The accelerometers are on projectors for automatic keystone correction - a projector is a stationary device once set up, so an accelerometer can be used to accurately estimate the angle due to gravity, and thus assuming the projector is aimed at a vertical surface (rather than a perpendicular surface), basic trigonometry can be used to skew the image to correct distortion automatically. The more you know!
Mike, you asked at 4:18. The reason is to allow for automatic geometry (trapezoid) correction when the projector's aiming is moved up and down. It looks quite fancy in action.
Accelerometer, checked in the manual, automatic image flip and maybe automatic keystone adjustment capability, it makes sense. The datasheet mentions automatic keystone. The laser diodes are not all populated because this is the unit with less brightness in the series, the same design can provide other models with a higher brightness, they all may be populated then. Thanks for the videos !
Faster startup/shutdown are nice with laser projectors vs lamp based ones especially in a presentation settings where people always love unplugging projectors before they cool down.
Auto-keystone... that's why there's an accelerometer! ;) That, and mounting it up-side down etc ;) and the longer green, is due to the fact that we perceive more shades of green, than blue... then red is in between them!
I bought two diodes harvested from this exact model of projector, they were 2 watts each, I built laser pens out of them using a pocket flashlight (torch) as a body, and had the heatsink professionally milled. They run off a single high quality 18650 cell. Duty cycle was 1:2 - 2 minutes on 4 minutes off. Stupidly powerful, and now you can get 7 WATTS in a single diode!
Many projectors have an automatic setup option now. They'll automatically detect orientation, angle and and adjust keystone. It's useful for "mobile" projectors.
@@meepk633 Correct, an accelerometer that is not moving (such as one that is in a stationary device, like a projector) can simply measure the acceleration forces due to gravity in each dimension, and then basic trigonometry can be used to calculate the angle of the projector with relatively high accuracy.
That's crazy, a company buying a truckload of projectors, then stripping them. You'd think they'd just source the lasers from a supplier. What a load of ewaste that has created.
Yea that's the first thing I thought , a friend of mine has auto key and I cry at how easy it is to set up compared to mine, then again mine was ten times cheaper.
I would say the accelerometer is to straighten the image when your projector is tilted. You can probably save a ton of time if you have many to install or even with a mobile one, put it on the table, adjust the zoom and you are ready.
A lot of people bought these but only harvested 3-6 diodes which maintained the brightness, then sold the diodes or made laser pointers. From what I remember that model (M series?) had the 2 watt diodes where the A series had 1 watt.
I don't think this is true, I think from the factory they add or remove diodes, then pair it with a brighter or dimmer red led (bin) for their various projectors with different brightness. I've opened many warranty sealed units with no evidence of tampering. Plus the glued in screws look factory
Thanks Quinn F, for directing me at this. I understood more than I thought I would, but I'm glad Mike understands more, like don't put wood into the projector (not that I would have).
My Casio XJ-A131 slimline is showing 13803 hours and still burning brightly, have a complete spare unit ready for judgement day and one with a bad DLP chip for spares. i would recommend these little laser projectors to anyone, mine is hardly ever powered down !!!
Do a lot of work in the cinema industry and Dcinema is going laser orientated these days. They tend to come in a few 'flavours'. Cheap end is laser phosphor with blue lasers and a spinning phosphor wheel to create white light which is then split to RGB via a prism. Moving up you end up with various colour laser sources with the phosphor to create the missing colour. Then finally the hugely expensive (like £100k+ per projector) 6P where you have discreet laser colours (2 main sources for each colour) this can then be used to create a 3d effect if required by having a slight shift in RGB wavelengths from the two source groups. With the user then wearing different filters for each eye - so a more direct version of Dolby's 3d which uses a spinning wheel to create the same wavelength shift
Some of the largest and expensive projectors don't even have the lasers built in. They have external laser enclosures that "feed" the projector through fiber optics.
Your comments around 16 minutes about being unable to access filters for maintenance is common for a lot of Panasonic laser projectors as well, including high end (20K-30K lumen) units. They seem to think anyone using these are in clean positive pressure lecture theatres etc. I can tell you that old heritage listed theatres are far from clean!! I have provided feedback to their engineers that something that is 'maintenance free' doesn't mean it should be un-maintainable!
