DMD Mirrors in a DLP-Projector Moving in Slow Motion (Stroboscopic Effect)

[@siubidua]

I am a technician of the projectors, and I repair them for a living. I know how DMD chip works in theory, but I wanted to see that in a real life. I searched for a video, and found yours. By the view count, not that many people are interested in how their projector creates an image. Nevertheless great video, with good explanation. So I want to say thanks for spending your time to create it, and satisfying my curiosity. THANK YOU!

[@HuygensOptics]

Hi Siubidua, Thanks for your feedback. I just started making these videos so I only have a very limited number of subscribers at this moment. More optics videos will be coming soon, including another video on an interesting application involving DMD-chips. Best regards, Jeroen

[@extradimension7356]

@@HuygensOptics I was at an SPIEE conference I think 2006 ??? On 3d stereo applications and they gave Dr Larry Hornbeck a life time achievement award (of sorts) and the keynote speech / pimp spot to explain how he developed the DMD methods. To me this seems like THE MOST improbable photonic device on the planet... Wiggly mirrors to create clean imagery. He seemed like a very nice guy.

[@FunnyHacks]

@@HuygensOptics I'd be really interested to see one on pixel shifting on DMD chips.

[@aa-ru6ni]

@@FunnyHacks Hi, what do you mean by pixel shifting ? I would like to know how to dismantle DMD chip from DLP video projector to get it flashed directly with laser to get reflected pixel projected on the wall. [e-mail] let me know your opinion thank you

[@siubidua]

@@FunnyHacks do you mean pixel shifting on 4k projectors that use 1080p dmd chips?

[@WilsonOlivierGazer]

The only video with the actual DMD in the highest quality, thumbs up

[@sferg9582]

Blows my mind how anything like this can actually work. The timing and computing power alone is astounding.

[@RCP-1136]

Maybe the image processor is an fpga.

[@niceshotapps1233]

I am more astonished with a device having more than 2 million moving parts cycling more than 15 thousand times a second and not breaking down in the blink of an eye.

[@sebulbathx]

Totally agree. It's great tech in combination of knowing how the brain works and exploit that to project a picture or video. Also I am amazed how it's even possible to make something small like this AND it have parts moving.

[@alexanderdaum8053]

@@RCP-1136 I'd guess they would be ASICs, FPGAs are far too expensive for mass produced devices.

[@shadowoffire4307]

Still science can't find the cur current on male pattern baldness and hair loss,we can land our craft on mars, make DMD mirror projector technologies but no cure on baldness,cancer,dibates,HIV,alibi met,dementia ect ect and of course covid. For me this failure of medical, science and technology blows my mind.

[@mildsauce5019]

8:14 A BRILLIANT example of the stroboscopic effect -- 10 seconds of viewing and you understand it perfectly.

[@elliotburing87]

This is actually a BEAUTIFUL explanation and demonstration. The KZbin algorithm got it right by pointing me here. Fantastic video!!

[@nicholaswilliams4507]

Texas Instruments should really link to this video in their docs. Hugely helpful!

[@Cyborg571]

Fantastic video with excellent explanations. Just spent my entire afternoon tearing apart my DLP TV to swap out the chip and was interested to see if anyone had viewed it working under a microscope. Thanks a ton for putting this together!

[@Thomas_Deering_King]

I know that a high quality video like this takes a ton of time to produce. So much detailed excellent information! Thank you for going through all the trouble to make this. I really enjoyed it!

[@NicolasSaudemont]

This video truly deserves way more upvotes. Good job ! Thanks a lot for the effort of making all this visible and understandable !

[@rorypenstock1763]

That's so cool how they split up the exposure time into "bitplanes." Of course it makes sense to do it that way, but it never would have occurred to me.

[@tookitogo]

Plasma TVs did the same thing, incidentally! I wouldn’t be surprised if OLED displays are driven the same way, but this is pure speculation.

