Advanced Display Specifications (Panelook Explained)
Categorized list of all available screens and their substitutes:
➨by Size, ➨by Laptop Brand & Model, ➨by Features
See also: How to determine the screen you need
Every screen manufacturer provides to its customers (in our case laptop manufacturers) a detailed datasheet for every screen model. These datasheets are sometimes hard to find, and not easy to understand. Fortunately anyone can use panelook.com for reference. Panelook is the largest screen marketplace with a lot of useful information about any product. I will explain in simple words below the meaningful specifications in the Overview section for a common laptop screen - N156HCA-EAB by Innolux. At the end I will mention which information is not available in Panelook.
2. Resolution - number of pixels columns and rows (1920x1080), abbreviation (FHD = Full HD), PPI - pixels per inch.
Number of columns divided by number of rows = aspect ratio. E.g. 1920:1080 = 1.77777777(7) = 16:9
3. Active Area - exact dimensions of viewable area in millimeters, width and height. These values are strictly related to Diagonal size.
4. Outline size - external dimensions of the screen. This parameter is very important when choosing a replacement, because there are screens with the same viewing area, but different outline size. E.g. the older 14" eDP screens ave 320mm external width, while newer ones have 315mm external width. So in many cases the newer models (315mm) can substitute the older ones (320mm), but the opposite is not possible.
The last dimension is the thickness of the screen - it is important to be taken into account, because sometimes thicker screens can't replace thinner ones.
5. Brightness - maximum brightness generated by the backlight, measured in Candellas per square meter, a.k.a. nits. The most common IPS screens nowadays come with 220-250nits. High end screens have brightness of 300nits, 400nits, or even more, which makes possible work at e.g. direct sunlight.
6. Viewing angle - the bigger, the better, <90 degrees. IPS screens, a.k.a. WVA (Wide Viewing Angle) or UWVA (Ultra-Wide Viewing Angle) provide visibility to up to almost 90 degrees from any direction. TN screens seldom provide good visibility when looked from about 45% horizontally, or even less vertically.
7. Display colors - there are 2 parameters on this row - color depth in number of colors or bits, and color gamut in sRGB, NTSC, or any other scale.
Color depth determines the number of achievable nuances of any color. The bigger the number is, the smoother transition between colors is. Sample values: 262141 or 262K - 18bits per pixel; 16777216 or 16.7M - 24bits per pixel, 1.07B - 30bits per pixel, etc. OLED screens have very high color depth, usually 1.07 billion colors.
Color gamut is the range of colors that a screen can generate. There are several measurement scales like sRGB, NTSC, DCI-P3, etc.
45%-47% NTSC is considered as standard gamut on laptop screens;
72% NTSC = 100% sRGB is considered as high gamut
High gamut screens are required by image and video processing professionals. In most cases a standard laptop screen can be upgraded to a high gamut screen if needed. You are always welcome to ask us for advice.
Detailed explanation on gamut and measurement scales can be found in these articles:
https://www.asus.com/content/understanding-color-gamut-specs-on-laptop-displays/
8. Frequency or Refresh rate - the number of times per second when the screen can change the image. Standard refresh rate on laptops is 60Hz. Gaming screens usually have 120Hz, 144Hz or higher refresh rate.
9. Signal interface - parallel (LVDS) or serial (eDP) data interface between the motherboard and the screen; number of pins. Please note that LVDS and eDP interfaces are not compatible with each other, although they may have the same connector. E.g. connecting a 40-pin eDP screen instead of 40-pin LVDS is mechanically possible, but it will ruin the laptop's motherboard.
10. Surface - can be glossy (glare) or matte (antiglare). This is not a functional parameter. It is meaningful only to the user, not to the laptop.
11. Contrast Ratio - difference between the lightest and the darkest possible color. The bigger, the better. Standard contrast for a modern laptop screen is 700:1 - 800:1. High end screens have contrast over 1000:1. OLED screens provie much higher contrast, e.g. 1000000:1.
12. Display mode - currently applicable for TFT LCD screens - this is the technology implemented in the screen.
The lowest grade LCD screens are built on TN technology, or "normally white", meaning that the LCD layer is transparent when switched off.
Higher grade LCD screens are built on IPS (In-Plane Switching) technology. Since the term IPS is patented by LG Display, other manufacturers use different terms for it - PLS, AAS, AHVA, etc. All of these names are recognizable by the attribute "normally black".
13. Response time - the lower, the better - a very important but neglected parameter. This parameter shows how fast a pixel can change its color. Standard value is about 25ms (milliseconds). Faster screens, e.g. for gaming or video processing must have faster response time, preferably below 10ms. A 144Hz gaming screen with 25ms response time is a nonsense, but such models exist.
The response time of OLED screens is about 1ms.
14. Touchscreen - indicate whether the screen has integrated touchscreen functionality like in-cell, on-cell, or other technologies. This parameter is not applicable for screens with attached separate digitizer like on most Lenovo Yoga laptops.
There are many more parameters on Panelook, especially in the Specs section like e.g. power supply voltage and power consumption, that I do not consider important for this tutorial, because they are related to the application of the screen. Since we are interested only in laptop screens, and these parameters have standard values, they are not a criterion for choosing a screen. E.g. the power supply voltage of all eDP laptop screens is 3.3V - no more, no less .
Panelook does not provide information about some important parameters, like connector pitch (width) and position; controller board width and height, etc. E.g. both NV156FHM-NY8 and BV156FHM-NY9 are 15.6" Full HD IPS screens with 165Hz refresh rate and 40-pin eDP connector. But they are not interchangeable, because the connector width of NV156FHM-NY8 is about 25mm (0.5mm pitch), while the connector width of NV156FHM-NY9 is about 20mm (0.4mm pitch). And of course, the reliability of a certain model is defined nowhere. Only an experienced seller can know which model as <1% fall out ratio, and which one has high fall out ration within or after the warranty period.
Ilian Petrov, LaptopDisplay.eu
