WEBVTT - The One About Plasma Televisions 0:00:04.480 --> 0:00:12.520 Welcome to tech Stuff, a production from iHeartRadio. Hey there, 0:00:12.560 --> 0:00:16.240 and welcome to tech Stuff. I'm your host, Jonathan Strickland. 0:00:16.280 --> 0:00:19.840 I'm an executive producer with iHeart Podcasts and How the 0:00:20.000 --> 0:00:24.919 Tech are Ya. So in the late nineteen nineties, televisions 0:00:24.960 --> 0:00:28.720 were changing, specifically here in America, but all around the world. 0:00:28.880 --> 0:00:31.240 So here in America we were used to big old 0:00:31.520 --> 0:00:35.920 CRT televisions that's cathode ray tube TVs to you and me. 0:00:36.280 --> 0:00:40.919 And they were real chonkers, bulky, they were heavy. They 0:00:40.960 --> 0:00:44.839 contained capacitors that remained dangerous even after you turned the 0:00:44.880 --> 0:00:47.839 television off. By the way, that's one reason to not 0:00:48.040 --> 0:00:51.600 smash an old TV. If they're still charge stored in 0:00:51.680 --> 0:00:54.920 the capacitors, you could get a real jolt, like a 0:00:55.040 --> 0:00:58.800 deadly one. Televisions at that time had a four to 0:00:58.840 --> 0:01:02.040 three aspect ratio in those days. That means for every 0:01:02.480 --> 0:01:06.720 three units of height, you had four units of width. 0:01:07.000 --> 0:01:10.200 That's why if you watch any old television programming today 0:01:10.440 --> 0:01:13.600 on a modern TV, and if that programming hasn't been 0:01:13.640 --> 0:01:17.080 adjusted to fit a modern television, there is always space 0:01:17.120 --> 0:01:20.880 on either side of the screen. Resolution was, you know, 0:01:21.120 --> 0:01:25.319 not great. If you wanted a really nice home entertainment system. 0:01:25.400 --> 0:01:28.400 You often leaned heavily on the other components to help 0:01:28.440 --> 0:01:30.520 pick up some of the slack you might have, like 0:01:30.560 --> 0:01:34.600 a projection television, maybe a rear projection television. But yeah, 0:01:34.640 --> 0:01:37.440 these things were huge. But that would really change in 0:01:37.520 --> 0:01:40.560 nineteen ninety seven or so with the introduction of flat 0:01:40.560 --> 0:01:43.919 screen televisions, led by a technology that took a different 0:01:43.959 --> 0:01:48.440 approach to creating images. So with a CRT, you're using 0:01:48.480 --> 0:01:52.840 a zapper, an electron gun, and it fires a stream 0:01:52.880 --> 0:01:55.320 of electrons at the backside of a screen, and that 0:01:55.360 --> 0:01:59.200 backside of the screen is coded in phosphor dots. And 0:01:59.360 --> 0:02:01.920 when the elect trunds hit the phosphors, it excites the 0:02:01.920 --> 0:02:05.840 phosphors and they end up glowing as they let out 0:02:05.920 --> 0:02:11.720 this excess energy. They luminess. But this new technology was 0:02:11.840 --> 0:02:14.480 using a different method to generate that light. It was 0:02:14.600 --> 0:02:18.560 using an excitable gas that could then be precision controlled 0:02:18.560 --> 0:02:22.280 by tiny electrodes. So this was the introduction of the 0:02:22.440 --> 0:02:27.080 plasma television. Now these days, plasma televisions are kind of 0:02:27.160 --> 0:02:31.800 like antiques or collector's items. No one is making them anymore. 0:02:31.800 --> 0:02:35.480 In fact, the last major companies to make plasma televisions 0:02:35.520 --> 0:02:38.240 stopped doing it in twenty fourteen, so it's been a 0:02:38.440 --> 0:02:42.520 decade since these were consumer items. I mean, you could 0:02:42.520 --> 0:02:46.080 still find them occasionally, but no one's making them for 0:02:46.160 --> 0:02:48.920 a while. However, plasma television was in the running for 0:02:49.240 --> 0:02:52.960 like the best television technology on the market. So I 0:02:53.000 --> 0:02:56.200 thought we could talk about where this idea came from 0:02:56.440 --> 0:03:00.320 and then what happened to plasma TVs. So we gotta 0:03:00.400 --> 0:03:05.399 start a ways back, like sixty years ago, in nineteen 0:03:05.600 --> 0:03:09.360 sixty four, and y'all, I'm going to just give highlights, 0:03:09.360 --> 0:03:12.040 but if you want a real breakdown on the development 0:03:12.080 --> 0:03:15.400 of the