[@monad_tcp]

naive young me though it was PWM, how silly, but older me is wiser now. (wiser in no more than exactly 12:40 minutes)

[@StefanReich]

Why is it better though? Because there are only 8 different times where mirrors are moved and not 256?

[@tookitogo]

@@StefanReich PWM would switch it _fewer_ times - once on, once off per cycle. A system like this (which sorta mixes PWM and PFM) increases the number of transitions, which would reduce flicker.

[@tookitogo]

@@monad_tcp It’s sort of a mix of PWM and PFM, in a way!

[@Tristoo]

holy shit. DLP is cool, and once I understood it was just mirrors I pretty much assumed all the rest correctly. but the stroboscopic effect and how you presented both the matrix and the wheel side by side there in the end - straight up blew my mind. I'm very glad I can understand all this and that I live in a time and world where not only is it possible but also there's people like you making these insane quality videos.

[@JoolsParker]

Your ability to explain things in easily understood ways should never be underestimated.

[@shashidharmurthy2226]

Yes,the only video in KZbin with entire details of dlp chip and the projector, far more complex than LCD projector, thanks sir

[@marshallrockwell4365]

Such a high quality presentation, thank you!!

[@gatekeeper84]

If there would be oscars for youtube videos you should be awarded one for this video.

[@screambmachine]

came to this channel for polishing lenses, as i'm a precision optician (who does many other things besides polishing in the production of our mirrors). and then the same guy uploaded an explanation of a colour wheel projector, which i chose to buy some years ago because of the low input delay for gaming (you mentioned the real time calculations). best thing about this is, that i didn't even know that it'll explain this mechanism, the title just seemed interesting hahaha. i wanted to know how it works for ages, but didn't know what to search for. at first the video appeared to be quite hard to understand, but it unfolded nice and logically. very well done, i love your setup and the depth of explanation.

[@juliankandlhofer7553]

The stroboscopic effect is really cool! There are actually old so called Sampling Oscilloscopes which use a simmilar effect. That way they could achieve multiple GHz apparent sampling rates when computers hadnt even reached MHz speeds.

[@untitled2792]

smart

[@anullhandle]

They still do that in a manner of sorts. Ludicrous speed scopes use multiple time shifted front ends combined in real time for 100 gig if you don't blink at a million + price of entry.

[@juliankandlhofer7553]

@@anullhandle if the price tag is "contact us" you know its good stuff :)

[@anullhandle]

@@juliankandlhofer7553 the signal path did a review of the uxd. They wouldn't let him take it apart but sent some boards along for analysis. Iirc a channel combined 3 36Gig adc. I probably couldn't afford the box a probe comes in :)

[@peterpaul9320]

It is amazing how advanced and complicated entertainment electronics got over the years.

[@elliotburing87]

This really deserves a huge amount of views.

[@floof9789]

I had no idea this is how projectors work, this is insane!

[@janami-dharmam]

I had read the principle before and it seemed more like some black art! How these mirrors are made and driven?

[@floof9789]

@@janami-dharmam It is actually quite amazing! Here is a great video that describes them: kzbin.info/www/bejne/b5_FaaCDaNp4f8U

[@BiffTannenBTTF]

Truly unbelievable. I would love to see how they manufacture these chips.

[@HuygensOptics]

I think this video gives a lot of info on MEMs devices (for DMD see around 11 minutes): kzbin.info/www/bejne/n4GqoaKLg5dssM0

[@BinaryBlueBull]

I do not understand why this channel doesn't have more subscribers. The ingenuity and complexity of both his projects and the experimental setups when he wants to explain something are amazing. I'm binge-watching these videos, damn this is interesting

[@DownhillAllTheWay]

That was very enlightening. I had never thought about how projectors worked, but I had supposed that they projected through an LCD screen with a bright light, that would then be focused with a lens, a bit like replacing the film in a film projector with an LCD. I didn't know of the existence of these DLP chips. It gives me something new to think about. Thanks for presenting it. You did a *_very_* good job. I designed and built a strobe, and I'm busy making a KZbin video on its construction and about strobes in general, and that's how I found myself here.