Great teardown! Learned a lot. Thank you! I had thought that laser projectors would require some type of moving diffuser to knock out the coherence of those red/blue laser beams. I know light produced from the phosphor is incoherent, so you're good there. But I'd think the the red/blue beams, expanded across the image plane would require some method to reduce coherence, otherwise all kinds of "speckle" would be seen across the projected field. Is this not true?
Accelerometer is likely so the onscreen menu and content is orientated properly since when you use it on a desk the top is pointed upwards but when you mount it on a ceiling the top faces the floor.
Another possible reason for the accel is theft detection. In a environment where the projector RS232 is being used for control the projector could send a theft warning message if the accel detects any movement.
We have installed quite a few of these , they have a habit of the image going pink after a while, they also lose light output. We dont use them much now mainly because the are only wxga. Laser projectors are also getting cheaper and cheaper all the time.
The habit of going pink is definitely not exclusive to this projector, or led projector... probably affects every possible technology, or at least that is my experience with projectors (though mostly just conventional Panasonics)
Interesting about the completely different methods for making each of the primary colors. As far as I know some other designs use the laser as only source by going through phosphors similar to those in high CRI white LEDs to create white light and then throw that onto a standard color wheel or dichroic mirrors. Someone I know bought a big professional Sony 10K lumen laser projector for a venue and the light source on that is specced as being just a 350W(!) blue laser array. Funny that blue lasers used to be that expensive and price has fallen off a cliff with 5W blue engraving lasers costing about 80 bucks from banggood now. On show lasers blue also always tends to be the most powerful one, seems blue is the cheapest per watt by now. As others have mentioned the accelerometer is likely for auto keystone compensation, most projectors have had that as a feature for quite a while now. Also a lot of projectors use LEDs as light source now, bulb-based ones are disappearing pretty quickly in favor of either LED or laser.
Interesting they would make the blue LEDs do double duty since blue LEDs typically have the lowest duty cycle? I suppose it keeps the number of LEDs down by doubling up colors onto one LED and if the blue goes the whole light engine has to be replaced. It must be easier to get green from blue than getting green from red or red from green. I was hoping with lasers since you can get all three primary colors from individual LEDs there wouldn't be any moving parts other than the micro mirrors on the DLP chips and the cooling fans but nope - still a fast spinning color wheel. The optics and engineering in this are amazing - especially when you think about the manufacturing scale and price point these things are made to. Incredible, really. Fascinating engineering! Also good to know to slap some external pre-filters onto those things. That's a horrible design with no filters!
Most of the manufactures are using laser for their high end 4k home theater projectors now. eg, EPSON / Sony / others. They are usually in the $5k-50k range
An office beamer I use from time to time has an auto-adjusting feature (focus, perhaps keystone). But it uses a tiny image sensor instead. Maybe I will try once to film it in slow-motion, as I don't see any fiducials being projected, it feels like magic.
Yeah I have a Hitachi that does automatic Keystone adjustment, as well as orientation. Of course its possible to manually override the automatic stuff if it gets it wrong
I saw a couple of sealing mounted projectors with anti theft feature, maybe the acc is for some kind movement detection. The projector I saw did not have an alarm or so, but would just lock up if moved. It even had a ton of warning labels saying this, and a bright orange housing... But I just read auto keystone correction in the comments, probably just this....
Nice video, as always. The accelerometer, to me, may serve as a digital and active interlock to stop the laser. If a laser is not mechanically stable, the light can shoot at undesired places, such as human eyes. I have seen similar designs on class-4 q-switched lasers. Not sure if it is designed for the same purpose here.
The algo for converting RGB into grayscale is (0.3 * R) + (0.59 * G) + (0.11 * B). So I guess thats why the green part of the wheel is longer than the passthrough blue.
I have an Epson projector that will automatically adjust the lens to project a flat image regardless of the angle the projector is sitting at. Auto leveling I guess, but you can turn it off.
Yes, its manually selectable but why not make auto the default? You could also have a trapezoid correction for mounting it at an angle have an auto setting.
Have wondered if it was possible to make a LEP flashlight ( think there is currently about a dozen models from a few manufacturers ) with a rotating wheel for changing colour of the light. Looks like blue, green and white would be at least possible.
