionic impurity several months Aggregation of ionic impurity at edge of White and Black Are video images also critical for the image retention In principle it is ideal to run moving images on a LCD monitor but e g in video surveillance applications the video image is moving very often but the windows have borders or fix labels during all the time Also it is possible that the video images of a surveillance camera are also very static when nothing happens in the field of surveillance That means here you have to change the position of the different video windows from time to time and more than that also the borders have to be shifted regularly eyevis GmbH www eyevis de Hundsschleestr 23 Seite 8 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Di
18. interpret visually For this reason the LED backlight should be preferred in order to enjoy quality display output The LED backlight also has dynamic colour contrast and works great in fast moving transitions so detailed video streaming can be expected This advantage of LED backlighting results in a provision of a wider colour gamut compared to CCFL backlit LCD s LED s cover a broader range of red and greens up to 114 of the NTSC standards the full area of the RGB natural colour space Being able to display a more extensive range of colours means the attribute of colors is more natural or lifelike as they are closer to the human eye s colour perception range More significantly is where that increased range is in the areas of greens and reds which really should make an impact on how accurately and vividly images are rendered on screen This is of key importance for a colour critical workflow situation The LEDs also emit a more uniform light and degrade less quickly than CCFL backlight which results in a more stable brightness over the lifetime LEDs have other advantages too There s virtually no warm up time required so you don t have to wait for your monitor to stabilise to get correct colours Next they are more eco friendly in that they don t contain mercury Thirdly they re more robust as they re much less susceptible to sudden failure or burnout They can fade over time but even with regular use you re looking at many years
19. mber 2010 DLP vs Flatscreen Displays Soft Picture Mode This technology is similar to a blur or softener effect This intelligent scaling mechanism smoothes out extreme contrast transitions in the displayed image The procedure is virtually invisible to the viewer It effectively prevents Boundary Line Image Sticking which is likely to occur on sharp detailed transitions e g black to white We recommend to keep the factory set value Level 1 See the user manual for more information on the adjustment Adjustment of the Backlight Brightness The backlight of the screen is controlled with the Backlight Value or Image Adjustment in the OSD The backlight brightness in continuous operation should not exceed up to 50 in an ambient temperature of 40 C up to 75 in an ambient temperature of 35 C for a brightness level of 100 the ambient temperature should not exceed 30 C The factory setting for the backlight brightness is 50 We recommend to keep this setting this setting allows approx 270cd m for a panel with a maximum brightness of 500cd m The lower the setting for the backlight the more this extends the lifetime of the device and the more image sticking is avoided Additional Measures We recommend to switch off the device or to switch it to stand by mode for at least 4 hours per day using the RS232 interface We recommend to display changing contents e g by using moving images or video eyevis
20. n in effects with static images as plasma displays are they may suffer from similar effects like memory effects and ghost images This memory eyevis GmbH www eyevis de Hundsschleestr 23 Seite 21 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays effect does not turn up immediately it is reversible and in general disappears completely when the display is switched off for about 24 hours There are several methods available to avoid this risk One possibility is to switch the display off for 4 6 hours within 24 hours Another solution could be to switch the images from on display to another from time to time e g different wall layouts for night and day operation With a scheduler tool like the one integrated in eyevis eyecon wall management software this can also be done automatically Of course it is also possible to use a kind of screen saver The eyevis EYE LCD series provides a so called running line screen saver option This running line is only one pixel wide and can be adjusted regarding time and speed activity This kind of screen saver does not affect the readability of the information displayed For control room applications one should keep hands off cheap fan less LC displays since heat is one of the main reasons for the appearance of memory effects The displays from eyevis EYE LCD series provide several fans which use special
21. nds or logos from time to time or rotate them within the display turn off the system while you don t use it e g lunch break meetings evacuate heat from the displays as heat is one of the major reasons for the memory effect use power saving modes the more regeneration time you give to your display the better it will be protected eyevis GmbH www eyevis de Hundsschleestr 23 Seite 6 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays ey EVIS Examples of Image Retention Line type image retention Position mark Area type image retention Area Type Image Retention LC Capacity CL changes with temperature and if LC temperature shifts the voltage symmetry collapses with parasitic capacity CP between gate and cell electrode Interface of the alignment layer and the LC material is charged during long term operation Area type image retention is the effect of this electrical charge Since there is a limit in the amount of electrical charges by the resistance RA RL it can only be seen in dark gray level images and disappears over time when turned off Gate electrode Color Filter Charged up re electric charge Electrode Cy Alignment layer Liquid crystal v LC 3 Mm Alignment layer 9 Electrode 8 Ca TFT on Glass oO O Cross section view of LC cell Equivalent circuit eyevis GmbH www eyevis de Hundssc
