how lcd monitors work for sale

LCD panelscan be categorized as flat-panel displays. What makes them distinct from other display technologies is the layer of liquid crystal material within. In this thin layer, liquid crystal molecules are aligned between two glass substrates. On the inner surfaces of each of those substrates lie electrodes that control charge carriers like electrons that then interact with the liquid crystals, creating an electric field that runs through them; this, in turn, can change the alignment of the crystals, also changing the overall behavior of the molecules. On the opposite sides of the substrate, polarizers are used to control the levels of light passage, affecting the overall image of the display.

Unlike CRT monitors, LCD monitors cannot illuminate themselves, and so they require a light source: the backlight. This backlight is most frequently made of the well-known LEDs which stand for light-emitting diodes. Sourced from the backlight, light is moved through the back polarizer and back substrate, into the liquid crystals. Now, the light waves can behave in a variety of ways. Backlight used in LCD displays can be LED (Light Emitting Diode) backlight or CCFL (Cold Cathode Fluorescent Lamp) backlight. LED backlights use less power which becomes more popular, while CCFL is lower cost for large size LCD displays such as large LCD TV. Recently, quantum dots technology is used to increase the LCD contrast.

Electrodes are the controlling factors of the liquid crystal behavior, and thus also the light behavior. By conducting or not conducting a current into the crystal layer, the light may or may not be able to pass through the liquid crystals in a manner that will allow passage through the polarizer. Because of this role, electrodes in LCDs are often made of indium tin oxide (ITO). ITO has good conducting properties and can also make for a transparent electrode which is essential to the appearance of displays today.

How the electrodes affect the liquid crystal alignment can vary depending on the method of alignment used (twistednematic,multi-domain,in-planeswitching). For example, twisted nematic liquid crystals are oriented in a twist when no electric field is present which then polarizes the light passing through the layer; when the electrodes apply the field in full, the twist will straighten out, no longer polarizing the light, and so no light passes. In each of these alignment types, the electrodes are placed differently within the structure, altering the properties of the display, such as width of viewing angle, power consumption, and response time. Despite these different alignment methods, the liquid crystal layer’s purpose remains the same: to polarize the light so that the polarized light passes through to the surface of the display. By polarizing the light transmitted from the backlight, the liquid crystal molecules play a role in how much of the light passes through the polarizing filters, whether it be all, none, or a partial amount.

how lcd monitors work for sale

At TeleTraders, we want to buy your used LCD Displays from you in bulk. If you’re older LCD Displays are still usable, consider selling them to TeleTraders to help offset your equipment upgrade costs. Give TeleTraders a call at

We are based in Georgia, but we work with companies all over the U.S. and are committed to offering the most competitive rates on logistics and used equipment.

When it comes time to update your office, offset your expenses and sell used LCD Displays. We will make you a competitive offer for your old monitors, LCDs, computers, modems, and laptops.

Our company is happy to purchase your old used, outdated LCD displays and monitors to free your business from the sometimes complicated electronics disposal processes. Please give us a call at 770-864-9179 or get a Free Online Quote to get started.

We work hard to repurpose or recycle the working items to save all companies money on their equipment costs and reduce the consumption of Earth’s natural resources. Equipment with minor problems may go through our refurbishment process to restore its functionality and improve its appearance to be resold again.

Our team utilizes industry experience to provide you with a fair and competitive price quote for your old used LCD displays and computer devices. We continue to upgrade our knowledge base as office equipment quickly becomes outdated in the constantly changing world of electronics. We team up with many companies around the world to quickly resell, repurpose, or recycle the LCD displays sent our way. Our efforts ensure the electronics remain in operation well beyond their initial run with your company.

When you sell your LCD displays and other office equipment to TeleTraders, we can also handle all of the packing, removal and transporting for the equipment, helping free up both your space and your time.

We understand that office technology needs change over time. The LCD displays and monitors that worked for your office a year or two ago may not be keeping pace anymore with your needs. We can help by offering you the best rates possible for your bulk LCD displays. Contact TeleTraders to get started right now.

When it’s time to upgrade your computer and LCD displays, you shouldn’t have to spend lots of time trying to figure out how to dispose of, sell or recycle your used LCD displays and office equipment – that’s where TeleTraders will be able to help you.

We request a detailed list of your used office LCD displays, including make, model, and quantity of units. Please, also include a photo of your equipment so we can gauge the current quality of the hardware.

