Home Theater Geeks 443 Transcript

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00:00 - Scott Wilkinson (Host)
In this episode of Home Theater Geeks, I answer a listener question about LED video walls. Don't go anywhere. Podcasts you love From people you trust. This is TWIT. Hey there, scott Wilkinson. Here, the Home Theater Geek. In this episode I answer a question from listener Palle Juhl Sorensen, who asks what do you think about LED video walls as TVs? Short and to the point, just as I like them.

00:50
Now, large LED video walls have been used for a long time. They've been around for years as jumbotrons in sports stadiums, baseball fields and such, and also as large outdoor signs. In Las Vegas you see them all over that town. They use red, green and blue LEDs which directly emit light to form the image. Now these large signs can use relatively large LEDs spaced relatively far apart, because they're meant to be viewed from very far away. Video walls used as TVs are a different story. The LEDs have to be much, much smaller. In fact, they're called micro LEDs for a reason and they need to be placed very close together. So we can see a couple examples of that. Here is one where the LED itself is probably four or five microns micrometers in diameter and they're separated by a few microns micrometers in diameter, and they're separated by a few microns. They are just really close together. Sony, who is one company working on micro LED video walls, also had a graphic that showed the fact that each the light source of each pixel of RGB LED trio is 0.003 square millimeters in size and they're surrounded by a lot of black. 99% of the surface area of each pixel is black, so they aren't terribly close together. They wanted to get good black level performance, and so they made these micro LEDs super tiny and surrounded them with quite a bit of black.

03:03
Now, in virtually all cases, micro LED displays which would be used for TVs and other professional applications consist of smaller tiles that measure roughly a foot or two square square, and we can see the Sony ZRD2 tile in graphic three, which shows you one of these tiles. Now an installer mounts a bunch of these tiles to the wall and we can see in graphic four several of them in a frame, if you will, six of them here and then the next graphic we can see the back of an entire installation at Sony Studios where there's this whole frame structure and there's a bunch of these tiles that are mounted together and then each tile is connected electronically to each other and to a central controller, and we can see a picture of a Sony ZR-CT200, which is that controller that basically sends an image out to this array of tiles and stitches them all together to form one image. Now you can build a screen of almost any size and aspect ratio by increasing or decreasing the number and arrangement of the tiles you use. In the next graphic, it's a picture of a Sony LED micro LED display, which they called Cletus, a crystal LED integrated system. This is a photo I took at CES 2017. And you can see that its aspect ratio is way wider than any TV would be, and it looked great. Interestingly, once you have a tile, it consists of a number of these micro LEDs, and so the resolution is fixed, and so, as you add more and more tiles, you get higher and higher resolution in the final image.

05:43
Now, what are the advantages of micro LED? They are super bright. At the last display week, which I talked about in a previous episode, there were at least a couple of micro LED displays that claimed peak brightness up to 10,000 nits. Most commercial consumer TVs are in the 1,000, now in 2024, getting up to 4,000 nits of peak brightness. These things did 10,000 nits, way higher than OLED and even LED LCD TVs, and they have super high contrast Because they're self-emitting. The LEDs can emit more or less light depending on the electrical signal sent to them, and they can go down to zero. So, just like an OLED, they can achieve perfect blacks and essentially infinite contrast. Also, leds even micro LEDs do not degrade over time like OLED material.

06:51
Now I don't want you to think that, oh, oleds are going to look crappy after a couple of years. They're not. They're going to last for 10, 20 years, easy. But micro LEDs degrade even less and you can make the screens arbitrarily large. Less and you can make the screens arbitrarily large. So how big a screen do you want depends on how much you want to pay. So what are the disadvantages of micro LED? Well, they're very difficult to manufacture. The LED placement must be perfect and if it's not, you have to throw the thing out. So the yields are very low.

07:35
Here's a couple of different ways that can be used to make these tiles. One is called pick and place, and a little arm picks up some LEDs and swivels around and places them onto the back plane. You can also use quantum dots to deposit in certain places there to get the red, green and blue pixels In the next graphic, a couple other examples where you can basically grow them or inkjet print them onto a substrate and do it that way. Even with all these different ways to do it, it's very, very difficult to make it perfect, which it needs to be in order to work. Another really significant problem, in my opinion, is making the seams between the tiles invisible. Now, when you first walk up to a big, giant micro LED display, it's very impressive, it's very bright, but if you look closely, under certain conditions, if the ambient lighting is about right or the image is a certain thing, you can see the seams between the tiles, and once you see them, you can't really unsee them, so they're not obvious. It's not like there's a bezel between each of the tiles, but it is not invisible. Then there's the problem of the sound system. With a projection screen, for example, you put the speakers behind the screen, which is acoustically transparent, and the sound seems to come from exactly where it's supposed to. What Sony did with its crystal LED at Sony Pictures was it put speakers above and below the screen, which can create a phantom image in the center of the screen, and that's how I think most micro LED displays are going to deal with sound, but it's not perfect, it's not ideal.

10:10
And finally, micro LED screens are exceedingly expensive. Exceedingly expensive, and I'm going to give you an example of that here in a second. The last few years, companies like Samsung in particular, have demonstrated micro LED displays intended for consumers at shows like CES, for example. I saw Samsung called it at the time the wall at CES 2018. And I took a picture of their wall there, graphic 12. And it was kind of interesting in that they had an image of a brick-like wall on the screen and they had it recessed into a brick wall and it was beautiful, just gorgeous, but again, astronomically expensive. Samsung recently, I think last year, an 89 inch version of the wall, which I don't think they use that name anymore, I think they just calling it micro led.

11:26
Okay, so an 89 inch version for $102,000. Good grief. They also offer 101 inch, 110 inch, 114 inch, which are correspondingly more expensive. All are 4k, interestingly enough, which means that the leds are a little farther apart in the tiles for the larger screens. Um, so that you know, and a larger screen, you need to sit farther back. So it Now if they can solve the visible seam problem and bring the cost down to more reasonable levels, micro LED TV will be the ultimate display technology for the home.

12:29
I don't see any other way. Anything else that could even come close to it if they solve those problems, anything else that could even come close to it if they solve those problems, but because of high manufacturing costs and low yields, I don't think this is going to happen. For quite a few years, micro LED displays are going to be the exclusive domain of the ultra rich, who can spend $100, dollars for an 89 inch TV, um, and then invite all their friends over for bragging rights. But uh, for you and me and most of humanity, uh, they ain't going to be available anytime soon, which is why I say I prefer OLED to LED LCD TVs, even though they aren't as bright as LED LCD TVs, but they still look fantastic and they're plenty bright enough for most situations. So there you go, my thoughts on micro LED TVs.

13:35
Now, if you have a question for me, please send it along to htg at twittv and, as always, we thank you for your support of Club Twit. Now you can always listen to the show audio version for free, and we certainly appreciate you doing that. But if you want to see the graphics and see the video and my smiling mug, all you have to do is join Club Twit. That gives you access to Home Theater, geeks and all the Twitch shows ad-free. You can also come into the Discord channel and watch us make the show live. So thanks again and we'll look forward to seeing you next time. Until then, geek out.