Harry Potter is staring down the dark path of the Triwizard Maze next to Cedric Diggory in the fourth Harry Potter film. The two young men are tasked with making it through the dark maze at night fighting whatever enchanted obstacles cross their paths. Even as wands light up with spells, the colors in the scene are muted. Harry Potter is not the only film with this problem; current displays are ill equipped to handle the dazzling colors that filmmakers could use to tell their stories. More dimming zones in a display would have allowed fans to enjoy these intense scenes with a more beautiful and accurate picture of the magic happening onscreen.
Mini and micro LED displays have the capacity to utilize exceptional control enabled by local dimming and the increased number of dimming zones in the displays. Local dimming is a feature of LED displays that dims the backlight in different regions, or zones. Controlling each region individually improves image
appearance with higher contrast ratios where dark elements of an image appear darker. Dimming zones are the small groups of LEDs that are controlled to produce more or less light.
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The number of dimming zones in a display contributes directly to the display’s ability to be amazingly bright and purely black. Contrast ratio, another boasted feature of mini and micro LEDs, is the difference between the brightest a display can be and the darkest. A high ratio means that the brightness of the display is closer to what a viewer sees in real life. The demo produced by BOE Pixey for CES 2020 has a contrast ratio of >1,000,000:1.
Merging mini and micro LEDs with quantum dot technology, already on the market, enables brightness and color enhancements, leading to an overall better picture quality and surpasses the standards set by OLED technology. The BOE Pixey 75-in. mini LED TV displayed at CES had more than 10,000 local dimming zones compared to Samsung’s Q series, which maxes out at 100. The blacks are truly black and the colors extraordinarily vivid with thousands of dimming zones.
For enhanced image quality, and to completely utilize the full capabilities of high dynamic range (HDR), local dimming is necessary. The advancement of mini and micro LED technology allows for a massive amount of controllable dimming zones, resulting in crisper edges between light and dark areas of the image.
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A greater quantity of zones means improved optical performance of displays. Theoretically, each pixel will have the means to be dimmed sufficiently to establish a visually remarkable pixel-level contrast ratio. With the high quantity of dimming zones, the “blooming” effect seen in current LED backlit displays is significantly reduced. In displays using larger LEDs with fewer dimming zones, the coarse backlight allows light to reach areas of an image that are intended to be darker because the liquid-crystal layer of a display cannot block 100% of the backlight.
Tackling the blooming effect provides an additional benefit to designers. Due to the higher density that mini and micro LEDs allow, the distance between the backlight layer and the LCD layer of the display can be reduced, which aids in the reduction of light bleeding into an area of the image where it is not desired. Without the concern of light reaching dark areas, the LEDs can be driven at higher power levels to achieve brighter and more vivid colors. As a result, sections of images can be correspondingly bright or dark dependent on what is being displayed and the overall experience is enhanced for the viewer.
Whether it’s an intense scene in Harry Potter or a part of your favorite video game, dimming zones are raising the bar for the viewer’s experience. It is possible for incredibly brilliant bright spots to be next to deep blacks. That’s what those dimming zones are for and why mini and micro LED backlights are ready to change the game.
Get to know our expert
MATT GERBER is CEO of Rohinni, a company focused on merging lighting applications with electronics manufacturing. He has more than 30 years of global high technology experience concentrated in the computing technology markets and is currently a Rohinni board member and its CEO. Prior to Rohinni, Gerber was a board member and CEO at Digital Fortress, a Seattle based provider of hybrid cloud and colocation services; a board member and EVP at 2nd Watch, one of Amazon Web Services largest global business partners; a board member and CEO at IT-Lifeline, one of Amazon Web Services first business partners; and a board member and CEO at SprayCool, a provider of thermal management technologies for high-performance computing applications. Gerber holds a bachelor’s degree in electrical engineering from the State University of New York at Stony Brook and a master’s of business administration with distinction from Hofstra University.
