Laptop Display Components

Question 1

What is a digitizer?

Answer 1

• Enables the “touch” in touchscreen.

- Placed between the glass and LCD/LED layers of a monitor

Question 2

What are the pros and cons of an IPS LCD monitor compared to VA and TN?

Answer 2

In Plane Switching

• Best contrast ratio makes it better suited for image editing and creative applications
• Worst refresh rate so not ideal for video games as TN
• Can be expensive

Question 3

What is the advantage of an active stylus compared to an inactive stylus?

Answer 3

Inactive styluses interact with a digitizer in the same way your finger does making it difficult for a machine to tell the difference. This can cause issues with the machine determining what inputs to accept.

Active styluses communicate with the machine they’re synced to, disabling hand inputs and only taking inputs from the stylus.

Question 4

What are pixels and what are they used for?

Answer 4

The individual units of light that make up a monitor.
Each pixel has Red, Green and Blue filters.
Images displayed on a monitor are created by manipulating the light coming through each individual pixel as well as the color that pixel produces.

Question 5

What are the distinguishing characteristics of OLED?

Answer 5

• LEDs are made with an organic material that produces its own light when a voltage is applied.
• Eliminates the need for a backlight and liquid crystal plane which allows OLEDs to be very thin.
• Allows production of darker darks as there is not as much diffusion to neighboring pixels
• Not as bright as LED or LCD

Question 6

What does OLED stand for?

Answer 6

Organic LED

Question 7

What are the three primary types of LCD monitor?

Answer 7

• Twisted Nematic (TN)
• Vertical Alignment (VA)
• In Plane Switching (IPS)

Question 8

How do VA LCD monitors compare to IPS and TN?

Answer 8

Somewhat of a middle ground between the two in terms of price, refresh rate and contrast ratio.

Question 9

What is polarization as it pertains to light?

Answer 9

Light can be what’s known as a transverse wave. Transverse waves oscillate perpendicular to their direction of travel. Light coming from a source traveling into your eye or a receptor can oscillate in all directions and is considered unpolarized.

Polarization occurs when some material is used to restrict the oscillations of light allowed through it. Only specific orientations of light make it through, limiting the overall light that makes it to the receptor.

Question 10

Describe the components of a typical laptop display.

Answer 10

• bezel: houses all of the components of the display
• webcam: pretty ubiquitous but may not be on some models
• microphone: for basic sound capture
• monitor: the assembly of pixels, liquid crystals and backlight used to display images
• WiFi antenna: runs around the perimeter of the display for improved reception of wireless signal

Question 11

What is refresh rate in a monitor and what does it affect?

Answer 11

Refers to the number of images a monitor can produce per second, measured in Hertz.
Higher refresh rates correspond to smoother videos and animations.

Question 12

What are some similarities of an LED monitor to an LCD? What are some advantages?

Answer 12

• Use Light Emitting Diodes as the light source
• Still uses liquid crystals to control polarization
• Better uniform light distribution
• Less energy used and less heat production
• No inverter needed for LED

Question 13

How does an LCD screen work?

Answer 13

In the case of LCD, each pixel consists of a color layer and two liquid crystal layers. Behind all of this is a light source.
Voltage applied to the liquid crystals allows manipulation of light polarization and what light, if any, makes it through to the color layers.
This allows control over what color or combination of colors a pixel displays. Manipulating all of the pixels on a monitor in this way allows for the creation of images.

Question 14

What are the pros and cons of a TN LCD monitor compared to VA and IPS?

Answer 14

Twisted Nematic

• Worst contrast ratio of all options which makes it the worst choice for image or video editing applications
• Capable of fastest refresh rate which makes it a good choice for gaming
• Can be cheap but also expensive for high end gaming monitors with fast refresh

Question 15

What is contrast ratio in a monitor and what does it affect?

Answer 15

Refers to the intensity of contrast between light and dark colors on the screen. A higher contrast ratio corresponds to better image quality.

Question 16

What is the primary difference between LCD and LED/OLED monitors?

Answer 16

The light source. While LCD uses a reflective surface to backlight its pixels, LED and OLED use Light Emitting Diodes (LEDs) to backlight each pixel.

Question 17

What is response in a monitor?

Answer 17

Response refers to how quickly the individual pixels in a monitor are able to change.

Question 18

Describe the types of digitizers and their differences.

Answer 18

• Resistive: Older style of digitizer that requires pressure to work
• Capacitive: Newer style and no pressure needed. Finger or stylus causes changes in capacitance of the digitizer which can be translated to location on the screen.

Question 19

What does LCD stand for?

Answer 19

Liquid Crystal Display

Question 20

What technology is used to backlight an LCD screen and what challenges are present with this solution?

Answer 20

LCDs are typically backlit using two Cold Cathode Florescent Lamps (CCFLs) on the top and bottom of a reflective surface behind the pixels.

• CCFLs require AC power so an inverter is needed to convert the DC power used by a laptop.
• The reflective surface provides pretty good general distribution of light across the entire monitor but is not perfect.