Chapter 17 - Display Technologies: Projectors, VR Headsets, and Common Monitor Features (1001)

Cold Cathode Fluorescent Lamp (CCFL)

An older backlighting technology that uses one or two fluorescent tubes to light a monitor panel. Popular for its low power, even brightness, and long life.

Viewing Cone

As little as 70 degrees from the center line a a fairly narrow viewing angle.

BtW

Black-to-White

Nits

Brightness is measured in this.

CRT

Cathode Ray Tube

CCFL

Cold Cathode Fluorescent Lamp

Pixels Per Inch (PPI)

Combination of resolution and physical size of a display determines this.

Virtual Reality (VR) Headsets

Create an immersive experience by mounting two high-resolution screens into a headset that blocks external visual sensory input.

LCD Panel

Creates Images.

Organic Light-Emitting Diode (OLED)

Current VR headsets use this techology to power the tiny, high-resolution stereo panels.

DLP

Digital Light Processing

DVI

Digital Visual Interface

Digital Visual Interface (DVI)

Digital interface used to connect a video source to a display device.

Pixel

Each tiny distinct group of three sub-pixels—one red, one green, and one blue.

Onscreen Display

Enables you to make a number of adjustments on your display technology.

Metal halide negatives

Excessive heat and noise.

Digital Light Processing (DLP)

From Texas Instruments uses a single processor and an array of tiny mirrors to project a front-view image.

Projectors

Generate an image in one device and then use light to throw (or project) it onto a screen or some other object.

GtG

Gray-to-Gray

HDMI

High Definition Multimedia Interface

Gray-to-Gray (GtG)

How long it takes the pixels to go from one gray state to another.

Black-to-White (BtW)

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

Backlights

Illuminate the image so you can see it.

IPS

In-Plane Switching, display beautiful color.

Thin Film Transistor (TFT) or Active Matrix

Is a special kind of field-effect transistor made by depositing thin films of an active semiconductor layer as well as the dielectric layer and metallic contacts over a supporting (but non-conducting) substrate.

Lumen

Is the amount of light given off by a light source from a certain angle that is perceived by the human eye.

Throw

Is the size of the image at a certain distance from the screen.

Color Depth

LCD panels vary in the amount of colors they can display.

LED

Light Emitting Diode

High-Definition Multimedia Interface (HDMI)

Many LCDs, projectors, and VR headsets connect to a computer using this. Laptops can connect to projectors using this as well.

Video Graphic Arrays (VGA)

Many monitors for Windows PCs use a 15-pin, three-row, D-type connector and a power plug.

Single-link DVI

Maximum Bandwidth of 165 MHZ. Displays 1920 × 1080 at 60 Hz or 1280 × 1024 at 85 Hz.

Viewing Angle

Meaning the screen fades out when viewed from the side (or any angle not dead center).

mDP

Mini Display Port

Dynamic Contrast Ratio

Number for their monitors, which measures the difference between a full-on, all-white screen, and a full-off, or all-black screen.

OSD

Onscreen Display

OLED

Organic Light Emitting Diode

PPI

Pixels Per Inch

PLS

Plane to Line Switching (PLS)

Direct LED Backlighting

Put a bank of LEDs behind the panel, providing better uniformity of image. More expensive and uses more electricity.

Refresh Rate

Refers to how often a LCD screen can change or update completely.

Native Resolution

Resolution of an LCD display that produces the best display quality.

Plane to Line Switching (PLS)

Samsung version that is proprietary, functions similar to IPS.

Inverters

Send powers to back-lights that need alternating current (AC electricity).

Static Charging

Shows the number zero, a display made possible by charging six areas to make an ellipse of sorts.

Thunderbolt (DisplayPort, DP)

Similar to HDMI, supports full-HD and audio.

Interpolation

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

VESA Mount

Standardized bracket option for mounting the monitor on the wall or on a special stand.

Resolution

Such as 2560 x 1440, describes the number of pixels on a display.

Contrast Ratio

The difference between the darkest and lightest spots that the monitor can display.

TFT

Thin Film Transistor

TN

Twisted Nematic, fastest.

Edge LED Backlighting

Typical implementation for back-lights and the drawback is you can see sometimes the edges are a little brighter than the center.

Thunderbolt 3 uses...

USB Type-C connector.

X Wires

Used in early LCD screens - horizontal wires ran every sub-pixel in the row.

Y Wires

Used in early LCD screens - vertical writes ran to every sub-pixel in the column.

DUal-link DVI

Uses more pins to double throughput and thus grant higher resolutions. Displays 2048 x 1536 at 60 Hz.

Passive Matrix

Varying the amount of voltage on the wires made different levels of red, green, and blue, creating colors.

VA

Vertical Alignment, fall somewhere in between the two in terms of responsiveness and color accuracy.

VR

Virtual Reality

Front-View Projectors

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

Lamps

Work hard in your projector, as they must generate a tremendous amount of light.

Milliseconds for response rates....

lower being better.

Response Rate

Amount of time it takes for all of the sub-pixels on the panel to change from one state to another.

LCD Measured by Manufacturers by...

1. Black-to-white (BtW) 2. Gray-toGray (GtG)

Lamp Technologies

1. Metal Halide 2. LED 3. Lasers

LCD Components

1. Panel 2. Backlight(s) 3. Inverters

Common Panel LCD Types

1. Twisted Nematic 2. In-Plane Switching (IPS) 3. Vertical Alignment (VA)

OLED differs from LCD in these ways...

1. Use organic compounds between the glass layers that light up when given an electrical charge. 2. No backlight, can turn off completely, enabling pure black and thus phenomenal contrast compared with LCD panels.

Monitors connect to computers via one of six connectors:

1. VGA 2. DVI 3. HDMI 4. DisplayPort 5. Thunderbolt

Small, Dark Room (Lumen)

1000-1500 lumens

Large Room (Lumen)

10000 Lumens

Color Depth (Higher End)

1024 (2^10) color variations

Standard Throw Projector

11-12 feet away from the projection surface.

Wide Extended Graphics Array (WXGA)

1366 x 768

Higher-end monitors for Refresh Rate...

144, 165, 240 Hz

Ultra-Short Projector

15 inches away from the projection surface.

Aspect Ratio Example

16:9

Full High Definition (FHD) or 1080p

1920 x 1080, now typical in today's screens.

Mid-Sized Room (Lumen)

2000 lumens

Color Depth (Most)

256 (2^8) color variations

Average LCD Panels has ____ nits.

300

Short-Throw Projector

4 feet away from the projection surface.

LCD Modern response rate

5 ms

Refresh Rate Standard

60 Hz

Color Depth (Old)

64 (2^6) color variations

Video Graphics Array (VGA)

640 x 480

Sub-Pixels

A color LCD screen is composed of a large number of tiny liquid crystal molecules arranged in rows and columns between polarizing filters.

Light-Emitting Diode (LED)

A diode that will produce light when current flows through it in LCD displays.