2025-02-08
The keyword 'contrast' that we often mention mainly appears in two scenarios.
One is the hardware specifications of the monitor. Contrast is an inherent property of displays and is one of the important indicators for measuring their quality. This indicator is determined by the characteristics of the display itself and cannot be adjusted by users. It is usually listed directly in product specifications in the form of "500:1". From a numerical perspective, the larger the number in front of the ratio, the higher the contrast, which also indicates that the display has better performance in this indicator.
The second is the adjustable contrast parameter in the image editor and monitor adjuster. When adjusting the 'contrast', the contrast between light and dark in the image will change accordingly. In this case, the higher the contrast parameter, the better. Different users will adjust it according to their preferences or specific needs.
What we are going to talk about here is the first type, which is the inherent hardware indicator of the display - contrast.
What is contrast?
For a monitor, contrast refers to the ratio of the brightest white to the darkest black that can be presented at the same point on the screen. This ratio is a key indicator of the difference in brightness levels that a monitor can provide.
For example, if the maximum brightness of a monitor can reach 500 nits and the minimum brightness is 1 nits, the contrast ratio is expressed as 500:1. This indicates that there is a 500 fold difference between the highest and lowest brightness that the monitor can produce on the same screen.
What are the benefits of high contrast?
The high contrast feature of a monitor means it can provide a wider range of brightness options. From the perspective of screen display effect, high contrast helps to enhance the screen's ability to represent brightness and darkness, thereby enhancing the sense of hierarchy and depth of the image.
Specifically, on high contrast displays, users can clearly observe both dark and bright details in the image, and even keenly capture subtle differences between closely related black colors.
Comparison Figure-04. PNG High contrast displays can display detailed image information between similar black colors, while low contrast displays may result in uniform and consistent black areas, lacking visible differences.
Micro OLED is inherently high in contrast
OLED has inherent excellent performance in contrast. OLED displays have the ability to independently light up and turn off at the pixel level. When presenting black images, their pixel light sources can be completely turned off, achieving an absolute black display effect. Silicon based OLED uses OLED as the display element and single crystal silicon as the back plate. This unique structure not only inherits the outstanding advantages of OLED panels, but also makes it extremely outstanding in pixel density. Under the same panel size, its pixel count can reach ten times that of traditional OLEDs, and it can display clear and realistic images.
Digital drive provides superior contrast performance
Digital drivers have advantages in contrast performance of silicon-based OLED microdisplays. In silicon-based OLED microdisplays, the current required for each pixel is very small. For some low brightness pixels with adjacent brightness levels, the current difference is often very subtle. How to make these low brightness pixels that are similar but different emit the correct light has become a challenge.
Analog driving controls the current by adjusting the voltage of each pixel driving transistor. This subtle difference in current makes it difficult to accurately distinguish analog signals, which may result in similar low brightness pixels being incorrectly assigned the same or difficult to distinguish brightness values in image display, and the image may appear to have low contrast. Even if there is a difference in brightness between the brightest and darkest areas, due to the lack of sufficiently delicate brightness levels, the transition between light and dark in the image appears quite abrupt. For example, some subtle shadows and object contours in the dark areas of an image cannot be accurately presented, and these dark areas become "flat" overall, reducing details and directly affecting the contrast performance of the image.
The digital driver controls the brightness by adjusting the ratio of the lighting and extinguishing time of each pixel. This control method does not rely on distinguishing small differences in current. For pixels of various brightness levels in silicon-based OLED microdisplays, no matter how small the required current is, digital drivers can accurately adjust the time ratio of pixel lighting and extinguishing through digital signals to restore accurate brightness levels. Even low brightness pixels still transition step by step, with clear details. This helps to enhance the difference between the dark and bright parts of the image, making the contrast of the entire picture more realistic and intense, and improving contrast performance!
Comparison Figure-03. png
In the application of silicon-based OLED microdisplays, excellent contrast performance plays a multifaceted and undeniable role, which is fully reflected in practical applications in many fields.
For example, in VR and AR applications, high contrast is one of the key elements in providing immersive experiences. In VR game scenes, players are in a virtual world where high contrast ensures that weak light and environmental details are clearly visible when facing dark or shaded scenes. In AR applications, the integration of virtual elements with real scenes requires displays to accurately display content of different brightness levels. High contrast allows virtual navigation arrows, information prompt boxes, and other elements to naturally overlay on top of the real scene. Whether outdoors in strong light or indoors in low light, users can clearly see these virtual elements, achieving a more realistic and smooth augmented reality experience.
For example, in the military field, night vision devices with high contrast can make it easier for soldiers to detect targets in the dark while performing night missions. In the aerospace field, cockpit displays require pilots to quickly and accurately read instrument data under various lighting conditions. During medical surgery, medical display devices can clearly display the subtle structures of internal tissues of the human body with high contrast
The contrast ratio of silicon-based OLED microdisplays, as a key hardware indicator, reflects its important position in modern display technology, both in terms of its own characteristics and application advantages in various fields. The digital driven micro display technology upgrade led by Yunguang Technology is driving new display technologies towards a new direction of higher quality and more accurate display.