plasma display and the various technological challenges that 0:03:15.480 --> 0:03:18.080 needed to be solved to make it a possibility, I 0:03:18.160 --> 0:03:21.480 highly recommend you search for a white paper, an article rather, 0:03:21.880 --> 0:03:25.440 and it's titled History of the Plasma Display Panel. It's 0:03:25.600 --> 0:03:31.480 by Larry F. Weber Weber of I Triple E, or 0:03:31.520 --> 0:03:35.600 as I used to say AE, and this article was 0:03:35.640 --> 0:03:39.760 published in a journal called Transactions on Plasma Science. This 0:03:39.880 --> 0:03:42.720 was back in two thousand and six. So knowing that 0:03:42.800 --> 0:03:44.320 it was back in two thousand and six when this 0:03:44.440 --> 0:03:47.320 was written, you need to forgive opening passages that say 0:03:47.360 --> 0:03:51.640 things like quote, plasma displays are enjoying an unprecedented degree 0:03:51.680 --> 0:03:55.160 of success as large screen televisions. End quote. Because that 0:03:55.400 --> 0:03:58.000 was true in two thousand and six. These days not 0:03:58.200 --> 0:04:01.040 so much. But despite the fact that you know it 0:04:01.080 --> 0:04:03.000 has that dated reference, I mean it was written in 0:04:03.000 --> 0:04:05.880 two thousand and six, the article itself phenomenal. I'll be 0:04:05.960 --> 0:04:08.720 referencing it a lot in this episode, and I highly 0:04:08.760 --> 0:04:11.480 recommend if you're more interested in the technical details that 0:04:11.560 --> 0:04:14.640 you check it out. It's great. So, as Weber points out, 0:04:14.720 --> 0:04:17.720 the early development of plasma displays, that work wasn't being 0:04:17.800 --> 0:04:21.360 done with home television as being an end goal. In fact, 0:04:21.400 --> 0:04:25.799 it wasn't even in the thought process at the time necessarily. Instead, 0:04:25.920 --> 0:04:29.719 this was part of an effort to develop computer systems 0:04:29.760 --> 0:04:32.760 that could be used for the purposes of education. So, 0:04:33.440 --> 0:04:37.480 how do you make a high resolution display for educational 0:04:37.480 --> 0:04:41.520 computer systems and do so in a way that makes 0:04:41.680 --> 0:04:45.159 sense doesn't break the bank. So engineers and researchers at 0:04:45.200 --> 0:04:49.360 the University of Illinois launched a project called the Programmed 0:04:49.520 --> 0:04:54.159 Logic for Automatic Teaching Operations, or PLATO. This was in 0:04:54.279 --> 0:04:58.000 nineteen sixty when they first formed this project, and plato's 0:04:58.040 --> 0:05:00.920 main aim was to research the possibilit of using computer 0:05:01.000 --> 0:05:06.080 systems for educational purposes. Now today, millions of students around 0:05:06.080 --> 0:05:09.320 the world do their homework on computers. They get class 0:05:09.320 --> 0:05:12.719 assignments on computers. Computers are like an integral part of 0:05:12.880 --> 0:05:16.960 education for lots of schools around the world. However, back 0:05:17.000 --> 0:05:21.480 in nineteen sixty computers were still these big, centralized machines 0:05:21.680 --> 0:05:25.479 that very few people had ever seen, let alone used. 0:05:25.880 --> 0:05:28.800 If you were a computer science student, or you know, 0:05:28.880 --> 0:05:31.080 if you worked at a research lab or perhaps some 0:05:31.200 --> 0:05:35.640 military installation, then maybe you had some contact with computers. 0:05:35.760 --> 0:05:38.320 I mean computer science, certainly you would have some contact. 0:05:38.480 --> 0:05:40.839 But other than that, these were things that you heard 0:05:40.839 --> 0:05:44.240 about but you never really encountered. Even as computers began 0:05:44.320 --> 0:05:46.839 to make their way into the business world, very few 0:05:46.839 --> 0:05:49.839 people still actually had the chance to get their hands 0:05:49.880 --> 0:05:54.440 on them because these were still largely centralized machines. That 0:05:54.480 --> 0:05:57.360 would pretty much remain the case until micro computers came 0:05:57.400 --> 0:06:00.000 on the scene in the seventies and eighties. But anyway, 0:06:00.279 --> 0:06:03.560 the folks on the Plato project were forward thinkers, and 0:06:03.640 --> 0:06:08.360 in nineteen sixty