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Understanding QLED:. Quantum Dot Technology. QLED – a New Display Technology?. QLED is a new approach to LCD display technology, produced by Samsung. QLED takes existing LCD technology, and enhances it to levels that were previously impossible: Wider color gamut Enhanced brightness
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Understanding QLED: Quantum Dot Technology
QLED – a New Display Technology? • QLED is a new approach to LCD display technology, produced by Samsung. • QLED takes existing LCD technology, and enhances it to levels that were previously impossible: Wider color gamut Enhanced brightness High dynamic range • QLED can be built on existing manufacturing, making it a more cost-effective approach to high performance display technology. • QLED is based on quantum dots, but replaces the organic components with metallic ones, for even greater performance than standard quantum dots.
Discovery of Liquid Crystal • Friedrich Reinitzer (1858–1927, Austria), discovered the liquid crystalline nature of cholesteryl benzoate, extracted from carrots. • As the temperature of the material changed, it also changed transparency and color. • This principle, that materials can be liquid at room temperature and manipulate light, makes LCD displays possible. • Liquid crystals do not emit light directly. A liquid crystal display uses the light modulating properties of liquid crystals to control light from an external source.
LCD Construction Principle • Two pieces of glass with polarizing films applied are assembled together with a carefully controlled gap between them. • Liquid crystal material is introduced in the gap. The molecules adjacent to the glass will align to the polarizer, resulting in a helical structure between the two glass plates. • As light strikes the first plate, it is polarized. • The molecules in each layer then guide the light through the display, changing the angle of polarization to match.
LCD Construction Principle • When light reaches the final layer of the crystal material its plane of polarization will have rotated 90 degrees, and now matches the plane of the top polarizing film, exiting the glass. • If we apply an electric field to liquid crystal molecules, they untwist. • When they straighten out, they change the angle of the light passing through them so that it no longer matches the angle of the top polarizing filter. • Consequently, no light can pass through that area of the LCD, which makes that area darker.
LCD Color Production • For an LCD monitor to produce color, each pixel on the screen has to have three sub-pixels, each being a primary color (red, blue and green). By taking each of the three colors, and varying the intensity of each, then blending it all together, the color LCD has a large possible palette of colors.
LCD Backlighting • The illumination source in most flat panel LCDs is a backlight, a light source placed behind the first polarizing layer, that provides the light needed for the display. • Today, this is commonly done with LEDs, hence why some call them “LED TVs”. • LEDs allow for several benefits: Uniform light with no color decay over time Low power consumption Low heat output Longer operational lifetime (50K hours or more) Low weight Compact size for smaller display form factors
LCD Backlighting Configurations • Edge lit LED Edge lit backlights use a ring of LEDs around the outside edge of the LCD panel. This allows for the display to be manufactured with a very shallow depth • Direct lit LED Direct light LED backlights use an array of LEDs placed behind the LCD panel, like a standard CCFL backlight. This type of backlight is thicker than an edge lit, but offers the potential for better contrast.
LCD Backlighting • Since the LED backlight is made up of many individual LED lamps, and LEDs can be varied in light output by manipulating the input voltage, an LED backlight can achieve what is known as localized dimming. • Localized dimming is the reduction in backlight output in coordination with the video signal. • Areas of the image that are darker will have the backlight dimmed to increase the level of black in the picture.
Quantum Dots – Quantum Phosphors • Quantum dots enable wide color gamut, higher brightness, and increased dynamic range by providing LCDs with an ideal light source. • The quantum dots are nano-sized crystal particles of phosphor, which can be tuned to produce specific wavelengths of light by varying their size. • The quantum dots are embedded into a film, that can replace the diffusion film traditionally used with LCD backlights.
Quantum Dots – Quantum Phosphors • The white LEDs in a quantum dot based LCD are replaced with UV blue LEDs. The blue light combines with red and green light produced from the quantum dots to create the illumination used by the LCD.
Quantum Dots: High Dynamic Range • HDR is a set of techniques used to reproduce a greater dynamic range of luminosity than possible using traditional digital imaging. • The aim is to present the human eye with a similar range of luminance that we see in nature. The human eye, through adaptation of the iris and other methods, adjusts constantly to the broad dynamic changes ubiquitous in our environment. The brain continuously interprets this information so that a viewer can see in a wide range of light conditions.
