In recent times, LCD panels with high brightness are becoming increasingly popular due to their feasibility and readability in bright environments. Many portable devices are now designed with high brightness LCDs for an optimal user experience.
Limitations of High Brightness
Of course, there are limits to LCD brightness, but small LCD panels continue to be practical for a variety of portable devices.
Engineers must consider that increasing brightness will cause LCDs to consume more power and produce more heat. Therefore, if an indoor space doesn’t have proper lighting, then the suggested LCD brightness should be close to 200 nits. Similarly, an indoor setting with proper lighting will need more than 300 nits of brightness. This type of consideration applies to commercial buildings, medical labs, and security systems.
As a rule of thumb, a display with a brightness of 700 nits or greater is considered sunlight readable. Any brightness less than 700 nits can be difficult or impossible to read in high brightness environments. With this in mind, companies can use a variety of techniques to achieve sunlight readability.
PWM and Resistors
In order to achieve high brightness, engineers can deploy techniques such as pulse width modulation (PWM) and eliminate limiting resistors.
PWM can give your display the ability to fluctuate brightness in accordance with the surrounding environment. This is beneficial for small, portable devices with concerns related to overheating and power consumption. When using PWM, you can program your product so that when the device is brought indoors, the brightness will decrease, allowing the display to cool down and decrease power consumption of the device until it is time to go outside again.
Limiting resistors are used to reduce and/or regulate a current in a circuit. By removing limiting resistors or decreasing the resister value, the backlight can draw more current, leading to an increase in brightness. However, it is important to note that removing limiting resistors can lead to a reduced LED half-life.
Another consideration for design engineers is to employ anti-glare and anti-reflection treatments to increase the readability of LCD panels. An LCD panel will achieve high readability if there is an anti-reflection treatment of the surface. Essentially, Anti-glare eliminates glare and balances reflections on LCD panels. The objective of AR is to decrease the reflection light that might reach an observer’s eyes.
If your device utilizes a touch panel or cover glass, optical bonding can also be helpful with increasing the brightness of your display. A touch panel or cover glass can be applied to the LCD glass in a number of ways. However, optical bonding will be the best option for displays that need to have high brightness.
Optical bonding removes any concern of an air gap between the lcd glass and the cover/touch panel, leading to increased contrast and decreased internal reflections. This is because the bonding is applied as a third layer between the LCD glass and the cover/touch panel. Whereas a bonding method such as double-sided tape is only applied to the outer perimeter of the display in between the LCD glass and cover/touch panel.
Ventilation Structure and Design
Another key consideration for manufacturers is to ensure proper ventilation of LCDs. If your display is sunlight readable, under certain conditions, you might face overheating issues. A sunlight readable backlight can emit excess heat when the LEDs are driven. The heat generated can damage the LCD or any other components contained within the portable device.
A proper ventilation design and structure in a portable device can help eliminate overheating issues.
The Future of High-Brightness LCDs
High brightness LCDs have become a new standard to attract audience. It’s a step in the right direction that would fuel the growth of more advanced small displays in the coming years.
It is crucial to understand that a brightness panel can have hundreds or even a thousand nits. But when it comes to small displays with high brightness, quality has to complement functionality. In retrospect, the science and tech behind the bright LCDs will continue to evolve and become more relevant in different industries.
Focus LCDs continues to provide an impressive collection of high-brightness display solutions. We offer a wide range of readable and high-brightness small LCD products to meet changing consumer expectations and demands. Contact us today for more information!