WEBVTT - TechStuff Classic: TechStuff Stares at OLEDs 0:00:04.120 --> 0:00:07.160 Get in touch with technology with tech Stuff from how 0:00:07.200 --> 0:00:13.760 stuff Works dot com. Hey there, welcome to tech Stuff. 0:00:13.800 --> 0:00:17.200 I am your host, Jonathan Strickland. I'm an executive producer 0:00:17.360 --> 0:00:19.840 with How Stuff Works, and I heart radio and I 0:00:19.920 --> 0:00:23.080 love all things tech. And now I'm going to talk 0:00:23.120 --> 0:00:25.560 to you a little bit about classic episode, an episode 0:00:25.560 --> 0:00:28.440 of tech Stuff that we published way back on March 0:00:28.560 --> 0:00:33.560 two thousand and twelve called tech Stuff Stairs at O LEDs, 0:00:34.080 --> 0:00:37.280 O L E d S. Chris Palette and I sat 0:00:37.320 --> 0:00:40.040 down to talk about what are O LEDs, how do 0:00:40.120 --> 0:00:43.080 they work, and why are they important? And I think 0:00:43.080 --> 0:00:46.400 it's funny to listen to this older episode because when 0:00:46.479 --> 0:00:48.839 we were recording it back in two thousand twelve, oh 0:00:48.960 --> 0:00:51.280 LED screens were still very much in that R and 0:00:51.360 --> 0:00:53.880 D kind of prototype stage. You didn't really see them 0:00:53.880 --> 0:00:56.840 in very many consumer products. And these days where you're 0:00:56.880 --> 0:01:00.880 seeing them and all sorts of stuff from smartphone too, tablets, 0:01:00.920 --> 0:01:05.399 to laptop computers to television sets. So it's neat to 0:01:05.400 --> 0:01:09.280 see how things have changed. Enjoy this classic episode. I 0:01:09.280 --> 0:01:11.959 think by when I first started at How Stuff Works, 0:01:11.959 --> 0:01:17.480 oh lads, we're still very very much in the prototype stage, 0:01:17.880 --> 0:01:21.000 and you didn't really see anything on the market at 0:01:21.040 --> 0:01:23.800 that time, the consumer market anyway, they had an O 0:01:24.000 --> 0:01:26.640 LEDs type screen and now they're much later in the 0:01:26.680 --> 0:01:30.800 prototype stage. But we're kidding the lads. Actually, now we're 0:01:30.800 --> 0:01:33.080 getting to the point where we're finally seeing them scaled 0:01:33.280 --> 0:01:36.720 up to large screen TVs. But for a long time, 0:01:37.160 --> 0:01:41.160 the biggest screen you're gonna get with something like eleven Yeah. Yeah, Well, 0:01:41.360 --> 0:01:44.280 the genesis of my joke being that people who are 0:01:44.319 --> 0:01:47.840 really interested in OLED technology have been waiting for them 0:01:47.880 --> 0:01:50.560 to come out for a very long time, and it 0:01:50.600 --> 0:01:54.400 seems like they're they've been in development of some kind 0:01:54.680 --> 0:01:57.120 for a for a long long time. They've been actually 0:01:57.120 --> 0:02:01.520 pretty common in smaller screens like smartphones, rins for example. Um, 0:02:01.560 --> 0:02:03.800 they're they're really great for that. They use less energy 0:02:03.800 --> 0:02:06.960 than a lot of the other technologies and they're excellent 0:02:07.000 --> 0:02:10.960 for that. But that's you know, getting them scaled up 0:02:11.000 --> 0:02:13.040 has taken a long time, and the people who have 0:02:13.080 --> 0:02:17.000 been waiting, I'm gonna buy an old TV like, well, 0:02:17.120 --> 0:02:20.320 you know, I wouldn't hold my breath. Well, but finally 0:02:20.400 --> 0:02:22.919 they're starting to hit now. But and and also the 0:02:22.960 --> 0:02:24.600 other thing people have been waiting for, and it's one 0:02:24.639 --> 0:02:26.639 of the types we'll talk about in a little a 0:02:26.680 --> 0:02:30.000 little further in in the podcast is the flexible oh lady, 0:02:30.280 --> 0:02:33.760 that idea of having a display that is actually malleable, 0:02:33.800 --> 0:02:36.440 that you can bend it around things. And you know, 0:02:36.560 --> 0:02:40.000 you might use that to have a foldable display. That's 0:02:40.000 --> 0:02:41.640 what a lot of people talk about. But there are 0:02:41.639 --> 0:02:44.000 other things you could use it for, Like you could 0:02:44.080 --> 0:02:46.680 use it in displays. Stay