1.2 - Laptop Displays

Question 1

Portable LCD

Answer 1

• Liquid crystal display
  – Light shines through liquid crystals
• Advantages
  – Lightweight
  – Relatively low power
  – Relatively inexpensive
• Disadvantages
  – Black levels are a challenge
  – Requires separate backlight
  – Florescent, LED, etc.
  – Lights are difficult to replace

Question 2

LCD technologies

Answer 2

• TN (Twisted Nematic) LCD
  – The original LCD technology
  – Fast response times (gaming!)
  – Poor viewing angles - color shifts
• IPS (In Plane Switching) LCD
  – Excellent color representation
  – More expensive to produce than TN
• VA (Vertical Alignment) LCD
  – A good compromise between TN and IPS
  – Good color representation
  – Slower response times than TN

Question 3

TN (Twisted Nematic) LCD

Answer 3

• The original LCD technology
• Fast response times (gaming!)
• Poor viewing angles - color shifts

Question 4

IPS (In Plane Switching) LCD

Answer 4

• Excellent color representation
• More expensive to produce than TN

Question 5

VA (Vertical Alignment) LCD

Answer 5

• A good compromise between TN and IPS
• Good color representation
• Slower response times than TN

Question 6

OLED

Answer 6

• Organic Light Emitting Diode
  – Organic compound emits light when
  receiving an electric current
• Thinner and lighter
  – Flexible and mobile - no glass needed
• No backlight
  – The organic compound provides the light
• Tablets, phones, smart watches
  – Very accurate color representation
  – A bit higher cost than LCD

Question 7

Wi-Fi antennas

Answer 7

• Multiple antennas
  – WiFi main and aux / Bluetooth
• Antenna wires wrap around the laptop screen
  – It’s up high!

Question 8

LED-backlit LCD display

Answer 8

• Backlight is LEDs instead of florescent
• LEDs around the edge of the screen
• An array of LEDs behind the screen
• The latest laptops are LED-backlit

Question 9

CCFL LCD

Answer 9

• Cold Cathode Fluorescent Lamp
• Higher voltage and power needed
• Added thickness to the display
• No longer a common backlight
• Older laptops will use these

Question 10

Backlight and inverter

Answer 10

• LCD displays need a backlight
  – Florescent lamp/LED to LCD display to your eyes
• Some laptops have inverters - Turn DC into AC
• Verify backlight
  – Look closely and use a flashlight
• May need to replace the LCD inverter or display
  – Choose carefully

Question 11

Digitizer

Answer 11

• Use a pen-like device as input
  – Stylus input - Useful for graphical input
• Used commonly on laptop / tablets
  – Or hybrid devices

Question 12

Touchscreen

Answer 12

• Merge laptop and tablet input
  – Digitizer responds to touch - No keyboard required
• But often still available
  – Many options for input - Use the best one for the job