What is Dynamic Range? • Display contrast is the difference between how dark and bright it can get. • Dynamic range describes the extremes in that difference, and how much detail can be shown in between. Think of grey scale segments. • Just expanding the range between bright and dark in a display is insufficient to improve a picture's detail. It can ultimately only show so much information based on the signal it's receiving. • Current popular video formats, including broadcast television and Blu-Ray discs, are limited by standards built around the physical boundaries presented by older technologies. • Black is set to only be so black, and white could only get so bright within the limitations of display technology. • While display technologies are improving, current video formats can't take advantage of it. Only so much information is presented in the signal, and a display capable of reaching beyond those limits still has to stretch and work with the information present.
What is HDR? • HDR (High Dynamic Range)removes the limitations presented by older video signals and provides information about brightness and color across a much wider gamut range. • Besides the wider range, HDR video contains more data to describe more steps in between the extremes. • This means that very bright objects and very dark objects on the same screen can be shown (if the display supports it), with all of the necessary steps in between described in the signal and not synthesized by the image processor. In other words, more shades of grey. • HDR produces deeper and more vivid reds, greens, and blues, and can show more shades in between. • Deep shadows show more detail and aren't simply black voids. • Bright shots shows fine details and aren't simply sunny, vivid pictures
Quantum Dots: Colorspace / Gamut • A colorspace is a standard that defines a specific range of colors that a specific technology is able to display, with maximum red, green and blue points, mapped to sit inside the full CIE XYZ space. • The space within the full CIE XYZ space that a particular colorspace covers is called its gamut. • No three points on the chart can cover 100% of what the human eye can see
Rec. 709 Color Space • Rec. 709is the international recognized standard video color space for HDTV with a gamut almost identical to sRGB. • For broadcast it is defined in 8-bit depth, where black is level 16, and white is level 235. • 10-bit systems are common in post-production, as typically the source from camera is of a much wider gamut and bit depth than Rec. 709. • In this case levels are between 0 and 1023 in post, but the result is mapped to broadcast standard 8-bit 16-235 when creating deliverables.
DCI-P3 Color Space • DCI-P3 is a wide gamut video color space introduced by SMPTE (Society of Motion Picture and Television Engineers) for digital cinema projection. • It is designed to closely match the full gamut of color motion picture film. It is not a consumer standard and is only used for content destined for digital theatrical projection. • Few monitors are able to display the full DCI gamut, but DCI spec projectors can.
Rec. 2020 Color Gamut • The newest generation standard color gamut is the impressively large Rec. 2020 standard. • It is a significant 72% larger than sRGB / Rec. 709 and 37% larger than DCI-P3. • The color gamut is extremely wide and the color saturation extremely high. • There is little existing content for Rec.2020 and few displays (yet) that will show it but that is increasing exponentially.
Quantum Dots Enhance Color Gamut • Quantum Dot technology allows LCD displays to produce a color volume equal to or potentially greater than, the DCI P3 and Rec. 2020 color spaces. • Users should always seek to select a display that can produce a colorspace at least as wide as the content they show, but wider if possible, for the most accurate representation.
OLED Lower black luminance: emissive technology, pixels turn off Lower maximum brightness: 500-700nits Thinner display: no backlight, fewer layers Flexible (depending on manufacturer) Strong possibility of burn in Limited lifespan – 20,000 hours High color volume Expensive Not proven for commercial applications A Brief Comparison… • QLED Higher black luminance: transmissive technology, pixels block backlight higher maximum brightness: 1000-2500nits No burn in Longer lifespan – commercial up to 60,000 hours Highest color volume – 100% DCI-P3 Lower cost Proven technology – LCD with new backlight
QHH Series QH55H (55”), QH65H (65”) • Full commercial QLED LFD, providing accurate true-to-life color, with one billion different variations available. Key Features: • 3840x2160 UHD 4K resolution • 100% color volume and full HDR support • 600 nit (peak 1500 nit) edge lit 16/7 QLED LFD • 500 nit (peak 1000 nit) portrait mode • Bezel-less design • No gap wall mount capable • SSSP 5.0 / S5 Player (SoC) onboard with Tizen 3.0 • Wi-Fi / BT onboard with integrated Miracast screen mirroring
For more information, contact your local Samsung representative, or Brawn Consulting: 1 (866) 754-6450 samsunglfd@brawnconsulting.com Jonathan Brawn Principal Brawn Consulting E: jonathan@brawnconsulting.com Brian Kosich Engineering Services Manager Brawn Consulting E: brian@brawnconsulting.com Thanks for Attending!
