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Flashcards in Display Technologies Deck (79)
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1
Q

CRT

A

Cathode Ray Tube:
An old type of display used by PC/Mac a while back.
Had toxic materials inside; required licensed recycling services to dispose.

2
Q

LCD

A

Liquid Crystal Display:
Primary visual output component today.

Uses liquid crystals that take advantage of polarization.

Tiny liquid crystal molecules arranged in rows and columns between polarizing filters.

3
Q

Liquid Crystals

A

Composed of specially formulated liquid full of long, thin crystals that always want to orient themselves in the same direction. Acts as a polarized filter.

4
Q

Sub-Pixels

A

Any of the units that make up a pixel. Each pixel usually has one red, green, and blue subpixel.

In LCD: Translucent sheet above the subpixels is colored red, green, blue.

5
Q

Pixel

A

Tiny distinct group of RGB subpixels.

6
Q

Static Charging (Older LCDs)

A

Didn’t use rectangular pixels.

Images were composed of different-shaped elements, each electrically separate from the others.

To create an image, each area was charged at the same time.

7
Q

Earlier LCDs (Functionality)

A

Matrix of wires on an X & Y axis running along rows & columns of subpixels.

Needed a charge on both wires to light a subpixel.

8
Q

Passive Matrix

A

Three matrices intersected very close together.

Above intersections: glass coated RGB dots.

Varying voltage on wires made different RGB levels to create colors.

9
Q

TFT

A

Thin Film Transistor (Active Matrix - Modern LCDs):
One or more tiny transistors control each color dot, providing a faster display, crisp definition, and much tighter color control.

10
Q

LCD Components (List)

A

LCD Panel: Creates the image
Backlight: Illuminates the image
Inverters (older): Send power to backlights that need AC

11
Q

TN (LCD Panel Tech)

A

Twisted Nematic: Fastest, but inadequate color

Main tech breakthrough that made LCDs practical.

Takes advantage of nematic substance ability to rotate the polarization of light beams.

12
Q

IPS (LCD Panel Tech)

A

In-Plane Switching: Beautiful color, best viewing angle

Designed to resolve limitations of TN (color, angle)

13
Q

VA (LCD Panel Tech)

A

Vertical Alignment: In between TN & IPS

Characterized by vertically aligned pixels. Liquid pixels run vertically to glass substrate on which they are used.

14
Q

LED (Backlight)

A
Light-Emitting Diode (Modern):
DC electricity; consumes less energy than CCFL.
Gives off no heat
Enables super thin screens
Does not need inverter
15
Q

CCFL (Backlight)

A
Cold Cathode Fluorescent Lamp (Older):
Low power use
Even brightness
Long life
Required high-frequency AC
Needed inverter to convert to AC from DC in monitor PSU
16
Q

Edge LED Backlighting

A

Two backlights: One at top, one at bottom

Drawback: can sometimes notice brighter edges

17
Q

Direct LED Backlighting

A

Puts a bank of LEDs behind the panel providing better uniformity.

More expensive & more energy than Edge backlighting.

18
Q

Resolution

A

Describes the number of pixels on display.

19
Q

Native Resolution

A

Specified resolution for a monitor. One should not use any other resolution than the native. (Cannot run higher, shouldn’t run lower)

20
Q

Interpolation

A

Softening the jagged corners of pixels when running at a lower resolution than the native.

21
Q

Video Modes (3 Names & Resolutions)

A
VGA = 640 x 480
WXGA = 1366 x 768
FHD = 1920 x 1080
22
Q

Aspect Ratio

A

Number of pixels arranged on the screen.

16: 9 = 1080p
21: 9 = 3440 x 1440 (on some laptops/phones)

23
Q

PPI

A

Pixels Per Inch:
Combination of physical size & resolution.

Higher res + smaller screen = Greater PPI
(Why phones and small screens can look so amazing)

24
Q

Brightness (LCD Backlight Measurement)

A

The strength of an LCD monitor’s backlights.

Measured in nits
100 = low end
300 = average
1000+ = high end

25
Q

Viewing Angle (Viewing Cone)

TN Viewing Angle
IPS Viewing Angle

A

LCD panels have a limited viewing angle.
The screen will fade when viewed from the side.

TN = 70 degree viewing cone
IPS = 178 degree viewing cone
26
Q

Response Rate

A

The amount of time it takes for all of the subpixels on the panel to change from one state to another (measured in ms).

