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How LED backlighting technology can improve HMI design

Here at RH Technical Industries Ltd., we are continually developing new LED backlighting solutions for our customers as an affordable and reliable alternative to other forms of backlighting.

LED Backlighting - Blue Glow - membrane keypads membrane switches membrane keyboards graphic overlay

How LED backlighting technology can improve HMI design

Technology is ever-evolving, and customers from every industry are seeking innovation to improve the quality and functionality of their products. Do your products have what it takes to keep the competition from your customer’s door, or is the competition starting to catch you up?

In the past, low light readable keypads, and human-machine interfaces (HMI) could only backlight with traditional lamps, or perhaps by electroluminescent (EL) backlighting. These technologies often had limited functionality and could only illuminate and reveal basic numbers, letters, symbols and other graphical elements, and often only lighting in a single colour. These constructions were often expensive and involved a secondary process such as printed light balancing, diffusers and moulded light pipes. Design flexibility often became compromised due to these limitations, with production builds being complicated.

The use of individual LEDs is now commonplace. The construction, durability and power implications of spot LEDs make it a practical and cost-effective solution to your backlighting requirements. Surface-mounted LEDs are easy to place on a printed circuit board, integrate into a membrane keypad or fit into a silicon rubber keypad design. Everywhere you look these days; there are little glowing dots that tell the user that an appliance or device is powered, or a button pushed.

What happens though when you want to design a product that goes beyond the basic requirement of an indicator LED or the user interface is mounted away from the main controller PCB. How can you simplify the construction and cut out the need for diffusers or expensive light pipes? Wouldn’t it be great if technology could illuminate larger areas with more detailed information? Even better, what if user-interface keys could change colour, or perhaps help the user navigate or anticipate the next selection.


Here at RH Technical Industries Ltd., we are continually developing new LED backlighting solutions for our customers as an affordable and reliable alternative to other forms of backlighting. We have devised better ways to illuminate areas of a keypad, which provides additional design options for a product. Our new LED backlighting innovations can breathe life back into an existing membrane keypad or control panel, or greatly improve its current functionality. Not only does the product perform better, improving the user experience, but it also looks better. Your customer’s equipment will be perceived to have a higher value. LED backlighting with the RH Thin Film Backlighting (TFB) solution will light up your customer’s world with safer, brighter and thinner interfaces while achieving ease of manufacture and product build.

If you are considering LEDs as a possible backlighting option for your HMI, then you must also consider the use of RH Thin Film Backlighting as the solution to improve your product, or perhaps meet a client specification.

So, what does RH Thin Film Backlighting have to offer over any other backlighting solution? Firstly, it’s a thin cost-effective solution driven by edge firing LEDs. It provides even illumination over a defined area; whether the application is a keypad, bar graph or indicator. RH TFB integration in the construction of a membrane keypad, under the graphic overlay and over the metal tactile domes, can even illuminate individual keys. The keys can come to life on activation, showing status or even changing colour with the inclusion of RGB LEDs.

Thin Film Backlighting

RH Thin Film Backlighting is daylight readable in most commercial settings. It is a flexible solution for most low light/night-time specifications, whether as a status indicator or to illuminate the keys of a control panel. Well suited to automotive, medical and military environments, RH Thin Film Backlighting can enhance the user experience for many other HMI applications as well.

Increasingly product design specifications are calling for control panel illumination, especially for products used in low light/night-time settings. Other design criteria may also include the ability to illuminate individual areas, or perhaps change colour on the operation of keys.

RH LED driven Thin Film Backlighting has already proved a solution for a variety of applications such as medical control panels, vehicle cab controls, marine instrumentation, door-entry systems and for military equipment.

RH Thin Film technology has replaced EL (electroluminescent) backlighting for the controls of an emergency vehicle, as well as for illuminating user interfaces inside fighting vehicles. In doing so, the operational life of these controls has been extended by moving to a LED driven source, and costly inverters are no longer needed, simplifying the design. The introduction of Thin Film backlighting on a medical keypad interface, achieved design flexibility and reduced cost over an existing system using a more expensive moulded light guide. In turn, the cost-savings were also maximised due to the ease of assembly in production.

If you have any questions about RH Thin Film Backlighting Technology, please contact our helpful team on 01264 721454 .