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I'm kinda curious if CRT technology advanced to the point where a TV like that would've been possible at a better weight and price tag? I assume that CRT techno

I'm kinda curious if CRT technology advanced to the point where a TV like that would've been possible at a better weight and price tag? I assume that CRT technology development stopped decades ago, but could we have e.g., replaced the heavy glass with some plastic-like material to save weight without compromising the picture? And are there any heavy components in the mechanism itself (Coils, Magnets?) that would have had alternatives? I know it's just theorycrafting, but I do wonder what kind of CRT someone could've created if it wasn't for market economy forces.

cesaref 2y ago
I imagine much of the weight is for the tube to be strong enough to hold the vacuum without shattering. As the screen area increases, you need stronger electron sources, and higher HT to get the electrons to the phosphor. I think small 14 inch trinitrons are already using 20-30kV so I imagine the power supply and associated HT stuff will be quite scary in these larger sets. There are all sorts of complex magnet arrangements to tune the beam to stay in focus across the image area, i don't know how that will scale with size, but it's probably more of a complexity when assembling the sets to calibrate the tubes.
- refurb 2y ago
  You’d be surprised how little glass is needed to be strong enough to withstand a near perfect vacuum. I worked in a lab where we routinely held a few micro-torr of vacuum, which is about the limit for mechanical pumps. Cathode ray tubes are typically thousands or tens of thousands higher pressure. We ran 1/4” wall thickness glass even in large flat stretches without issue. I’m guessing the weight of large cathode ray tubes are more for durability than need for the vacuum inside.
  - ssl-3 2y ago
    How much did the flat sections bend or deflect under vacuum?
  - Karliss 2y ago
    That's a bit misleading the level of vacum might differ by factor of 10000, but most of the force is still coming from atmosphere. For overall mechanical strength it doesn't matter that much if its 0.99 or 0.99999999999 atmospheres of pressure difference, temperature and other wheather changes are probably causing much bigger change in force applied to glass.
    - willis936 2y ago
      I don't think it's that misleading. At the end of the day you need a 14.696 psi negative pressure vessel. That isn't very dramatic. If you can confidently make something that works to 14.696 psi then you can be confident it will work at 14.65 or 14.5 psi. The meat of the comment is that you don't need much material to withstand Earth's atmosphere compared to pressure vessel. It's a common misconception for folks who don't work with vacuums. Having carried my share of heavy CRTs I can share that most of the weight is in the front glass. It needs to support the phosphor wire mesh and withstand the pokes and stabs of the world while not compromising the fragile thin-walled neck.
  - guenthert 2y ago
    Living room tv sets need to be child-save, unlike lab equipment.
Animats 2y ago
Here's the last gasp of thinner, bigger CRTs, in 2005.[1] "Today, CRT markets are being threatened by flat-panel displays (FPDs) even though the screen quality of the CRT is one of the best of existing display devices. The depth of CRTs is one of its most important design factors to maintain its dominant position in the display market. Thus, a 32-in.-wide deflection-angle 125° CRT (tube length of 360 mm) has been developed, and mass production began in January 2005." That was the Samsung Vixlim.[2] Apparently worked OK, but obsolete at launch. Goes down in history as another last and greatest achievement of the wrong technology, along with the Doble steam car, the SS United States, 3-projector Cinerama, quadrophonic phonograph records, and the Olivetti Divisumma 24 mechanical four-function calculator. [1] https://sid.onlinelibrary.wiley.com/doi/abs/10.1889/1.2166838 https://sid.onlinelibrary.wiley.com/doi/abs/10.1889/1.216683... [2] https://www.reddit.com/r/crtgaming/comments/xgtmdw/does_anyone_know_whatever_happened_to_samsung/ https://www.reddit.com/r/crtgaming/comments/xgtmdw/does_anyo...
- Aeolun 2y ago
  32 inch wide, 14.5 inch deep. Not bad. You could actually fit that on a 80cm desk.
- cubefox 2y ago
  "These wide-deflection CRTs attracted an extraordinary amount of attention even from end users in a variety of display shows last year and will help maintain the solid positions of CRTs in the coming era."
- medstrom 2y ago
  /r/crtgaming ... calling it, this the new hip before it's cool
joezydeco 2y ago
