1.2 - Laptop Displays Flashcards
How do LCDs work?
There is a backlight that passes through liquid crystals associated with color filters that produce the image we see.
What are the advantages of an LCD?
They are lightweight, and relatively inexpensive.
Whare are the disadvantages of an LCD?
The backlight shining through makes it difficult to achieve true blacks, and the light is difficult to replace should it fail.
What are the three main types of LCD displays?
TN, VA, IPS.
What is a TN LCD? What are the benefits and drawbacks?
Twisted nematic liquid crystal display. Great response times (e.g., for games). The drawback: bad viewing angles.
What is an IPS LCD? What are the benefits and drawbacks?
In-plane switching liquid crystal display. Benefit: best color representation. Drawbacks: more expensive than TN.
What is a VA LCD? What are the benefits and drawbacks?
Vertical alignment liquid crystal display. Good color representation, but response times are slower.
What is an OLED display? What are the benefits?
Organic light emitting diode. This doesn’t have a backlight, the organic material emits light when powered by a current. Because there is no backlight, these are typically thinner, and don’t require glass to protect them.
What is one thing to keep in mind when replacing a laptop screen, wrt wireless connections?
There is often an antenna wire running to the top of the display that must be reconnected when the laptop screen is replaced.
What is the most common LCD backlight in older laptops? What is it today, and how do they compare?
CCFL - Cold Cathode Fluorescent Lamp. These require more power than LEDs (today’s standard), and are thicker.
What might the matrix of LED lights behind a display look like?
LED strips. Like the ones under your desk.
What are inverters, and when and why are they used?
They are used in laptops with CCFL-backlight LCDs. The CCFL requires AC (alternating current), but the laptop requires DC (direct current). These convert the DC to AC.
How can you tell if a backlight is out?
Shine a flashlight at the display. If you can make anything out, the backlight might be out.
What a (touchscreen) digitizer?
A device that converts analog inputs (i.e., a pen/stylus) on a screen into digital signals.
