Power consumption - Page 18

DisplayMate posted yet another interesting display shoot-out, this one testing Samsung's new QHD (2560x1600) Super AMOLED displays used in the upcoming Galaxy Tab S (8.4 and 10.5) tablets. As these displays are very similar to the GS5 display, it's not surprising that DisplayMate found those tablets to offer the best performing displays ever. This is yet another testimony to how great OLED displays are - and the rate of improvement in OLEDs is very rapid.

As DisplayMate found out, the Galaxy Tab S establishes new records for best Tablet display performance in: Highest Color Accuracy, Infinite Contrast Ratio, Lowest Screen Reflectance, and smallest Brightness Variation with Viewing Angle. These are also the highest resolution tablets at QHD.

According to UBI Research, the AMOLED market reach $2.3 billion in Q1 2014, up 42% from Q4 2013 (which was a soft quarter, 36% lower than Q3 2013). Samsung Display is still of course the major AMOLED producer.

LGD's market share was only 2% - producing flexible OLEDs and 55" OLED TV panels. But UBI expects LGD's market share to expand gradually. UBI says that LGD sold 50% more OLED TVs in the quarter compared to Q4 2013 (this is by revenue, which means that shipments almost doubled as the price keeps dropping). UBI expects LGD's OLED TV sales to grow by more than 60% in Q2 2014 as Chinese TV start marketing TVs with LGD's OLED panels, and LG Electronics expand OLED TV sales to more countries.

In January 2014, Sharp unveiled 7" WXGA MEMS-based displays, promising to release them within six months. Last week during the SID conference, Sharp unveiled new prototypes, saying that they will start shipping those displays in Q4 2014 (yes, still half a year away).

Sharp's display use an IGZO backplane and MEMS technology developed by Pixtronix (a subsidiary of Qualcomm). The 7" 1280x800 panels offer a color depth of 24 bits and a 122% NTSC color gamut. Sharp says that this display is very power efficient - with full color it consumes less than half the power an an LCD panel. A monochrome display will use 1/10 of the power used by an LCD.

On March 2014, Konica Minolta announced it developed the world's most efficient OLED lighting panel - at 131 lm/W. Only two months later, the Japanese company announced it developed an even more efficient panel at 139 lm/W.

Konica's new panel has an emitting area of 15 square centimeters, a lifetime of 55,000 hours (LT50) at a brightness of 1,000 cd/m² and a CRI of 81. The color temperature is 2857K.

Universal Display report several OLED technology advances at DisplayWeek. First up, the company is showing several advances in OLED lighting. UDC is presenting a new approach to make white OLEDs. The panels are based on RGB stripes, each controlled with a separate current driver. UDC says that this approach potentially improves the OLED panel performance, manufacturing yield, brightness uniformity and color-tunability.

UDC calls this new architecture "RGB monochrome striped", and they demonstrate a 15x15 cm color-tunable white OLED that features an effifacy of 63 lm/W and a color temperature of 3000K. UDC is also showing a 100 lm/W all-phosphorescent warm white OLED with a lifetime (LT70) of 60,000 hours at 1,000 cd/m². Finally, UDC is also showing a remarkable high R9 warm white WOLED with CRI of 96.

Knockr is a new (and free) Android application that enables lock-screen gestures. The idea is that you can setup your phone so that a certain gesture opens a specific application. Knockr only works on devices with OLED screens - because it actually does not turns-off the display on the lock screen, it simply turns it black. On an LCD display, there will be a significant battery drain...

As more and more phones adopt OLED displays, we can expect software to take advantage of the OLED features. In the past few weeks we've seen two interesting patents (here and here) that detail innovative ways to save power on OLED displays.

Researchers from Seoul National University developed a new algorithm that remaps gray levels in image pixels so the image consumes less power on an OLED display. The researchers say that this algorithm can save about 10% while actually enhancing the contrast by 9%. The algorithm is linear and can be applied in real-time to high resolution videos.

The algorithms analysis the histogram of the image and changes the gray levels while maintaining the contrast. The key idea is that a large number of gray levels are never used in the images and these gray levels can be effectively exploited to reduce power consumption. To maintain the contrast, the algorithm takes into account the object size in the image to which each gray level is applied - so it does not perform changes to large objects.

Researchers from the University of Southern California developed a new software platform that can automatically rewrite web pages and web applications so that they consume less energy on OLED pages (i.e. reduce average pixel brightness). They report that using the software can achieve a 40% reduction in display power consumption.

The software, called Nyx, changes the colors of the web pages (or application) by choosing a new and efficient color scheme. The clever part is that the software chooses colors that are more efficient but that still maintain the color relationships between neighboring HTML elements as before.

LG Chem had a large presence at L+B 2014, and the company sent us a few photos and a video of their OLEDs in action. In the past few weeks, the company announced new 320x110 mm panels and also the world's largest OLED at 320x320 mm. All of their new panels feature an increased lifetime (to 40,000 LT70) and a high CRI (over 90).

LG Chem also revealed their efficiency roadmap. Currently all their panels feature 60 lm/W. They already developed 100 lm/W panels and these will be released commercially later in 2014. By 2016 the company hopes to reach 140 lm/W. The standard luminance of the company's panels is 3000 cd/m², but they can also supply panels with 5,000 or even 8000 cd/m² (this decreases the lifetime, though).

Last month Samsung unveiled the Galaxy S5 with its 5.1" FHD (432 PPI) Super AMOLED display. The phone is set to launch globally on April 11th, but my friend Raymond Soneira from DisplayMate received a GS5 from Samsung to test the display. And his conclusions? The GS5's display is a major improvement over the GS4 display. In fact, the GS5's AMOLED is the best mobile display ever tested at DisplayMate, outperforming all other OLED and LCD displays.

But just how is the display better than the 5" Full-HD one on the GS4 and every other mobile display on the market? DisplayMate says that the new display is features the highest brightness, the lowest reflectance, the highest color accuracy, the highest contrast rating in ambient light and the smallest brightness variation with viewing angle. That's quite impressive!