back to article Prysm pitches ultra-green laser telly tech

US company Prysm has taken the covers off what it claims is a new type of ultra-low power HD TV that combines old-style CRT elements with laser technology. Called Laser Phosphor Display (LPD), the system replaces a CRT's electron beam with a directed laser beam. The phosphor-coated screen that's excited by the beam to emit …


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  1. Robert Grant Silver badge

    Yeah, but how thick is it?

    Cos...oLED makes for thin TVs.

    1. Anonymous Coward
      Anonymous Coward

      im guessing no kids

      i would love a oled display

      but would last about 20seconds till it got knocked over, still using CRT everywhere.

      Would be nice to have a cheapo alternative too :)

      I would buy 1

  2. Peter Kay

    Bright? and size?

    CRT technology is not bright compared to LCD/DLP/LCOS, but it does offer a much wider dynamic range, multiple resolution support and true blacks.

    I'd be interested to see how large it is - they appear to be using low power small laser diodes, so it's not a projection device. It must still be subject to phosphor degradation - of course this probably still means a lifespan of 10,000 hours-ish before brightness is reduced by half.

    I also suspect increasingly larger sizes will be vastly expensive and face competition from front and rear projection. Prysm's technology works with a phosphor coated screen, so at some point the economics of a source device that projects onto a screen from the front or rear, vs increasingly larger coated displays will be rather interesting.

    The holy grail is still, as far as I'm aware, a front projected laser system. Resolution, convergence and response to die for - but won't be cheap.

  3. Anonymous Coward

    Is this really useful?

    Does it need to be in a vacuum tube like CRT? If it does the things will be bulky and heavy.

    Also, like CRTs and Plasmas they will be prone to image burn. A problem made worse by the advent of cable/sat TV that insist on putting they channel logos in the corner.

    Nothing like watching a horror movies with "Cartoon Network" emblazon in the corner......

  4. Jamie Kitson

    Prysm didn't say...

    How massive the final product would be.

  5. Anonymous Coward
    Thumb Down

    That'll hang nicely on the wall then....

    Am I missing something here? The main reason for me ditching my last large CRT TV was the fact that it took up an entire corner of the room.

    An HD CRT will probably be the same size as my sofa then....

  6. James Geldart

    sounds great but...

    who's going to want to go back to a big heavy square box after using nice thin lightweight flat screens?

  7. Tony Smith, Editor, Reg Hardware (Written by Reg staff)

    Re: sounds great but...

    There's no reason to assume LPDs won't be flat. CRTs are big because of the electron gun assembly and beam control magnets. Guiding a light beam - perhaps fired vertically then angled onto the phosphor using a controlled reflector - requires a lot less gubbins.

    1. Subliteratus
      Thumb Down

      Angles are tricksy

      If the beam's being bounced in from the sides to a centre reflector then out to the screen, the edges of the display would be a lot dimmer than the middle (especially the left and right edges) because the beam is hitting the screen at a much more oblique angle. You could compensate by having the beam linger towards the edges and sweep the centre faster, I suppose, but it'd increase the complexity and there'd be one more thing to go wrong.

      Even if it did ever get to market, the only reason to buy it over a proper telly would be because of the "carbon footprint". Newsflash: crusties and road protestors don't have the cash to stump up for a new telly.

    2. ChrisC

      Or perhaps multiple lasers

      There's also no reason to assume LPDs would be using just one laser to scan the entire area...

    3. jubtastic1

      yeah but no but yeah

      Assuming there's some overlap in the mechanics of this with DLP projectors and laser projectors (which is exactly what this sounds like), you're unlikely to get a single unit anywhere near as thin as an LCD, of course the screen and laser gubbins don't have to be connected so it could just be a small box projecting (lasing?) onto a fixed screen, wall or 2" steel slab with attached secret agent.

  8. edward wright


    From their website:

    "For a single display panel or tile of 55 inch size the system consumes less than a single light bulb"

    Even if that's 100W, it's not bad... note they say 'tile', so you can mosaic these things together. It would be a bit dishonest if they were talking about some 1kW halogen bulb :)

    I doubt lasers need a vacuum, light travels better in air than free electrons!

  9. Anonymous Coward
    Anonymous Coward

    I presume...

    They will be using some kind of 'side projection' technique to create a flat pannel format?, wonder is old Sir Clive might be in for some patent royalties...

  10. JoeH 1

    Re: sounds great but...

    CRTs are heavy because of the thickness of the glass required to maintain the vacuum inside, which is needed for the electron beam. Lasers work fine through air, so all that is required is enough plastic to keep fingers out of the way. Maybe dustproof to keep the inside of the phosphor screen clean, but there is no need for it to be air-tight.

  11. Will Godfrey Silver badge

    @Tony Smith

    Sinclair tried that with his flat (monchrome) CRT.

    Less gubbins maybe, but once you start using reflectors, which would have to employ some 'interesting' optical corrections, the gubbins that IS there has to be many times more precise :(

  12. Robert Carnegie Silver badge


    Projector replaces your existing overhead light fitting, screen is pasted onto the wall having removed a suitably sized piece of existing wallpaper. It's a thought.

  13. John Smith 19 Gold badge

    Checked the website

    It runs like a *dog*. I think I've seen faster loads from friends home PC's.

    If you don't want people to visit your website, don't have one.

    Getting your site hosted on a *reasonably* fast host is basic to tech company marketing. Either they know this and don't care (we have enough money and everyone *we* want to know about us already does) or they don't. The first is arrogant (and very unwise given the stakes they are playing for) and the second is ignorant (which you cannot afford to be given the selling job they have ahead of them).