four, Donald L. Bitzer and Jene Slatto, 0:06:09.000 --> 0:06:12.400 both of whom were professors at the University of Illinois, 0:06:12.560 --> 0:06:16.680 and apologies for my terrible pronunciation, but they, along with 0:06:16.760 --> 0:06:20.640 a graduate student named Robert Wilson, tackled this challenge of 0:06:20.680 --> 0:06:23.880 building a new display system that would be suitable for 0:06:23.920 --> 0:06:27.159 the latest iteration of the project's computer, which at that 0:06:27.200 --> 0:06:29.760 point was the Plato three. They were up to the 0:06:29.800 --> 0:06:32.920 third generation of this computer system. So this next bit 0:06:33.080 --> 0:06:36.920 gets technical, but it's also an example of a fortuitous 0:06:36.960 --> 0:06:41.960 discovery that only happened because of an accident. As doctor 0:06:42.000 --> 0:06:46.120 Frankenfurter would say, So, okay, it's the nineteen sixties swing 0:06:46.160 --> 0:06:49.840 in sixties and semiconductor based memory has yet to really 0:06:49.880 --> 0:06:53.400 become a thing, so that's not really an accessible technology 0:06:53.440 --> 0:06:57.080 if you're designing a computer system. Still, your graphics displays 0:06:57.160 --> 0:07:00.760 need access to memory in order to you know, display 0:07:00.760 --> 0:07:04.520 stuff like bitmaps, so it's not just like a blip 0:07:04.560 --> 0:07:07.760 on the screen. It's actually a sustained image. So a 0:07:07.760 --> 0:07:11.040 bitmap is literally just a map of bits that represent light, 0:07:11.440 --> 0:07:16.320 and older displays relied upon an external scan converter memory 0:07:16.360 --> 0:07:20.160 tube in order to achieve this memory. These things, I mean, 0:07:20.280 --> 0:07:22.920 they're external, so they're not part of the system itself. 0:07:23.120 --> 0:07:26.080 They were bulky, They were expensive, and they were kind 0:07:26.080 --> 0:07:29.880 of limiting in order to actually have this computer memory. 0:07:29.880 --> 0:07:32.960 It was a big deal. So the team was trying 0:07:33.000 --> 0:07:36.840 to figure out how to achieve memory internally in the 0:07:36.880 --> 0:07:41.920 display itself and they started to work with neon. Now, 0:07:42.040 --> 0:07:47.119 this neon depended upon a vacuum system for it to work, 0:07:47.480 --> 0:07:50.400 but it turned out that the system they were using 0:07:50.480 --> 0:07:53.559 as they were developing this display actually had a little 0:07:53.560 --> 0:07:56.240 bit of a leak in it. And that's the accident 0:07:56.280 --> 0:07:58.280 I was talking about. There was a leak in the 0:07:58.360 --> 0:08:02.280 vacuum system and that allowed some air to mix with 0:08:02.520 --> 0:08:07.120 the neon. However, that turned out to actually be beneficial 0:08:07.280 --> 0:08:11.160 to the project because when the neon gas with this 0:08:11.280 --> 0:08:14.840 mix of air in it would be excited, it would 0:08:14.880 --> 0:08:17.840 emit an orange glow. Now, normally, if it were just 0:08:17.920 --> 0:08:21.280 pure neon, if there were no other gases mixing with 0:08:21.320 --> 0:08:25.040 the neon, that glowing would stop once the excited electrons 0:08:25.320 --> 0:08:28.360 returned to their normal state. Essentially, once the electric charge 0:08:28.400 --> 0:08:31.880 was turned off, it would just stop glowing. However, that 0:08:31.960 --> 0:08:36.760 mixed air caused something interesting, and that's hysteresis. And if 0:08:36.800 --> 0:08:39.800 you're wondering what the heck that is, allow me to explain, 0:08:39.920 --> 0:08:43.640 because I just learned about it myself, So I know 0:08:43.840 --> 0:08:46.480 about this, but I didn't know the word for it. 0:08:46.520 --> 0:08:50.600 So hysteresis refers to the tendency of some phenomena to 0:08:50.760 --> 0:08:55.000 linger after the cause of that phenomena has already gone. So, 0:08:55.440 --> 0:08:58.360 for example, let's say you make an electromagnet out of 0:08:58.400 --> 0:09:01.440 an iron nail and some copper wire, and you coil 0:09:01.520 --> 0:09:04.360 the copper wire around the nail. You connect the wire 0:09:04.440 --> 0:09:07.280 to a battery. You got yourself an electromagnet, and you 0:09:07.360 --> 0:09:08.840 use it for a while to pick up paper clips 0:09:08.920 --> 0:09:12.720 or whatever. And then maybe once you're done, you've disconnected 0:09:12.760 --> 0:09:15.400 the wire from the battery, you've taken the nail out 0:09:15.400 --> 0:09:19.400 of the coil. Maybe you notice that, hey, this nail 0:09:19.559 --> 0:09:23.320 still is displaying some magnetic qualities that can still pick 0:09:23.400 --> 0:09:27.199 up paper clips, even though it's no longer inside the 0:09:27.200 --> 0:09:30.960 coil with electricity running through it. It's no longer an electromagnet. 