Keeping airline seats under control

Qantas was keen to develop new seat units for its planned first and business class upgrade, and in particular, to upgrade the seat controllers. Mounted within the seat, the controller is a sealed membrane keyboard unit.

The previous designs were relatively unreliable in service, and employed electro-luminescent (EL) backlighting.

Britax Rumbold, supplying the first class seats, and Britax Contour with the contract for business class, approached IGT Industries for assistance in developing the membrane keyboard. It had to be sealed to IP67, provide additional insulation layers on the top and bottom to prevent short circuiting, and to be optically sealed to prevent any extraneous light leakage from the edges of the unit. For this application low voltage bulbs are mounted directly onto the PCB substrate of the keyboard. Plastic light guides are used to direct the light to the key areas in the membrane. The key areas are delineated by dome embossing of the surface graphics layer, and when pressed, a transparent plunger depresses the metal dome mounted on the PCB. Depression of the dome completes the electrical circuit and also provides the tactile feedback to the operator. The plunger transmits the light through the clear regions of the graphic layer to provide the required illumination.

IGT Industries. Tel: 01703 610818