in a store where you've 0:02:46.720 --> 0:02:49.320 got round columns and you could have a display wrapping 0:02:49.360 --> 0:02:53.440 around this round column. Uh yeah, things like that. Well, yeah, 0:02:53.440 --> 0:02:56.919 and it's uh, and that's the thing about it. I think, Um, 0:02:57.080 --> 0:02:59.359 despite the fact that it's taken a while to get 0:02:59.760 --> 0:03:02.680 law er oh lad screens, the technology will be worth 0:03:02.720 --> 0:03:04.840 the way. But I think it's uh. I think it 0:03:04.919 --> 0:03:06.520 is a good idea to go ahead and talk about 0:03:06.520 --> 0:03:10.120 the similarities. And there I think three major similarities between 0:03:10.160 --> 0:03:16.639 the technologies red, green, and blue light. Well, the purpose 0:03:16.680 --> 0:03:19.680 of all all the technologies we're talking about here, you know, 0:03:19.720 --> 0:03:23.560 plasma l C D and uh you know the oh 0:03:23.680 --> 0:03:26.280 lads or l E D screens and organic l E 0:03:26.400 --> 0:03:29.760 D screens. Um, you know, it's it's to display information 0:03:30.200 --> 0:03:35.280 and it shows us light. Um. The trick is really 0:03:35.400 --> 0:03:37.600 how they go about doing that. And we've talked about 0:03:37.640 --> 0:03:39.720 some of the other technologies in the past, like for example, 0:03:39.880 --> 0:03:44.760 plasma uses uh gases ionized gas, and basically you they 0:03:44.760 --> 0:03:47.680 show the different colors by running a charge through the 0:03:47.720 --> 0:03:52.360 gas and then look like l c D uses liquid crystals, 0:03:52.680 --> 0:03:56.040 and these liquid crystals actually form a barrier between light 0:03:56.560 --> 0:03:59.280 and the clear part of the screen, and then the 0:03:59.440 --> 0:04:03.560 l c D these through various running an electric current 0:04:03.600 --> 0:04:06.720 through change shape and that allows light to pass through 0:04:06.760 --> 0:04:08.920 and there's some color filters in there and that's where 0:04:08.960 --> 0:04:11.600 we get the displays through that. So that's a liquid 0:04:11.600 --> 0:04:15.000 crystal display. L E d s are light emitting diodes 0:04:15.720 --> 0:04:19.200 and we've had those around for for quite some time 0:04:19.680 --> 0:04:22.240 and they're pretty efficient. They're more efficient than a lot 0:04:22.279 --> 0:04:24.920 of other forms of lighting. But an O l e D, 0:04:25.160 --> 0:04:28.719 as Chris had mentioned, is an organic light emitting diode. 0:04:29.080 --> 0:04:33.039 And you might think, well, what how that huh, And 0:04:33.080 --> 0:04:35.720 it really comes down to uh kind of a an 0:04:35.839 --> 0:04:39.280 organic sandwich. Yes, And the thing is, uh, they're not 0:04:40.680 --> 0:04:43.800 terribly different from from the typical l E d s, 0:04:44.080 --> 0:04:46.520 but it's it really comes down to the materials used 0:04:46.839 --> 0:04:51.760 to make that sandwich. So they're they're they're very thin, alright, 0:04:51.800 --> 0:04:54.800 So an O L D it's it's solid state, all right, 0:04:55.279 --> 0:04:59.960 And it is usually between one to five hundred natomie 0:05:00.000 --> 0:05:04.960 eaters thick, which is pretty thin. That's according to UH 0:05:04.960 --> 0:05:10.000 to most estimates. And this does change from one source 0:05:10.040 --> 0:05:13.320 to another, but it's about two hundred times thinner than 0:05:13.320 --> 0:05:16.760 a human hair in diameter. Now, human hair is actually 0:05:16.800 --> 0:05:20.960 come into a variety of diameters. It's like one person's 0:05:20.960 --> 0:05:25.120 hair might be thinner than another's. Some people have clear 0:05:25.160 --> 0:05:29.320 hair like me, My hair is invisible to the human eye. 0:05:29.880 --> 0:05:34.719 But yeah, at any rate, the two hundred it's an average, 0:05:34.760 --> 0:05:36.760 So it's two hundred times smaller than the diameter of 0:05:36.839 --> 0:05:42.880 human hair. And uh, it's they're different layers within this sandwich, right, 0:05:43.680 --> 0:05:47.840 and that's what is creating the light that you see. 0:05:47.920 --> 0:05:51.600 And there's the basics