0:09:31.000 --> 0:09:35.360 It's acting more like a magnet. Well, that's hysteresis. The 0:09:35.440 --> 0:09:39.520 electric current that generated the magnetic field is gone, but 0:09:39.600 --> 0:09:43.200 the nail retains some magnetism, at least for a while. 0:09:43.240 --> 0:09:46.000 It does fade over time and eventually just becomes a nail. 0:09:46.280 --> 0:09:49.920 So with the neon display, the mixed and air caused 0:09:49.960 --> 0:09:53.520 the neon to remain lit up after the charge had left, 0:09:53.840 --> 0:09:58.280 so the display kind of had a memory, so to speak. 0:09:58.520 --> 0:10:01.400 That was the solution to their problem, and again it 0:10:01.440 --> 0:10:04.640 was all due to an accident. So this discovery prompted 0:10:04.679 --> 0:10:08.920 the researchers to change their approach. They would purposefully introduce 0:10:09.040 --> 0:10:13.120 a tiny bit of nitrogen into the neon gas in 0:10:13.240 --> 0:10:17.720 order to accomplish on purpose what had first happened by accident, 0:10:18.120 --> 0:10:22.680 which is a pretty darn cool story. I love stories 0:10:22.720 --> 0:10:25.880 like that where you know, surely we would have arrived 0:10:25.880 --> 0:10:29.480 at this discovery at some point, but the fact that 0:10:29.559 --> 0:10:33.760 it happened by sort of luck, and in what you 0:10:33.760 --> 0:10:36.560 would first think was bad luck because it relies on 0:10:36.600 --> 0:10:39.280 your equipment not working the way it was intended to that, 0:10:39.360 --> 0:10:41.960 to me is pretty cool. Now. I think it also 0:10:42.000 --> 0:10:46.000 helps if we consider for a moment how plasma displays work, 0:10:46.320 --> 0:10:48.960 like that's going to help us understand a lot about 0:10:49.000 --> 0:10:52.760 this topic. So let's get to some basics. Images on 0:10:52.840 --> 0:10:57.000 televisions and other displays, those are made up of pixels, 0:10:57.080 --> 0:10:59.240 and you can think of pixels as being kind of 0:10:59.360 --> 0:11:04.160 like at it's a basic unit of light. On a screen, 0:11:04.240 --> 0:11:07.480 it's a point of light. So the full screen is 0:11:07.520 --> 0:11:11.600 made up of thousands or millions of pixels, depending upon 0:11:11.640 --> 0:11:16.160 the resolution of your screen. Typically, these pixels have one 0:11:16.200 --> 0:11:19.400 of three colors associated with them, red, green, or blue. 0:11:19.760 --> 0:11:25.200 Or they have subpixels like little cells filled with red phosphor, 0:11:25.200 --> 0:11:29.600 green phosphor or blue phosphor. These RGB pixels are spread 0:11:29.640 --> 0:11:33.199 evenly across the screen, so by controlling the brightness the 0:11:33.600 --> 0:11:38.320 luminosity of each of those three colors, you can show 0:11:38.360 --> 0:11:41.400 potentially millions of different shades of color. If you light 0:11:41.520 --> 0:11:45.720 all three of those subpixels equally, you get white, right. 0:11:45.800 --> 0:11:48.320 If you like none of them, you get black. If 0:11:48.360 --> 0:11:51.840 you like combinations of them at different intensities, like you know, 0:11:52.200 --> 0:11:55.720 like forty percent red, ten percent blue, etea that kind 0:11:55.760 --> 0:11:58.360 of thing, then you can get lots of other different 0:11:58.440 --> 0:12:03.480 colors represented on screen. In a plasma television, the pixels 0:12:03.520 --> 0:12:07.360 are made up of individual cells that are sandwich between 0:12:07.400 --> 0:12:11.600 other layers. I'll give you the typical outline of how 0:12:11.679 --> 0:12:16.440 this works, because it depends specifically on the manufacturer and 0:12:16.480 --> 0:12:19.120 what method they used, but generally speaking, we can get 