LED backlights for PC monitors – myth and reality

Lighting has undergone a shift in recent years towards energy-efficient LEDs (Light Emitting Diodes). Compared to older fluorescent lamps LEDs are far more efficient – they convert more energy into light and waste less as heat. Display technology has also benefitted from this ‘green’ technology. In 2009 we started seeing the first LED-backlit screens aimed at general consumers. Since then the technology has gathered pace and is now the go-to choice for LCD (Liquid Crystal Display) monitors.

Although certainly beneficial when it comes to energy efficiency, the way that some manufacturers and retailers have promoted the technology has simply confused consumers. This article will look at some common misconceptions (or ‘myths’) and set the record straight with a healthy dose of reality.

Myth – LED and LCD are distinct technologies

Reality – in this case ‘LED’ simply refers to a backlight type used in modern LCD monitors and isn’t an alternative to LCD. Older displays used CCFLs (Cold Cathode Fluorescent Lamps) for their backlight.

 

Myth – LED gives monitors better contrast with deeper blacks and brighter whites

Reality – LED backlights can improve dynamic contrast performance because they can change their brightness very rapidly. Dynamic contrast is a measure of contrast over time using a dynamic backlight brightness setting. In other words the overall brightness of the monitor itself will change to coincide with changes in scene brightness. The industry standard and important setting for most users is static contrast, which is a measure of the ratio between ‘black’ and ‘white’ at a fixed brightness. This typically yields a ratio of around 1000:1 (3000:1 for Vertical Alignment panels) and isn’t influenced by backlight type.

 

Myth – LEDs give screens better colours

Reality – it’s just a light source. It dictates the colour gamut (potential range of colours) of a display and in this respect LEDs and CCFLs are now on par. The underlying panel and LCD technology is crucial to a monitor’s colour reproduction characteristics and the backlight doesn’t alter this.

 

So if the image performance characteristics aren’t improved by the use of an LED backlight, why have things moved in this direction? The main reasons are the environmental benefits. First and foremost is the improved energy efficiency. LED backlights typically offer a power saving of 30-40% over an equivalent CCFL design at the same brightness. They also produce less heat as a result, which can make a big difference if you consider an office or another room with multiple monitors close together. Another environmental benefit is that unlike CCFL bulbs, LEDs are free from mercury and can be more easily recycled.

Improvements in PC Monitors

Technology in general has advanced greatly over the past several decades. This progress includes PC monitors. Can you remember how monitors used to look? They used to be these huge, clunky boxes with a tiny screen. The screens were made of glass that had a slight curve, and created an annoying glare. They have definitely come a long way from those early days.

One big improvement is in the screen size of monitors. Where old ones were mostly plastic with a tiny viewing area in the middle, the new ones are the exact opposite. Today’s monitors have very little plastic along the edge of the screen, leaving as much room as possible for the viewing area. You can buy screens that are as big as you could possibly want or need. Many of today’s monitors have screens that are the equivalent of a small to medium sized television.

Besides the improvement in screen size, they are no longer clunky. Instead of having a huge plastic box, the monitors you find today have been streamlined. They are much thinner, comparable to a flat screen TV and their overall design is more aesthetically pleasing. Most monitors also use a matte polarising filter rather than the old glass screens, eliminating much of the glare. The display is most often LCD – the colours displayed by today’s PC monitors are much more brilliant than the ones displayed by older computers.

As much as monitors have been improved upon, progress does not stop there. Makers are constantly asking for customer feedback, holding focus groups and doing everything they can to make their products even better.

One interesting trend at the moment is in 3D (stereoscopic) imaging. In the past few years there have been numerous movies released in 3D. One of the problems of 3D viewing has been that the glasses can be uncomfortable, or even restrictive. Some computer manufacturers have created a 3D monitor that does not require the use of any special glasses. This is just one more way that they have tried to improve on their product.

Now you can also buy monitors that are completely interactive. They come equipped with a touch screen feature that gives you a fresh new way to browse the internet. This may have been prompted by the popularity of touch screen mobile phones, tablets and also music players. So the modern monitor is large and flat whilst capable of displaying interactive 3D images at high resolution. PC monitors continue to get better every single day and you truly do not know what they will come up with next.