Jan 30, 2012

Lenovo ThinkVision LT1421 - USB LCD Monitor

Gear: Lenovo ThinkVision LT1421, Toshiba 14" Monitor, AOC E1649FWU 16", MIMO UM-710S.

The ThinkVision LT1421 is a USB powered 14 inch LCD monitor. The strong point is that this is a mobile system, and it works very well.

Box Contents:
  • ThinkVision LT1421
  • Case/Cover
  • USB cable (about 90  about 70 inches long)
  • CD with drivers
  • Manual

Just like all DisplayLink technologies I highly recommend installing the software before plugging in the ThinkVision.

Screen Size + Resolution
The Mimo monitor that I checked had a 7 inch screen, which was not functional for most web browsing. The ThinkVision with it's 14 inches and a resolution of 1366x768 offers a great amount of functionality. My current HP laptop has a resolution of 1366x768 and with the addition of the ThinkVision it makes me very productive when programming, and editing videos, it's perfect for the job.

Unlike the glossy screen of my laptop this screen offers a very pleasant matte finish. I love matte finish screens because they don't reflect the rest of the world while I'm trying to get the job done.

According to Lenovo it does a 200 cd/m2 on the brightness, and what that basically means is that it's bright enough. With a 400:1 contrast ratio the ThinkVision does a fine job. One important thing is the 16 different brightness levels. During the day you can have the screen bright, and at night time you can dimn down the screen.

The ThinkVision is a USB powered monitor and offers 262 thousand colors. VGA/DVI/HDMI monitors can offer millions of colors. I would not use the ThinkVision for professional level image editing, but I would use it for most other uses. While there's a big difference in the color range the ThinVision does a good job.

Viewing Angles
The angles matter here. If the screen is at a 90 degree angle and your eyes are looking straight to them it does work. However, when you tilt the screen things change. Left and right angles dimn the screen a bit, viewed from the bottom darkens the screen, from the top it makes things bright.

The monitor has a "leg" that when extended functions as a stand. It can be adjusted to give different viewing angles (12 degrees to 40 degrees). The stand/leg is a bit small which hurts the stability. If you accidentally bumped the monitor with enough force there's a good chance that it would roll to the side (and maybe even fall if put in a small table).

Along with the system you will get a case/cover which can be added to protect the screen when being mobile. This plastic cover does require a bit of practice when attaching/detaching it. The case can also work as a "stand", although it's not required.

The benefit of the Mimo was that because it was so small it meant that it didn't weigh much at all. The Lenovo ThinkVision being a 14 inch system does have weight and volume to consider.

ThinkVision: 0.878 KG, or 1.937 lbs (official docs say 1.8lbs)
With Case: 1.077 KG, or 2.375 lbs (official docs say 2.97 lbs)

Of course this doesn't include the usb cable, which doesn't add much. The screen is portable enough that it won't be too heavy to carry. Of course if you are carrying many other things (including laptop) then the weight is important to know.

On the back of the screen there are two buttons to adjust the brightness. Unlike the Toshiba and the Mimo these buttons work the way they should. Since the buttons are located in the back it makes a bit harder to access than compared to the Mimo and Toshiba monitors. But with enough practice you get used to them.

One thing that is not a positive is that there is no power on/off button. The lack of the on/off button really is a downer for me, to turn off the screen on the ThinkVision you have to unplug the power or manually turn it off from Windows. Turning it off with these methods results in an unpleasant experience in Windows because of readjustments of resolution.

On the back there's also a Kensington lock slot. There may be cases where this is useful, for business I think this is a good feature to have.

Overall text looks crispy clear and easy to read. Videos also look good. When videos are played in full screen and a window is dragged ontop text loses it's sharpness. Lenovo mentions that there's a 8mm response time on the screen, which is not bad considering it's USB powered.

USB Cable
The Lenovo ThinkVision includes a 90 inch USB cable 70 inch USB cable which is long enough for you to place the monitor anywhere you want. The Toshiba has a short cable that limits the possible positions. I really like this because I can position the monitor to the left or right of the monitor without feeling restricted. Of course 90 inches 70 inches of length may be too much, you can buy shorter cables for very little money these days.