22. nuous operation or to display static images because it will burn in at this is irreversible If you display on LCDs relatively still or static pictures it can cause image retention image sticking image persistence ghost images or memory effects these are in the most cases reversible In order to avoid memory effects you should not use fixed images and very frequently repeated clips When this is not possible you have to take necessary precautions This could be using screen savers switch the system off for certain hours check regularly image retention occurrence vary video clips as much as possible use moving images all this could help to reduce the risk of image persistence In addition to this it is eyevis GmbH www eyevis de Hundsschleestr 23 Seite 12 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays important avoiding static bars at image boundaries Also high contrast colours as black white are not recommended to be positioned next to each other in a static content or frequently repeated image High contrast when displaying video doesn t affect much but repetition of the same image is not recommended High contrast is accepted when there is a gradient from one colour to the other Regarding contents there are several rules which have to be respected like avoiding to use a combination of characters and background colour
23. ons for use concerning duration of operation and display settings Following screensaver functions have to be activated Pixel Shifting minimum 4 pixels Dynamic Pixel Refresh at least level 1 Soft Picture Mode at least level 1 Maximum Backlight Brightness according to the ambient temperature Additional instructions for use The backlight brightness in continuous operation must not exceed following values up to 50 in an ambient temperature of 40 C up to 75 in an ambient temperature of 35 C for a brightness level of 100 the ambient temperature must not exceed 30 C The maximum ambient temperature must not exceed 40 C An internal temperature sensor initiates the switch off of the device when the ambient temperature exceeds permitted values A status message of the temperature bit reports the value out of range Recommendations for enhanced lifetime of TFTs in continuous operation We strongly recommend to switch the device to Power Mode 2 power save for at least three hours within a 24 hour period via RS232 control This is a special screen eyevis GmbH www eyevis de Hundsschleestr 23 Seite 17 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays regenerating mode which switches the panel to white while the backlight is switched off 2 3 Measures to prevent premature damage to the display In
24. r EYE LCD5200M W They are available in wall mounting version EYE LCD4000 4600 5200W or as a modular stackable version EYE_LCD4000M EYE eyevis GmbH www eyevis de Hundsschleestr 23 Seite 22 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays LCD4600M EYE LCD5200M But with approximately 14mm per LC display the resulting gap is still much wider than with cubes which provide a gap of only about 0 3mm per cube As technology is continuously developing further the gap for LC displays has become smaller for example with the eyevis EYE LCD4600 SN with a gap of 7 3 mm display to display available in 1 366x768 pixels The aspect ratio of LC displays is always 16 9 whereas many software applications in control rooms produce images in 4 3 or 5 4 also very rarely 16 9 16 10 This results in distorted images when the displayed in full screen mode Or the display shows black zones bottom and top or on both sides if the image is displayed in native aspect ratio DLP cubes are available with all common aspect ratios 16 9 16 10 4 3 and 5 4 Further differences can be observed when we look at the available display resolutions for both technologies LC displays usually only offer two different resolutions these are 1366x768 and 1920x1080 pixels Here cubes can once more show their higher flexibility since they are available with 1024x768 128x102
25. s with a large difference in luminance Use colours with little difference in luminance alternate the character colours in complementary manner from green to red to blue alternate background colours every 30 minutes to a new position As we have heard heat is the top reason for image persistence it means avoid exposing your displays to high ambient temperatures try to evacuate the heat created by the displays At every time ventilation holes should always be dust and dirt free Also you should respect aspect ratios as for example if the signal is 4 3 and it should be shown on a 16 9 display keep in mind that there will be black areas and the borders of these black areas could persist when image is changed eyevis GmbH www eyevis de Hundsschleestr 23 Seite 13 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays 2 Professional LCDs made in Germany eyevis is offering LCD monitors for video wall applications lilke the EYE LCD4000 4600 5200W or M series as well as the EYE LCD4600 SN Advantages eyevis narrow and super narrow bezel LCDs compared to standard products on the market Special scaler for excellent presentation of images with resolutions which deviates from a native resolution of 1 920 x 1 080 pixels The converted images are represented in a very good representation Experience and references in continuous operations with th
