Yeah - I didn't actually connect all the dots on that one did I? I'll try to be better. What I was getting at was that the 1D solution needs additional parts to smear it across 2D, and it has other issues (potentially) due to this smearing. So it seems to me that as cost of MEMS drops a 1D solution would benefit less.

In other words if each device costs $0.0005 to make and the rest of the assembly is as follows:

2D - (just exemplary)

Chip $500
Other 100
-----------
$600

1D

Chip $ 12
Other 250
-----------
$262

12 months later.... device cost $0.00005

2D

Chip $ 50
Other 100
-----------
$150

1D

Chip $ 2
Other 250
-----------
$252

Sort of like that.

Among the other potential issues I can see so far are the one I mentioned earlier, plus the 1D reflective array has no benefit of phosphor persistence to lengthen its' on time. In effect each pixel would only be on 1/1920th of the time or less, even if very brightly. This would seem to indicate a possible flicker issue unless the scan is considerably faster than 30FPS. The image could be painted more than once at a higher frame rate, but then we're adding complexity again. I'm not even sure if this is an issue, but the potential seems to be there. I'm also quite sensitive to flicker.

I bought a de-interlaced TV 9 years ago (not cheap) simply to get rid of it as much as I could at the time.



Because it's not germane to the discussion unless I know whether there's a convergence adjustment inside. And because (to a lesser degree) it's not DLP.



The technology is very young. In a short period of time it will improve dramaticly. Most failures in MEMS devices are (typically) attributed to defects in manufacturung, even if the fail in the field. I'm not up on failures in DMD specifically, but motion sensors which use the same basic fab techniques (accelerometers, gyros) are in this class and I have no reason to believe DMD is any different. As quality improves this is becoming less and less of an issue.

Also, consider what a failed 1D device would look like if it ever happened.

Have a good one.

EDIT:

Here are some items from DMD failure analysis and QC docs:

"We now estimate,as we have demonstrated, that hinges will not break during at least 10 years of normal use in any application and more than 50 years in most applications."

And the overall conclusion:

"Through the use of accelerated life testing, the development of rudimentary
models, and environmental qualification, we have identified what we believe to be the complete list of life-limiting factors. As
discussed previously, hinge fatigue and environmental exposure are not life limiting. Particulate contamination appears to be random and not dependent on time or stress. We have not identified any correlation between light exposure and life. Through design robustness and process
control, we have eliminated all known contributors to surface adhesion degradation. This leaves hinge memory. Because hinge memory is so predictable, we have easily estimated our lifetime to be
greater than 100,000 hours, as long as the DMD die temperature is maintained at 45 °C or below.

Although an actual lifetime of 100,000 hours has not yet been demonstrated,
there is supporting evidence that DMD lifetime is measured in thousands of hours. Existing data through nearly 2 years of product deliveries have confirmed no DMD failures due to parametric curve
degradation (bias voltage parametric curves and reset voltage parametric curves). Several DMDs remain on test through 19,000 actual operating hours with no failures to date. This certainly supports the test results and estimates. In terms of random failures, few devices have failed during enditem use. We anticipated that particles would dominate random failures,
and that has proved to be true. Particles remain our primary cause of yield loss, but we have not observed a significant amount of customer returns caused by particles. In fact, even though particles are our primary
pareto item (Figure 12), the field failure rate for all DMDs delivered to date is less than 0.2%. We have estimated a mean time
between failures (MTBF) by using the total number of units shipped, multiplied by an estimate of usage hours per month, divided by the total number of reported DMD failures. Using conservative estimates
for all three of these factors, we have a demonstrated MTBF (random failures) of 119,000 hours."

That means the average DMD would fail in my house after about 80 years. I can live with that.

[This message has been edited by charlie (edited November 27, 2002).]