0:12:19.160 --> 0:12:22.959 an idea of how this works. But inside these individual 0:12:23.080 --> 0:12:26.040 cells that are sandwiched between other layers, you have an 0:12:26.080 --> 0:12:29.400 ionized gas. In other words, of plasma. Plasma is the 0:12:29.440 --> 0:12:32.400 most plentiful state of matter in the universe. So when 0:12:32.440 --> 0:12:34.640 I was a kid, I was taught about three states 0:12:34.640 --> 0:12:38.840 of matter, solid liquid, gas. Plasma is technically a fourth 0:12:38.960 --> 0:12:41.440 state of matter. It's a special kind of gas. It's 0:12:41.520 --> 0:12:44.520 a gas that has free floating electrons, which means that 0:12:44.559 --> 0:12:48.400 can do stuff like conduct electricity. Stars are made out 0:12:48.440 --> 0:12:52.640 of plasma. Anyway, if you have plasma in a contained environment, 0:12:52.760 --> 0:12:55.880 like an enclosed air type tube, and you apply voltage 0:12:55.920 --> 0:12:58.920 to this tube, then you have electrons that are rushing around, 0:12:59.120 --> 0:13:02.600 and you have positively charged atoms rushing around, and the 0:13:02.679 --> 0:13:05.400 electrons are heading to the positively charged atoms, and the 0:13:05.480 --> 0:13:09.440 positively charged atoms are heading toward the negatively charged electrons. 0:13:09.520 --> 0:13:12.160 Because you know, opposite charges attract and when they collide, 0:13:12.440 --> 0:13:15.800 you get excited atoms, and those atoms eventually let out 0:13:15.800 --> 0:13:18.440 some of that excess energy in the form of photons 0:13:18.840 --> 0:13:22.600 aka light. Now, with a lot of gases, the light 0:13:22.640 --> 0:13:25.480 that's being released is actually invisible to us. It's in 0:13:25.520 --> 0:13:31.040 the ultraviolet range, so we cannot directly perceive this light. However, 0:13:31.480 --> 0:13:36.800 in turn, this ultraviolet light can excite special atoms called phosphors, 0:13:37.000 --> 0:13:39.920 and some phosphors can emit light that is within the 0:13:40.000 --> 0:13:44.320 visible spectrum. So you excite the gas atoms and you 0:13:44.400 --> 0:13:48.040 get ultraviolet light. The ultraviolet light in turn excites the phosphors, 0:13:48.040 --> 0:13:50.640 and then you get visible light. Okay, we're going to 0:13:50.679 --> 0:13:52.880 take a quick break here. When we get back, we're 0:13:52.880 --> 0:13:55.800 going to talk about that sandwich I mentioned earlier, and 0:13:55.840 --> 0:13:57.600 I'm going to try not to have my stomach growl 0:13:57.840 --> 0:14:12.520 because it's also lunchtime sandwiches. We'll be right back. Okay, 0:14:12.559 --> 0:14:15.040 all right, we're back. I still haven't eaten lunch, so 0:14:15.120 --> 0:14:17.200 we're gonna see how this goes. But if we do 0:14:17.280 --> 0:14:20.760 think of a plasma display as a kind of sandwich, 0:14:21.120 --> 0:14:24.440 the typical description of plasma displays goes something like this. 0:14:24.840 --> 0:14:28.280 Your bottom piece of bread. The base of your sandwich 0:14:28.560 --> 0:14:31.560 is a plate of glass, which I admit does not 0:14:31.600 --> 0:14:34.520 sound that appetizing. On top of this plate of glass, 0:14:34.560 --> 0:14:38.640 you have a series of vertically aligned electrodes, so they're 0:14:38.720 --> 0:14:43.440 columns of electrodes. This is called the address electrodes. Then 0:14:43.600 --> 0:14:46.800 you would have the layer of cells that contain the 0:14:47.200 --> 0:14:49.840 gas that can be turned into a plasma once you 0:14:49.880 --> 0:14:53.200 apply voltage to this gas, plus the cells that have 0:14:53.320 --> 0:14:57.400 the subpixels coated in red, green, or blue phosphors, each 0:14:57.640 --> 0:15:02.000 one assigned to one of the these cells of gas. 0:15:02.440 --> 0:15:06.440 Then you have another layer that's a clear magnesium oxide layer. 