I did a bit of reversing on the LED/Laser driver board on a similar model a while ago... photonlexicon.com/forums/showthread.php/11883-Running-the-XJ-A140-With-Missing-Diodes?p=216586#post216586 Unfortunately, none of the photo links work any more, but I basically just soldered SMD resistors and single strands of wire to the MCU on the board, to fool it into thinking it's getting feedback from the current shunt resistors for the laser bank. I had to use resistor dividers from the driving signals, to match up the levels that the MCU was expecting. Before then, there were a few mods where people were putting high wattage resistors in place of the laser diodes, often requiring water cooling. lol It was a very interesting time when these projectors were released, because it immediately started to devalue people's "industrial" blue laser modules, at least for laser show purposes. Back then, a 500mW Blue laser module could easily cost £600 upwards. These projectors had 24 diodes, each capable of power outputs of around 1-2 WATTS. Obviously the optics on a proper laser module are generally higher quality, with anamorphic lenses etc., but still. Some people were buying hundreds of these projectors brand new, just to salvage the diodes from them, and selling the diodes at around $60-70 each.
Oh, the motivation for me wanting to get the projectors running without lasers was because the projector "carcasses" were selling for only around £30 for a while. So I bought the Blue and Green versions of the same Phlatlight LEDs, and planned to make a driver board for them. As is usually the case, that project never got finished. lol i.imgur.com/LTnSdmQ.jpg (I had a previous project years ago doing a similar thing, to drive high-power RGB LEDs in sequence with the segments of the colour wheel, to replace the original lamp. It worked quite well, but the LEDs weren't particularly powerful nor affordable back then.)
Generally the medium which the projector will be projecting on will be vertical(Hanging or a wall). So it will change the vertical aspect ratio depending on the tilt? Edit, just read other comments. Keystoning. Always learning.
@@bacphan7582 Not really, Direct diodes multi watt green lasers at 525nm exists and can be had for 60$ a pop off ebay. They are used in projectors with both Blue and Green direct diodes.
@@cambridgemart2075 You are very much mistaken, The earliest projector (XJ-M130/A130) Came to the marker around 2013 and as you can see here: ua-cam.com/video/1KAqlEoQKrU/v-deo.html Cheap direct diode greens were very much available. The one-watt green diodes appeared around 2014-15.
@@Gianns_TDM YOU are very wrong, they launched much earlier than 2013, I bought several well used (10 000 hours +) ones in around 2011. Plus you contradicted yourself with the introduction date of the direct green diodes.
A bit late. Green is the most significant colour used for brightness. They may even increase laser brightness during the 'geen sectors' to get the white balance right.
Projectors can be quite intresting to take apert, the modern cheap ones are not as there optics are super simple. Got some intresting examples from the uni WEEE bin quite a few years ago now.
Projectors are sensitive to alignment issues if dropped, even from a few cm. Could have an accel so they can refuse warranty with proof the unit has been roughly handled by the customer. Or claim the shipping company warranty if a pallet arrives at distributor that they suspect was dropped. Does the PCB have a backup battery to run the accel while unpowered? I guess the question is, is their damage losses from bad unit handling costing them enough to justify a 20c accel per unit. I think it probably is. One damaged $2000 projector would pay for a lot of units to have an accel.
I'd love to get my hands on a DLP module that I can control for a DIY project. I have a dumb-but-fun project in mind where having control over a micro-array of mirrors like that would be absolutely ideal.
www.ti.com/tool/DLPDLCR2000EVM is about the cheapest available evaluation hardware. What level of control do you need? This only allows for video input which is then processed by a TI ASIC and then sent to the DMD. No direct control of individual mirrors possible.
@@JakePulliam Thanks for the lead. It"s low res and limited wrt interfacing, but otoh it's cheap and I have an unused BBB laying around so I've ordered one.
I think TVs and monitors are biased to show more green. The is called a Bayer Filter. It has to do with the human sensitivity to different colors. Nevermind, Bayer Filters are used on photo sensors like cameras.
I have long wondered why there are no projectors that would straight up use the laser beams and two really fast spinning mirrors instead of a delicate DLP. As far as I know, the diodes should handle multiple kHz of modulation just fine, and you'd even be able to adjust the resolution with some finely controlled motors spinning the mirrors. And you could also requlate brightness by voltage instead of super fast pulsing. Spreading the beam and have it run through several mirrors and prisms and what not seems like wasting a lot of potential output brightness, and direct laser beams wouldn't even require any optics or focus! Does anyone know why these things don't exist?
