Common Display Types

Before moving on, it seems a good idea to explain just what is meant by a Horizontal IPS (H-IPS) display type.

Active matrix LCDs are currently the standard for Liquid Crystal Displays, for your PC your TV or any other display that you will find on the market. An active matrix LCD is made up, among other things, of two layers of Thin Film Transistors each on their own glass substrate, one layer lying horizontally providing rows and one layer lying vertically providing columns. The layer consists of rows or columns of paired transistors and capacitors along with the liquid crystal they control. Integrated circuits at the edges of the monitor can send electrical signals to change the state of the liquid crystal to vary the amount and frequency of light that is emitted. These ICs send the electrical signal to the targeted transistor using the grid, firing a charge down the row or column of transistors and liquid crystals that the targeted transistor is located on and opening a ground on the crossing row or column so that the signal can be addressed to a specific liquid crystal’s controlling transistor.

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Thank you wikipedia

On a colour monitor three of these TFTs combine to make a pixel, a sub-pixel of red, one of blue and one of green. The TFTs are three times as long as they are wide, creating the square that we think of as a pixel when we talk about a screen’s resolution. Calculating the number of pixels on a screen is a matter of multiplying the number of vertical columns of pixels by the number of horizontal rows, hence the familiar HD resolution of 1080 x 1920 results in 2,073,600 pixels. However the count of sub-pixels is three times as high resulting in 6,220,800 TFTs and if even one of those fails you will have a bad pixel as that particular pixel will have lost the ability to show one of the three primary colours (four if you bought your display from George Takei). This creates a very serious problem for those using larger monitors as the size of the pixel scale with the size of the monitor unless the resolution is increased commensurately. It also explains just why video cards have had to increase their computing power enormously with each generation.

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Thank you again Wikipedia

There are several ways to go about creating TFTs, each having their own benefits and drawbacks so it becomes important to know which technology creates the image you are staring at. A graphic designer and a gamer have very different needs when it comes to choosing a display. These are the four major solutions in use on the market today although each of these categories have numerous sub-categories that represent the maturation of the technology.

Type of LCD Technology Benefits Drawbacks
Twisted Nematic (TN) Twists the liquid crystal using a single transistor.  That twist changes the amount of backlight allowed through a crystal thus brightening, dimming or eliminating a coloured sub-pixel  from the pixel Inexpensive thanks to the use of one single transistor per TFT sub-pixel.  The twisting happens very quickly, thus resulting in a fast response time which prevents ghosting in gaming and action movies. Colour accuracy leaves something to be desired for professionals, most TN monitors are incapable of presenting true 24-bit colour; gamers are unlikely to notice the RGB value of the blood splatter on their screen is slightly off.  The viewing angle is also very limited, move even a few degrees off center and the colours will start to wash out or change.  Touching the monitor creates trails and bright spots and can prevent proper screen updating
Multi-domain vertical alignment (MVA) A middle ground between TN and IPS.  The liquid crystal is not completely parallel to the monitor like IPS, but more aligned than TN LCDs It combines most of the speed of a TN display with an improved viewing angle like an IPS display.  This also tends to put its price in between the two types of panels. Lacking the fine control of VPA, blacks are not perfect but are improved from TN.  The alignment of liquid crystal does not happens quickly as with TN, leading to slower reponse times than TN.  Overall it does make a good middle man to the two types.
In Plane Switching (IPS) aka S-IPS, AS-IPS, H-IPS Two transistors allow much greater control over the twisting of the liquid crystal in the sub-pixels Huge increase in viewing angle compared to a TN based LCD.  It can be used as a touchscreen without the issues of a TN.  The ability to produce true 24-bit colour with no aberrations. Very expensive when compared to TN monitors.  Brightness and response time are significantly better than they were historically, but can still lag behind other technologies.  Blacks will not be black, the back light on this type of monitor is bright enough to bleed through sub-pixels that are turned off unless it’s back light is comprised of LEDs.
Vertical Pattern Alignment (VPA) aka S-PVA Two transistors offer the same level of control as an IPS LCD, however with VPA the liquid crystal acts as if there are two zones which can be controlled individually offering even finer control over the amount of light let through a sub pixel. The viewing angle is almost as good as an IPS monitor but without sacrificing the response time for large colour changes.  Superior contrast ratios.  Colour reproduction is comparable to IPS LCDs however with VPA your blacks will be black. Expensive and with slightly slower response times than a good TN LCD.  Artifacting and blurring can occur during fast moving image reproduction thanks to the slower response rate, especially for subtle colour changes that only affect one of the two sub pixel zones.

 

For this monitor Dell chose one of the more popular types of LCD, an active matrix Horizontal In Plane Switching Thin Film Transistor LCD. That particular type of display is intended more for graphics professionals than for gamers but with a 30” monitor watching HD movies is not out of the question and proper colour representations can add greatly to your enjoyment of the movie or show. The Dell U3011 is capable of 30bit colour depth (aka 10bit per channel, 10 bit per pixel) over a DisplayPort connection for a total of 1.07 billion colours, most displays are content with 24bit colour depth (aka 8bit per channel, 8bpp, TrueColour) which can display 16.7 million colours. Another way of looking at those two statistics is that 8bpp provides the 256 values each of red, blue and green whereas with 10bpp colour you have 1021 values of each. If you are wondering why it is 1021 and not 1024, this post from AnandTech does a good job of explaining the reasons. Most GPUs do not support that level of colour, you tend to need Quadro or FirePro cards though there are exceptions like the HD5970 which can support the full colour depth. You also need to realize that only DisplayPort and HDMI 1.3 are capable of transmitting that much colour depth, previous HDMI and all DVI connections are limited to 8bpp colour.

The native resolution of this 16:10 display is a whopping 2650×1600 (aka 1600p) which puts out twice as many pixels as 1080p with a grand total of 4,240,000 pixels (12,720,000 sub pixels). That requires the quality of manufacturing to be extremely high in order to avoid screens with a noticeable amount of bad or stuck pixels. Again, your connection matters a great deal as neither HDMI nor DVI are capable of reaching this resolution, they are both limited to 1,920 x 1,200 on this particular display; they are theoretically able to provide higher resolutions than that but you won’t be able to on the U3011. In order to see the full resolution the Dell UltraSharp U3011 is capable of you need to connect to it using DisplayPort.

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