[@borkborkfoxxo279]

I had some exposure to optics in a college physics class (1000 level, so simple thin lenses, spherical mirrors, etc) and I got curious so I checked on youtube to see how complicated it could get, and here I am. You explain everything in a wonderfully simple way that I constantly strive for in life science. Awesome channel.

[@gryfandjane]

Fascinating! I was a projector tech for a school district before I retired, and I was really intrigued by how they worked. Thanks for such a clear illustration of the process.

[@00LAH00]

I was pretty convinced this technology was inherited from the decepticons. Now after watching this video, I am fully convinced.

[@zagaberoo]

Great video, both the deeper details in DMD function and the breakdown of your stroboscopic recording were fascinating!

[@ariochiv]

It's weird to think that such a sophisticated device uses something as primitive as a piece of plastic dyed certain colors.

[@Maric18]

dyed plastic is pretty sophisticated if you think about it

[@xxportalxx.]

Idk in the one I took apart they were high quality glass filters, in higher intensity models they used switched arrays of lasers

[@richarddrenka]

one of the best explanations and practical in-depth exhibition of the technology.. I thank you Sir for you effort!

[@guily6669]

It's awesome how it's so simple yet so damn complicated at the same time. It's all about perfect timing.

[@videolabguy]

That was awesome! It answered the lingering question of how the pixels are time sliced to get grey scale. I imagined linear PWM (256 equal time slices per frame/field) instead of the binary (only 8 non linear time slices) method shown. Thank you.

[@mikefromwa]

Fascinating video and clear, succinct explanations of the details. Thank you.

[@RyanSchweitzer77]

Thanks for producing and posting this video, it's very well-done and does an excellent job in explaining and showing how DMD devices work, especially for DLP projection. The stroboscopic capture effect mentioned from 6:02 to 8:38 is pretty much exactly how an automotive timing light gun works for checking (and aiding in adjusting) an engine's ignition timing, it uses the same stroboscopic techniques to "slow down" the motion.

[@xmlthegreat]

Just to clarify, the reason for the weird flashing with a normal camera is the rolling shutter of CMOS sensors, which scans the sensor from top to bottom, and this means that a short period of time passes during each frame, and for rapid events like strobes this means that by the time the sensor reads the bottom part that event is already over, or a next cycle has already begun. So the flash looks like it terminates or starts up at the bottom of the screen.

[@ZTenski]

Excellent footage. Really is incredible technology.

[@Miata822]

Very cool, I've always wanted to see a DLP chip in operation.

[@frankdogui7195]

Great video! Very clear explanation and presentation.

[@leozendo3500]

Extremely extremely good. the strobe time sampling is incredibly useful in cost-cutting techniques or in extreme high-frequency signal measurements. Thank you!!

[@beyondcompute]

Wow! Thanks for putting all the effort to make this video!

[@KISHORENEDUMARAN]

Brillant Explanation and well-made video! Thanks for sharing this! :)

[@armanx2]

Very educational , the technology we humans have archived is truly amazing. No one does really appreciate the fact what kind of crazy technologies we have these days. Truly amazing thx for the video

[@OnnieKoski]

This was awesome! Thank you!! I’ve known how this works for a while but I’ve never SEEN it work.

[@alcyonecrucis]

Amazing methodology for this man!!

[@jamescallaghan209]

Fascinating, thanks for producing and sharing this. I had a DLP TV and was always intrigued by the technology, so clever.

[@RobertMilesAI]

Extremely cool to see the whole cycle in "slow motion real time". I also like that you pronounce "magenta" two different ways in this video and neither one is right! The g actually has a j sound. English pronunciation is pure chaos

[@thetruthexperiment]

These chips are an absolute miracle of engineering and absolutely nobody ever made a big deal about it. If I had an employee tell me it was theoretically possible to make a million tiny actuated mirrors with lithography I would just say, no, no, you can’t. You’re dumb. Go away. But here it is. The tech just snuck into our lives with absolutely no fanfare whatsoever.