the the bread on this sandwich, 0:05:51.600 --> 0:05:56.320 if you will, is our pair of electrodes. Right, you've 0:05:56.320 --> 0:05:58.680 got your cathode and you've got your technically, you also 0:05:58.720 --> 0:06:01.960 have the substrate. This substrate is the foundation that the 0:06:02.040 --> 0:06:05.960 O LED sits upon. So substrate is also part of this. 0:06:06.040 --> 0:06:08.880 But I'm looking mostly at the components that actually make 0:06:09.279 --> 0:06:13.040 the lad work. Right, So, yeah, you've got the cathode 0:06:13.040 --> 0:06:15.120 and the anode, and you've got the jobs of the 0:06:15.160 --> 0:06:17.400 cathode and the anode are to create a circuit for 0:06:17.440 --> 0:06:20.560 electricity to flow through, right, right, The electrons flow from 0:06:20.560 --> 0:06:23.480 one to the other. Yea, from the cathode to the anode. 0:06:23.839 --> 0:06:25.440 And in a way you have to kind of think 0:06:25.480 --> 0:06:30.080 of this in uh interesting terms, like, so, cathode is 0:06:30.120 --> 0:06:37.360 injecting negative particles into this o led sandwich. Are you positive? Yes, 0:06:37.640 --> 0:06:40.240 I am positive that they are negative electrons, is what 0:06:40.400 --> 0:06:45.159 cathodes are putting into their The anode is creating, well 0:06:45.160 --> 0:06:49.480 what we call them electron holes. They're positive. It's they 0:06:49.640 --> 0:06:52.640 turn an element to a positively charged element. They actually 0:06:52.680 --> 0:06:55.360 pull electrons out of it, and so now it's positively charged. 0:06:55.680 --> 0:06:58.000 So that means that the electrons coming from the cathode 0:06:58.000 --> 0:07:02.279 are attracted towards the anno side. Hey, you're pretty cute. 0:07:02.920 --> 0:07:05.080 And so it has to pass through the other layers 0:07:05.080 --> 0:07:09.280 of the sandwich. And there are two or three other layers, 0:07:09.320 --> 0:07:11.560 depending on the type of oh ledge you're looking at, 0:07:12.080 --> 0:07:16.600 but really the two layer is the most common, So 0:07:17.000 --> 0:07:20.360 I'll just stick with that. So you've got your emissive layer, 0:07:20.600 --> 0:07:24.320 this is the layer that actually emits light, and you 0:07:24.400 --> 0:07:28.840 have your conductive layer, which is the layer that attracts 0:07:28.840 --> 0:07:33.119 the electrons through the other materials. So if we're looking 0:07:33.120 --> 0:07:35.960 at top to bottom and the bottom is the substrate, 0:07:36.680 --> 0:07:39.880 then the top layer is your cathode. Next down you 0:07:39.880 --> 0:07:42.080 have your emissive layer, that's where the light comes through. 0:07:42.720 --> 0:07:44.880 Then you have your conductive layer that's what's pulling the 0:07:44.920 --> 0:07:47.960 electrons down. Then you have the annode layer. That's what's 0:07:48.040 --> 0:07:51.160 really pulling the electrons down. It's what's allowing the conductive 0:07:51.200 --> 0:07:53.680 layer to pull these electrons through. And then you have 0:07:53.720 --> 0:08:00.280 the substrate. So, uh, why are we getting light? Boy? 0:08:00.400 --> 0:08:05.040 This this gets into some interesting physics here. Okay, So 0:08:05.120 --> 0:08:07.840 you've got the electrons coming through from one side, you've 0:08:07.840 --> 0:08:10.640 got the electron holes coming through from the other side. 0:08:10.960 --> 0:08:13.040 So in a way, you can think of negative charge 0:08:13.040 --> 0:08:15.800 and positive charge. I know that sounds weird, but just 0:08:15.920 --> 0:08:19.640 go with me here. And when those two meet, the 0:08:19.680 --> 0:08:24.240 molecule that they meet at becomes uh, actually drops an 0:08:24.240 --> 0:08:28.120 electron into that positive hole, and as a result, there 0:08:28.200 --> 0:08:32.320 is a difference in energy. It releases some energy as 0:08:32.360 --> 0:08:35.400 a result of that that reaction, and that energy is 0:08:35.400 --> 0:08:38.200 released in the form of a photon. And we've talked 0:08:38.200 --> 0:08:41.840 about this before about how if you excite an atom, 0:08:42.440 --> 0:08:44.280 you know, by telling you it's going to dine world 0:08:44.360 --> 0:08:48.320 or something, and the electrons moved to a higher energy state. 