Electronics

Researchers demonstrate advanced display technology

Researchers from the University of Michigan have unveiled a more efficient, brighter and higher definition display technology than that used in today's LCDs
Researchers from the University of Michigan have unveiled a more efficient, brighter and higher definition display technology than that used in today's LCDs
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Researchers from the University of Michigan have unveiled a more efficient, brighter and higher definition display technology than that used in today's LCDs
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Researchers from the University of Michigan have unveiled a more efficient, brighter and higher definition display technology than that used in today's LCDs
Optical microscopy images of seven plasmonic colour filters illuminated by white light
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Optical microscopy images of seven plasmonic colour filters illuminated by white light
(a) Scanning electron microscopy image of the fabricated 1D plasmonic spectroscope with gradually changing periods from 400 to 200 nm (from left to right)(b) Optical microscopy image of the plasmonic spectroscope illuminated with white light(c) SEM image of the fabricated 2D spoke structure(d) Optical microscopy images of the spoken structure illuminated with unpolarized light (centre) and polarized light (four boxes)
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(a) Scanning electron microscopy image of the fabricated 1D plasmonic spectroscope with gradually changing periods from 400 to 200 nm (from left to right)
(b) Optical microscopy image of the plasmonic spectroscope illuminated with white light
(c) SEM image of the fabricated 2D spoke structure
(d) Optical microscopy images of the spoken structure illuminated with unpolarized light (centre) and polarized light (four boxes)
An optical microscopy image of a 12-by-9-micron U-M logo produced with this new color filter process
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An optical microscopy image of a 12-by-9-micron U-M logo produced with this new color filter process

Only a small percentage of backlight actually makes its way out through the multiple layers that make up the ubiquitous LCD displays we use today. That may change with the development of new filter technology at the University of Michigan. White light is sent through tiny, precisely spaced gaps on nano-thin sheets of aluminum and is said to result in brighter, higher definition color reproduction. Other benefits of the technology include efficiency gains and simpler manufacturing.

A traditional LCD display is made up of two layers of polarizers, a color filter sheet, and two layers of electrode-laced glass in addition to the liquid crystal layer. The new color filter cuts out a couple of extra layers by acting as a simultaneous polarizer. It's less than 200nm thick, and consists of a layer of Zinc Selenide sandwiched between two sheets of aluminum.

At precise intervals, tiny slits trap and transmit white backlight out through the structure. Different spacings essentially result in different wavelengths being caught. Gratings set at around 360 nanometers apart emit red light, those spaced at 270 nanometers emit green, and blue colored light comes from slits spaced about 225 nanometers apart.

The research team, led by Jay Guo, an associate professor in University of Michigan's Department of Macromolecular Science and Engineering, used the technique to produce a tiny University logo which is about a sixth the size of a human hair at 12 x 9 microns. OK, so it looks a little blurred in the photo, but that's because it has been magnified about 5,000 times.

An optical microscopy image of a 12-by-9-micron U-M logo produced with this new color filter process
An optical microscopy image of a 12-by-9-micron U-M logo produced with this new color filter process

The pixel size produced by the new filter is around eight times smaller than those on an iPhone 4 and "about an order of magnitude smaller than those on a typical computer screen," according to Guo. "Amazingly, we found that even a few slits can already produce well-defined color, which shows its potential for extremely high-resolution display and spectral imaging." Future uses for the technology include wearable or extremely compact displays as well as monitors and projectors.

The university is currently looking at patenting the technique while the researchers look to make the technique production-ready, a task said to be made easier by the potential for simpler manufacturing processes.

Detailed information on the technology can be found in the research paper, entitled "Plasmonic nano-resonators for high resolution color filtering and spectral imaging", which has now been published in Nature Communication.

3 comments
Paul van Dinther
Finally we might see displays small enough and with sufficient resolution to be used in virtual reality glasses. An area of technology that has virtually stood still for a decade. I also recall a tech idea where a super small display is mounted inside a mobile device. The user would then view the screen through a lens similar to the way you look through a monocular. Imagine placing two of such tiny displays in each corner of a phone which could provide a high quality stereoscopic vision. Imagine earplugs with two in-line micro displays. The piece of wire between them is more rigid and bendable so it can sit on your nose with only two small rectangles visible on front of the eyes.
Paul van Dinther
Further more on the article: Given the fact that the \"M\" logo is 12 miron wide. That is 0.012mm for a single character! I tried resizing the \"M\" example and in terms of pixels, a character with such detail would measure at least 64 px wide! So that display has the potential to have a pixel pitch of 0.0001875! That means a 20\" wide screen can contain 270933px across! Based on the 12 miron example I wonder why the article states that the pixel size on this display is only 8 times smaller that the pixel size on a IPhone display. According to my calculations the pixel size on this new display is closer to 412 times smaller not 8. That is astonishing. I wonder if the quoted 12 micron for the entire \"M\" logo is correct.
wealthychef
@Paul Van Dinther: I was also surprised to see them boast about 8x improvement. It sounds like it\'s better than that. What are your calculations where you get 412?