VueReal Demos microLED Displays at DW24

Chris Chinnock here for Insight Media in the VueReal booth at DisplayWeek taking a look at their microLED devices. The first thing I want to show are these two small ones here. You can actually see the image a lot better in the reflection back here. That’s blue. Over here is the green. These are available in red, green, and blue. All the VueReal devices are RGB, so discrete devices. Their position in the market is they use solid printing technology. It’s a very proprietary transfer technology. These particular ones are passive matrix based. They use 28×15 micron flip chip devices on a 35 micron pixel pitch so very small. They are 160 x 120 each and 0.4 inch diagonally. This is kind of application here would be information snacking, maybe a sports goggle or things like that.

This is a transparent active-matrix device. So, this is LTPS on glass at about 172 PPI and 80% transmissivity. I think these are about a 150-micron pixel pitch. This was actually used by Tier 1 OEM at CES in one of their demos. I can’t really name the customer at this point.

Moving down the line, this is now a passive matrix device with RGB 28×15 micron flip chip microLEDs in this guy. They must have separate drivers of course, chip on film drivers in the back. This is a dimmer now at about 300 nits.  I’m not sure what this one is but it’s probably 1500 or so (with a new backplane in development that will reach 5,000 nits.)

Moving down the line, we’ve got red, green, and blue. These are wow, two-micron size micro emitters, so very small. But now you move to a vertical microLED. With a flip chip the contacts are both on the bottom, so it makes for easy mounting. With a vertical microLED you have one contact on top and one contact on the bottom. The reason you might want to do that is if you want to go down to really, really small devices. At two microns for example, it gets really hard to do flip chip devices. Now the disadvantage of a vertical is you have to do some postprocessing to make contact on the upper part of the LED. You need two contacts of course, it’s a diode. You have to do a metalization layer for electrodes to make contacts on the top. If it’s a transparent electrode, then you can get the emission from the whole surface. If it’s not you’re losing some emission surface area. With flip chip you can get the whole surface to emit of course. So, what’s kind of interesting this is also a 0.7 inch device. The way they want to use things like this, they have a patent on this for an AR application. This is what that you can do.

If you look at this diagram, each of these devices here, these are the displays. This is very similar to a combiner for a DLP engine, for example. In a DLP engine these would be simple LEDs – just bright red, green, and blue LEDs. They go into this combiner, and you get light out that goes to the DLP engine. In this case, instead of just LEDs there’s actually imagers so you can combine these to create a very compact way of creating a full color display. And this is extendable. You could have a deep blue and a light blue you could have a sensor you could have cyan. You could do lots of different things with this architecture, so it’s pretty cool.

 

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