The next big thing was supposed to be Field Emission Displays. Microscopic electron guns directly behind each phosphor. The big manufacturers experimented and tried getting it commercialized for decades, then pretty much gave up in the 2000s when LCDs got stupid cheap. https://www.engineersgarage.com/field-emission-display/ https://www.engineersgarage.com/field-emission-display/
- Gare 2y ago
  There was also a brief reign of plasma TVs in-between, now almost a forgotten technology
  - floam 2y ago
    A good 720p plasma is still a great display to this day.
    - phibz 2y ago
      I have the second to last generation Panasonic plasmas. 42" 1080p display. At first the picture was amazing but over time it degraded slightly with what looks like subtle noise affecting the entire display. Solid colors have a faint shimmer of noise in them. As if white noise was blended with everything. I still use it as a bedroom TV. I can barely lift it myself and it claims to use 450watts of power. It's certainly a lot. It's notably warm near it and will heat my room if I don't open the door. Still the picture quality is very good at a distance. Only oled or micro led displays look better.
      - pandaman 2y ago
        This could be that you just noticed it? Panasonic plasma cells brightness is controlled by PWM off a 600 Hz carrier (it's even proudly advertised as "600 Hz!" on the TV box and stickers). While the number is quite big and stands out nicely against "240 Hz" advertised as refresh rate for the competing LCD TVs, it did not provide many different brightness levels per pixel (keep in mind that it's divided by 60 Hz or higher frame refresh) so those TVs were running temporal stochastic dithering to create more levels. If you looked closely at a new plasma TV screen it was very noisy with random pixels firing up at high frequency.
shrubble 2y ago
The glass has to be thicker, thus more weight, to withstand implosion from the vacuum it is holding.
- NikkiA 2y ago
  Gorilla glass or sapphire glass might have enabled lighter tubes at a higher price, had CRTs retained popularity, but from what I can see, Corning never even considered it as a use case for Gorilla glass in their original 1960s attempt at development.
  - MBCook 2y ago
    Would there be any point? Given the TV sizes of the 60s standard glass was probably more than strong enough, and the tube wouldn’t be very heavy. No one would need to really think about until around 2000.
perihelions 2y ago
On top of the mechanical issues, CRT glass also functions as x-ray shielding, for which reason it is leaded (Pb). You can't really make that part lighter. https://en.wikipedia.org/wiki/Cathode-ray_tube#Body https://en.wikipedia.org/wiki/Cathode-ray_tube#Body https://www.epa.gov/hw/frequent-questions-about-regulation-used-cathode-ray-tubes-crts-and-crt-glass https://www.epa.gov/hw/frequent-questions-about-regulation-u... (This isn't really an answer to the overall question—just a narrow observation of interest).
- MBCook 2y ago
  Oh I didn’t know that. Neat.
- throwaway2037 2y ago
  This is an interesting point. Does anyone know how much lead would be in a 21 inch monitor?
  - RetroSpark 2y ago
    According to [0], about 1.2 kg (2.6 lbs). Surprisingly this is mostly in the neck and funnel of the tube - the screen itself uses different metals because lead would affect its optical performance. [0] https://www.sciencedirect.com/science/article/pii/S1878029616001213 https://www.sciencedirect.com/science/article/pii/S187802961...
grishka 2y ago
I remember reading somewhere that there was this wild prototype flat CRT where the electron gun was at the top, shooting down, and the beam did a 180 degree turn at the bottom before being deflected into the surface of the screen.
- deleted 2y ago
  [deleted]
- UncleSlacky 2y ago
  Yes, the Sinclair TV80 worked on that principle: https://en.wikipedia.org/wiki/TV80 https://en.wikipedia.org/wiki/TV80
  - grishka 2y ago
    Nope, it's that, but folded in half. Found a mention of it (that I commented on, lol): https://mastodon.social/@tubetime/111219376410543899 https://mastodon.social/@tubetime/111219376410543899
userbinator 2y ago
I assume that CRT technology development stopped decades ago, but could we have e.g., replaced the heavy glass with some plastic-like material to save weight without compromising the picture? Metal-cone CRTs were common in the early decades, and had a flatter screen than typical all-glass construction; here's the largest of those, a 30": https://www.earlytelevision.org/dumont_30bp4.html https://www.earlytelevision.org/dumont_30bp4.html a TV using it cost almost $1800 in 1952 (equivalent to over $21k today): https://www.earlytelevision.org/dumont_ra-119.html https://www.earlytelevision.org/dumont_ra-119.html I think metal-cone CRTs became unpopular due to the glass-to-metal seal not being as reliable, and difficulties with insulation (the whole cone is at the final accelerating voltage.)