[@PplsChampion]

working on a similar build, ive been looking for this exact info about DLP devices for a long time, brilliant thank you

[@sachinvelankar4867]

Excellent video! thank you for taking the time to explain.

[@AjitV]

Thank you sir for your time and patience and clearly explaining DMD's

[@Arsenic71]

Wow, this is really interesting, thanks a lot for creating and sharing this video with us. It's much appreciated!

[@MacroDuPontOfficial]

the irregular flashing is not due to the framerate of the camera but because of the surface scanning of itself, taking in account the cameras acts as old crt screens (for comparison on the way they work) they scan each pixel from one end to the other thus creating the image, so in the proces, if something is happening at a faster speed than the one happening when the camera is scanning betwen each frame, you get chopped images and some weird effects best seen when taking photos.

[@craigkoehn9253]

Bloody awesome, mate. Love the channel 👍

[@Thats_Mr_Random_Person_to_you]

Great video! Worth noting in the Cinema industry (which is majority Texas instruments DLP based - Sony has pulled out of manufacturing new models as of 2020 so their LCD tech wont appear in new models) instead of a spinning wheel they use 3x DMD chips with the light source either split via prism to produce RGB light for its respective DMD or in certain breads of Laser projects individual Laser sources.

[@Mnkmnkmnk]

The rotating wheel must have been the most unreliable component of the projector. Great to see it gone. I wonder what the reliability of the dmd chips are like since they are also technically moving parts.

[@verschepard]

Someone people say that KZbin don't makes you smart. Watching great Videos Like this, i feel i can build a moon rocket 😁 thank

[@allenwp]

Thank for this video, I was able to learn a lot from your explanation! I knew about colour wheels, but I didn't understand the DLP technology that always seemed to be used with them. Now I think I have a very good grasp of how this works!

[@HarryHobo]

Thank you very much. Very interesting to really see the DMD working. Good explanation also.

[@chris-hayes]

This video is seriously underrated

[@JakobWells]

Thank you so much! This really helped me understand how DLP projectors work!

[@jasonmcintosh2632]

Supurb video. Thank you. I love how you explain what you know and not to try to sound knowledgeable about things you dont know.

[@ishtiaqali1117]

this video is great...but one will admit that we, humans are true genius on this planet …creating such thing which looks so simple yet so complex..2 millions of Nano mirrors on a half inch chip which give us beautiful images and the viewer don't know what's happening there...and when you dissemble a Dlp or a 3lcd projector ..inside... a complex world of electronics.. optics... lights arrangements. Heat arrangements. And all packed in a 12 inch plastic box...marvel of human inventions

[@sebulbathx]

I've always been curious how DLP projectors works in reality I know the principle in theory but never understood fully in reality. DLP is a really cool and great technique in showing video although I have a hard time watching it IRL because it strain my eyes. Thanks for a great video!

[@RamClaw]

Very well explained and I love the demonstrations 👍

[@ThomAnno]

Amazing. Wouldn't believed it if I haven't seen it. Really brilliant. Many thanks for the video. I now understand the color / image process in these projectors / screens a lot more. Math always amazed me but I'm kind of blunt in understanding it. Lol. The double split video and other features are really well produced. Thank you for all your effort. 👍👍👍👌

[@frankiemacaulay9417]

amazingly informative! perfect video

[@loleq2137]

Superb explanation and quality. Thank you for this video!

[@Nebenstehender]

Cool stuff dude! You've just earned another subscriber with this awesome video 👍

[@HuygensOptics]

Thanks for the compliment, I'm glad you enjoyed it.

