How to choose outdoor sunlight readable LCD display monitor?

Introduction

When display devices are brought outside, oftentimes they face the brightness of sunlight or any other form of high ambient light sources reflecting off of and overwhelming the LED backlight's image. With the growth of the LCD panel industry, it has become more important than ever to prevent the sun's wash out of displays used outdoors, such as automobile displays, digital signage, and public kiosks. Hence, the sunlight readable display was invented. 

High Brightness TFT LCD

One solution would be to increase the luminance of the TFT LCD monitor's LED backlight to overpower the bright sunlight and eliminate glare. On average, TFT LCD screens have a brightness of about 250 to 450 Nits, but when this is increased to about 800 to 1000 (1000 is the most common) Nits, the device becomes a high bright LCD and a sunlight readable display.
Doing this is an affordable option for enhancement of image quality in the outdoors, including features like contrast ratio and viewing angle, in a common use setting like with phones. 

Since many of today's TFT LCD display devices have shifted to touchscreens, the touch panels on the surface of LCD screens already block a small percentage of backlighting, decreasing the surface brightness and making it so that the sunlight can even more easily wash out the display. Resistive touch panels use two transparent layers above the glass substrate, but the transparent layers can still block up to 5% of the light.

In order to optimize the high brightness of the backlight, a different type of touchscreen can be used: the capacitive touchscreen. Though it is more expensive than the resistive touch screen, this technology is more ideal for sunlight readable displays than the resistive due to its usage of a thinner film or even in-cell technologies rather than two layers above the glass of the display, and therefore, light can pass more efficiently.

Disadvantages of High Brightness LCDs

However, with this method comes a list of potential problems. Firstly, high brightness displays result in much greater power consumption and shorter battery life. In order to shed more light, more power will be needed which can also consequently result in device overheating which can also shorten battery life. If the backlight's power is increased, the LED's half-life may also be reduced.

Second, the brightness bring heat problem for electronic devices: Higer brightness, more power consumption and Heat, it's disturbing.

Then, While in bright exterior light settings, these devices reduce eye strain as the user attempts to view the image on screen, the brightness of the display itself can also cause eye strain, seen as the brightness may overwhelm your eyes. Many devices allow the user to adjust brightness, so this concern is oftentimes not too severe.

Finally, High brightness display cannot be used if outdoor environment is very sunny. The intense sunlight shines on the screen, and the strong reflected light will make the display screen hard to see clearly.

Transflective TFT LCD

A recent technology falling into the sunlight readable display category is the transflective TFT LCD, coming from a combination of the word transmissive and reflective. By using a transflective polarizer, a significant percentage of sunlight is reflected away from the screen to aid in the reduction of wash out. This optical layer is known as the transflector.

In transflective TFT LCDs, sunlight can reflect off the display but can also pass through the TFT cell layer and be reflected back out off a somewhat transparent rear reflector in front of the backlight, illuminating the display without as much demand and power usage from the transmissive nature of the backlight. This addresses both the issues of wash out and the disadvantages of high brightness TFT LCDs in high ambient light environments. Because of its transmissive and reflective modes, this type of device is very useful for devices that will be used outdoors but also indoors.

While it does greatly reduce power consumption, transflective LCDs are much more expensive than high brightness LCDs. In recent years, the cost has decreased, but transflective LCDs continue to be more costly.

Surface Treatment: AR AG

In addition to adjustments to the internal mechanics of LCDs, it is possible to make devices more sunlight-readable using surface treatments. The most common are anti-reflective (AR) films/glass and anti-glare processing.

Anti-reflective focuses on depositing multiple transparent thin film layers. With the thicknesses, structures, and properties of each individual layer composing the film, reflecting light wavelengths are changed, and thus less light is reflected.

When anti-glare is used, reflected light is fragmented. Using a rough surface as opposed to a smooth one, anti-glare treatments can reduce the reflection's disruption of the actual image of the display.

These two solutions can also be combined, which is greatly useful in outdoor displays.

Head Sun is the wholesale industrial lcd panel factory, if you need any LCD display, please contact our team.