You need insanely accurate, fast scanning and well controlled beam shape, and speckle is a significant issue. There was a pocket projector (Microvision Showwx - I did a teardown a long time ago) that used a MEMS scanner but the product seems to have disappeared now.
@@mikeselectricstuff I dimly remember that! Quite possible that this had sparked my thoughts. The term MEMS definitely rings a bell. Must have gone like "huh, where is that $60k Sony version of this for 3m+ screens, that hopefully everyone else copies within 2 years?" in my head back then. I've been waiting out for affordable projectors that bring at least a small quantum leap in tech - be it just being 4k for < 1000€. I've had my Benq W1070 for too long now =) (Still cool though.) I think I have once seen some video about how to get rid of laser speckle, but that might as well have been wishful thinking. Here's to hoping that someone will tackle it one day soon enough! (Seriously, even the benefit of having no optics to focus would be incredible. Especially for artsy use on non-planar surfaces.)
I have a ASUS DLP pico projector and it can automatically adjust the screen direction and keystone depending on how the device is oriented.
The accelerometers are on projectors for automatic keystone correction - a projector is a stationary device once set up, so an accelerometer can be used to accurately estimate the angle due to gravity, and thus assuming the projector is aimed at a vertical surface (rather than a perpendicular surface), basic trigonometry can be used to skew the image to correct distortion automatically. The more you know!
Mike is still alive! I am pretty sure we all have missed you.
Auto-keystone correction can be done with an accelerometer
The accelerometer could be for tilt/roll angle measurement for automatic trapezoidal perspective correction of the projection.
Mike, you asked at 4:18. The reason is to allow for automatic geometry (trapezoid) correction when the projector's aiming is moved up and down. It looks quite fancy in action.
Accelerometer, checked in the manual, automatic image flip and maybe automatic keystone adjustment capability, it makes sense. The datasheet mentions automatic keystone.
The laser diodes are not all populated because this is the unit with less brightness in the series, the same design can provide other models with a higher brightness, they all may be populated then.
Thanks for the videos !
Really nice PCB layout, components grouped by function, many labels, some folks have pride in their jobs at Casio.
Accelerometer: For automatic tilt correction of the projected picture. Takes care of making straight vertical lines and also adjusts picture height.
Glad to see you uploading again Mike!
The accellerometer is probably being used for the auto keystone feature
Probably, yes. Or to automatically void the warranty if you accidentally drop the projector on the floor ;-)
Faster startup/shutdown are nice with laser projectors vs lamp based ones especially in a presentation settings where people always love unplugging projectors before they cool down.
Auto-keystone... that's why there's an accelerometer! ;)
That, and mounting it up-side down etc ;)
and the longer green, is due to the fact that we perceive more shades of green, than blue... then red is in between them!
Absolutely correct.
I hope someone can get hold of one of the new Audi headlamp laser projectors with DLP, they sound interesting.
NICE screwdriver tip..... thanks a lot for that one!
Accelerometr for Automatic keystone correction
I thought it was for detecting if someone used it as a light saber :-)
Projectors that don’t have the ability to turn that off is dead to me
I bought two diodes harvested from this exact model of projector, they were 2 watts each, I built laser pens out of them using a pocket flashlight (torch) as a body, and had the heatsink professionally milled. They run off a single high quality 18650 cell. Duty cycle was 1:2 - 2 minutes on 4 minutes off. Stupidly powerful, and now you can get 7 WATTS in a single diode!
In which projector?
Many projectors have an automatic setup option now. They'll automatically detect orientation, angle and and adjust keystone. It's useful for "mobile" projectors.
The accelerometer measures for screen flip and automatic keystone correction.
this
accelerometer is for trapisodial correction, for situations where the projector is not perpendicular to the projection surface.
So they can detect an orientation without acceleration?
Gravity?
@@meepk633 Correct, an accelerometer that is not moving (such as one that is in a stationary device, like a projector) can simply measure the acceleration forces due to gravity in each dimension, and then basic trigonometry can be used to calculate the angle of the projector with relatively high accuracy.
That's crazy, a company buying a truckload of projectors, then stripping them. You'd think they'd just source the lasers from a supplier. What a load of ewaste that has created.
You left the best to last! Glad to see I'm not the only one who finds those extra screws! 😂
The accelerometer is for auto keystone which is built in as a part of the TI DLP solution.
