DIGITAL LIGHT PROCESSING AND IT’S FUTURE APPLICATION

OUTLINE:

Introduction

History of Evolution

Basic components of DLP

How DLP works?

Pixel structure of Digital Micro-mirror Device (DMD)cell

Advantages & Disadvantages

Applications

Conclusion

Future roadmap

References

Introduction:

Digital Light Processing (DLP) is a display technology developed

by Texas Instruments.

It is based on an optical semiconductor, called a Digital Micro-

mirror Device (DMD), which uses mirrors made of aluminium to

reflect light to make the picture.

DMD can be combined with image processing, memory , a light

source and optics to form a DLP system capable of projecting images

with better colour fidelity and consistency than current technology.

It provides all-digital projection displays that offer superior picture

quality in terms of resolution, brightness, contrast.

History of innovation:

DMD was invented in 1987 by Dr. Larry Hornbeck of

Texas Instruments.

In 1993, it named the new technology DLP and formed a

separate group to develop commercial display

applications .

In 1994, TI demonstrated DLP projectors for the first time.

Since 2000, several DLP technology based products such as

projectors, HDTV’s, “Instant theatre”, etc were introduced .

Why DLP?

• The traditional CRT projectors have RGB tubes which makes the entire cabinet bulky.

• The LCD projectors use LCD light gates for projecting, which introduces pixelation effect.

• In order to overcome all the drawbacks of previous techniques, DLP was developed.

Components required for DLP:

Light source

Colour wheel

DMD

Memory

Projection lens & screen

How DLP works?It digitally manipulates light to produce film-like, all-digital images. DLP integrates a projection lamp and an electronic video signal from a source and the processed light produces an all-digital picture.

DLP projector internal structure:

DLP accepts analog or digital signals, which is converted into an entire picture frame video signal through processing.

Isometric schematic of DMD cell:

DMD comprises of over one million mirrors, where each mirror represents a pixel.These mirrors reflects light in either of two directions depending on the state of underlying memory cell.

Pixel structure of DMD cell:

The mirror is rigidly connected to an underlying yoke, which is in turn connected to the hinges to support posts that attaches the substrate. This DMD mirror is electronically driven.

Chip models of DLP:

Single chip model Three chip model

One chip DLP systems use a projection lamp to pass white light through a colour wheel that sends red-green-blue colours to the DMD chip in a sequential order to create an image on-screen.

In three chip DLP systems use a projection lamp to send white light through a prism, which creates separate red, green and blue light beams. Each beam is send to their respective red, green and blue DMD chip to process the image for display on-screen.

Advantages:

Brighter -Because it brings more light from lamp to screen.Sharper

-As it can produce the closest mirror image of an incoming video of any resolution .Versatile -DLP projectors are small and light weight.Reliable

-it is capable of recreating the source material .

Disadvantages:

The only real disadvantage of DLP projectors is "rainbow effect." •The Rainbow Effect often referred to as RBE, is a affect that has some people seeing flashes of red, green and blue. This is caused by the eye/brain dealing with the effects of projectors using high speed, spinning colour filter wheels. •Since a colour wheel is needed for this to occur, the only types of projectors affected are DLP projectors, since they are single chip devices, and require a colour wheel to add colour.

LCD Vs DLP Projector:

DLP Vs LCD

LCD DLP

LCD projector tends to produce more saturated colors and sharper images.

LCD Projectors operate by shining light through transparent LCD cells.

DLP Projectors typically offer deeper blacks and higher contrast.

DLP projectors operate by reflecting light through mirrors placed in the form of a matrix over a DMD device.

Applications:

DLP Televisions

Digital Light Processing Television is a technology that uses one, or sometimes three, electronic chips called Digital Micro-mirror Devices, or DMDs, to produce a vivid picture with a high contrast ratio on a high-definition large-screen TV.

Conclusion:

As compact disc revolutionized the audio industry, DLP will revolutionize the video projection.

Based on the reflected light produced by multiple mirrors, DLP creates a final link to display visual information.

Future Roadmap:

DLP projectors are becoming more common in business environments as it incorporates high-definition image creation.Scientist and developers are likely to discover even more uses for DMDs and DLP technology in the future.

References:

Digital light processing and its future applications, International Journal of Scientific and Research Publications, Volume 3, Issue 4, April 2013 1 ISSN 2250-3153.Digital Light Processing™: A New MEMS-Based Display Technology Larry J. Hornbeck Texas InstrumentsP. Van Kessel, L. Hombeck, R. Meier and M. Douglass, “A MEMS-Based Projection Display,” Proc. IEEE, Vol. 86, No. 8, pp. 1687-1704, August, 1998 .Rainbow effect,http://www.projectorreviews.com/articles-guides/rainbow-effect-2/#sthash.DEBP38Ek.dpuf