Sharp Notevision XG-NV7XU, Service Manual

Page: 22 / 110

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XG-NV7XU
3. Switching of Mirror
The mirror reflects light in one of two directions,
depending of the state of underlying memory cell. The
mirror rotates by a force of electrostatic attraction
produced by voltage difference between the mirror and
the memory cell. With the memory cell being in the ON
(1) state, the mirror rotates by +10 degrees. With the
memory cell being in the OFF (0) state, the mirror rotates
by -10 degrees. Figure 5. shows a close-up of DMD
mirrors operating.
Mirror – 10 deg
10 deg
CMOS
Substrate
Landing Tip
Yoke
Hing
Figure 4. Two DMD pixels
(mirrors are shown as transparent)
By combining the DMD with a suitable light source and
projection optics ( Figure 6.), the mirror reflects incident
light either into or out of the center of the projection lens
by a simple beam steering technique. Thus, the (1) state
of the mirror appears bright and the (0) state of the mirror
appears dark.
Figure 5. Images of operating DMD
Figure 6. DMD optical switching principle
Flat
Pixel
Image
+10
°
–10
°
+10
°
20
° 20
°
40
°
Projection
Lens
Light From
Illuminator
Flat
Pixel
Mirror
–10
°