Yea that's the first thing I thought , a friend of mine has auto key and I cry at how easy it is to set up compared to mine, then again mine was ten times cheaper.
Accelerometer is most likely for detecting which way the projector is mounted as well as automatic key stone.
"Only a few screws leftover, but they always put so many of these things..." Haha! 🤣
I would say the accelerometer is to straighten the image when your projector is tilted. You can probably save a ton of time if you have many to install or even with a mobile one, put it on the table, adjust the zoom and you are ready.
A lot of people bought these but only harvested 3-6 diodes which maintained the brightness, then sold the diodes or made laser pointers. From what I remember that model (M series?) had the 2 watt diodes where the A series had 1 watt.
The Ms had more powerful diodes than the As, but I don't think it was 2:1. Also the Ms have 24 but the As had 20 LDs
I don't think this is true, I think from the factory they add or remove diodes, then pair it with a brighter or dimmer red led (bin) for their various projectors with different brightness. I've opened many warranty sealed units with no evidence of tampering. Plus the glued in screws look factory
What's the reason behind red being powered by an LED and the blue and green by laser?
Older unit probably. Newer ones may have red and green lasers, though the green are a bit off color at 520nm instead of 532nm.
LAZORS! Always good to see new content from Mike!
Thanks Quinn F, for directing me at this. I understood more than I thought I would, but I'm glad Mike understands more, like don't put wood into the projector (not that I would have).
Mikes video on fixing a firefighter thermal camera is a masterclass in practical fault finding theory.
My Casio XJ-A131 slimline is showing 13803 hours and still burning brightly, have a complete spare unit ready for judgement day and one with a bad DLP chip for spares. i would recommend these little laser projectors to anyone, mine is hardly ever powered down !!!
Accelerometer could be for automatic keystone correction or automatic ceiling og table projection without having to press any buttons.
The accelerometer is for auto keystone/rotation
the trick for those threadlocer screws is to heat with a soldering iron
Do a lot of work in the cinema industry and Dcinema is going laser orientated these days. They tend to come in a few 'flavours'.
Cheap end is laser phosphor with blue lasers and a spinning phosphor wheel to create white light which is then split to RGB via a prism.
Moving up you end up with various colour laser sources with the phosphor to create the missing colour.
Then finally the hugely expensive (like £100k+ per projector) 6P where you have discreet laser colours (2 main sources for each colour) this can then be used to create a 3d effect if required by having a slight shift in RGB wavelengths from the two source groups. With the user then wearing different filters for each eye - so a more direct version of Dolby's 3d which uses a spinning wheel to create the same wavelength shift
The downside for the laser phosphor projectors is the color reproduction. Not as good as RGB.
Some of the largest and expensive projectors don't even have the lasers built in. They have external laser enclosures that "feed" the projector through fiber optics.
I have a projector that automatically adjusts the keystoning based on its orientation. I'd bet that's what the accelerometer is for.
Keystoning... yikes
I remember when these projectors were discovered on the Photonlexicon forum :)
Your comments around 16 minutes about being unable to access filters for maintenance is common for a lot of Panasonic laser projectors as well, including high end (20K-30K lumen) units. They seem to think anyone using these are in clean positive pressure lecture theatres etc. I can tell you that old heritage listed theatres are far from clean!!
I have provided feedback to their engineers that something that is 'maintenance free' doesn't mean it should be un-maintainable!
Great teardown! Learned a lot. Thank you! I had thought that laser projectors would require some type of moving diffuser to knock out the coherence of those red/blue laser beams. I know light produced from the phosphor is incoherent, so you're good there. But I'd think the the red/blue beams, expanded across the image plane would require some method to reduce coherence, otherwise all kinds of "speckle" would be seen across the projected field. Is this not true?
Auto keystone adjustments?
Accelerometer, as you surmise is probably for automatic image flip, and possibly some level of automatic keystone correction.
or free-fall detection :)
It automatically trips a warranty void efuze if dropped, jokes aside it's for the auto keystone correction feature
6:15 That looks to be a "game bit" which is common with many older game consoles. You can find those screwdrivers all over Amazon.
Accelerometer is likely so the onscreen menu and content is orientated properly since when you use it on a desk the top is pointed upwards but when you mount it on a ceiling the top faces the floor.
Mike can make anything look interesting. Thank you!