26. splays 1 4 Operating your display Don t use your LCDs at maximum brightness and contrast levels as already mentioned above heat is the major factor for image persistence means operating your system at full power as well as the light and the heat from the backlights will have negative effects You should not operate your system over 80 brightness and contrast some manufacturers even don t recommend to go over 60 It is also important to think about the colour usage e g avoiding to display graphics with a high contrast black graphics on a white background or white graphics on a black background Use different colours and change them from time to time Like every machine or device also your LCD needs maintenance E g your coffee machine at home needs to be decalcified periodically otherwise it will break In other words service your system make sure that the holes and fans are dust and dirt free at all time Check your system frequently if there are signs of image retention as if you start counter measurements too late it could be problematic to remove image retention Such an image retention check could be done by showing a grey shade image on the display for example if you show a 50 grey image and you can see the boundary lines of image retention it means you will have to change the layout of your screen quickly or to start immediately the regeneration processes Every LCD monitor suffers from image retention one more as the oth
27. sult With DLP cubes with LED light source you can save MTBF in an operation of 10 years compared to DLP cubes with UHP lamps 25 313 70 or 85 02 With DLP cubes with LED light source you can save MTBF in an operation of 10 years compared to LCD Displays 14 305 50 or 76 24 eyevis GmbH www eyevis de Hundsschleestr 23 Seite 29 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22
28. t 60 000 h for the LEDs no lamps required no colour wheels required MTBF gt 150 000 h for the power supply High end Optical Performance High contrast High Colour Gamut RGB Illumination System excellent colour representation and contrast improved black values lower costs for operation and maintenance more eco friendly since no mercury is used better colour adjustment eyevis GmbH www eyevis de Hundsschleestr 23 Seite 24 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 eyevis December 2010 DLP vs Flatscreen Displays Comparison of standard UHP lamp colour wheel DLP cubes with LED light DLP cubes over 10 years 1 cube Component UHP lamp systems LED light systems Lamps MTBF 8 000 10 000 h gt 60 000 h Required spares 12 lamps 3 LEDs Colour wheels MTBF 25 000 30 000 h Required spares approx 4 colour wheels Power supplies 40 000 50 000 h gt 150 000 h BE 2x low voltage PS Required spares 2x high voltage PS Labour costs Approx Approx 15 interventions 4 interventions Total cost saving gt 50 LC displays have no lamps for illumination Here the light comes from the so called panel backlight which can be either LED based or a kind of tubular fluorescent lamp In general these panel backlights are indicated with an MTBF of about 50 000 hours The core of a DLP cube is the DMD Digital Micromirror Device chip with an MTBF of 100 000 hours
29. tandards Numerous of these cubes can be combined to almost seamless large screen walls The main advantage of these systems is their invulnerability for burn in effects with static image content Further these cubes offer several optimising features such as automatic double lamp systems or automatic adjustment of colour and brightness In addition to that the components used for these devices are designed for long term operation Another display technology primarily used in domestic environments are plasma displays These are excellent for the display of video data for consumers but not for control room applications Plasma displays are very likely to suffer from burn in effects already after short time when static images are displayed This can even happen with video images from cameras since they usually show the same area and much of the content remains unchanged Burn ins can also happen with On Screen elements of the camera signal like the camera number or channel ID Burn in describes an irreversible affection of the phosphor layer and therefore a sustainable defect of the device Lower costs when the system is purchased may now turn into the opposite In the recent past we observe an increasing number of large screen systems using a matrix of LC displays Here it is important to note that professional devices are used providing optimised features for long term operation Although LC displays are not so much endangered by bur
30. te 4 info eyevis de D 72766 Reutlingen Tel 49 0 7121 43303 0 Germany Fax 49 0 7121 43303 22 December 2010 DLP vs Flatscreen Displays S TI anmas tock information 1 3 Is image retention permanent Contrary to the burn in of CRTs or Plasmas image sticking is in most cases not permanent Therefore we can say it reversible while burn in is irreversible or permanent The liquid crystals have a natural state and can shift depending on the amount of current used to generate the required colour If these colours shift periodically the liquid crystals for that pixel will fluctuate enough that the image will not be memorized into the crystals In other words image retention can be reversed in most cases but in some cases the time you will have to wait until it is removed is long at least as long as the image was shown on the display This means you have to switch off the display completely turning off the backlight only is not sufficient During this switch off time the LCD panel will regenerate After this regeneration period you can turn it on again and the memory effect on your display will be removed But the exact regeneration time depends on the content you have shown and the duration of displaying this still content For example if you have displayed a static content for one year or longer it is possible that the image sticking could not be reversed because the physical structure of the liquid crystals might have change
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