Display Devices Flashcards
A flat panel screen that uses a liquid crystal solution sandwiched between two polarizing filters and glass panels
LCD liquid crystal display
A flat panel screen that uses an organic substance as the semiconductor material in LEDs
OLED organic light emitting diode display
A flat panel screen that uses small cells filled with noble gases and phosphors to create color
Plasma
Contains a large vacuum tube with a flat end covered in phosphors
CRT Cathode Ray Tube
Uses a grid of horizontal and vertical wires with an LCD element at each intersection
Passive Matrix
There is a transistor at each intersection which controls the light for each pixel
Active Matrix
What are the two technologies to polarize the liquid crystals in an LCD?
Passive & Active Matrix
What are three ways of illuminating an LCD panel
Reflective
Transmissive
Transflective
A mirror behind the panel bounces ambient light back to the user
Reflective LCD backlighting
A backlight behind the panel shines light toward the user, making the display readable in low light situations
Transmissive LCD backlighting
Uses both a backlight and a partially reflective layer between the backlight and the LCD display to capture ambient light
Transflective LCD backlighting
What is the purpose of a screen inverter in a laptop?
The inverter takes DC from the motherboard and converts it into AC for the backlighting.
Three common types of liquid-crystal technology
TN (Twisted Nematic)
IPS (In-Plane Switching)
VA (Vertical Alignment)
Use crystals which are horizontally aligned with the screen, best viewing angles and able to produce the most accurate colors. Increased power consumption and slower response times
IPS: In-Plane Switching displays
Displays that have crystals which are vertically aligned when there is no electrical current and horizontally aligned when current is applied
VA: Vertical Alignment displays
Newer technology that uses a single chip with a reflective surface composed of thousands of tiny mirrors corresponding to individual pixels
Digital Light Processing (DLP)