AOC International (formerly Admiral Overseas Corporation) may not be in the same league as the likes of Samsung and LG when it comes to marketing clout, but it does produce some innovative products. This particular monitor has only one connector - a USB port - which provides the power as well the video signal to the display.
The e2251Fwu is one of a growing number of USB only monitors. Lenovo unleashed the ThinkVision LT1421 (opens in new tab) earlier in 2012 and Asus showcased a 24in model with USB 3.0 at Computex in 2011 (opens in new tab) but the concept has yet to take off in a big way. Maybe USB 3.0 interfaces will help (opens in new tab), thanks to the increased bandwidth available.
This is a 22in full HD monitor that uses a LED backlit TN-panel with a very thin chassis (10mm thick) although the bezel is still substantial at 12mm. It is designed to be transportable (weighs less than 3kg) and can either be used with a short “stub” stand (like a photo frame) or with a classic monitor stand that slots into the short stub stand. You can’t pivot and its height is not adjustable but you can tilt it by up to 15 degrees.
The back of the monitor is adorned with a woven pattern, something similar to the back of the Motorola Razr series (opens in new tab) with its Kevlar back. Sadly, there’s no VESA mount option although since this screen is designed for transportability, that's not a big surprise. Bucking the fashionable trend, this AOC screen doesn't have a glossy display, making it potentially more suitable to an office environment. That said, the bezel surrounding the screen is very glossy, which some may find distracting.
Other than the USB 2.0 port at the back of the monitor, there’s a port for a 5V power supply which allows you to use one rather than two USB ports on the host computer. Not surprisingly, the e2251FWu earnt an Energy Star 5.0 compliant and an EPEAT silver rating.
Using USB to transfer data comes with some drawbacks; you will be constrained by bandwidth and processing resources. In the case of laptops, USB monitors will reduce your battery life and can suck up to 25 per cent of your CPU's resource when viewing a full HD video.
Also forget about trying to play games at very high resolution or watch full HD movies full screen, you will be sorely disappointed. Anything lightweight (i.e. anything normally condoned in a working environment) should be fine as delays and lags are not noticeable. That said, if you're working on a notebook under battery power, you might find that the dynamic clocking of the CPU can affect video processing.
In theory, you should be able to connect up to six of these monitors to a desktop computer (although you will need an additional USB card if you do not want to use six power adaptors).
There’s no power-on button or any way to adjust image quality other than using the DisplayLink software (the latest version of DisplayLink dates from 7 September 2012 (opens in new tab) and is Windows 8 compatible). The screen has a claimed 5ms response time and an average 800:1 contrast ratio plus its brightness is fairly reasonable at 150cd/m2 in a normally lit office, but it won’t blow you away.
Viewing angles were average for a TN panel, great for sharing, but vertical angles could be better. Ditto for the contrast ratio which can best be described as being run-of-the-mill. Again, the lack of adjustment exacerbated these problems, but ultimately this screen isn't going to compete with expensive IPS panels when it comes to viewing angles and image quality.
(opens in new tab)Part of the issue stems from the fact that the screen’s overall performance is constrained by the power provided by two USB ports (around 15W), which in turn dictates the visual properties of the e2251Fwu. All in all, this is an excellent monitor provided you know its limits and accept that it has been designed first and foremost to be used as a portable display.
With a three-year standard warranty and a price starting from under £120 with delivery (from Amazon (opens in new tab)), the e2251Fwu deserves a 7 out of 10. But if you don't need the portable versatility that this screen provides, there are better options.
Brightness (typical, in cd/m2)
Contrast ratio (typical)
Pixel size (mm)
0.2482 x 0.2482
Display Area (mm)
477.5 x 268.5
Viewing Angle (in degrees)
Response time (in ms)
Scanning Frequency (Horizontal/Vertical, in Hz)
Pixel Frequency (in Hz)
1,920 x 1,080
Colours (in millions)
Power consumption (On in Watts)
CE, Energy Star 5.0, EPEAT Silver, TÜV-Bauart
Dimensions (W x H x D, in mm)
512.2 x 389.1 x 193.7
Weight (in Kg)
Warranty (in Years)