0:08:48.360 --> 0:08:51.160 When those electrons move back down, once that energy has 0:08:51.280 --> 0:08:54.440 has been removed from the system, once the electrons move 0:08:54.480 --> 0:08:57.000 back down, they have to release that extra energy, and 0:08:57.040 --> 0:08:59.040 they often will do this in the form of photons, 0:08:59.080 --> 0:09:03.400 which we perceive as light. That's exactly what's going on here. Actually, 0:09:03.480 --> 0:09:06.640 I saw a great video on this uh M my 0:09:06.800 --> 0:09:11.199 t S site where a professor was explaining how oh 0:09:11.280 --> 0:09:14.520 LED's work by shocking the heck out of a pickle. 0:09:15.800 --> 0:09:18.680 He had a had a cathode and an anode um 0:09:19.559 --> 0:09:22.040 attached to a pickle and was running a very high 0:09:22.040 --> 0:09:24.720 electric current through it, which was making the pickle glow. 0:09:25.600 --> 0:09:27.320 And it was this is what was happening. You had 0:09:27.360 --> 0:09:29.640 the positive charge in the negative charge meeting and the 0:09:29.679 --> 0:09:33.760 molecules where it met at that's where it was releasing 0:09:33.800 --> 0:09:36.839 this electron and uh and and releasing a photon or 0:09:37.040 --> 0:09:39.120 or it was the electron states were moving down and 0:09:39.200 --> 0:09:41.160 the photons were being released, and that's why we were 0:09:41.160 --> 0:09:46.520 getting light. Um pretty cool. Actually, I kind of wanted 0:09:46.559 --> 0:09:48.400 to build one, except for the fact that I'm sure 0:09:48.440 --> 0:09:52.560 I would probably electric you myself. For a second there, 0:09:52.600 --> 0:09:55.800 I thought you were girk in my chain. Ha ha. Anyway, 0:09:56.120 --> 0:09:58.480 so when we're talking about electricity, we're not talking about 0:09:58.520 --> 0:10:01.719 a lot. It said, these are pretty efficient, so we're 0:10:01.720 --> 0:10:04.120 talking in a realm of just a few volts that 0:10:04.160 --> 0:10:08.600 are needed in order to excite these molecules so that 0:10:08.640 --> 0:10:11.120 they emit light. That's one of the major benefits of 0:10:11.559 --> 0:10:14.679 old screens is that they don't require as much electricity 0:10:14.720 --> 0:10:17.480 as some others. You know. Of course, plasma TVs are 0:10:17.559 --> 0:10:21.080 are notorious for using a lot of electricity. Well, you 0:10:21.120 --> 0:10:24.040 have to keep pouring in electricity to keep that gas ionized. 0:10:24.559 --> 0:10:29.120 So yeah, plasma display is not They've gotten a lot 0:10:29.200 --> 0:10:32.240 better last few years, but is it is, by its 0:10:32.320 --> 0:10:37.079 very nature, is not the most environmentally friendly way of 0:10:37.800 --> 0:10:40.920 creating television. Not that TV is terribly environmentally friendly no 0:10:40.960 --> 0:10:43.720 matter how you do it, but but it's it's less 0:10:43.720 --> 0:10:47.199 So yeah, plasma has a reputation for being for being 0:10:47.280 --> 0:10:50.760 less energy friendly. So yeah, there there there have been 0:10:50.800 --> 0:10:54.120 some better ones, but still uh and those two different 0:10:54.200 --> 0:10:59.520 layers of molecules are are are organic, but they're organic 0:10:59.600 --> 0:11:05.600 plastic thick. It's pretty cool organic plastic like poly aniline 0:11:06.480 --> 0:11:11.280 and polyfluorine. Okay, all right, you know Pollyanna, you know 0:11:11.280 --> 0:11:14.120 when you when you say we're organic plastic, that sort 0:11:14.120 --> 0:11:17.720 of sounds like it's oxymoronic, like you know organ chuah 0:11:17.760 --> 0:11:22.839 wa um. Well that that's actually UM. We should talk 0:11:22.840 --> 0:11:26.080 about to the different types of OH leads because there 0:11:26.080 --> 0:11:29.080 are r G B OH lead screens and then there's 0:11:29.120 --> 0:11:32.920 the white lead screen UM, which sort of uses a 0:11:32.960 --> 0:11:37.840 color sandwich to UM, and by by activating red, green, 0:11:37.960 --> 0:11:42.320 and blue, you get