27
Q

BtW

A

Black-to-White (Response Rate Measurement):

How long it takes for the pixels to go from pure black to pure white and back to black again.

28
Q

GtG

A

Gray-to-Gray (Response Rate Measurement):
How long it takes for pixels to go from one gray state to another (always faster than BtW time)

Manufacturers usually advertise GtG over BtW

Avg modern time: 5ms

29
Q

Refresh Rate

A

How often the screen can change or update completely.
“Metronome/timer”
Regular standard: 60Hz
Gaming Monitors: 120Hz, 144Hz, 165Hz, 240Hz

30
Q

Contrast Ratio

Lower Level Ratio
Good Ratio
High Level Ratio

A

The difference between the darkest and lightest spots that the monitor can display.
Lower Level: 250:1
Good: 450:1
High Level: 1000:1

31
Q

Why old CRTs lingered in a few professions in 2000s

A

Early LCDs could not match the color saturation & contrast of CRT.

32
Q

Dynamic Contrast Ratio

A

Difference between full-on (all white) vs. full-off (all black)
Doesn’t affect viewing on computer monitors
Focus on regular contrast ratio
Manufacturers like to advertise this number.

33
Q

Color Depth

A

The amount of colors that can be displayed.

Old TN: 6-bit panel (64 variations per color channel)

Modern Monitors: 8-bit panel (256 variations per channel)
AKA: 24-bit color

High-End: 10-bit panel (1024 variations per channel)
= 1 billion + variations

34
Q

Projectors (Function)

A

Generate an image in one device and use light to throw (project) it onto a screen.

35
Q

Front-View Projectors

A

Shoot an image out the front and count on you to place a screen at the proper distance.

36
Q

CRT (Projector)

A

Cathode Ray Tube Projector:
Beautiful images
Very expensive, large, and heavy (abandoned now)

37
Q

LCD (Projector)

A

Much lighter and inexpensive compared to CRT.

38
Q

DLP (Projector)

A

Digital Light Processing (Texas Instruments):
Uses a single processor and an array of tiny mirrors to project a front-view image.

Differs substantially from LCD:
Softer image, more electricity, and not as heavy

39
Q

Lumens

A

Brightness measurement for projectors

The amount of energy given off by a light source form a certain angle that is perceived by the human eye.

Best rating depends on room size and lighting.

40
Q

Small, Dark Room (Lumens Recommendation)

A

1000-1500 Lumens

41
Q

Mid-sized, Typical Lighting (Lumens Recommendation)

A

2000+ Lumens

42
Q

Large Rooms (Lumens Recommendation)

A

10,000+ Lumens (very expensive)

43
Q

Throw

A

The size of an image at a certain distance from a screen.

Always in terms of distance required to project 100 inch diagonal screen.

44
Q

Standard Throw

A

11-12 feet from projection surface.

45
Q

Short-Throw

A

4 feet from projection surface.

46
Q

Ultra-Short-Throw

A

15 inches from projection surface.

Lens prices go way up.

47
Q

Lamps

A

The bane of every projector.
Generate tremendous amounts of light.

Generate lots of heat (fan needed to prevent overheating)
Fan runs until lamp is fully cooled (even after turned off)

Expensive to replace (at least a few hundred dollars)

48
Q

Metal Halide (Lamp Technology)

A

Produce a tremendous amount of lumens with a small form factor.

Excessive heat & fan noise

Average life: ~3000 hours

49
Q

LED (Lamp Technology)

A

Use red, green, and blue LEDs to provide light.

Don’t heat up; quieter/smaller fans.

Not nearly as many lumens as metal halide.
Requires a darker room.

Average life: 20,000+ hours

50
Q

Lasers (Lamp Technology)

A

White lasers hitting color wheels.
OR
Colored lasers doing all the work.

Vibrant, high-contrast images
Very little heat

Average life: 30,000+ hours

Most expensive lamp tech

51
Q

VR Headsets

A

Immersive 360-degree experience created by mounting two high-resolution screens into a headset that blocks external visual sensory input.

Use OLED technology.

52
Q

OLED

A

Organic Light-Emitting Diode:
Use organic compounds between glass layers that light up when given an electrical charge.

No backlighting required (creates its own light)

Pixels can turn off completely, enabling pure black.
Results in phenomenal contrast compared to LCD panels.