0:15:06.440 --> 0:15:09.760 This is to protect the next layer, which is another 0:15:09.840 --> 0:15:12.600 layer of electrodes. Now these are arranged at a ninety 0:15:12.600 --> 0:15:15.880 degree angle compared to the first ones. The address electrodes 0:15:15.920 --> 0:15:18.760 that are on the bottom right, So these are in rows. 0:15:19.240 --> 0:15:23.280 These are the display electrodes, and they by necessity need 0:15:23.320 --> 0:15:25.320 to be transparent because the light needs to be able 0:15:25.360 --> 0:15:26.720 to go through them in order for you to see 0:15:26.720 --> 0:15:29.080 what's on a display. So now you actually have a 0:15:29.120 --> 0:15:32.440 grid of electrodes. Right, You've got some that are running 0:15:32.800 --> 0:15:35.040 along the bottom and vertical columns and some that are 0:15:35.080 --> 0:15:38.000 running on the top and horizontal rows. Next you have 0:15:38.040 --> 0:15:42.680 a dielectric material that insulates those display electrodes. And finally 0:15:42.680 --> 0:15:46.360 you have the front plate of glasses the top slice 0:15:46.360 --> 0:15:49.880 of bread on your sandwich. These displays are able to 0:15:49.920 --> 0:15:53.320 send a specific voltage to a pair of electrodes at 0:15:53.320 --> 0:15:55.560 a specific point on the display. You can think of 0:15:55.600 --> 0:15:58.480 the display as just being a series of xy coordinates, 0:15:58.680 --> 0:16:01.800 so you can see and end a voltage signal to 0:16:01.880 --> 0:16:05.000 that pair of electrodes specifically at one location on the 0:16:05.040 --> 0:16:08.760 screen in order for them to excite the gas inside 0:16:08.800 --> 0:16:11.480 the cell, which then of course gives off ultraviolet light, 0:16:11.760 --> 0:16:14.960 which in turn excites the phosphors coding the subpixels for 0:16:15.000 --> 0:16:17.200 that cell, and then you get a point of light 0:16:17.360 --> 0:16:20.440 on the display. Of course, this is actually happening at 0:16:20.440 --> 0:16:23.480 different points all across the display at the same time, 0:16:23.520 --> 0:16:26.600 and it's rapidly changing, right. That's how you get your 0:16:26.840 --> 0:16:29.960 moving plasma image. All of those points of light on 0:16:30.000 --> 0:16:33.640 a plasma display are coming from specific voltages applied at 0:16:33.640 --> 0:16:37.720 precise locations on that grid of electrodes, thus exciting the 0:16:37.760 --> 0:16:41.280 gas in that spot that then excites the phosphors, which 0:16:41.280 --> 0:16:44.240 to me is super cool. Like, that's such a neat 0:16:44.600 --> 0:16:47.880 approach to creating an image on a screen. I just 0:16:47.920 --> 0:16:51.400 think it's incredibly interesting. I don't know, maybe it's just 0:16:51.440 --> 0:16:54.280 because I'm a geek. Now, one benefit to this approach 0:16:54.360 --> 0:16:56.720 is that you don't need as much depth to your 0:16:56.760 --> 0:17:00.040 display as you would with a CRT, so remember I 0:16:59.880 --> 0:17:03.920 said that CRT televisions are chonky. Well, a cathode ray 0:17:03.960 --> 0:17:08.119 two displays width determines how deep it has to be 0:17:08.119 --> 0:17:12.520 because the wider the screen is, the longer the tube 0:17:12.720 --> 0:17:14.879 needs to be in order for the electron gun to 0:17:14.880 --> 0:17:18.560 be able to reach across the entire width of the screen. Like, 0:17:19.080 --> 0:17:22.479 larger screens get really super bulky. It's kind of like 0:17:22.560 --> 0:17:25.240 having a projector, right, Like if you have a projector 0:17:25.520 --> 0:17:28.320 and you're too close to a screen, well, the image 0:17:28.320 --> 0:17:30.760 that you're projecting isn't going to take up the whole screen. 0:17:30.960 --> 0:17:32.639 It's just going to take a part of it. You 0:17:32.680 --> 0:17:34.920 have to move the projector back in order for it 0:17:34.960 --> 0:17:37.640 to take up the whole screen. Same thing with these 0:17:37.680 --> 0:17:40.320 cathode ray tube electron guns. They need to be a 0:17:40.320 --> 0:17:42.640 certain distance from the back of the screen in order 0:17:42.680 --> 0:17:45.280 to illuminate the whole thing. So the bigger your screen is, 0:17:45.359 --> 0:17:48.240 the further back the electron gun needs to be, so 0:17:48.400 --> 0:17:50.760 the larger the television would get. And you just get 0:17:50.800 --> 0:17:55.720 these enormous, heavy, bulky TVs and it wouldn't make sense 0:17:55.760 --> 0:17:57.560 beyond a certain amount, which is why you would get 0:17:57.800 --> 0:18:01.320 like projection televisions instead. If you want a really big screen, 0:18:01.520 --> 0:18:03.639 you need