What Is a Sunlight Readable Display, and How Does It Work?

The term “Sunlight Readable” refers to a display that can be viewed in high ambient light settings, such as direct sunlight. Standard screens are difficult to observe in direct sunlight, as the brightness of the sun is far more than the brightness of the display. Reflections on the LCD obliterate the images. Outdoor applications, vehicle computers, and public kiosks frequently demand sunlight viewable displays.

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What exactly is a TFT LCD?

Before addressing the following questions, it would be prudent to understand how a TFT LCD operates briefly. An LCD panel is included in every monitor or touchscreen computer. You are now viewing the LCD panel. This panel is composed of a thin layer of TFT LCD pixels, each of which contains a rectangle in each of the three primary colors. With a drop of water on the monitor, you can see the individual pixels. The drop enlarges the pixel area and reveals a rectangle in red, blue, and green. Each red, blue, and green rectangle has a little lens that can be adjusted to let in varying quantities of light. Thus, the colors seen on your monitor are determined by the amount of light traveling through each pixel’s changeable red, green, and blue elements.

The light you see is not emitted by the pixels themselves but by the backlight behind them, which is a sequence of properly spaced LEDs that emit white light projected through the LCD pixels. When you look at your monitor, you cannot see the individual backlight LEDs because a layer of light-diffusing material separates the LED backlight from the LCD pixel layer. The light-diffusing material disperses the light emitted by each backlight LED, preventing them from appearing as glaring spots on your display.

To summarize, an LCD panel is comprised of three layers: a TFT LCD pixel layer, a diffuser layer, and an LED backlight layer. It’s worth noting that certain LCDs use edge-lit illumination, but the principles remain the same. This concludes the introductory course on LCD panels. Now, what makes a display readable in direct sunlight?

What makes screen sunlight readable?

There are two basic methods for increasing the brightness of an LCD and thus its readability in direct sunlight. The most straightforward method is to boost the backlight’s brightness. Nits are used to describe the brightness of LCDs. LCD panels typically have a display brightness of 250 to 450 Nits. LCD screens with a brightness of 800 nits or greater are considered sunshine viewable. However, the majority of sunlight readable displays have a brightness of 1000 nits. Therefore, the most frequent approach to making an LCD panel sunlight-readable is to increase the brightness of the LCD panel backlight. This type of sunlight-readable LCD is standard on most Golden Margins’ industrial panel PCs and touchscreen displays.

Another technique to make an LCD visible in direct sunlight is to put a “transparent” diffuser material between the LED backlight and the LCD pixels. The reflective material is similar to that seen on reflective sunglasses or a one-way window, with the glossy side facing the LCD panel. When transflective material is used on an LCD screen, sunlight enters through the pixels, bounces off the transflective material, and is reflected through the pixels to your eyes. In this situation, sunlight has a significantly smaller effect on viewability than on a conventional LCD panel. The sunlight is reflected through the LCD pixels, contributing to the LCD’s brightness. One disadvantage of transflective diffuser LCDs is that because less of the backlight passes through the diffuser material, the LCD appears less bright in low light circumstances. As a result, LCDs with a diffuser are less prevalent than LCDs with a high-intensity backlight.

Optical Bonding Technology

Optical bonding enhances the visibility of touchscreen personal computers in direct sunshine or other bright situations. The touchscreen sensor and the LCD panel are two distinct components of a touchscreen computer. The touchscreen is positioned in front of the LCD, with a small air gap between the two. As a result, when sunlight passes through the touchscreen layer, some of it is reflected between the LCD surface and the touchscreen, reducing the LCD’s viewability.

Continue Reading: Optical Bonding

Optical bonding is a technique that involves the application of a clear adhesive gel between the LCD and the touchscreen. The gel hardens and adheres the touchscreen to the LCD, eliminating the air gap and enhancing contrast and clarity. Numerous Golden Margins touchscreen PCs and industrial displays have optical bonding.

Is it possible to dim sunlight-readable displays at night?

At night, when there is little to no ambient light, the brightness of a sunlight-readable display may be overbearing. Therefore, the majority of industrial computers with sunlight-readable LCDs are optionally equipped with auto-dimming capabilities. This function utilizes an ambient light sensor on the front bezel to detect incoming light and alter the brightness of the backlight to fit the current lighting conditions. This is often a need for industrial touchscreen computers that are utilized in both natural and artificial light.

Apart from outdoor use, are there any other circumstances in which a bright display is required?

Because of the ambient light passing through the windows, touchscreen computers in vehicles sometimes require high-brightness LCDs. Sunlight-readable LCDs are also employed in various indoor applications that include air traffic control centers, railroad coaches, maritime vessels, agriculture machines, and public kiosks.