Laptop Screens and LCD Panels: The Technical Lowdown

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Laptop Screens and LCD Panels: The Technical Lowdown

The market for computer displays is significant. The bulky old cathode ray tube (CRT) style of monitor is disappearing at a phenomenal rate and is being replaced with sleek, new designs that consume less space and energy. More importantly, the images that these high-definition (HD) replacements render are improved substantially, with even more improvements to come in the future. Prices have dropped to the point where nearly every display not only provides an enhanced image, but does so at a lower price than ever before.

With those improvements have come additional complexities. It is no longer just a matter of plugging in the display and connecting it to a computer tower. There are a lot of distinguishing features that may or may not be useful to buyers. To avoid purchasing more or less functionality than necessary, it is important to understand the technical terminology in use. This is particularly useful for buyers wishing to understand what a 23-inch LG LCD-LED HD IPS 1080p HDMI display may have to offer. A good source for any laptop screens or LCD panels is eBay.

Defining LCD and LED

There are differences between LCD and LED displays. In addition to their unique features, there are a number of other abbreviations and terms in use within product descriptions that benefit from translation, such as TFT and IPS.


LCD (liquid crystal display) is the technology that has been replacing CRTs. Compared to CRTs, LCD displays offer flat screens, consume far less energy, and are able to render high-definition images. LCDs by nature do not emit any light and therefore require an external light source. All computer displays rely on active matrix backlighting, as distinct from passive matrix displays common with watches and calculators. Standard LCD lighting is produced by CCFL (cold cathode fluorescent lamp) internal devices at either side of the display. Polarisers and a diffuser are used to disperse the lighting evenly. The use of an internal transformer limits how thin the monitor can be.


TFT (thin film transistor) LCD was one of the early versions of LCD panel development. The biggest issue with TFTs is that they tend to distort the image when viewed from the side and mute some of the colours. This is rarely an issue for those using the display for work; typically, it is fine for nearly direct line of sight viewing by a single user. However, gaming and streaming that often involve several people viewing from wider angles can be a problem.


IPS (in-plane switching) LCD eliminates much of the concern of TFT LCD. TFT crystals are essentially perpendicular to the screen, causing the light to bend to some extent. IPS technology arranges the crystals so that they are in-plane, or parallel, to the display. The result is an improved viewing experience from extreme angles and directly. There is now an S-IPS, or super IPS, category that incorporates enhanced colour reproduction and improved response times.


LED (light emitting diode) technology modifies LCD considerably, with improved brightness and reduced operating costs, but a higher price tag. There is a debate as to whether there is a sufficient gain in value to offset the purchase price, which can be about 30 percent more. LEDs eliminate much of the problem that LCDs have with the thickness of the panels. LEDs meet the demand for the thinnest, lightest, and most efficient product. LEDs are often marketed as LCD LED. Unless the LCD term is followed by LED, it is safe to assume CCFL lighting.

Technical Definitions for Laptop Screens and LCD Panels

There are several other technical terms to learn about before buying a display. All of these affect the price and should be considered in relation to the intended use. Bear in mind that for everyday computing involving word processing and basic video streaming, even a relatively simple, small LCD provides a quantum leap from traditional CRT monitors. Those who require intense gaming capabilities or demand top of the range performance should consider factors other than price.

Size of Laptop Screens and LCD Panels

The typical range of sizes for laptop screens and LCD panels is from 17 inches to 24 inches. Measurements are always based on the diagonal dimension of the viewing screen. Those with smaller 13-inch laptops or even smaller netbooks and tablets may choose to consider a larger size to enable more workspace.

Bezel for Laptop Screens and LCD Panels

The bezel refers to the frame that surrounds the actual display viewing area. It is typically plastic. The width of the bezel can become an issue with multiple panels as wider ones increase the non-viewable area between screens. Some companies promote zero or near to zero bezels and charge more to minimise or eliminate it with a more expensive internal frame.

Resolution for Laptop Screens and LCD Panels

Resolution refers simply to the number of pixels, or dots of light, on a screen. This number is usually represented as 1900 x 1080 for example, or simply 1080p. The first digit indicates the number of pixels horizontally and the second is the vertical count. The "p" in 1080p represents "progressive", the video scanning technology associated with HD images. This is distinct from "i" for "interlacing", the technology associated with CRT and plasma displays.

A resolution of 1900 x 1080 presents a much clearer image on an 18-inch display than it would on a 22-inch display. Most computers enable different resolutions to accommodate different sized displays with varying aspect ratios.