53
Q

VGA

A

15-pin, 3 row, D-type connector

d-shell, d-subminiature

54
Q

DVI

A

Digital Visual Interface
DVI-D = Digital
DVI-A = Analog
DVI-I = Digital/Analog

55
Q

Single-Link DVI

A

Max bandwidth of 165MHz

Limited to 1920 x 1080 at 60Hz
or
1280 x 1024 at 85Hz

56
Q

Dual-Link DVI

A

Uses more pins than Single-Link to double throughput.

2048 x 1536 at 60Hz

57
Q

HDMI

A

High Definition Multimedia Interface:
Carries both HD audio & video
Can handle just about any resolution monitor

Mini & Micro versions for smaller devices.

58
Q

DisplayPort & Thunderbolt

A

Support full HD audio & video

mDP (miniDisplayPort) = Thunderbolt 1 & 2 connectors

59
Q

HDBaseT

A

Enables long-range connectivity for uncompressed HD audio/video over a Cat 5a or Cat 6 network cable.

60
Q

Monitor Adjustments

A
Brightness
Contrast
OSD (on-screen display)
Physical screen adjustment
Color adjustment (adjust RGB levels)
61
Q

Monitor Adapter Types (4)
+
Alternative to Adapters

A

DVI-VGA | DVI-HDMI
Thunderbolt-DVI | Thunderbolt-HDMI

Alternatively: cables with different end connectors

62
Q

VESA Mounts

A

A standardized bracket option for mounting to a wall or special stand.

63
Q

VESA Standards

A

FDMI (Flat Display Mounting Interface)
MIS (VESA Mounting Interface Standard)

Curved panels do not have VESA mount options.

64
Q

Display Adapters (Video Cards)

A

Processes data from CPU and outputs commands to the display.

Needs its own RAM (VRAM)

Needs fast connectivity between monitor, CPU, and system RAM

65
Q

PCI

A

Peripheral Component Interconnect:
32-bit transfers at 33MHz
(132MBps max bandwidth)

Cannot handle current systems’ needs.

66
Q

AGP

A

Accelerated Graphics Port:
Single, special port dedicated to video.
Only found on ancient systems.
Only 1 motherboard slot.

67
Q

PCIe

A

Peripheral Component Interconnect Express:
Can take advantage of all 16 lanes
(8Gbps lanes)

Modern GPUs use this.

68
Q

HDCP

A

High-bandwidth Digital Content Protection:
Stops audio & video copying between high-speed connections.

Stops playback of HDCP-encrypted content on devices.

69
Q

GPU Manufacturers

A

NVIDIA, AMD, Intel

NVIDIA & AMD sell to third parties (ex: EVGA)
Intel mostly does integrated GPUs.

70
Q

Video Memory (VRAM)

A

Hardest working set of electronics in a PC.
Constantly updates to reflect every change on screen.

Memory bus on card can be many times wider than 64-bit pathway, so data can be manipulated very quickly.

Can read/write data at the same time.

71
Q

VRAM Bottlenecking (Cause & Solution)

A

Data throughput, access speed, and capacity limits reached.

Overcame by increasing the bus width.

72
Q

Video Processor Chip

A

Handles rendering/processing of graphics.

73
Q

VRAM Types

A
DDR3: Budget cards & laptop video cards
GDDR3: Faster speeds & different cooling requirements
GDDR4: Upgrade of GDDR3; faster clock
GDDR5: Doubles I/O rate of GDDR4
GDDR5X
GDDR6

HBM (High Bandwidth memory): Competitor to GDDR5
HBM2: Competitor to GDDR6

74
Q

Onboard Video

A

Motherboard with built-in GPU

75
Q

Integrated GPU

A

Separate chip attached to motherboard or built into northbridge chip.

76
Q

APU

A

AMD Accelerated Processing Unit:
Integrates 2-4 CPU cores
Memory controller (supports DDR4 for system & cache)
GPU
Requires far less electricity than competitors

77
Q

GPU Installation 3 Issues

A

Length of card

Proximity of nearest expansion card
(Leave room for fan ventilation space)
(Some cards are double-wide for air vents)

Presence of power connectors

78
Q

Inverter Dangers

A

Powered by high-voltage electrical circuit
Charge remains after unplugged (wait a bit)
Gets very hot, can burn you.

79
Q

Cleaning a Monitor

A

DO NOT use window cleaners (ammonia/liquid)
It can get into the monitor.

Use a microfiber cloth (anti-static monitor wipe)