white UM. And uh. You know 0:11:42.600 --> 0:11:45.560 those the red, green and blue are are pressed together 0:11:45.840 --> 0:11:49.680 in the same pixel. So by doing that you can 0:11:49.760 --> 0:11:54.080 you can have the have basically a pure white UM 0:11:54.440 --> 0:11:57.880 and it's it. It works a little slightly differently than 0:11:57.960 --> 0:12:02.679 than the others simply because of at UM. There are 0:12:03.400 --> 0:12:06.120 people say that it has a longer life than the 0:12:06.160 --> 0:12:11.040 traditional O lead screens UM, but that is supposed to 0:12:11.080 --> 0:12:14.080 be one of the advantages of it UM. And it's 0:12:14.080 --> 0:12:18.000 also possible to uh to scale the white OH lead 0:12:18.040 --> 0:12:21.520 screens up a little easier from what I understand. Yeah, 0:12:21.520 --> 0:12:25.280 it's also been talked about as a potential replacement for 0:12:25.320 --> 0:12:28.600 things like fluorescent lights, where not just for displays, but 0:12:28.640 --> 0:12:32.719 for actual lighting, because that's it's even more efficient than 0:12:32.800 --> 0:12:35.840 fluorescent lighting is. And uh, you know you don't have 0:12:35.880 --> 0:12:40.560 that mercury that you gotta worry about in fluorescent lights. Yeah. Guys, 0:12:40.679 --> 0:12:43.080 if you have those little fluorescent bulbs, which are you know, 0:12:43.120 --> 0:12:46.240 more energy efficient incandescent bulbs will good on you, but 0:12:46.360 --> 0:12:49.120 be very careful with them, yes, because those suckers do 0:12:49.440 --> 0:12:52.480 contain some very toxic chemicals in them that can be 0:12:52.559 --> 0:12:55.040 very dangerous. Yes, you do not want to bust them, right, 0:12:55.160 --> 0:12:59.120 So the O lead lights might be a nice alternative 0:12:59.160 --> 0:13:01.960 to that, you know, if if it's efficient enough so 0:13:02.000 --> 0:13:05.679 that they make economic sense to the consumer, because you know, 0:13:05.679 --> 0:13:08.480 you gotta worry about that, uh, and also the fact 0:13:08.480 --> 0:13:12.000 that they don't have these toxic chemicals necessarily inside them. 0:13:12.080 --> 0:13:14.160 If they are just as efficient or more so, then 0:13:14.559 --> 0:13:16.920 makes perfect sense to go and switch to a We're 0:13:16.960 --> 0:13:19.760 gonna get back to our discussion about how oh LEDs 0:13:19.840 --> 0:13:22.600 work and what they are all about in just a second, 0:13:22.600 --> 0:13:25.120 but first let's take a quick break to thank our sponsor. 0:13:32.800 --> 0:13:36.400 There are actually several different types of oh LAD screens 0:13:36.520 --> 0:13:40.199 just LAD displays. We talked about the foldable oh LEDs. Now, 0:13:40.200 --> 0:13:44.320 these are using a substrate that is flexible. So you know, 0:13:44.360 --> 0:13:46.520 your typical substrate. When I think of substrate, I think 0:13:46.559 --> 0:13:49.160 of something that is that is, you know, pretty solid, 0:13:49.720 --> 0:13:52.200 or sometimes it can be a little brittle or whatever, 0:13:52.200 --> 0:13:55.040 but it doesn't bend. It's not bendi bendy. Right. Well. 0:13:55.080 --> 0:13:57.520 The the idea being that you're going to build your 0:13:58.080 --> 0:14:02.280 circuit material on top of this material. So I mean 0:14:02.280 --> 0:14:05.040 you're this it's a board, so you you know, you're 0:14:05.080 --> 0:14:07.320 I'm going to add the stuff to it, right, Yeah, 0:14:07.440 --> 0:14:09.760 Usually you want something that's fairly solid, although you know, 0:14:10.040 --> 0:14:13.520 obviously for other applications you would need something that's flexible. 