1. DLP / DMD Technology & Texas Instrument
Jessica Lau

2. Background - DMD Digital Mircomirror Device (DMD)
Invented by Larry Hornbeck
of Texas Instrument
Semi-conductor light switch
Rectangular array of up to 1.3 million of hinge-mounted movable microscopic mirrors
Size of a fifth of human hair
Each mirror correspond to one pixel of image
Mounted over a CMOS SRAM
SRAM – Static Random Access Memory

3. DMD 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.

4. Background - DLP DLP – Digital Light Processing
Proprietary Display Technology developed by Texas Instrument
Imaging system employ the use of one or two or three DMDs
Consisted of a light source, color filter system, cooling system, illumination and projection optics, memory and signal processing support.

5. DLP Imaging System

6. How DLP works ? DMD chip DLP I – Gray Scale Image
DLP II – Digital Color Creation
Applications and Configurations

7. Step 1 – Signal Conversion
Accepts both analog or digital signal
All signals must be converted into digital
Each pixel mapped directly to its own mirror at 1:1 ratio
By electrically addressing the memory cell below each mirror with the digital signal,
enables mirrors to tilt towards “On” or away from “Off” light source.

8. Step 2 – Gray Scale Image “On” – light Pixel vs. “Off” – Dark Pixel
Mirror switched on more frequently than off – Reflects Light Gray Pixel
Mirror switched off more than on – Reflects Dark Gray Pixel
Rapid Switching allows up to 1024 shades of gray reflections
Digitalized video signal entering DMD get converted into highly detailed grayscale image

9. Step 3 – Color Creation
Color is added as white light from the lamp passes through a color wheel filter
Color Wheel – RED, GREEN & BLUE
As wheel spin, 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.

10. Step 4 – Applications 1-chip DLP Projection System
16.7 millions of colors
TV, projector, home theater system
3-chip DLP Projection System
35 trillion of colors
3 DMD configuration
Each DMD dedicated to 1 color only
White light passes through a prism to divide red, green and blue and later recombine to form image

11. Advantages Smaller package size Light in weight Higher Contrast Ratio
( by increasing the tilt of mirror to12 degrees, and featuring a black substrate under mirrors)
Reduced Pixelation
(less visible pixel grid compared to LCD)

12. Disadvantages “ ” Varies for different people
“ ”
(Use of spinning color wheel to modulate image causes color to separate out in distinct red, green and blue in any given instant of time)
Varies for different people
Break out and rapid sequencing of color blamed for headaches and eyestrain
1st generation – 60Hz, 3600RPM, 1x
2nd generation – 120Hz, 7200RPM, 2x
Today – 120Hz, 7200RPM, 4x (6 segments of color wheel, double refresh rate)
THE RAINBOW EFFECT
60 hz - Update color 60 times per second 1x – rotational speed

13. Q & A