[@Nebenstehender]

@@HuygensOptics Yes I did! I'm an engineer and very curious about almost any electronics and mechanical things. It's surprisingly hard to find good explanation how beamers and such devices work. I have to admit I do not spend enough time with doing researches. Anyway this video is a very good ressource to get my newbie questions answered. Keep up the good work!

[@ShopperPlug]

This is really cool. It's bizarre how you're able to capture the DLP mirror MEMs in real time at home...

[@graphenepixel8231]

he put a lot of money into all this for a project to make this kind of content.

[@complexobjects]

Incredible engineering. The only thing I'm left wondering is how the mirrors are individually flipped.

[@verschepard]

Power on and Power off for wach mirror...it's that simple

[@jamescallaghan209]

@@verschepard You mean they don't actually physically flip, just switch on and off?

[@verschepard]

@@jamescallaghan209 Sure, they physically flip, but only with power on, or power of for each mirror...power comes - flip, power Off -flip to start

[@jamescallaghan209]

@@verschepard thanks, but how? what's the mechanism? I wondered if there were two, set at different angles which switched on and off. It seems incredible that they actually move. Just trying to imagine the mechanics of it.

[@verschepard]

@@jamescallaghan209 check this Video also. Hope that will let you understand better kzbin.info/www/bejne/b5_FaaCDaNp4f8U

[@justgimmeaminute]

Absolutely amazing. Well done on a great video. That was really impressive

[@Zalo29]

Fantastico! Gran aporte. Nunca creí que un proyector funcionase con espejos. Da mucho juego para equipos DIY, los espejos pueden reflejar UV e IR Muchas gracias y sigue así!

[@HuygensOptics]

Thanks. Depending on the wavelength, reflecting IR light with this chip could be difficult given the size of the individual mirrors (7.56um).

[@paranoiia8]

That chip calculating it all that in real life is amazing just like idea and technology of moving whole matrix of tinny little mirrors... I seriously sometimes think that this or lcd/crt technology is pure magic...

[@caleballen4721]

The stroboscopic effect almost seems like a physical, discrete manifestation of the Fourier transform! Like holding the signal and "turning" it around in the time domain (like modulating f1 and f2 in your video) to get a better perspective of it

[@kchiew9839]

I wonder if this device had been use in telescope equipment - to compensate for atmospheric thermal distortion. Large telescope use its primary and /or secondary mirror to remove atmos. distortion.

[@victortitov1740]

I spotted two mistakes in the video. 1) additional colors in the color wheel are there not to improve color accuracy. Quite the opposite, actually: they are there to improve brightness of the image by sacrificing some color accuracy. But i suppose that theoretically it may be possible to improve color accuracy by trading brightness with more colors in the wheel. 2) images are encoded with 8-bit-per-channel srgb, where the code relates to brightness in semi-logarithmic manner. This nonlinearity cannot be reproduced by such a system. It can be done by using higher-bitness modulation, and/or by temporal and/or spatial dithering.

[@obensustam3574]

Thank you very much for this detailed explanation.

[@picksalot1]

Beautifully explained and demonstrated. With the mirrors moving so rapidly, I'm wondering what holds them in place and moves them in a way that they don't shatter. Thanks

[@myself248]

What an incredible video! I thought I had a pretty good idea of how these things worked, but I just learned a bunch more. Is there an advantage to the bitplane scheme instead of simple duty cycle? Is it easier to compute within the driver chip, perhaps? Do we know why certain mirrors (the upper-right three in the 100% white, for instance) seem to behave differently from the rest of the square? Is this perhaps some sort of subpixel rendering like ClearType trying to optimize the edges?

[@HuygensOptics]

The advantage of using bitplanes is that all the hard work is done in this process. The display chip just needs to display the consecutive bitplanes with the corresponding timing values (1 to 128 time units). So the process streamlines/simplifies the information transfer within the DLP chip. As for the different behaviour of certain pixels: there seems to be additional image processing in the projector, which resizes certain aspects of the original image (anti-aliassing, key stone correction etc.). This processing can make the pixels at the edge of a shape to become grayscaled. Due to the different gray scale, they also have a different timing scheme. I hope this anwers your questions.