0:14:13.600 --> 0:14:16.480 Let's say that you want to create a display on 0:14:16.920 --> 0:14:20.360 say a jacket, which might very well be something not 0:14:20.440 --> 0:14:23.560 necessarily that the consumer would ever see. But let's say 0:14:23.560 --> 0:14:27.160 an advertising company creates this, uh, this type of of 0:14:27.360 --> 0:14:29.760 jacket that can have a flexible screen on the back 0:14:29.800 --> 0:14:32.160 of it, and then next thing you know, you've got 0:14:32.160 --> 0:14:35.840 this new way for at trade shows where people can 0:14:35.880 --> 0:14:41.160 show off cool technology and it's literally playing on their backs. Um, 0:14:41.360 --> 0:14:43.760 I mean, I could even imagine it going so far 0:14:43.840 --> 0:14:47.120 as to let's say you've got a courier service and 0:14:47.240 --> 0:14:51.320 you are sponsored, they run ads on your back as 0:14:51.360 --> 0:14:56.560 you you're a bike courier. I look forward to seeing that. 0:14:57.160 --> 0:14:59.240 I look forward to seeing all the accidents that will 0:14:59.240 --> 0:15:01.560 happen as result people turning their heads to see what 0:15:01.640 --> 0:15:03.760 to watch. Yeah, they're like, I want to follow this 0:15:03.800 --> 0:15:05.920 guy another mile. I have to see how this turns out. 0:15:06.560 --> 0:15:08.320 Clearly that if you did that, you would have to 0:15:08.320 --> 0:15:12.560 make very visually stunning types of ads that don't need 0:15:12.600 --> 0:15:15.440 any audio. That would be that would be the real 0:15:15.520 --> 0:15:19.120 challenge there. Look, I'm just trying. I'm just I'm just 0:15:19.120 --> 0:15:21.560 trying to create some jobs out there. That's what I'm 0:15:21.560 --> 0:15:23.800 trying to do. Okay, But you also have you have 0:15:23.840 --> 0:15:28.240 your passive matrix oh LED. Now passive matrix, oh lads. 0:15:28.720 --> 0:15:31.160 You know we talked about the cathodes and the anodes. Well, 0:15:31.240 --> 0:15:34.160 that's not necessarily a sheet on top of you know, 0:15:34.240 --> 0:15:36.560 when I said sandwich, it sounds like you're talking about 0:15:36.560 --> 0:15:41.000 solid sheet. That's not necessarily the case, although that can 0:15:41.040 --> 0:15:44.760 be done a passive matrix oh LED. What it does 0:15:44.840 --> 0:15:48.440 is it arranges the cathodes and anodes into strips, and 0:15:48.880 --> 0:15:51.320 one sets strips are vertical and the other sets strips 0:15:51.320 --> 0:15:53.360 are horizontal. So you could think of it like all 0:15:53.400 --> 0:15:56.720 the anodes are streets and all the cathodes are avenues. 0:15:57.640 --> 0:16:00.280 So at these intersections where the cathode and and O 0:16:00.440 --> 0:16:03.200 meat that's where you have your pixels and your pixels 0:16:03.200 --> 0:16:05.720 of course, that's the point of light. So when you 0:16:05.720 --> 0:16:08.120 talk about how many pixels the display has, as so 0:16:08.160 --> 0:16:10.520 many points of light it is capable of displaying at 0:16:10.520 --> 0:16:14.120 one time more than that, it would be a very 0:16:14.160 --> 0:16:18.360 low resolution television. Uh. The so this is one way 0:16:18.360 --> 0:16:20.720 of doing that where you have the just at the 0:16:20.720 --> 0:16:23.720 intersections of these strips, that's where the pixels are uh. 0:16:24.000 --> 0:16:29.160 Not terribly efficient compared to other oh leads and uh 0:16:29.240 --> 0:16:32.880 and also for all of these screens, if you're wondering 0:16:33.040 --> 0:16:36.640 about controlling brightness, that's a function of how much electricity 0:16:36.680 --> 0:16:39.360 is flowing through the system. If you're pouring more juice 0:16:39.360 --> 0:16:42.160 into it, it's gonna be brighter less juice not as bright, 0:16:42.480 --> 0:16:45.800 which makes sense. Next, we have the active matrix OH 0:16:45.840 --> 0:16:49.480 lead and this has a full sheet of the cathode 0:16:49.480 --> 0:16:52.400 and and it's sort of like the sandwich example I 0:16:52.480 --> 0:16:57.200 was giving earlier. So in this case, there is a 0:16:57.320 --> 0:17:03.920 film transistor that is uh gotta. It's an anode layer overlay, 0:17:04.320 --> 0:17:07.680 and that's what forms the matrix. Uh not the kind 0:17:07.760 --> 0:17:10.560 that NEO goes through with all the zeros and ones, 0:17:10.640 --> 0:17:13.800 but this in the it forms the same feature as 0:17:13.880 --> 0:17:17.600 the intersections on the passive matrix. OH lead, tank, I 0:17:17.640 --> 0:17:21.720 eat an exit. Oh gosh, wow, out of all of those, 0:17:21.760 --> 0:17:24.280 you know, I'm surprised you didn't say