LCD Display Pixel Term, Resolution & Aspect Ratio
Introduction: LCD Resolution
What is the Native Resolution of a LCD Display?
In order to understand the native resolution of a LCD display, it will be better to understand a little about the LCD display technology, especially TFT LCD manufacturing process. First, we need to understand what are pixels.
What Are Pixels?
Pixel, also called Picture Element, A pixel is the smallest unit of a digital image or graphic that can be displayed and represented on a digital display device. A pixel is the basic logical unit in digital graphics. Pixels are combined to form a complete image, video, text, or any visible thing on a computer display
LCD display doesn’t operate the same way as CRT displays , which fires electrons at a glass screen, a LCD display has individual pixels arranged in a rectangular grid. Each pixel has RGB(Red, Green, Blue) sub-pixel that can be turned on or off. When all of a pixel’s sub-pixels are turned off, it appears black. When all the sub-pixels are turned on 100%, it appears white. By adjusting the individual levels of red, green, and blue light, millions of color combinations are possible
Fig.1 LCD Pixel With RGB Sub-pixels
The pixels of the LCD screen were made by circuitry and electrodes of the backplane. Each sub-pixel contains a TFT (Thin Film Transistor) element. These structures are formed by depositing various materials (metals and silicon) on to the glass substrate that will become one part of the complete display “stack,” and then making them through photolithography. For more information about TFT LCDs, please refer to “An Overview of The Thin Film Transistor And Its Use in Displays “.
The etched pixels by photolith process are the Native Resolution. Actually, all the flat panel displays, LCD, OLED, Plasma etc.) have native resolution which are different from CRT monitors
HD TV has 1280×720 = 921,600 pixels; Full HD has 1920x 1080=2,073,600 pixels; 8K TV has 7,680×4,320=33,177,600 pixels. he “K” in 8K stands for Kilo (1000), meaning a TV that has achieved a horizonal resolution of about 8,000 pixels.
What Is DPI / PPI?
Although we can define a LCD display with resolution, a Full HD resolution on screen size of a 15” monitor or a 27” monitor will show different. The screen “fineness” is very important for some application, like medical, or even our cell phone. If the display “fineness” is not enough, the display will look “pixelized” which is unable to show details.
Fig.2 Pixelized Bug Shown After Zoom In
How we can define the “Fineness” of a LCD display ?
A lot of times, we heard about what is the DPI of your monitor, actually it is not a exact correct saying. Please find the definition of DPI and PPI as below.
DPI stands for dots per inch and refers to the resolution of a printer. It describes the density of ink dots placed on a sheet of paper (or another photographic medium) by a printer to create a physical print.
PPI stands for number of pixels per inch. It is kind of pixel density. PPI describes the resolution of a digital image, not a print. PPI is used to resize images in preparation for printing
Now, we are clear about the confusion.
How do you read the display resolution of my LCD monitor or laptop?
It is easy to find on your laptop. Simply find display setting in your control panel. The highest resolution shown is your native resolution.
Fig.3 My Laptop Screen has Native Resolution of 1920 x 1200
But you see other lower resolution available, that is because video cards are doing the trick. A video card can display a lower LCD screen resolution than the LCD’s built-in native resolution. The video cards can combine the pixels and turn a higher resolution into lower resolution, or just use part of the full screen. But video cards can’t do the magic to exceed the native resolution.
What resolution is 1024×768? What is 1920×1080 resolution?
You might hear a lot of ways to describe a LCD screen properties. That depends on what characteristic or function you focus on.
- Resolution: 1024×768, 1920×1080 etc. This is very straightforward but difficult to remember.
- Abbreviation: QVGA, VGA, HD, FHD, 1080p, 1440p, 4K etc. It is very straight forward for different applications. For TV buyers, they can simply focus on 4K, 8K etc; for industrial engineers, they most likely focus on VGA, HD, WVGA etc.
- Aspect Ratio: You might hear 4:3 which is full screen, 16:9 is for widescreen; 21:9 is for ultrawide computer monitors and televisions, as well as cinematic widescreen projectors. Some ultrawide monitors are trying to replace dual monitor.
Fig.4 Ultrawide vs Dual Monitors
- Special names by individual companies: Apple Macbook Pro Retina 6K display, Acer Nitro, ASUS Pro Art , ViewSonic Elite, ASUS TUF ,Samsung edge Infinity-O Display etc.
LCD Screen Resolution Chart
|LCD Standard||LCD Pixels||LCD Term|
|SQCIF||128 x 96||Sub CIF|
|QCIF||176 x 144||Quarter CIF|
|CGA||320 x 200||Color Graphics Adapter|
|QVGA||320 x 240||Quarter VGA|
|CIF||352 x 288||Common Intermediate Format|
|WQVGA||400 x 240||Wide QVGA|
|EGA||640 x 350||Extended-Graphics-Adapter|
|VGA||640 x 480||Video Graphics Array|
|WVGA||800 x 480||Wide VGA|
|SVGA||800 x 600||Super VGA|
|XGA||1024 x 768||Extended Graphics Array|
|HD||1280 x720||HD, High Definition|
|XVGA||1280 x 960||Extended Video Graphics Array|
|SXGA||1280 x 1024||Super SGA|
|SXGA+||1400 x 1050||Super eXtended VGA plus|
|SXGA-W||1600 x 1024|
|UXGA||1600 x 1200||Ultra XGA|
|WXGA||1366 x 768||Wide XGA|
|WSXGA||1680 x 1050|
|1080p||1920 x1080||Full HD|
|WUXGA||1920 x 1200||Widescreen Ultra XGA|
|QXGA||2048 x 1536||Quad Extended Graphics Array|
|WQXGA||2560 x 1600|
|QSXGA||2560 x 2048|