cesaref 2y ago

I imagine much of the weight is for the tube to be strong enough to hold the vacuum without shattering. As the screen area increases, you need stronger electron sources, and higher HT to get the electrons to the phosphor. I think small 14 inch trinitrons are already using 20-30kV so I imagine the power supply and associated HT stuff will be quite scary in these larger sets. There are all sorts of complex magnet arrangements to tune the beam to stay in focus across the image area, i don't know how that will scale with size, but it's probably more of a complexity when assembling the sets to calibrate the tubes.

refurb 2y ago
You’d be surprised how little glass is needed to be strong enough to withstand a near perfect vacuum. I worked in a lab where we routinely held a few micro-torr of vacuum, which is about the limit for mechanical pumps. Cathode ray tubes are typically thousands or tens of thousands higher pressure. We ran 1/4” wall thickness glass even in large flat stretches without issue. I’m guessing the weight of large cathode ray tubes are more for durability than need for the vacuum inside.
- ssl-3 2y ago
  How much did the flat sections bend or deflect under vacuum?
- Karliss 2y ago
  That's a bit misleading the level of vacum might differ by factor of 10000, but most of the force is still coming from atmosphere. For overall mechanical strength it doesn't matter that much if its 0.99 or 0.99999999999 atmospheres of pressure difference, temperature and other wheather changes are probably causing much bigger change in force applied to glass.
  - willis936 2y ago
    I don't think it's that misleading. At the end of the day you need a 14.696 psi negative pressure vessel. That isn't very dramatic. If you can confidently make something that works to 14.696 psi then you can be confident it will work at 14.65 or 14.5 psi. The meat of the comment is that you don't need much material to withstand Earth's atmosphere compared to pressure vessel. It's a common misconception for folks who don't work with vacuums. Having carried my share of heavy CRTs I can share that most of the weight is in the front glass. It needs to support the phosphor wire mesh and withstand the pokes and stabs of the world while not compromising the fragile thin-walled neck.
- guenthert 2y ago
  Living room tv sets need to be child-save, unlike lab equipment.

Animats 2y ago

Here's the last gasp of thinner, bigger CRTs, in 2005.[1] "Today, CRT markets are being threatened by flat-panel displays (FPDs) even though the screen quality of the CRT is one of the best of existing display devices. The depth of CRTs is one of its most important design factors to maintain its dominant position in the display market. Thus, a 32-in.-wide deflection-angle 125° CRT (tube length of 360 mm) has been developed, and mass production began in January 2005." That was the Samsung Vixlim.[2] Apparently worked OK, but obsolete at launch. Goes down in history as another last and greatest achievement of the wrong technology, along with the Doble steam car, the SS United States, 3-projector Cinerama, quadrophonic phonograph records, and the Olivetti Divisumma 24 mechanical four-function calculator. [1] https://sid.onlinelibrary.wiley.com/doi/abs/10.1889/1.2166838 https://sid.onlinelibrary.wiley.com/doi/abs/10.1889/1.216683... [2] https://www.reddit.com/r/crtgaming/comments/xgtmdw/does_anyone_know_whatever_happened_to_samsung/ https://www.reddit.com/r/crtgaming/comments/xgtmdw/does_anyo...

Aeolun 2y ago
32 inch wide, 14.5 inch deep. Not bad. You could actually fit that on a 80cm desk.
cubefox 2y ago
"These wide-deflection CRTs attracted an extraordinary amount of attention even from end users in a variety of display shows last year and will help maintain the solid positions of CRTs in the coming era."
medstrom 2y ago
/r/crtgaming ... calling it, this the new hip before it's cool

joezydeco 2y ago

The next big thing was supposed to be Field Emission Displays. Microscopic electron guns directly behind each phosphor. The big manufacturers experimented and tried getting it commercialized for decades, then pretty much gave up in the 2000s when LCDs got stupid cheap. https://www.engineersgarage.com/field-emission-display/ https://www.engineersgarage.com/field-emission-display/

