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http://uk.mouser.com/search/refine.a...&Ntt=187183644
Micromirrors have been around for a while in video projectors - now they're available as components. Size looks useful for laser use, I guess it depends how well they can stand any power absorption.
That's rather interesting. And seems reasonably priced - at least for that component.
nope.
Attachment 37319
"the myth of the killer ape is true"
The datasheet http://www.ti.com/lit/ds/symlink/dlp3000.pdf goes into some detail on how to calculate the thermal dissipation. Clearly no good for a big laser, maybe a small one?!
From what I can tell from the datasheet each mirror in the array can go from -12* to + 12* in a binary fashion.
There is no way to position the mirrors between these two positions controllably.
I looked into these a few months ago. I was so impressed with DLP video projection bandwidth (100Mpps) that this seemed inevitable. The spec sheets I saw listed power handling more like 10 W/cm2. My projector OUTPUTS 4,000lumens from a single 2-3cm2 chip. But, I'll look for this.
The deal killer however, is the limit of three states:-12degrees, center rest and +12degrees. This seems unnecessary as they are electrostaticly moved against an infinitely varying silicon cantilever. but TI's tech support confirmed this and so any area you do not want bright means that those pixels that cover that area have to send their light to a dump. They cannot send the light to another region as a typical galvo mirror does.
Then there is diffraction. The typical DLP projector re-images the chip on the far field screen (greatly magnified). This allows a pixel ,that is 5 um across, to produce a sharp point of light 3mm across at a baseline distance of 10M. A laser reflecting directly off of one of these pixels would diverge at about one radian. If that laser were to use the projector's optics in the same way the projector does to re-image the pixel, then the scan angle would be severely limited; the beam would hardly move at all. This is the same reason why we can't use a lens after the scanners to improve the divergence of a typical laser projector without proportionally reducing the scan angle. And because the step distance from one angled pixel to the next and so on across the chip changes with scanned angle, you can forget about these pixels acting cooperatively as a phased array.
Where I think this is going (if you ask me) is where lasers as extremely bright,monochromatic light sources are coupled to these extremely fast chips to permit 40,000 lumen instead of 4,000 lumen projectors to run at khz refresh rates.
Color control/intensity is fun as well:
Quote:
Therefore, a single video frame is composed of a series of bit-planes. Because the DMD mirrors can be either on
or off, an image is created by turning on the mirrors corresponding to the bit set in a bit-plane. With the binary
pulse-width modulation, the intensity level of the color is reproduced by controlling the amount of time the mirror
is on. For a 24-bit RGB frame image inputted to the DLP300, the DLPC300 creates twenty-four bit planes, stores
them on the mDDR, and sends them to the DLP3000 DMD, one bit-plane at a time. Depending on the bit weight
of the bit-plane, the DLPC300 controls the time this bit-plane is exposed to light, controlling the intensity of the
bit-plane. To improve image quality in video frames, these bit-planes, time slots, and color frames are intertwined
and interleaved with spatial-temporal algorithms by the DLPC300.
Endth Quote.
The above is from the data sheet for the 135$ DLPC300ZVB controller chip needed for the DLP. You need to add external ram to it.
A while ago TI was offering a demo board for 256$ to the general public. Some PLers bought them. Maybe we can solicit a comment from one who has it.
Were it not for the expense, I'd rather have AO scanning in the future. 1024 by 1024 max, and you need lenses, but the power level is unlimited by our standards.
Steve
If anyone is looking to mess around with DLP devices, the carcuses from Casio projectors are one of the cheapest ways to get a working DLP chip (and they are much larger, good for tens of watts of power).
*shameless plug*
I also have them for sale... http://www.photonlexicon.com/forums/...without-diodes
take a look at HDI who are now owned by RED and will release the REDRAY projector this year.
Looks good but I bet its expensive.Quote:
Originally Posted by Picasso