DLP / DMD TechnologyDLP / DMD Technology& &

Texas InstrumentTexas Instrument

Jessica LauJessica Lau

Background - DMDBackground - DMD

Digital Mircomirror Device (DMD)Digital Mircomirror Device (DMD) Invented by Larry Hornbeck Invented by Larry Hornbeck

of Texas Instrumentof Texas Instrument Semi-conductor light switchSemi-conductor light switch Rectangular array of up to 1.3 million of hinge-Rectangular array of up to 1.3 million of hinge-

mounted movable mounted movable microscopicmicroscopic mirrors mirrors Size of a fifth of human hairSize of a fifth of human hair Each mirror correspond to one pixel of imageEach mirror correspond to one pixel of image Mounted over a CMOS SRAM Mounted over a CMOS SRAM

DMDDMD Not operating – parked at 0 degree On – Tilt +10 degrees Off – Tilt –10 degrees On/Off Switching – 1000 times/sec

848 x 600 DMD Consists of 508,800 tiny,

tiltable mirrors A glass window seals and

protects the mirrors.

Background - DLPBackground - DLP DLP – Digital Light ProcessingDLP – Digital Light Processing ProprietaryProprietary Display Technology developed by Display Technology developed by

Texas InstrumentTexas Instrument Imaging system employ the use of one or two Imaging system employ the use of one or two

or three DMDsor three DMDs Consisted of a light source, color filter system, Consisted of a light source, color filter system,

cooling system, illumination and projection cooling system, illumination and projection optics, memory and signal processing support.optics, memory and signal processing support.

DLP Imaging SystemDLP Imaging System

How DLP works ?How DLP works ?

1.1. DMD chipDMD chip

2.2. DLP I – Gray Scale ImageDLP I – Gray Scale Image

3.3. DLP II – Digital Color CreationDLP II – Digital Color Creation

4.4. Applications and ConfigurationsApplications and Configurations

Step 1 – Signal ConversionStep 1 – Signal Conversion

Accepts both analog or digital signalAccepts both analog or digital signal All signals must be converted into digital All signals must be converted into digital Each pixel mapped directly to its own Each pixel mapped directly to its own

mirror at 1:1 ratiomirror at 1:1 ratio By electrically addressing the memory cell By electrically addressing the memory cell

below each mirror with the digital signal,below each mirror with the digital signal,

enables mirrors to tilt towards “On” or enables mirrors to tilt towards “On” or away from “Off” light source. away from “Off” light source.

Step 2 – Gray Scale ImageStep 2 – Gray Scale Image ““On” – light Pixel vs. “Off” – Dark PixelOn” – light Pixel vs. “Off” – Dark Pixel Mirror switched on more frequently than off Mirror switched on more frequently than off

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

Dark Gray PixelDark Gray Pixel Rapid Switching allows up to 1024 shades Rapid Switching allows up to 1024 shades

of gray reflectionsof gray reflections Digitalized video signal entering DMD get Digitalized video signal entering DMD get

converted into highly detailed grayscale converted into highly detailed grayscale imageimage

Step 3 – Color CreationStep 3 – Color Creation Color is added as white light from the lamp Color is added as white light from the lamp

passes through a color wheel filterpasses through a color wheel filter Color Wheel – RED, GREEN & BLUEColor Wheel – RED, GREEN & BLUE As wheel spin, mirrors on DMD are tilted As wheel spin, mirrors on DMD are tilted

on for the exact amount of time required on for the exact amount of time required for each basic colorfor each basic color

Only 1 color is shined onto DMD at a timeOnly 1 color is shined onto DMD at a time When spinning fast enough, human eyes When spinning fast enough, human eyes

blend alternating flashes to view “more” blend alternating flashes to view “more” colors in the projected image.colors in the projected image.

Step 4 – ApplicationsStep 4 – Applications 1-chip DLP Projection System1-chip DLP Projection System 16.7 millions of colors16.7 millions of colors TV, projector, home theater systemTV, projector, home theater system

3-chip DLP Projection System3-chip DLP Projection System 35 trillion of colors35 trillion of colors 3 DMD configuration3 DMD configuration Each DMD dedicated to 1 color onlyEach DMD dedicated to 1 color only White light passes through a prism to White light passes through a prism to

divide red, green and blue and later divide red, green and blue and later

recombinerecombine to form image to form image

AdvantagesAdvantages Smaller package sizeSmaller package size Light in weight Light in weight Higher Contrast Ratio Higher Contrast Ratio

( by increasing the tilt of mirror to12 ( by increasing the tilt of mirror to12 degrees, and featuring a black substrate degrees, and featuring a black substrate under mirrors)under mirrors)

Reduced PixelationReduced Pixelation

(less visible pixel grid compared to LCD)(less visible pixel grid compared to LCD)

DisadvantagesDisadvantages “ ”“ ”

(Use of spinning color wheel to modulate image causes (Use of spinning color wheel to modulate image causes color to separate out in distinct red, green and blue in any color to separate out in distinct red, green and blue in any given instant of time)given instant of time)

Varies for different peopleVaries for different people Break out and rapid sequencing of color blamed Break out and rapid sequencing of color blamed

for headaches and eyestrainfor headaches and eyestrain 11stst generation – 60Hz, 3600RPM, 1x generation – 60Hz, 3600RPM, 1x 22ndnd generation – 120Hz, 7200RPM, 2x generation – 120Hz, 7200RPM, 2x Today – 120Hz, 7200RPM, 4x (6 segments of Today – 120Hz, 7200RPM, 4x (6 segments of

color wheel, double refresh rate)color wheel, double refresh rate)

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