dlp, mirrors switch off how? Light source "chopped"?

http://www.dlp.com/home_entertainment/default.asp

Just viewed the TI DLP demo and have a question about 'off'.

The mirror creates shades of gray by integrating white light. The
longer
is stays on, the whiter the pixel. I would think that during the
switch 'off'
a streak of light would appear on the screen as the mirror moved to
off screen.

I assume it must switch so fast that you can't see the line, the DLP's
version of a CRT's retrace, or is the light source 'chopped'. Does the

light source shutdown during mirror adjustments?

If it's so fast one couldn't see it, I wonder if there is a combination
where
a small black area is effected by large gray area switching
'off' thru it. Perhaps 'off' is mapped randomly to different offscreen
areas. (Or is off an "null" mirror, in which case the retrace would
always be the same path thru the black area).

And for color, does the light source shutdown for a short period
between the color changes to allow mirrors to move?

TI said the chip could generate 1024 levels of gray.

Thanks

Do you understand that a specific mirror on the DMD just has to change about
1/2 of a degree to change from full on to full off state? Also, since there
are just how many actual mirrors on the DMD and physically how large they
are, do you actually think we would be capable of actually seeing the
physical change, other than acknowledging that indeed it did switch off or
on? Also, in many cases, unless more than one mirror in a given physical
area changed state, an actual difference on the screen may not be noticed.
Therefore if just one mirror is changing position we probably would not
notice it's effect.
However, if one of the mirrors were jammed in the full on display mode, we
would notice it since there probably would be a non-extinguishing pixel on
the screen, dependent on the surrounding colours, it would be quite
noticeable.
"werwer" wrote in message
oups.com...
http://www.dlp.com/home_entertainment/default.asp

Just viewed the TI DLP demo and have a question about 'off'.

The mirror creates shades of gray by integrating white light. The
longer
is stays on, the whiter the pixel. I would think that during the
switch 'off'
a streak of light would appear on the screen as the mirror moved to
off screen.

I assume it must switch so fast that you can't see the line, the DLP's
version of a CRT's retrace, or is the light source 'chopped'. Does the

light source shutdown during mirror adjustments?

If it's so fast one couldn't see it, I wonder if there is a combination
where
a small black area is effected by large gray area switching
'off' thru it. Perhaps 'off' is mapped randomly to different offscreen
areas. (Or is off an "null" mirror, in which case the retrace would
always be the same path thru the black area).

And for color, does the light source shutdown for a short period
between the color changes to allow mirrors to move?

TI said the chip could generate 1024 levels of gray.

Thanks

So the answer is......


(Geezzzz Art, you do go on. Does anyone just answer questions anymore?
"Do you actually"... no, I didn't know.)

werwer wrote:
So the answer is......


(Geezzzz Art, you do go on. Does anyone just answer questions anymore?
"Do you actually"... no, I didn't know.)

There is one mirror/pixel which controls all the colors for that 1
pixel. The RGB display is synchronized with the color wheel so that the
red data is displayed when the red zone of the wheel is in front of the
DLP chip and the same for the blue and green.

Earlier sets like mine have a 1280x720 DLP chip for 921,600 mirrors.
Art is correct that the mirrors only move a small amount - and being so
small - can move very fast. Varying the on vs off time of the
individual mirror controls the brightness of the individual colors for
each pixel. That is definition of Pulse Width Modulation (PWM).

The image on the screen is not 'painted' on line-by line like a CRT.
All the RBG data is loaded into the chip and transferred from the
'load' buffer to the display section 30 frames/second. The RGB pictures
are shown sequentially in sync with the color wheel to make a full
color image.

Did I go on too long? HTH

GG

Maybe Texas instruments, the originator of the DLP Technologies, could fill
you in a bit more?
"G-squared" wrote in message
ups.com...

werwer wrote:
So the answer is......


(Geezzzz Art, you do go on. Does anyone just answer questions anymore?
"Do you actually"... no, I didn't know.)

There is one mirror/pixel which controls all the colors for that 1
pixel. The RGB display is synchronized with the color wheel so that the
red data is displayed when the red zone of the wheel is in front of the
DLP chip and the same for the blue and green.

Earlier sets like mine have a 1280x720 DLP chip for 921,600 mirrors.
Art is correct that the mirrors only move a small amount - and being so
small - can move very fast. Varying the on vs off time of the
individual mirror controls the brightness of the individual colors for
each pixel. That is definition of Pulse Width Modulation (PWM).

The image on the screen is not 'painted' on line-by line like a CRT.
All the RBG data is loaded into the chip and transferred from the
'load' buffer to the display section 30 frames/second. The RGB pictures
are shown sequentially in sync with the color wheel to make a full
color image.

Did I go on too long? HTH

GG

Art wrote:
Maybe Texas instruments, the originator of the DLP Technologies, could fill
you in a bit more?
"G-squared" wrote in message
ups.com...

werwer wrote:

So the answer is......


(Geezzzz Art, you do go on. Does anyone just answer questions anymore?
"Do you actually"... no, I didn't know.)

There is one mirror/pixel which controls all the colors for that 1
pixel. The RGB display is synchronized with the color wheel so that the
red data is displayed when the red zone of the wheel is in front of the
DLP chip and the same for the blue and green.

Earlier sets like mine have a 1280x720 DLP chip for 921,600 mirrors.
Art is correct that the mirrors only move a small amount - and being so
small - can move very fast. Varying the on vs off time of the
individual mirror controls the brightness of the individual colors for
each pixel. That is definition of Pulse Width Modulation (PWM).

The image on the screen is not 'painted' on line-by line like a CRT.
All the RBG data is loaded into the chip and transferred from the
'load' buffer to the display section 30 frames/second. The RGB pictures
are shown sequentially in sync with the color wheel to make a full
color image.

Did I go on too long? HTH

http://dlp.com/

Check out the flash demo

werwer wrote:
http://www.dlp.com/home_entertainment/default.asp

Just viewed the TI DLP demo and have a question about 'off'.


Here's even more info

http://www.ti.com/sc/docs/products/dlp/spie-paper.pdf

Art wrote:
Do you understand that a specific mirror on the DMD just has to change about
1/2 of a degree to change from full on to full off state?

You sure about the 1/2 degree?

http://www.ti.com/sc/docs/products/dlp/spie-paper.pdf

Page 2 says *12* degrees. I don't think it's a typo, and their
illustration would seem to imply that as well.

Art wrote:
Maybe Texas instruments, the originator of the DLP Technologies, could fill
you in a bit more?
"G-squared" wrote in message
ups.com...
snip
There is one mirror/pixel which controls all the colors for that 1
pixel. The RGB display is synchronized with the color wheel so that the
red data is displayed when the red zone of the wheel is in front of the
DLP chip and the same for the blue and green.

Earlier sets like mine have a 1280x720 DLP chip for 921,600 mirrors.
Art is correct that the mirrors only move a small amount - and being so
small - can move very fast. Varying the on vs off time of the
individual mirror controls the brightness of the individual colors for
each pixel. That is definition of Pulse Width Modulation (PWM).

The image on the screen is not 'painted' on line-by line like a CRT.
All the RBG data is loaded into the chip and transferred from the
'load' buffer to the display section 30 frames/second. The RGB pictures
are shown sequentially in sync with the color wheel to make a full
color image.

Did I go on too long? HTH

GG


Ok Art. Did I get some part wrong?

GG