  14. Paul Shirley

    CRT just looks better

    Spent the last 5 years looking for a replacement for my 20yr old desktop CRT TV and not yet seen anything that looks right, LCD's just don't do SD video as well as phosphor, don't know why but its plain to see. If the old TV holds out another few years looks like I'll actually have a viable upgrade to HD phosphor.

    ...and I hope they aren't too flat, that's valuable shelf space on top of my current sets ;)

  15. Nexox Enigma

    Ah finally...

    Lets just hope they make a desktop model, preferably with higher pixel density than the current standard (crap) LCDs. There'll come a day when my beautiful (the image, not the huge plastic box) CRTs release their magic smoke, and I'll need something better than huge-pixeled 24" LCDs to replace them...

  16. I didn't do IT.

    Why even bother with side mounting?

    Why tie yourselves down to the idea of a central emitting source?

    As far as I understand it, the reason why TFT screens are so pricey is because of the required strength of the visible light diodes in the viewing matrix. With a LPD, you wouldn't have to worry about the lasers being visible spectrum since its the _phospors_ that emit visible light.

    Use non-visible spectrum (ie. infrared, ultraviolet, etc) and can get much for effiecient, smaller and _cheaper_ lasers on the "backing" matrix material, probably in trinary clusters for RGB. To achieve 1080 high def on a 17in standard monitor (337mm x 270mm), each pixel only needs to be 0.25mm. These would only be bigger on a larger screen. This would require a fab machine capable of a 84,000nm (250,000 / 3 due to trinary clusters) process. I'm sure Intel and AMD (and even TI!) have those machines back in the shipping dept. being used to hold up the lorry doors, if they aren't already in the back lot collecting rain...

    I'm sure you could still do 0.01mm (yes - MM!) fab cheap as chips, achieving 1080 hidef on a 4.32cm x 3.2cm (1.7in x 1.2in) tile, and multiple tiles achieving 1440 (4 tiles = 3.4in x 1.4in), 2210 (9 tiles = 5.1in x 3.6in), etc. Yes, really. Check out the spec; the 720 and 1080 is the number of pixels on the vertical axis, regardless of size of screen. That's why its actually cheaper (lower resolution fab process) to make a HD TV if you make the screen bigger, and why they only look good from a "recommended viewing distance".

    The phosphors could be either spray deposited onto another layer or impregnated _into(?!)_ a plastic substrate, each trinary cluster having one for blue, one for red and one for green. They would react in a directly proportional manner to the varied intensities of each dedicated laser (more power to the laser, the brighter the phosphor glows) right behind them. Heck, make it a black, infrared invisible material, and you have your true black again. :)

    Aligning it could be a field operation with set screws and would be a normal part of QC. Yes - really. Simple steel gears can achieve increments of 5/1000in (.0127mm) tolerances on a single axis - calipers, for instance - and do it reliably and cheaply. That's well within our 0.25mm per trinary.

    So, you have a nice, big surface with all of these little trinary laser clusters (3 per pixel for RGB) that uses next to nothing in power compared to current tech. It would also be just as flat as standard LCD/plasma tech, and probably moreso without the need for the same heat dissapation, power distribution, etc. This could provide an inexpensive solution to a 1/2in (1.7cm) thick, 55in (139.7cm) diag. display. :)

  17. Simon B

    Say no to brick, yes to flat!

    Like those above me, I wont go backwards to a brick, I llike my flat space saving wall hanging panel thank you

  18. Anonymous Coward
    Anonymous Coward

    A laser in your living room. pointing at you?

    When the machines take over, part of the coordinated first strike will be to remove the safety limits on the lasers and get as many of us as they can in one go, as many of us will be arranged neatly in line of sight of this device.

    They're likely to go for either a sporting event or during Eastenders in order to eliminate as many of the low quality fleshies who would make poor slave labour anyway.

    The upside to this is of course the eliminiation of fans of Eastenders and televised sport, so what remains of humanity and finally triumphs will finally be able to expect decent SF on BBC2 without "this program has been rescheduled becuase World Championship Snooker went into extra time" or other such silliness.

  19. Anonymous Coward
    Thumb Down

    I've seen such a product...

    At a major electronics company before rear projection TV product line was finally killed.

    It was a few years ago now and cooling for the laser was then a significant issue. Also for picture quality the chassis had to be incredibly stiff which meant it was heavy. The later of these may still be a problem.

    That unit was probably a little under 30cm deep.

    Thin is in, even at the cost of picture quality and beyond where it makes a practical benefit (see edge LED). This projector will need some depth I think from the description.

  20. markp 1

    LCD motion blur?

    Errr.... hands up anyone who sees significant motion blur on a screen made in the last few years... ok, hands down anyone using an inexplicably low-contrast and blur-a-riffic Macbook or really cheap Tesco-Special TV...

    My lappy's nearly 4 years old and I did a side by side test with my 2-3 y.o. widescreen and the macbook (and how i wish I could have pulled out the ancient STN-driven old Acer in my cupboard). TV and PC were sharp as tacks, and fast enough to make the 60Hz movement seem more jerky than blurry. The mac was a blurfest... but the fact that it stands out notably as such shows that the vast majority of LCDs now in use don't have that problem. We reached sub-10ms (equivalent of 100Hz frames, or 50Hz strobe - twice as fast as UK CRT TV) full-white to full-black (& vice versa) times quite a while ago, I had a cheap-when-bought 17" monitor that I gave away because it was getting old.... still with a "8ms!" sticker in the corner.

    Maybe now in the days of motion-upscaling and interpolation it may be important, but as the human eye can't much detect anything beyond 80-90Hz anyway, what's the point? 3D applications, maybe? But then you're relying on LCD shutterglasses anyway...

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