Illumination increases power consumption and complicates the wiring design, so why should design engineers consider the option? Because illumination is one the simplest and most flexible ways of designing an intuitive control panel.
If you see a blinking red light, what is your first thought? That something is wrong and needs immediate attention. What about a steady blue light? Perhaps an on-off button on electronics.
Illumination allows for a quick and intuitive read of your solution making it easy for your operator to use the application efficiently.
However, illumination is not only about color and the length of the signal, but also about the placement, the size and intensity of the light source.
Can be used to indicate the urgency of the function. Traffic light colors are commonly used in indicating function, whereas purple, orange and blue are more ambience related colors.
LENGTH OF SIGNAL
The shorter the signal the more urgent it will feel to the operator. Furthermore, the quicker the blinking the easier it is for the eye to catch it.
Of the light depends on the purpose of it. Highlighting different parts of the button or the panel gives a different feeling to the solution. If you want to guide the finger to the function, then a line around the press area is recommended. If it is to indicate the status of the function, then a spot illumination or a legend illumination can be the solution. If a level of a function needs to be shown, then multiple lights in a bar graph may be the solution.
Of the light source can indicate the importance of it but can also be about the overall feeling of the design. If there is a 30mm red indicator on your dashboard, you know that it means business. On the other hand, discreet legends or small lenses may be more suitable for high-end electronics.
Can be used to show the urgency of the function but more importantly it is used to adapt the illumination to the environment the application is in. E.g. Is it used outside or inside, does the operator stand close by or at long distance?
NOTE! Remember to only use illumination where it serves a purpose. Adding too many lights can drown out the critical illuminations and therefore make the solution more difficult to use. Plus, it would add unnecessary power consumption to the application, which is especially critical for battery-powered devices such as belly boxes and AGVs.