FMM - Page 8

Samsung is aiming to improve their AMOLEDs in the near future. They claim they will double the efficiency (from 20cd/A to 40cd/A), the lifetime (from 50,000 to 100,000 hours) and the power consumption (from 62W to less than 30W). Samsung will use advanced color pattern methods to overcome the current FMM method large-size limitation. They will also move from glass encapsulation to thin-film, and apply Oxide substrate. They will also use only triplet OLED emitters instead of using both singlets and triplets.

Samsung has recently began to construct their new 5.5-Gen AMOLED plant, which will start production in July 2011. Samsung plans to invest $2.2 billion on that plant that will have 3 production lines (1300X1500mm). Having a larger wafer size results in better efficiencies for both small and large panels (such as 30" or 40" OLED TV panels). Samsung did not say whether the new methods will apply in the new plant only, or also in the current one.

Back in CES 2010, Samsung has shown a transparent-laptop prototype, with a 14" display. Today they are revealing the structure of that display. The screen has a 960x540 resolution, and a brightness of 200cd/m².

The top-emission OLED panel uses a LTPS TFT for its drive element. About 75% percent of each pixel is transparent, says Samsung, and this can be achieved by forming drive elements and organic EL elements (anode electrode, luminescent layer) on gate or source wiring. The OLED elements are made by using a metal stencil mask, and the cathode electrodes are made from a newly developed metal material.

OLEDNet has posted an interesting article talking about OLED production yields in evaporating deposition equipments. They say that current TFT-LCD production processes take around a minute to complete, while AMOLED processes take around 4 minutes. Both Samsung and LG are developing new ways to make this faster (Samsung is developing a vertical evaporating deposition system, while LG is working on a horizontal one). But even those new methods will still take around 2 minutes.

White-OLED panel, Fraunhofer

OLEDNet suggests using a white OLED with a color filter. White OLED can reduce the evaporating deposition time to one minute in In-line evaporating deposition method because it could produce the light emitting floor using RGB and other parts in only one sheet of shadow mask.

There are two major problems with this approach. First of all, white AMOLED materials aren't ready for this yet (but they will be soon). Second, you lose color quality. But OLEDNet claims that such displays will still be better than TFT-LCDs in terms of contrast. OLEDNet concludes that developing white OLED materials should be the core technology for the future of AMOLED displays.

AU Optronics are showing a new 14" OLED panel, with full HD resolution at 157 ppi. The brightness on an all-white image is 200cd/m2, the contrast is 100,000:1, the frequency is 120Hz and they say it's shows 72% NTSC color gamut. 

AUO claims that this panel are ready for mass production. They are using an evaporation method with a metal stencil mask.

Samsung Mobile Displays announced 14.1" and 31" OLED TV panels, using what they call Fine Metal Mask (FMM) technology. Those panels are 'ready for production'.

The 14.1" WXGA is aimed for laptop computers. It's got a 1366x768 resolution, 200cd brightness, color gamut of 107% NTSC and a 1,000,000:1 contrast ratio. The whole panel is just 2.7mm thick.

The 31" FHD (1920x1080) TV panel is using LTPS, and also has 200cd brightness,  color gamut of 107% NTSC and a 1,000,000:1 contrast ratio. The panel is thicker at 8.9mm.

Samsung 31-inch HDTV

The last display is a 40" FHD OLED TV, with pretty much the same features as the 31" TV. This one is not 'ready for production', yet.

Samsung is showing a window made from OLED Panels (12.1", 840x504 with 200cd/m2 luminance). The panels are 30% transmittive - which means they are transparent. You can see in the image to the right how it looks. From the back the window is almost (70%) transparent. 

The OLED panel employs LTPS TFTs for the drive element. The device structure is a top emission type, and organic EL materials for RBG colors are separately applied by using a metal mask. Samsung declined to comment on the details of the technology that realized the high transmittance.