The cable is a two full USB (data/power) to mini USB cable. It would seem that with such a cable you would need to plug both of those full USB connections, but you don't have to. If you have USB 2.0 ports on your system a single full USB to mini USB cable will work.

Power Consumption
If you use a laptop with the ThinkVision the power withdrawn will reduce the battery life. Lenovo states that "Actual power consumption depends on the chosen display mode, the images, displayed, and user control settings".

  • Max: 5 watts
  • Normal: 4.2 watts
  • Standby: 0.1 watts
  • Suspend: 0.1 watts

Without the monitor my laptop has a rate of 27,883 mW, when I connect the ThinkVision and play a Youtube video the power consumption goes up to 30,402. Basically it consumes 2.519 watts, which is less than what Lenovo mentioned.  I used BatteryBar Pro to measure this.

My laptop has a capacity of 88,733 mWh... so I would get 3.18 hours normally. With the additional power consumption I would get 2.918 hours. So, the difference would be .262 hours, which is about 16 minutes less (15.72 to be more exact). Obviously every system will have different results because of different usages.

Using the ThinkVision with my laptop would consume 16 minutes of battery life, which is not bad considering I'm getting a second monitor which increases my productivity.

At $200 this is a very good monitor. You can obviously get other VGA/DVI/HDMI bigger monitors for less money and they would provide better refresh rates and color range, but they don't offer the portability that USB powered offers. The ThinkVision because it's powered by USB allows you to carry it anywhere and not have to worry about bringing a separate power supply. I'm typing this on a couch with the laptop on my lap, and the ThinkVision to my left, it's amazing.

This is a neat monitor.  It is really well made and very well priced.  If you buy this product you will be very happy with the results.


I strongly recommend viewing the Toshiba 14 Inch video/post because it covers differences that are important.
Toshiba 14 Inch USB Mobile LCD Monitor


What about portrait mode with the ThinkVision LT1421?

The Lenovo ThinkVision LT1421 was designed for landscape mode. With the Display Link drivers you can manually rotate the resolution to portrait mode.

Because the leg/kickstand was made for landscape mode you cannot depend on it for portrait mode. Instead you will have to find something to lean the system against, which is not very stable and may lead to accidents. If you were an expert on building cases you could make a case that holds the system in a more stable method, but most people cannot do this.

The resolution of the LT1421 is 1366x768 which is fine for landscape content, for portrait mode you would have a resolution that most likely won't fit your content properly. If your content doesn't resize to the width of 658 pixels and height of 1366 you will notice that content cuts off.

The viewing angles of the LT1421 suit the landscape mode the best. If the system is placed in portait mode the views from the left and right angles are different, from the left the screen is darker, and from the right the screen is brighter. The best viewing angle is the front.


  1. Looks like a great monitor, except for the resolution.

    1366x786 is bad enough on the 12.5 inch x220. The same resolution on a 14 inch screen is unacceptable.

    1. 1366x768 may be the best resolution the USB monitor can do without taking a bigger toll on power needs. The higher the resolution the higher the data and power needs become. Personally I wish my HP laptop had the 1080p screen, but it does not. Even if it had a larger resolution having a secondary monitor helps to keep things organized.

      There is a good amount of anti 1366x768 people. Then there are others who make a valid point of stating that most people can't tell the difference of quality on 1080p or 720p screens during video playback on these smaller screens. Once the screen is big enough then resolution matters.

      As my eyes degrade in a way I'm thankful of having a lesser resolution and a bigger screen, which helps a lot when reading text. Usually younger pc users prefer higher resolutions in small screens, while older folks prefer a smaller resolution on their screen because it makes things easier to see.

      So... some people will like it and some will not. That's just how life goes.

    2. True, but resolution independence is a popular trend right now.

      Mac OSX 10.7 Lion has the feature already, and it is rumoured that Windows 8 will have it too. I bet a lot of the popular Linux desktop environments have that feature buried in some .conf file somewhere. With that in mind a lot more people will be wanting the higher resolution display (did you notice that most of the new 13" ultrabooks introed at CES had 1600x900?)

