Multicolor LEDs

Publish date 2021-12-09
Status and indicator lights are some of the primary uses of LEDs. They perform an important function in electrical devices, informing the user about their operation or status. However, there is a way to drastically increase the functionality of these inconspicuous indicators. Multicolor LEDs, capable of emitting many different colors of light, make it possible. The concept of a multicolor diode is very simple – an additional emitter, with a different light wavelength, is placed in the LED component package. Thus, a single diode is able to produce two different colors of light. But that's not all – individual colors can also be mixed with each other, creating new ones. For example, a red-green diode is also able to emit yellow or orange light. To reduce the number of leads, the poles of individual semiconductors are often internally connected. Those types of diodes are known as common anode/cathode LEDs, and also bipolar LEDs. There are also diodes with a built-in controller, which allows the adjustment of color via digital signal.

Multicolor LEDs as indicators – why is it worth it?

Thanks to multicolor LEDs, a single indicator light is able to give us much more information. This allows to reduce the space required, the complexity of the device and, above all, the cost. Choosing an appropriate multicolor LED for any application is not a problem – diodes with many different color combinations, various properties and in different packages are available. There are red-blue and white-orange diodes, as well as the most versatile RGB diodes, which allow to achieve almost every color of light. A good example of their use are notification LEDs, which were formerly very common in smartphones and mobile phones. Thanks to them, a single glance was enough to read the most important information. Blue light – new message! Red light – low battery. Simple and intuitive. Did you know that thanks to InterElcom, your product can also have an intuitive, multicolor LED indicator? For example, the RGB LED in SMD-1616 (0606) package, which we offer is ideal for this purpose. Contact us today!  

Decorative, mood and landscape lighting

Multimedia fountain in Wroclaw – an example of multicolor LED application

  It is undeniable that the vivid, dynamically changing colors of multicolor LEDs are attractive to the eye. For this reason, one of the main applications of those types of LEDs – especially RGB ones – is decorative lighting. A wide range of lighting products using multicolor LEDs is available, including lightbulbs, strips and chains. The exceptional aesthetic qualities of such lighting can give rooms a new character. Decorative lighting is also used to transform the appearance of gardens, buildings and even landscape features.

RGB diodes and white light 

In some cases multicolor RGB LEDs are also used as white light sources. Combining equal intensity of each of the component colors produces white. However, such a solution has some drawbacks. First of all, to obtain white, individual colors must be accurately mixed. Most multi-color LEDs and lighting products use special color mixing optics – an example of that would be a diffuser or reflector. Lighting products without such optics use spatial color mixing, based on the distance between the light source and the illuminated object. The quality of color mixing is also facilitated by placing individual color emitters in close proximity to each other. This way, spatial color mixing can be achieved even by using separate diodes of each color. This technique is used in some LED strips or stage spotlights.    

Color mixing in RGB diode (5050) - microscopic image. The lens of the diode (illuminated ring surrounding the emitters) acts as the color mixing optic.

    Another issue is that the white light achieved this way has a relatively low color rendering index (CRI). The reason for this is that the narrow emission bandwidth characteristic of LEDs prevents uniform coverage of the entire color spectrum. There are various approaches to overcome this problem. One of them is placing an additional, white emitter in the housing of a multicolor diode. Those are known as RGBW diodes (Red, Green, Blue, White). They are an ideal choice for home lighting products, allowing them to serve both as main and decorative lighting. Read also: LEDs – characteristics of key parameters Another approach is to broaden the spectrum of a RGB LED by adding a fourth color (amber) – such diodes are called RAGB LEDs. The additional color fills the gap in the spectrum between red and green, consequently allowing to achieve a higher CRI. This type of LEDs also have another interesting property – they allow to obtain a given color through more than one combination of component colors. This flexibility allows for better adjustment of the brightness of individual colors to achieve the best possible color rendering.

LED matrices and displays

By connecting diodes into a grid of columns and rows, we obtain a LED matrix. Similarly to TFT LCD displays, a single diode acts as a pixel. By controlling the brightness of individual colors of each diode, the LED matrix may become a full-fledged color display. Although the pixel density of such a panel is much lower, they feature a very good color reproduction and high refresh rate. This allows them to display smooth animations or video content, making color LEDs a good alternative to other types of displays. Read also: Everything about TFT LCD displays Another major advantage of LED matrices is their high brightness, allowing good image visibility even in daylight. In addition, the use of ready matrix modules allows you to easily build a display in any size and shape. That is why LED matrices are the ideal solution for wall screens and stage screens – wherever high brightness is important and the image is observed from a distance. It is also a much cheaper solution than most competing technologies, especially in the case of very large video walls.

We invite you to shop at InterElcom

Optoelectronics is our specialty. We work with the best LED manufacturers to ensure that our products are perfectly suited to your needs. In InterElcom's offer you will find a wide range of LEDs for any application, including multicolor LEDs and high-brightness LEDs. We encourage you to browse our product catalogue and, in case of any questions, to get in touch with us via the contact form on our website.