Gare 2y ago
There was also a brief reign of plasma TVs in-between, now almost a forgotten technology
- floam 2y ago
  A good 720p plasma is still a great display to this day.
  - phibz 2y ago
    I have the second to last generation Panasonic plasmas. 42" 1080p display. At first the picture was amazing but over time it degraded slightly with what looks like subtle noise affecting the entire display. Solid colors have a faint shimmer of noise in them. As if white noise was blended with everything. I still use it as a bedroom TV. I can barely lift it myself and it claims to use 450watts of power. It's certainly a lot. It's notably warm near it and will heat my room if I don't open the door. Still the picture quality is very good at a distance. Only oled or micro led displays look better.
    - pandaman 2y ago
      This could be that you just noticed it? Panasonic plasma cells brightness is controlled by PWM off a 600 Hz carrier (it's even proudly advertised as "600 Hz!" on the TV box and stickers). While the number is quite big and stands out nicely against "240 Hz" advertised as refresh rate for the competing LCD TVs, it did not provide many different brightness levels per pixel (keep in mind that it's divided by 60 Hz or higher frame refresh) so those TVs were running temporal stochastic dithering to create more levels. If you looked closely at a new plasma TV screen it was very noisy with random pixels firing up at high frequency.

shrubble 2y ago

The glass has to be thicker, thus more weight, to withstand implosion from the vacuum it is holding.

NikkiA 2y ago
Gorilla glass or sapphire glass might have enabled lighter tubes at a higher price, had CRTs retained popularity, but from what I can see, Corning never even considered it as a use case for Gorilla glass in their original 1960s attempt at development.
- MBCook 2y ago
  Would there be any point? Given the TV sizes of the 60s standard glass was probably more than strong enough, and the tube wouldn’t be very heavy. No one would need to really think about until around 2000.

perihelions 2y ago

On top of the mechanical issues, CRT glass also functions as x-ray shielding, for which reason it is leaded (Pb). You can't really make that part lighter. https://en.wikipedia.org/wiki/Cathode-ray_tube#Body https://en.wikipedia.org/wiki/Cathode-ray_tube#Body https://www.epa.gov/hw/frequent-questions-about-regulation-used-cathode-ray-tubes-crts-and-crt-glass https://www.epa.gov/hw/frequent-questions-about-regulation-u... (This isn't really an answer to the overall question—just a narrow observation of interest).

MBCook 2y ago
Oh I didn’t know that. Neat.
throwaway2037 2y ago
This is an interesting point. Does anyone know how much lead would be in a 21 inch monitor?
- RetroSpark 2y ago
  According to [0], about 1.2 kg (2.6 lbs). Surprisingly this is mostly in the neck and funnel of the tube - the screen itself uses different metals because lead would affect its optical performance. [0] https://www.sciencedirect.com/science/article/pii/S1878029616001213 https://www.sciencedirect.com/science/article/pii/S187802961...

grishka 2y ago

I remember reading somewhere that there was this wild prototype flat CRT where the electron gun was at the top, shooting down, and the beam did a 180 degree turn at the bottom before being deflected into the surface of the screen.

deleted 2y ago
[deleted]
UncleSlacky 2y ago
Yes, the Sinclair TV80 worked on that principle: https://en.wikipedia.org/wiki/TV80 https://en.wikipedia.org/wiki/TV80
- grishka 2y ago
  Nope, it's that, but folded in half. Found a mention of it (that I commented on, lol): https://mastodon.social/@tubetime/111219376410543899 https://mastodon.social/@tubetime/111219376410543899

userbinator 2y ago

I assume that CRT technology development stopped decades ago, but could we have e.g., replaced the heavy glass with some plastic-like material to save weight without compromising the picture? Metal-cone CRTs were common in the early decades, and had a flatter screen than typical all-glass construction; here's the largest of those, a 30": https://www.earlytelevision.org/dumont_30bp4.html https://www.earlytelevision.org/dumont_30bp4.html a TV using it cost almost $1800 in 1952 (equivalent to over $21k today): https://www.earlytelevision.org/dumont_ra-119.html https://www.earlytelevision.org/dumont_ra-119.html I think metal-cone CRTs became unpopular due to the glass-to-metal seal not being as reliable, and difficulties with insulation (the whole cone is at the final accelerating voltage.)