Vacuum fluorescent displays

Discussion in 'PC Hardware, Software and Displays' started by Squeak, Feb 4, 2009.

  1. Squeak

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    http://en.wikipedia.org/wiki/Vacuum_fluorescent_display
    Why has VFD displays never been done for real screens with pixels and high resolution?
    Limited resolution pixel VFDs (128x32) has been made, but why not higher res and in colour? It would seem an ideal alternative to LCD and much cheaper to produce than plasma.
     
  2. Silent_Buddha

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    If you read that wiki article you'll find out for yourself why they are impactical for anything but very limited applications.

    Regards,
    SB
     
  3. Squeak

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    I see no reason for it to be impractical and neither can I see where the article says so.
    A screen using VDF tech. could be made to work basically like a plasma screen, but much cheaper, without the need for millions of pockets of rare gas, probably also more energy efficient and stable to watch (without the need for blinking pixels).
    OLED still has plenty of problems to deal with before it can become mainstream. Two of the most obvious problems being lifetime and size.
     
  4. Albuquerque

    Albuquerque Red-headed step child
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    Then you didn't read very well. I have almost no experience with VFD technology, but directly from that article I see three things:

    • Higher power usage compared to LCD
    • Higher cost of construction compared to OLED and LCD
    • Mono-color elements

    I also see mention of fade, but no mention of expected half-life of the phosphors. So ignoring the fade portion, you have a technology that has is already surpassed by OLED designs and uses more power. The only examples of "full screens" using this technology were a monochrome output for a portable iPod-like media player.

    So, given what I saw in that article, it looks relatively uninspiring for large-scale display technology to me.
     
  5. Silent_Buddha

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    Add to that VFD's have to be formed into specific elements. You can't just make VFD pixels. Take a look at many of the old VFD based clocks and diplays. You'll see they have predefined VFD blocks. Blocks are then lit up in combination to form basic letters, numbers and pictures. Each picture is one VFD.

    So to animate say a horse running in an old VFD based handheld game for example. You have 1 VFD for each animation layered on top of each other.

    Not even remotely suitable for use in computer displays.

    Regards,
    SB
     
  6. Squeak

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    Plasma has all of the above "problems". They could/have be(n) solved in almost the same way for a VDF display.
    The article does mention that it's very easy to fix fade. Anyone who has an old video or watch with a VDF display around know just how durable and readable these displays are.

    OLED is not ready for the limelite at all yet. VDF is some 40 years old and we know just about everything worth knowing about fade, colour etc. with regards to the tech.

    Now you are not reading the article. Pixel displays has already been done.
    You just have to implement an active matrix controller, like in a plasma or TFT to address the pixels instead of individual wires to the "filaments".
     
    #6 Squeak, Feb 5, 2009
    Last edited by a moderator: Feb 5, 2009
  7. Albuquerque

    Albuquerque Red-headed step child
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    What does this tell us then? You need to look at this the other direction: we ARE indeed talking about a technology that has been around 40 years and is incredibly well understood.


    So here's the obvious answer: If it made economic, technological or business sense to use VFD's in some other way, we'd already be there. One of the things mentioned in that article is total element brightness -- plasma has massive light output properties. If current-generation OLED is beating a new VFD in the brightness category (which the Wiki clearly states), then obviously VFD is lacking in a key area.

    What about state-change speed? Plasma has a very strong speed advantage over LCD and OLED, but we have no figured for VFD. An educated guess, based on the few VFD items I have to look at, suggests that VFD is somewhere behind LCD technology as well.
    Your response shows that you've entirely made up your mind, and in doing so, are also entirely ignoring the issues that are presented to you in a direct and obvious manner -- both by the Wiki, and by the discussion in this thread. Rather than automatically assuming you're right, instead you should question why 40 years of technological evolution has left VFD to languish in LED clock obscurity...
     
  8. Squeak

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    It's far from always that the obviously best technology wins out, history is full of examples of that.
    There might be any number of reasons for it not happening. Patents, corporate pride, ignorance, critical mass etc.
    Plasma is an example of such a tech. It had to be nursed forward by its inventor until Pioneer finally took notice in 1994.
    Until then, it had lived life as a niche product, with varying degrees of success and only implemented in small scale, just like VFD and in some of the same applications. Even today it's declining in popularity, despite some people thinking that it's a superior tech to LCD.

    There is nothing to suggest that the technology should be inherently slow. Not slower than a CRT at least, since they are based on the same basic principles.
    My guess is that like LCD before it, the speed of the update hinges on the integration of the controller in the screen (active matrix).

    How is that? The very thing that I ask the question, shows that I have by no means made up my mind. I just haven't gotten any satisfactory answers yet.
    At some point people must have considered doing a VFD screen, but for some reason decided against it. I would like to hear about those reasons, and if possible also the experiments.
     
  9. Blazkowicz

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    that sounds exactly like the old LCD "handhelds" displayed black blobs with the shape of a human, monkey, car etc. ;)
     
  10. Silent_Buddha

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    Hehe, they actually still have LCD handheld games like that. Cheap and low powered. Something that can't be achieved by VFDs. Which is why VFDs don't even have a presence in that market anymore.

    Regards,
    SB
     
  11. RudeCurve

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    I don't see why a VFD made into a colored dot matrix display couldn't be done. VFD started out just like LCDs single color "prebaked" shapes that "light" up. Same with LED displays. Plasma displays started out as monocrhome to, remember those old Toshiba "notebook" computers with the amber plasma displays? Squeak has a valid observation imo. I also wonder why no company advanced VFD displays like the way they did with LCD and LED displays.
     
  12. Davros

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    dont you know vacuum's suck :D
     
  13. Silent_Buddha

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    Power consumption is significantly higher than LCDs which it why it lost out to LCD in virtually all competing markets.

    Regards,
    SB
     
  14. Squeak

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    Not if you want your LCD backlit, then it isn't necessarily.
     
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