Light box for back-lit screen for example of aircraft panel instrument has light deviation and distribution plate behind diffuser screen

摘要

The light box (11) has a series of luminous tubes (16) and a light deviation and distribution plate (21) behind the diffuser screen (18), illuminated through its edge (22) by an auxiliary light source (19) and a guide (20) for viewing the screen in a very low light level. The light box (11) has a series of luminous tubes (16) behind a diffuser screen (18) and providing a light intensity that is variable on demand for day or night viewing. It has a light deviation and distribution plate (21) behind the diffuser screen, illuminated through its edge (22) by an auxiliary light source (19) and a guide (20) for viewing the screen in a very low light level. The light guide has a coating of a reflective material or is totally reflective.