Is it super bright even to you?

Probably even a less experienced designer knows, that a colour TFT display is usually more attractive and mainly better readable if it has a relatively higher brightness (backlight). That´s a well known fact, but despite this only recently standard displays had a brightness of approx. only 200 Cd/m2. That was fully sufficient for indoor use, however when using at a strong ambient light or even a sunlight, the readability went rapidly down. New more efficient white LEDs enabled construction of substantially more powerful backlight while keeping a low power consumption, that´s why nowadays TFT displays usually feature brightness of approx. 300-400 Cd/m2.

Such displays are already subjectively pleasantly bright and contrast (indoor). And outdoor - let´s say they are usable.

Why is a more powerful backlight necessary for outdoor use?

The answer is relatively simple. Contrast of a display is simply said ratio of a white surface brightness (white pixels) to a black surface brightness. The problem is, that a black surface is never fully black, what in praxis means, that small portion of backlight leaks through (contrast drop in a dark environment). At the same time the black surface also reflects some light portion falling from outside (contrast drop in a strong-light environment). When we realize, that a light intensity outdoor can be in order of magnitude higher then indoor, especially on a direct sunlight, so even in case that a black surface would reflect only 2% of a falling light, the resulting brightness of black pixels will rise significantly. Finally, white to black pixels brightness ratio will substantially fall, what´s a main reason of a poor contrast of TFT displays at a strong ambient light.

A solution of this problem can be a usage of high brightness displays. „Super bright“ TFT displays commonly feature brightness of 600-1000 Cd/m2 (or even more). Company Winstar offers super bright TFT displays in 3,5/4,3/5,7 a 7,0“ sizes with resolution of 320x240 to 1024x600 pixels. Practically all sizes are available without touch panel, as well as with a touch panel (resistive or capacitive). All are with enhanced operating temperatures range (-20...+70´C) and also available is a 4,3“ type, which besides a high brightness features enhanced viewing angles range (O-film TFT display).

Maybe it´s worth to mention, that if you´re searching for the highest brightness of a display and you can live without a touch panel, in that case you´ll gain 25-35% higher brightness in comparison with the same display with a touch panel.

Overview of available TFT types with a high brightness can be found in this document.

In respect to a wide range of versions and modifications, these type are so far as items upon order. Upon request we´re able to promptly supply you with samples as well as main batches for production and in case of interest also to keep desired types on stock.

In case of interest in any display from company Winstar, please don´t hesitate to contact us at sales@soselectronic.com.