to either have a projector and a screen, 0:18:04.119 --> 0:18:07.040 or you needed to have like rear projection, which was 0:18:07.040 --> 0:18:09.440 still bulky, but not as big as if it were CRT. 0:18:10.080 --> 0:18:14.000 So plasma displays didn't need to have so much depth 0:18:14.040 --> 0:18:17.520 to them because the electrode grid does the same job 0:18:17.560 --> 0:18:20.760 that the electron gun did in a CRT essentially, and 0:18:20.800 --> 0:18:24.640 so plasma displays could be much thinner than CRTs were now. 0:18:24.680 --> 0:18:27.439 By much thinner, I do mean, they still were thick 0:18:27.600 --> 0:18:30.960 compared to the flat screen televisions you would buy today. 0:18:31.240 --> 0:18:35.320 Like we're talking like six inches thick. That's still pretty 0:18:35.400 --> 0:18:37.480 hefty if you compare it to the sort of stuff 0:18:37.520 --> 0:18:39.800 you can buy, you know, in a store today. I mean, 0:18:39.840 --> 0:18:44.600 some of the latest televisions are incredibly thin, but back 0:18:44.600 --> 0:18:48.240 in the nineteen nineties, a six inch deep TV that 0:18:48.400 --> 0:18:51.520 was velt. Anyway, It obviously would take quite some time 0:18:51.560 --> 0:18:55.200 between pioneering this technology in nineteen sixty four and seeing 0:18:55.200 --> 0:18:59.119 plasma televisions available in stores around nineteen ninety seven. I mean, 0:18:59.160 --> 0:19:02.600 that's like three decades of time. So let's go back 0:19:02.640 --> 0:19:04.240 to the history for a bit to look at some 0:19:04.400 --> 0:19:07.800 of the milestones that led the way. Now as Weber 0:19:07.840 --> 0:19:10.399 points out in that excellent article I mentioned at the 0:19:10.400 --> 0:19:13.000 top of the show the plasma display researchers at the 0:19:13.080 --> 0:19:16.040 University of Illinois. The thing they built it was great 0:19:16.080 --> 0:19:20.640 for establishing that this was a viable technology, but their 0:19:20.680 --> 0:19:25.040 display was a far cry from being suitable for commercial 0:19:25.160 --> 0:19:29.160 or consumer applications. For one thing, the display itself measured 0:19:29.240 --> 0:19:32.080 a total of one inch per side, so a one 0:19:32.080 --> 0:19:34.720 inch by one inch screen. I think we can both 0:19:34.760 --> 0:19:37.359 agree that's a bit on the small side, right. But 0:19:37.480 --> 0:19:40.560 for another, it was made of some really fragile material, 0:19:40.680 --> 0:19:44.200 so it wouldn't stand up to any sort of rigorous 0:19:44.320 --> 0:19:48.720 shipping for example, much less like if you had kids 0:19:48.800 --> 0:19:51.440 or pets, or maybe you like to play the Wii 0:19:51.680 --> 0:19:55.280 and you don't use the risks straps, you know, like 0:19:55.359 --> 0:19:59.560 you're instructed to come on be more responsible gamers. Anyway, 0:20:00.000 --> 0:20:04.119 it was also kind of cluged together, this prototype display. 0:20:04.320 --> 0:20:08.600 It had like really visible epoxy holding it together, and 0:20:08.880 --> 0:20:11.199 they had problems with leaks and stuff like that. So 0:20:11.280 --> 0:20:16.040 in short, the display panel showed that plasma displays could work, 0:20:16.520 --> 0:20:18.520 but there were a lot of challenges that would need 0:20:18.560 --> 0:20:21.200 to be addressed before it could approach being a reliable 0:20:21.359 --> 0:20:26.960 display option, let alone a consumer television. So development continued 0:20:27.480 --> 0:20:29.359 and within just a couple of years there were some 0:20:29.440 --> 0:20:33.760 breakthroughs that saw massive improvements in design and that led 0:20:33.800 --> 0:20:37.399 to the ability to do a little bit more streamline 0:20:37.400 --> 0:20:42.320 manufacturing and the displays were able to develop. As a result, 0:20:42.440 --> 0:20:45.480 they were still small, and they still had fairly low resolution, 0:20:45.640 --> 0:20:48.879 but the improvements showed that plasma based displays could in 0:20:48.920 --> 0:20:52.159 fact be a reality. Each success drove more innovation in 0:20:52.240 --> 0:20:55.080 the space and allowed for larger displays with greater resolution. 