[@galfisk]

Bit planes can be calculated using a few logic gates. I can think of a couple of schemes that'd use less components, but they'd be analog. Better to use the D/A converter inherent in our photoreceptors, and keep the chip wholly digital.

[@vega6379]

This is amazing the way you have explained it ...crazy...thanks!

[@donfreed2892]

This technology is amazing. Thanks for the video. I learned a lot.

[@raymondhuot1684]

Very interesting ! I have seen a different setup with 3 dip (red, blue, green) with a prism to ad the 3 beam through a single lens. It should be interesting to see how it work.

[@fabriziodutto7508]

Wow! What an explanation! Great video, thank you so much for sharing! Stay safe!

[@rapsod1911]

Amazing video!

[@hiibrain]

DMD chips are best mems device, also the software that runs this is amazing.

[@yuanhangzhang9555]

This is a great project! I learnt a lot

[@QuanrumPresence]

Really amazing idea. I didn't know it was this easy. I will have to try this

[@gudenau]

Huh, that bitplane thing is pretty clever from the point of view of system complexity.

[@MVVblog]

SUPERB VIDEO EVER!

[@sadiqpasha6622]

Superb video. Keep up the great work!

[@pete3897]

Been working with projectors for just over 3 decades now and never once until this day have I heard them referred to as 'beamers' :) In the local education circles they call them 'datashows' but they've always just been projectors to me.

[@henzelmen]

In Europe we call them beamers for decades, try Google for beamer.

[@flipschwipp6572]

brilliant video and explanation.

[@AndersonDusReparos]

isso é basicamente como aqueles relogios de holograma na hélice funcionam, o pixel tem q ligar na hora certa, por exemplo, no momento q a roda passa pela cor azul na luz e aquele determinado pixel precisa da cor azul para formar a imagem dejesada, então ele sera acionado muito rapidamente conforme a demanda.

[@Hubieee]

Thanks a lot, great video!

[@joshuaunderwood7]

Great video. Really cool stuff.

[@justinsmith2227]

Amazong work. Thank you, sir

[@GeirAtleStorhaug]

Great video, thanks! One thing I noticed: Are you sure the ON and OFF states are not reversed at 1:19? I would think that the ON state would require more precise aligning of the mirrors (to project precise pixel positions on the screen), and that may be easier to achieve in the flat/resting state. In the OFF state, the light is reflected to the beam stop/black body/heat sink, and precise reflection is not required.

[@HuygensOptics]

No the on state is the tilted state. The orientation is not too critical as long as most of the light hits the lens.

[@brendawilliams8062]

Thank you

[@williamsnyder193]

The mirrors do not sit flat when the DMD is running. They can only be +/- 12 degrees (angle differs btwn models). This is because there are mechanical stops tightly controlling the angle when the mirrors are being electrostatically driven. The position of the mirrors is not perfectly flat when 'floating', and so it is not a state used for display.

[@ediposantos6574]

5:00 bitplanes actually are a simple way to reduce calculations, its a wat to send the raw bit data directly to the mirrors without processing, in expense to more mirror commutations, wich seens to be no burden at all.

[@MikinessAnalog]

Auto mechanics also use a strobe to set the engine timing while it is running. It is cool how human eyes can use real life, real time "stop motion" like that.

[@Mnkmnkmnk]

It is amazing how we can take a simple operation and make it so fast that it looks like video to us. Now make this 2x faster and draw double the pixels on screen and we get pixel shifting 4k resolution. Then make it 2x faster and draw double of them at alternate times and we get active 3d. Then make it 2x faster and we get 120hz refresh rate 3d 4k enhanced video.

[@Twosies20]

Some 4K pixel shifters only do 2x pixels, but some do a full 4x pattern already, and are capable of 1080p240