Another possible reason for the accel is theft detection. In a environment where the projector RS232 is being used for control the projector could send a theft warning message if the accel detects any movement.
We have installed quite a few of these , they have a habit of the image going pink after a while, they also lose light output. We dont use them much now mainly because the are only wxga. Laser projectors are also getting cheaper and cheaper all the time.
The habit of going pink is definitely not exclusive to this projector, or led projector... probably affects every possible technology, or at least that is my experience with projectors (though mostly just conventional Panasonics)
Man optical stuff is crazy. We know so much and so little at the same time.
and to think before lasers, it was long considered a settled science with little left to learn.
lazors! great teardown! I thought the lasers were used to project the image, but it's for the true RGB colors.
Interesting about the completely different methods for making each of the primary colors. As far as I know some other designs use the laser as only source by going through phosphors similar to those in high CRI white LEDs to create white light and then throw that onto a standard color wheel or dichroic mirrors. Someone I know bought a big professional Sony 10K lumen laser projector for a venue and the light source on that is specced as being just a 350W(!) blue laser array. Funny that blue lasers used to be that expensive and price has fallen off a cliff with 5W blue engraving lasers costing about 80 bucks from banggood now. On show lasers blue also always tends to be the most powerful one, seems blue is the cheapest per watt by now. As others have mentioned the accelerometer is likely for auto keystone compensation, most projectors have had that as a feature for quite a while now. Also a lot of projectors use LEDs as light source now, bulb-based ones are disappearing pretty quickly in favor of either LED or laser.
The accelerometer is there to help with auto adjusting keystone
Accelerometer is probably for mounting orientation=, i.e upside down
many projectors have auto keystone and auto orientation, likely the accelerometer is for keystone adjustment
I've alway been curious about these - thanks for doing this!
Interesting they would make the blue LEDs do double duty since blue LEDs typically have the lowest duty cycle? I suppose it keeps the number of LEDs down by doubling up colors onto one LED and if the blue goes the whole light engine has to be replaced. It must be easier to get green from blue than getting green from red or red from green. I was hoping with lasers since you can get all three primary colors from individual LEDs there wouldn't be any moving parts other than the micro mirrors on the DLP chips and the cooling fans but nope - still a fast spinning color wheel.
The optics and engineering in this are amazing - especially when you think about the manufacturing scale and price point these things are made to. Incredible, really.
Fascinating engineering!
Also good to know to slap some external pre-filters onto those things. That's a horrible design with no filters!
Accelerometer as many have said is for the keystone far as i know they dont detect ceiling mounting
Most of the manufactures are using laser for their high end 4k home theater projectors now. eg, EPSON / Sony / others. They are usually in the $5k-50k range
I believe the accelerometer is used to help perform auto-keystone operations. I'm certain this projector has that ability. I have A-142
An office beamer I use from time to time has an auto-adjusting feature (focus, perhaps keystone). But it uses a tiny image sensor instead. Maybe I will try once to film it in slow-motion, as I don't see any fiducials being projected, it feels like magic.
Yeah I have a Hitachi that does automatic Keystone adjustment, as well as orientation. Of course its possible to manually override the automatic stuff if it gets it wrong
Focus is easy, just adjust for maximum high-frequency content
Always a good day when mike uploads
I saw a couple of sealing mounted projectors with anti theft feature, maybe the acc is for some kind movement detection. The projector I saw did not have an alarm or so, but would just lock up if moved. It even had a ton of warning labels saying this, and a bright orange housing...
But I just read auto keystone correction in the comments, probably just this....
Accelerometer = auto keystone
Hah! I saw one of these on ebay uk a week or two ago, didn't bid on it but looked for a teardown. Glad you got one!!
Really thought it would mechanically scan the collimated beam like a CRT does. Great video btw, keep em coming.
The MicroVision ones do.
"laser speckle"
Yay he's back
Nice video, as always. The accelerometer, to me, may serve as a digital and active interlock to stop the laser. If a laser is not mechanically stable, the light can shoot at undesired places, such as human eyes. I have seen similar designs on class-4 q-switched lasers. Not sure if it is designed for the same purpose here.
No need as it's enclosed
Would the sensor be used to determine angle to automatically offset Keystone distortion? Pretty fancy.
The algo for converting RGB into grayscale is (0.3 * R) + (0.59 * G) + (0.11 * B). So I guess thats why the green part of the wheel is longer than the passthrough blue.
