Display Technology

Category:

1. Video Displays

Eg: LCD,LED,CRT,DLP

2. Non-video displays

Eg: Seven-segmentDisplay

3. 3D Display

Eg: Multiscopic, Hologram

4. Static Media

Eg: Movie Projector, LaserBeam, SlideProjector

Digital Light Processing (DLP)

Digital Light Processing (DLP) is a type of MEMS(Micro Electro Mechanical System)technology that uses a digital micromirrordevice(DMD).

Introduction to DLP:

• It provides all-digital projection displays that offer superior picture quality in terms of resolution, brightness, contrast.

• This provides an overview of the digital video processing solutions like scan conversion, picture enhancements, color processing.

• DLP™ technology is in use wherever visual excellence is in demand.

Important Basic Concepts of DLP

1. DMD

2. Color Wheel

DMD:

This device combines aluminum alloy mirrors, silicon based electrostatic drives, and silicon micro electronics to create a "light switch".

Construction & Mechanical Operation::

How DLP works?

1. Signal Conversion

2. Gray Scale Image

3. Color Creation

Step 1: Signal Compression

• Accepts both analog or digital signal

• All signals must be converted into digital

• The digital signal, enables mirrors to tilt towards “On” or away from “Off” light source.

Step 2: Gray Scale Image

• On” – light Pixel vs. “Off” – Dark Pixel

• Mirror switched on more frequently than off – Reflects Light Gray Pixel

• Rapid Switching allows up to 1024 shades of gray reflections

• Digitalized video signal entering DMD get converted into highly detailed gray scale image

not present

Step 3: Color Creation

• Color is added as white light from the lamp passes through a color wheel filter

• Color Wheel – RED, GREEN & BLUE

• mirrors on DMD are tilted on for the exact amount of time required for each basic color

• Only 1 color is shined onto DMD at a time

• When spinning fast enough, human eyes blend alternating flashes to view “more” colors in the projected image.

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• colour wheel present

Working Model

Practically Implemented Model:

Advantages:

• Lighter weight than LCD and plasma televisions

• It produces bright, high-contrast images

• It can be projected onto any size screen

• DLP Technology allows for a clear smooth picture with no glare due to its embossed coating technology:

Disadvantages:

• Replacement of the lamp / light bulb in lamp based units. The average life span of a mercury lamp averages 2000–5000 hours and the replacement cost for these range from $99 – 350, depending on the brand and model.

• Some viewers are bothered by the "rainbow effect" -particularly in older models.

• May use more electricity, and generate more heat, than competing technologies.

Application:

• Room Projectors, home theater, CRT, institutional projectors.

• 1-chip DLP Projection System

• 3-chip DLP Projection System