I know kung 0:17:24.400 --> 0:17:31.080 fu or just whoa uh you got your transparent oh lads. 0:17:31.119 --> 0:17:34.240 Now these are really super cool. Like everything every single 0:17:34.320 --> 0:17:38.920 element in this oh lead is transparent. So when light 0:17:39.119 --> 0:17:42.800 is uh is flowing through this system, then you see 0:17:42.840 --> 0:17:47.080 it projected within a clear screen, and when it's not, 0:17:47.280 --> 0:17:49.760 you can just look through the screen. Now, this is 0:17:49.840 --> 0:17:53.240 used in things like heads up displays, so you know 0:17:53.400 --> 0:17:57.359 you're flying exactly flying a plane, driving a car or whatever. 0:17:57.400 --> 0:17:59.280 If you've got a heads up display that can show 0:17:59.359 --> 0:18:03.840 within the uh the windscreen or or cockpit screen or whatever, 0:18:04.520 --> 0:18:09.160 that is very likely a transparent oh lad. I've also 0:18:09.640 --> 0:18:14.640 seen this used in smart Windows, which was something new. 0:18:14.880 --> 0:18:17.000 I mean, I had heard about smart windows before, but 0:18:17.040 --> 0:18:18.399 it was the first time I had seen one was 0:18:18.440 --> 0:18:22.800 at CS where I think it was Samsung that had it. 0:18:23.040 --> 0:18:25.880 Where it's a smart window. What that could display information 0:18:26.240 --> 0:18:28.520 and it could do things that give you like little 0:18:28.600 --> 0:18:31.960 information like news items or the weather or whatever. Although 0:18:32.000 --> 0:18:34.280 when you're looking out a window, if you need a 0:18:34.280 --> 0:18:38.119 weather report, when you're looking out a window, you're not 0:18:38.160 --> 0:18:41.600 being terribly observant. Well, it might be nice to know 0:18:41.680 --> 0:18:44.720 what the temperature is going to be. You can open 0:18:44.840 --> 0:18:47.199 the window. Oh okay, all right, so you're looking at 0:18:47.240 --> 0:18:53.920 the future forecast. Alright, fine, fine, yeah, you know, all right, Okay, 0:18:54.320 --> 0:19:00.720 I withdraw my objection. Uh what about active matrix leeds. 0:19:01.040 --> 0:19:02.760 I talked about those. That's one of the that's the 0:19:02.760 --> 0:19:04.399 one with the thin film transistor. Do you want to 0:19:04.440 --> 0:19:07.080 just okay? Now they used as a lot in the phones. 0:19:07.200 --> 0:19:08.960 So oh yes, yes, yes, yes, that's the one that 0:19:09.040 --> 0:19:11.520 does have that thin film transistor I was talking about. 0:19:11.560 --> 0:19:13.760 That's the one that ends up taking the place of 0:19:13.840 --> 0:19:19.119 the intersections. The thin film transistor itself has the connections 0:19:19.160 --> 0:19:22.080 on it on the anode side where it activates where 0:19:22.080 --> 0:19:25.720 the pixels are, and these pixels are active the fact 0:19:25.720 --> 0:19:27.920 that they are so thin is a benefit when you're 0:19:27.960 --> 0:19:31.360 talking about these electronic devices. It makes it so much 0:19:31.400 --> 0:19:34.880 easier to uh, you know, fit it into these things 0:19:35.080 --> 0:19:38.880 tablet form factors and smartphones. Yeah, if we were still 0:19:38.960 --> 0:19:41.480 using if we were using things like l c D 0:19:41.600 --> 0:19:46.440 technology for all of these devices, they would be significantly 0:19:46.640 --> 0:19:50.600 or at least noticeably larger, like thicker and and somewhat heavier. 0:19:50.880 --> 0:19:52.919 And I mean heavy being a relative thing. But in 0:19:52.960 --> 0:19:55.439 the case of it, every ounce counts. Yeah, and in 0:19:55.480 --> 0:19:57.399 a tablet or something like that, you know, if it 0:19:57.440 --> 0:20:00.920 adds six ounces. Yeah. There's one more type of O 0:20:01.080 --> 0:20:04.040 lead thy talk about, which is the top emitting OH lead. 0:20:04.640 --> 0:20:08.480 And this has got a substrate that is either opaque 0:20:08.560 --> 0:20:12.200 or reflective, and they are often used. This is often 0:20:12.400 --> 0:20:15.520 uh like this, this is just one subtype of O lead. 0:20:15.600 --> 0:20:19.679 It can actually be combined with another type of O lead. So, 