Aspect Ratio for Laptop Screens and LCD Panels

Aspect ratio is the relationship between the width and height of the display. It is closely related to resolution. The most common ones are 4:3, 16:9, and 16:10. Aspect ratio is always defined by the size of the display.

Contrast Ratio for Laptop Screens and LCD Panels

With HD technology, the contrast ratio is a measurement of the number of shades the display can produce from its lightest white to its darkest black. It is presented as a number such as 2500:1. The higher the first number, the wider the range of shades.

Response Time for Laptop Screens and LCD Panels

The response time is the time that it takes a pixel to transition from the most extreme black to the most extreme white and then back to black. This measurement appears in milliseconds. Many manufacturers manipulate this figure by stating a grey to grey time rather than black to black. It is important to recognise the difference as extreme black takes longer and there are many degrees of grey that they can choose to measure.

Display Colours for Laptop Screens and LCD Panels

Display colours are simply the number of unique colours that the display can render. A common measure is 16.7 million, also referred to as 24-bit colour because 2 to the power of 24 is around 16.7 million. Note that IPS panels greatly exceed 16.7 million, which makes them very popular for graphic designers and others concerned with extreme colour detail.

Brightness for Laptop Screens and LCD Panels

Brightness is measured as a function of the number of candelas, units of luminous intensity, per square metre. Look for numbers in the 250 to 300 range as an average. If the display is in an intensely sunlit room, consider higher numbers.

Summary of Technical Features

The table below consolidates the most important technical features of laptop screens and LCD panels. It also offers guidelines for comparing displays.

Technical Feature

Common Range


Aspect ratio

4:3 to 16:9

16:9 is best for DVDs and streaming broadcasts

Contrast ratio

Typically 1000:1 to 30,000:1

Higher is better

Avoid anything less than 2500:1

Response time

1 to 10 ms

No longer than 5 ms

Display colours

10 million to 100 million

16.7 million minimum


100 to 1000 candelas

250 minimum

Bear in mind that even the lowest of any of these specifications for laptop screens and LCD panels far exceeds the specification for CRTs. The most important thing is taking the time to review comments by previous buyers.

Connectivity for Laptop Screens and LCD Panels

HDMI is the standard connection, as it transmits both audio and video through the same cable. It also renders the sharpest images and best sound for most applications. Serious video or audio production requires more sophisticated connectivity.

HDTV for Laptop Screens and LCD Panels

Buyers considering the purchase of a replacement or additional computer display should be interested in knowing that most high-definition televisions can serve quite well. They too are built upon LCD or LED technology and usually provide the required connectivity.

New or Used Condition for Laptop Screens and LCD Panels

Laptop screens and LCD panels have few replaceable parts. That is good news, as essentially either they work or they do not. There is no routine servicing that may have been ignored by a previous owner. The bad news is that newer displays are not likely to last as long. That may not be much of an issue as technology is developing so quickly that models may become obsolete well before they stop functioning.

When considering whether or not to buy a used display, it is important to assess its reliability. It may not it is possible to get technical assistance, so do the necessary research to compare specifications and confirm connectivity. Then, if the price looks good, then a used display may be a viable option.

Buying Laptop Screens and LCD Panels on eBay

After understanding the technical lowdown on laptop screens and LCD panels, consider starting your search for a new or used display on the eBay home page. Every eBay page provides a search tool that takes you directly to the specific product you want. If you want to view all of the available 19-inch displays currently available, just enter that phrase into the open field. From there you can specify features of the display, new or used condition, and other variables to get to a manageable number of listings. Take a few minutes to read eBay ' s search tips for other suggestions.

eBay Delivery Options

Most sellers offer a range of delivery options to satisfy different budgets and how quickly buyers need the display. Standard delivery may take the longest time to arrive. There may be an express delivery option for buyers who need their item quickly. All of the delivery details, including prices, should be displayed prominently within the item description.


Most of those who use laptop screens or LCD panels as part of their day to day computing may be interested to understand some of the technical terms used to describe displays. This is especially true if buyers wish to purchase an additional screen. Those who use a computer largely for recreation may prefer a large display that enhances video content and gaming enjoyment significantly. Understanding some of the technical jargon, such as resolution, aspect ratio, and response time, goes a long way towards ensuring that the new display matches the needs of the buyer.

Finding the right laptop screen or LCD panel is as simple as logging onto eBay and searching the listings. The best thing about eBay is that it enables shoppers to do the necessary research, compare thousands of competing merchants, purchase for a low price, place the order, and arrange doorstep delivery all from a home or office computer.

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