Ch4 BB Flashcards
What is a VDU? Pg 184
Video Display Unit. A device that produces a display of the computer.
List all VDU types. Pg 184-185
Liquid Crystal Display(LCD), Plasma, OLED, and Projection systems
What is a Liquid Crystal Display? Pg 185
Current passed through a semi-crystalline liquid make the crystals align with the current, when a transistor is used patterns are able to be formed, this is how LCD displays information.
What is the difference between twisted nematic(TN) and in-plane switching(IPS) LCD? Pg 185
TN is faster and less expensive, while IPS has the best color representation in all angles and requires more power to operate.
What is an active matrix LCD panel? Pg 187
Made up of several independent LCD pixels with a transistor at each pixel location. When the transistor is switched among various levels, activates two opposing electrodes that change the shade of the pixel. Active matrix produces a crisp picture, can be viewed from various angles, and does not require constant refreshing to maintain an image but does use a substantial amount of power in return.
What is a passive matrix LCD panel? Pg 187-188
Unlike active matrix, does not have a dedicated transistor for each pixel instead, passive matrix sends a current along x and y coordinates to turn on a particular pixel. Passive matrix has limited angles of visibility and longer response time(the time to change a pixel). The picture can also be muddied due to “crosstalk” that can happen between a pixel and its surrounding pixels.
What is dual scan? Pg 188
A variation of passive matrix, dual scan splits the screen in two which improves quality but still does not rival the quality of active matrix.
