GMDSS Trainer
Subelement D: Display & Control Systems - 10 Key Topics – 10 Exam Questions— Topic 29: Displays

Question 8-29D4

Element 8 (RADAR)

LCD patterns are formed when:

Explanation
LCDs (Liquid Crystal Displays) operate by harnessing the unique properties of liquid crystals. When an electric field, created by applying voltage (and thus current) across specific segments or pixels, is introduced, the rod-shaped liquid crystal molecules align themselves. This alignment changes how light passes through the crystal and polarizing filters, either blocking it or allowing it through. By selectively controlling these fields across an array of pixels, visible patterns, images, and text are formed. Option B describes raster scan displays, which are characteristic of older Cathode Ray Tube (CRT) technology, not LCDs. Reducing voltage generally dims a display rather than forming patterns. Option C, involving deflection coils and resonance, also pertains to CRTs, where coils steer an electron beam. Option D, concerning an antenna's bearing, is completely unrelated to display technology.

Ready to test your knowledge?