Power consumption - Page 34

Researchers say that exciton quenching and photon loss processes limit OLED efficiency and brightness. Organic light-emitting transistors (OLETs) are alternative, planar light sources combining, in the same architecture, the switching mechanism of a thin-film transistor and an electroluminescent device.

Trilayer OLET device and chemical structure

OLETs can be used to replace OLEDs in both display and lighting applications. According to new research, they are more than 100 times more efficient than equivalent OLEDs, and over 2 times more efficient than optimized OLED with the same emitting layer. There are still challenges for OLETs (the major one is operating voltage).

The STI Group is showing a package that has an organic solar cell and a white OLED. The packaging is a limited edition slipcase that holds a book, and it's made from environmentally friendly corrugated paper enhanced with various varnish effects, including an open-face corrugated inlay to offer an interesting contrast.

The OLED is a 20x20mm white OLED, and the solar cell is an organic solar cell. The solar cell only operates as a sensor (light detector) - the OLED is powered from a battery. All the electronics (including the OLED and solar cell) were provided from OES (Organic Electronics Saxony Association partners).

QuickLogic announced the verification of their Visual Enhancement Engine (VEE) and Display Power Optimizer (DPO) technologies with OLED displays for mobile devices. These technologies enhance the viewability of displays in low-brightness or bright-ambient-light conditions by dynamically optimizing video characteristics to provide a better user experience. They also allow the brightness to be lowered and thus enhance battery life.

QuickLogic's proprietary VEE technology enhances image and video quality by optimizing the dynamic range, contrast, and color saturation of content on the display on a pixel-by-pixel basis. This provides a superior viewing experience for the user under any ambient light condition. QuickLogic's DPO technology can significantly reduce display power consumption through intelligent control of the display brightness.

Researchers from the University of Florida has developed a new night-vision technology using OLEDs. They are using thin-film OLED panels to convert infrared light to the visible spectrum. The design has 7 separate OLED layers - each one amplifying the signal and converting it to the visible spectrum.

They say that a full-scale night vision can weight less than 125 grams and be very efficient. This can revolutionize night vision as we know it. They have currently made a prototype that's only 1 square cm in size, but in 18 months they hope to scale it up to a cell-phone display size, or even a car windshield. This research is funded by DARPA.

The kind folks over at Osram has sent us one of their new ORBEOS OLED Lighting panel for a review. The ORBEOS is a round (88mm diameter) glass panel that's only 2.1mm thick (it weights 24g). The efficiency is 25lm/W. The brightness of the panels is 1,000cd/m² with power input of less than a watt, and they should last around 5,000 hours. The panels are available now via OSRAM's
site, they cost €240 each. The panels were actually released back in November 2009, and OSRAM say that they are happy with the sales and interest so far.

OSRAM ORBEOS

Read on to see my impressions of this OLED panel, and how it compares to Philips' Lumiblade panels which were the first available OLED panels...

India's Council of Scientific and Industrial Research (CSIR) has announced a new $10 million project to develop LED and OLED lighting, with first versions of LEDs expected by March 2012. The LED chips will be packaged with phosphor coating and converted into white LED. The target for luminous efficacy of the LED chip is 25-50 lumens/watt.

After they finish the R&D phases, they plan to transfer the technology to an Indian LED chip maker and LED packaging companies.

Nippon Seiki has developed new technology that enabled 75% reduction in power consumption for PMOLED displays. They have already commercialized this with a 0.8" green monochrome OLED panel that will be shipping in samples this month. The company also plans to develop panels of other colors including white. It's not clear whether this technology can also be used to make AMOLED panels more efficient.

new green PMOLED vs regular PMOLED

Nippon Seiki says taht the new panel is as efficient as a LED-backlit LCD, and has the same visibility as their previous PMOLED panels. The lower power consumption was realized by making improvements to the structure of an organic EL element, production processes and manufacturing management.

Technocorp Energy (formed by ex-Kodak employees) will license Kodak's OLED Lighting technology from Global OLED Technology (LG's company that holds the 2,000 OLED patents bought from Kodak). Technocorp plan is to produce efficient OLED panels (70lm/W) at $64/m². This will take time and a lot of effort of course, and the company is looking for funding, partners and joint-ventures to achieve this goal.

Pocketnow reports that Microsoft's engineers chose black backgrounds in Windows Phone 7 because it will be very useful with AMOLEDs (it'll save a lot of energy because OLEDs do not use any power on black pixels). There's also the option for a white background, used to enhance readability.

It's great to hear that Microsoft expects most devices to have AMOLED displays, although this is not really a surprise - back in January we ran a story that Microsoft will advice device makers to use AMOLEDs...

Remember Samsung's flexible OLED for ID cards or passports? Bundesdruckerei is showing their e-passport that uses that AMOLED display at CeBIT. It still says "future product", but it seems to get getting closer to production every time we see it.

The display is a flexible 2" QVGA (240x320), 260K color OLED with a 10,000:1 contrast ratio. It is very low on power, and actually uses the RF power from the contactless reader - there's no battery at all here.