It's just the other way round when mixing light from rgb souces. You need waaaaay less green power than red and blue.
The accelrometer or gyro is used for autokeystone correction based on the agnle the front leg is raised at.
VERY interesting !!!
Thanks for all the effort in filming
Good stuff! Are there some exciting projects we can expect to see using some of these components?
This was very interesting! I'm about to buy one of this new laser projector.
I have an Epson projector that will automatically adjust the lens to project a flat image regardless of the angle the projector is sitting at. Auto leveling I guess, but you can turn it off.
accelerometer could also be for "automatic" keystone adjustment?
12:57 the phosphor wheel is damaged and should have a plastic diffuser in the slot. Mine was loose and halfway out of the wheel. CA glued it back
Yes, its manually selectable but why not make auto the default? You could also have a trapezoid correction for mounting it at an angle have an auto setting.
Have wondered if it was possible to make a LEP flashlight ( think there is currently about a dozen models from a few manufacturers ) with a rotating wheel for changing colour of the light. Looks like blue, green and white would be at least possible.
I did a bit of reversing on the LED/Laser driver board on a similar model a while ago...
photonlexicon.com/forums/showthread.php/11883-Running-the-XJ-A140-With-Missing-Diodes?p=216586#post216586
Unfortunately, none of the photo links work any more, but I basically just soldered SMD resistors and single strands of wire to the MCU on the board, to fool it into thinking it's getting feedback from the current shunt resistors for the laser bank.
I had to use resistor dividers from the driving signals, to match up the levels that the MCU was expecting.
Before then, there were a few mods where people were putting high wattage resistors in place of the laser diodes, often requiring water cooling. lol
It was a very interesting time when these projectors were released, because it immediately started to devalue people's "industrial" blue laser modules, at least for laser show purposes.
Back then, a 500mW Blue laser module could easily cost £600 upwards.
These projectors had 24 diodes, each capable of power outputs of around 1-2 WATTS.
Obviously the optics on a proper laser module are generally higher quality, with anamorphic lenses etc., but still.
Some people were buying hundreds of these projectors brand new, just to salvage the diodes from them, and selling the diodes at around $60-70 each.
Oh, the motivation for me wanting to get the projectors running without lasers was because the projector "carcasses" were selling for only around £30 for a while.
So I bought the Blue and Green versions of the same Phlatlight LEDs, and planned to make a driver board for them.
As is usually the case, that project never got finished. lol
i.imgur.com/LTnSdmQ.jpg
(I had a previous project years ago doing a similar thing, to drive high-power RGB LEDs in sequence with the segments of the colour wheel, to replace the original lamp. It worked quite well, but the LEDs weren't particularly powerful nor affordable back then.)
A few people did some slightly less responsible vids with the laser bank. lol
ua-cam.com/video/gF4HG6v29UY/v-deo.html
he is back!!! yes!!!
1:40 nice hack... but tbh I'd have assumed you'd got every conceivable type of screwdriver immediately on hand when you were at home
Generally the medium which the projector will be projecting on will be vertical(Hanging or a wall). So it will change the vertical aspect ratio depending on the tilt? Edit, just read other comments. Keystoning. Always learning.
Hey! Any idea why we don't use UST laser pico projectors for smaller screens? Like laptop-sized screens?
Some projectors have automatic orientation detection, but possibly also warranty protection for units that are treated roughly?
That starry screw looks like the screws that held NES and SNES cartridges together.
Why did they produce the green with phosphor? Arent there high power green lasers?
Cost: Green laser is much expensive than blue laser, since it requires crystal. Also adding green laser consumes space and gereates heat
@@bacphan7582 Not really, Direct diodes multi watt green lasers at 525nm exists and can be had for 60$ a pop off ebay. They are used in projectors with both Blue and Green direct diodes.
@@Gianns_TDM The direct greens weren't available when these projectors came onto the market.
@@cambridgemart2075 You are very much mistaken, The earliest projector (XJ-M130/A130) Came to the marker around 2013 and as you can see here: ua-cam.com/video/1KAqlEoQKrU/v-deo.html Cheap direct diode greens were very much available. The one-watt green diodes appeared around 2014-15.