      There is a HUGE difference in sharpness between the 1366x786 resolution on the x220 and the 1920x1080 resolution on the Vaio Z (13" display). For video it doesn't make a big difference, but fonts look a lot sharper (I believe that if the resolution goes up a bit more, the need for anti-aliasing will go away completely).

  2. I like the 1366x786 because it is the same as my laptop (Lenovo x220t). That way I never have to re-size windows when dragging them across to the external. I'm very happy with the monitor, I agree with you that the kickstand is very touchy but I like the adjustability. They apparently designed it to work with the cover as a tray. I don't like doing that because it takes up more room on my desk. I didn't realize how much space I was giving up to have a not-much-bigger external monitor with it's stand and power cables. I love that this is just like a little tablet...which brings me to a question.

    Is there a way to use a 10" tablet (Android, preferably) as an extended monitor? That would be a killer feature and would cause me to finally buy one. This monitor is mostly worth it's $200 price. If good 10" tablets with fantastic screens can be had for $300-$400 then they'd be a much better value.

    1. I'm not sure about Android. But I am sure of Windows and iPad tablets which can be used as a secondary monitor in "extended" mode with a program called MaxiVista.

      MaxiVista - http://www.maxivista.com/laptop-as-a-second-monitor.htm

    2. Hey Nathan,

      iDisplay is available for both Android and IOS and acts as a second monitor.


      Unfortunately the reviewers on the android market say it's rather laggy. Since I don't have an android tablet (and am not willing to fork out 5 bucks to turn my phone's 4.65" display into a monitor) I'm operating on hearsay here only though.

  3. Wow, thanks for the link. I assumed when asking that a solution didn't exist. Though it seems it does it through wi-fi. Which I'm guessing would lead to annoying lag, like when you use things like go-to-my-pc. Also I hate apple. This would be a killer feature on the upcoming windows 8 tablets though!

    1. Yes. The current Wifi technologies are not fast enough and there's a good chance of lag. As much as I like the idea wifi is generally not fast enough for the "smoothest" experience.

      A different solution is something like KVM switches, which allow you to control a separate system with one mouse and keyboard. This is NOT using a second system as secondary monitor. After using software to do this for a long time I eventually tried hardware and that works better.

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  5. Folks, if you want portrait mode, just get a portable plastic book lifter. Voila! I recommend "Fellowes Booklift Copyholder,Platinum".

  6. Yo! I hope you could help me with this.

    Is the video data computed by the CPU or the GPU? Is there a notable difference when gaming on a laptop screen than gaming on the portable monitor but with the laptop screen off (using the portable as the main montor)?

    I'm looking into getting this as a gaming screen for the retina macbook so that I don't need to use the retina screen. The super high reso hurts performance when maxed out but the screen isn't nice when I lower the reso so I'm looking for a monitor to game on that has a lower max reso.


    1. The monitor's data is computed by the CPU. I would NOT use this monitor for gaming, because the refresh rates are slow.

    2. I presonally don't have a Macbook Retina so I could be wrong, but I suggest you lower the resolution to 1440x900, assuming you haven't tried it already. Most people I see gaming with the Retina use 1920x1200, which is the wrong choice because of the improper scaling. 1440x900 is the exact quarter of 2880x1800 so the scaling will be much neater, as if it was native res. Also, a good balance of performance and definition; the GT650M can run basically ANYTHING at 1440x900.

      In my laptop, it's either 1920x1080 or 960x540. Hmmmmm....

  7. "Because the leg/kickstand was made for portrait mode you cannot depend on it for portrait mode."

    1. What a silly statement, sorry! I have corrected it.

  8. Please explain what type of signal it uses; I mean 'composite video'or 'component video' or 'dvi' or...

    1. I no longer possess the monitor and therefore cannot answer your question. Lenovo might have some documents with the info, or you can ask one of their reps at their website.