0:20:55.480 --> 0:20:59.520 So by nineteen seventy one, a glass company called Owen's 0:20:59.560 --> 0:21:03.880 Illinois was able to produce the first commercial plasma display. 0:21:04.160 --> 0:21:07.800 Now by today's standards, this was a pretty low resolution display. 0:21:07.880 --> 0:21:11.440 It measured only five hundred twelve by five hundred twelve pixels, 0:21:11.680 --> 0:21:13.919 so that meant the display had a little more than 0:21:13.960 --> 0:21:16.920 two hundred and sixty thousand pixels in total if you 0:21:17.000 --> 0:21:20.040 were to add them all up. Future high definition plasma 0:21:20.080 --> 0:21:24.040 televisions could have as many as more than two million pixels. 0:21:24.240 --> 0:21:28.040 But still, this twelve inch display made by Owens Illinois 0:21:28.240 --> 0:21:31.359 was a big deal, and the Plato Project at the 0:21:31.400 --> 0:21:34.840 University of Illinois became the first customer to order these 0:21:34.880 --> 0:21:39.600 displays as part of their Plato Educational Computer System project, 0:21:39.880 --> 0:21:43.080 and as Weber points out, it was a remarkably quick 0:21:43.119 --> 0:21:46.920 turnaround to go from the first implementation of the technology 0:21:47.359 --> 0:21:50.800 in nineteen sixty four to a finished product in nineteen 0:21:50.840 --> 0:21:54.120 seventy one. I mean that's like, well seven years, that's 0:21:54.320 --> 0:21:57.439 really fast for a brand new technology to go from 0:21:57.960 --> 0:22:01.120 we just proved that this works to here's a product 0:22:01.240 --> 0:22:04.119 based on that tech. Many other technical issues had to 0:22:04.160 --> 0:22:08.280 be solved for plasma TVs to become a practical possibility, Like, 0:22:08.680 --> 0:22:11.320 even with the advancements that had been done by nineteen 0:22:11.359 --> 0:22:14.199 seventy one, we were a far cry from something that 0:22:14.240 --> 0:22:18.160 would be acceptable in a home. For one thing, the 0:22:18.440 --> 0:22:23.440 early displays were monochromatic, right, like, they did not have 0:22:23.520 --> 0:22:26.800 full color capability for the earliest versions. It would take 0:22:26.880 --> 0:22:31.240 some time to develop that. And even with chromatic displays, 0:22:31.240 --> 0:22:33.800 there were still challenges. One of those was solving for 0:22:33.960 --> 0:22:37.000 gray scale right, different levels of brightness so that you 0:22:37.040 --> 0:22:40.760 could have something between the brightest bright and the darkest dark. 0:22:40.880 --> 0:22:43.439 So in the early days of plasma displays, a pixel 0:22:43.480 --> 0:22:46.200 could either be on or it could be off. It 0:22:46.320 --> 0:22:49.040 was either as bright as it could be or it 0:22:49.119 --> 0:22:52.000 was dark. You had nothing in between, so there was 0:22:52.040 --> 0:22:56.000 no way of showing any kind of resolution within an image. 0:22:56.320 --> 0:22:59.640 In the early nineteen seventies, companies like Hitachi and Mitsubishi 0:22:59.680 --> 0:23:01.879 came up with a method to deal with this, and 0:23:02.040 --> 0:23:05.440 essentially it involved cutting down the length of time each 0:23:05.520 --> 0:23:09.880 pixel would fire, so you would create like pulses that 0:23:10.160 --> 0:23:13.360 would light up a pixel, and to make a pixel 0:23:13.440 --> 0:23:17.120 less bright, you would just pulse it less frequently, and 0:23:17.240 --> 0:23:20.159 that would make it appear to be dimmer than the 0:23:20.200 --> 0:23:23.720 neighboring pixels and thus would allow for grayscale. It was 0:23:23.880 --> 0:23:28.919 known as the address while display method the AWD method, 0:23:29.160 --> 0:23:31.280 and it would remain in use for several years before 0:23:31.320 --> 0:23:35.639 engineers found alternative methods to achieve similar results. Now to 0:23:35.640 --> 0:23:40.200 get color displays rather than monochromatic ones, engineers figured out 0:23:40.320 --> 0:23:45.960 that placing little glass ribs in between the subpixels was key, 0:23:46.119 --> 0:23:50.600 otherwise you would get these weird kind of saturated images. 0:23:50.640 --> 0:23:53.320 Everything would come across kind of pastel. You didn't get 0:23:53.440 --> 0:23:58.520 very vibrant color representation in early color plasma displays because 0:23:58.520 --> 0:24:01.040