0:20:19.720 --> 0:20:21.879 in other words, that active matrix old we were just 0:20:21.960 --> 0:20:26.080 talking about, that method of display could be combined with 0:20:26.119 --> 0:20:28.840 the top admitting OH lead. Uh. And this is something 0:20:28.880 --> 0:20:31.640 that's often used in things like smart cards. Future Jonathan 0:20:31.680 --> 0:20:33.800 here saying, hey, these old leads are pretty great. I 0:20:33.880 --> 0:20:37.040 bet pasted Jonathan and Chris would have really dug them. Anyway, 0:20:37.119 --> 0:20:39.040 it's typ for us to take another quick break to 0:20:39.080 --> 0:20:50.040 take our sponsor. So lots of different applications of oh leads, 0:20:50.119 --> 0:20:56.080 not just uh displays on phones or um or TVs 0:20:56.240 --> 0:20:59.280 or or even you know, computer monitors that kind of thing. Uh. 0:20:59.480 --> 0:21:02.400 It's interest seeing because even though it sounds pretty complex, 0:21:03.000 --> 0:21:08.159 really it's simpler than things like l c D technology. 0:21:08.160 --> 0:21:12.240 It is. It is much simpler in the grand scheme 0:21:12.240 --> 0:21:15.439 of things, um, even though it's more advanced technology, and 0:21:15.440 --> 0:21:17.639 it's taken years to kind of get the prototype, the 0:21:17.640 --> 0:21:21.960 manufacturing process efficient enough so that we can build screens 0:21:22.040 --> 0:21:26.560 that are at the size that we're used to. Even so, 0:21:27.240 --> 0:21:30.119 you know, we have mentioned that, yes, there are television 0:21:30.160 --> 0:21:33.919 screens coming out like large ones TVs that use oh 0:21:34.000 --> 0:21:38.160 LAD displays. They are incredibly thin, like to the point 0:21:38.160 --> 0:21:40.320 where you can't even really get a good picture of 0:21:40.320 --> 0:21:43.040 them when you look at them in profile. UM. However, 0:21:43.400 --> 0:21:47.200 they also tend to cost a princely some Yes, that's 0:21:47.240 --> 0:21:49.399 what I was getting at, is that we have reached 0:21:49.400 --> 0:21:51.879 the point where the manufacturing process has allowed us to 0:21:52.000 --> 0:21:56.760 build these, but they're still prohibitively expensive. For I'd say 0:21:57.040 --> 0:22:00.680 the majority of the consumer market, new TV is likely 0:22:00.720 --> 0:22:03.400 to cost you several thousand dollars. We're talking like ten 0:22:03.520 --> 0:22:09.240 grand easy, ten tho dollars for lad screen easy. Um 0:22:09.320 --> 0:22:12.880 that that's a lot of money for a new television set. 0:22:13.320 --> 0:22:15.639 I would not be prepared to spend that much on 0:22:15.680 --> 0:22:19.360 a TV. And if you're talking about using a competing 0:22:19.400 --> 0:22:23.280 technology that costs say one fifth of that, you know 0:22:23.640 --> 0:22:26.439 or or or yeah or less? Well, yeah, it depends 0:22:26.400 --> 0:22:28.800 I think the last thing. So for example, I I 0:22:28.920 --> 0:22:32.200 purchased an l E ED l c D h D 0:22:32.320 --> 0:22:37.960 t V for um way less than that, like less 0:22:38.000 --> 0:22:40.959 than a tenth of that. And so you look at 0:22:41.000 --> 0:22:45.280 that and you're you're saying, yeah, the the technology, the 0:22:45.320 --> 0:22:49.560 display technology is clearly superior in that clearly clearly huh, 0:22:49.880 --> 0:22:53.480 in that it's got a very crisp picture. The colors 0:22:53.480 --> 0:22:57.520 are are very true true blacks. Yes, because you don't 0:22:57.520 --> 0:23:01.359 have that backlighting, just like plasma. Plasma does not have backlighting, 0:23:01.400 --> 0:23:03.720 but l c D does, which is why if you've 0:23:03.760 --> 0:23:05.840 ever had l C D television new mine is an 0:23:05.920 --> 0:23:08.159 l c D t D. It's just back split by 0:23:08.280 --> 0:23:10.040 l E D S. Yeah, so that's why L E 0:23:10.119 --> 0:23:13.240 D l C D. Yeah, so when you both. But 0:23:13.240 --> 0:23:15.440 but if you're watching in a dark room and it's 0:23:15.480 --> 0:23:19.440 a scene that is like someone walks into a pitch 0:23:19.480 --> 0:23:22.760 black room in the house, or there's suddenly like a 0:23:22.840 --> 0:23:25.479