Why use them?
Conventional LED displays have to be mounted close to the display windows, often on a separate PCB. The arrays themselves are expensive and bulky. Since most PCB's use SM devices, an additional operation is needed to place the LED array onto the board. If a separate PCB is required, then additional fixing brackets have to be designed and extra assembly time taken to fix it in place. Finally, the proximity of the LEDs to the front of the display means that the devices are more prone to breakdown from electro-static discharge.

Light guides overcome all of these problems and offer a substantial part cost saving. The benefits to the designer are significant:

• Parts Cost reduction
  Typically, a 30-40 stalk LED lightguide can be made for £0.2-0.25 each. Comparable, LED arrays cost at least £2.50.

• Use SM technology for the PCB
  Surface mount devices can be used throughout the manufacture of the PCB. The light guide can be designed to mount directly onto the PCB, so that during assembly an operator only has to plug the part onto the PCB, screw fixings are not required.

• Reduced number of piece parts
  If the main PCB is at 90° to the display window, then the light guide can be designed to re-route the light without having to mount the LEDs on a separate PCB. Less parts are required and the moulding complexity reduced.

• Design Flexibility & Isolation
  The designer is no longer constrained by the size of conventional LEDs and can often reduce the complexity of the main case moulding, thus saving additional cost. By siting the LEDs remotely from the display window the risk of device failure arising from an electrostatic discharge is considerably reduced.

If your company's products are in the medium to high volume market, have LED displays and you want to cut costs, light guides are the answer.

Tel. +44 (0) 1223 84 44 44