@@Gianns_TDM YOU are very wrong, they launched much earlier than 2013, I bought several well used (10 000 hours +) ones in around 2011. Plus you contradicted yourself with the introduction date of the direct green diodes.
Agreed, manufactures use way to meany screws.
That's how they screw you.
Hello again
I wanna know Could you run this projector with just the red led without the blue laser diode module
A bit late. Green is the most significant colour used for brightness. They may even increase laser brightness during the 'geen sectors' to get the white balance right.
i thought it was something to do with human perception, we have greatest sensitivity to green.
Projectors can be quite intresting to take apert, the modern cheap ones are not as there optics are super simple. Got some intresting examples from the uni WEEE bin quite a few years ago now.
I'm glad I'm not the only one pulling useful stuff out of WEEE bins! 😎
2:22 probably the ceiling mount bracket goes there
Projectors are sensitive to alignment issues if dropped, even from a few cm. Could have an accel so they can refuse warranty with proof the unit has been roughly handled by the customer. Or claim the shipping company warranty if a pallet arrives at distributor that they suspect was dropped. Does the PCB have a backup battery to run the accel while unpowered?
I guess the question is, is their damage losses from bad unit handling costing them enough to justify a 20c accel per unit.
I think it probably is. One damaged $2000 projector would pay for a lot of units to have an accel.
No battery. You can get mechanical shock indicators-sometimes used for shipping damage detection
I'd love to get my hands on a DLP module that I can control for a DIY project. I have a dumb-but-fun project in mind where having control over a micro-array of mirrors like that would be absolutely ideal.
Been looking for the same for a while but TI is absolutely anal about it and prices dev kits out of reach for messing around..
@@plemli From what I've found, TI's DLP tech is closed. So no cheap DIY/experimenter stuff.
www.ti.com/tool/DLPDLCR2000EVM is about the cheapest available evaluation hardware. What level of control do you need? This only allows for video input which is then processed by a TI ASIC and then sent to the DMD. No direct control of individual mirrors possible.
@@JakePulliam Thanks for the lead. It"s low res and limited wrt interfacing, but otoh it's cheap and I have an unused BBB laying around so I've ordered one.
As long as there is an odd number of screws left it it is good to go, if you have an even number you better find where they go 😅
Always kind of Casio to include spare screws!
Accelerometer is for detecting tilt and auto adjusting
It would be very nice if you could upload in 1080p
I think TVs and monitors are biased to show more green. The is called a Bayer Filter. It has to do with the human sensitivity to different colors. Nevermind, Bayer Filters are used on photo sensors like cameras.
...hmm...wanders off to see how much ebay will rob from me this browsing session...
Woulda been neat to see high speed camera footage of a movie or something. Great vid though!!
I have long wondered why there are no projectors that would straight up use the laser beams and two really fast spinning mirrors instead of a delicate DLP. As far as I know, the diodes should handle multiple kHz of modulation just fine, and you'd even be able to adjust the resolution with some finely controlled motors spinning the mirrors. And you could also requlate brightness by voltage instead of super fast pulsing.
Spreading the beam and have it run through several mirrors and prisms and what not seems like wasting a lot of potential output brightness, and direct laser beams wouldn't even require any optics or focus! Does anyone know why these things don't exist?
You need insanely accurate, fast scanning and well controlled beam shape, and speckle is a significant issue. There was a pocket projector (Microvision Showwx - I did a teardown a long time ago) that used a MEMS scanner but the product seems to have disappeared now.
@@mikeselectricstuff I dimly remember that! Quite possible that this had sparked my thoughts. The term MEMS definitely rings a bell. Must have gone like "huh, where is that $60k Sony version of this for 3m+ screens, that hopefully everyone else copies within 2 years?" in my head back then.
I've been waiting out for affordable projectors that bring at least a small quantum leap in tech - be it just being 4k for < 1000€. I've had my Benq W1070 for too long now =) (Still cool though.)
I think I have once seen some video about how to get rid of laser speckle, but that might as well have been wishful thinking. Here's to hoping that someone will tackle it one day soon enough! (Seriously, even the benefit of having no optics to focus would be incredible. Especially for artsy use on non-planar surfaces.)
1:56 just use the hex socket as an extension on the triwing!
Hello, I have the same model. When power on only the lights power and temp stay on red , help . Thank you
Оппа.. И этот может спички поджигать! Интересно.. Спасибо за интересный контент! 🤝🍻