TeleTraders is happy to accept most major and minor brands of common IT office LCD displays, office LCD display systems, and also other IT office equipment. If there is any question about whether we will accept your brand of equipment, feel free to contact us by phone or email at any time and we will respond to your inquiry as quickly as possible.

We are always looking to help businesses, small and large, offset the costs of upgrading their IT office LCD displays and IT office LCD display systems. In order to make an inquiry about a possible trade-in valuation, please Contact Us so we can work with you to evaluate used IT office LCD display gear. You may also Call Us directly for immediate assistance.

how lcd monitors work for sale

Unlike the old projection or tube televisions that were nowhere near as flat, LCD screens function in a totally different way. The pixels in the liquid crystal panel are tiny blocks that each display a portion of the overall image. Typically, the more pixels, the better the image quality. Each pixel can display a broad array of colors by controlling the combination of primary colors used -- red, green, and blue. In more expensive models, entire layers are dedicated to controlling the levels of single colors.

LCDs also work by blocking unwanted light. Some of the light that moves from the backlight could potentially interfere with the desired image because it is not traveling at the same angle or is a different color than what is needed. This is why polarizers work so well, as they also block this unwanted light in addition to allowing only certain amounts through. When several polarizers are stacked on top of each other (but rotated to various angles), the LCD has an even greater ability to filter and harness different colors of light.

The advantage of having an internal light source is the ability to illuminate the display independently of any other source. But, this comes at a cost, as lighting the display requires a very high amount of energy. Reflective technology significantly reduces the amount of energy required to generate an image. And, although it does not involve emitting light, it is quickly improving how efficiently the displays can utilize what light is already available. This makes reflective displays much more cost-effective – especially when used for long periods of time.

Reflective LCD technology is constantly improving and consumers are becoming noticeably more aware of it. Between its outstanding ability to conserve power and its number of useful applications, its usage is expected to continue growing. It is perfect for outdoor use and purposed to withstand extreme weather. If you enjoyed what you’ve read so far and would like to learn more, please take a look at our website:www.Sunvisiondisplay.com. Also, if you’re interested in seeing a short clip about how Reflective LCD technology works, you can watch the video below.

how lcd monitors work for sale

Abbreviated LCD, liquid crystal display is a flat, thin display device that has replaced the older CRT display. LCD provides better picture quality and support for large resolutions.

Generally, LCD refers to a type of monitor utilizing the LCD technology, but also flat-screen displays like those in laptops, calculators, digital cameras, digital watches, and other similar devices.

There"s also an FTP command that uses the letters "LCD." If that"s what you"re after, you can read more about it on Microsoft"s website, but it doesn"t have anything to do with computers or TV displays.

As liquid crystal display would indicate, LCD screens use liquid crystals to switch pixels on and off to reveal a specific color. Liquid crystals are like a mixture between a solid and a liquid, where an electric current can be applied to change their state in order for a specific reaction to occur.

These liquid crystals can be thought of like a window shutter. When the shutter is open, light can easily pass through into the room. With LCD screens, when the crystals are aligned in a special way, they no longer allow that light through.

It"s the back of an LCD screen that"s responsible for shining light through the screen. In front of the light is a screen made up of pixels that are colored red, blue, or green. The liquid crystals are responsible for electronically turning a filter on or off in order to reveal a certain color to or keep that pixel black.

This means that LCD screens work by blocking light emanating from the back of the screen instead of creating the light themselves like how CRT screens work. This allows LCD monitors and TVs to use much less power than CRT ones.

LED stands for light-emitting diode. Although it has a different name than liquid crystal display, it"s not something entirely different, but really just a different type of LCD screen.

The major difference between LCD and LED screens is how they provide backlighting. Backlighting refers to how the screen turns light on or off, something that"s crucial for providing a great picture, especially between black and colored portions of the screen.

A regular LCD screen uses a cold cathode fluorescent lamp (CCFL) for backlighting purposes, while LED screens use more efficient and smaller light-emitting diodes (LED"s). The difference is that CCFL-backlit LCDs can"t always block out all black colors, in which case something like a black on white scene in a movie may not appear so black after all, while LED-backlit LCDs can localize the blackness for a much deeper contrast.

If you"re having a hard time understanding this, just consider a dark movie scene as an example. In the scene is a really dark, black room with a closed door that"s allowing some light through the bottom crack. An LCD screen with LED backlighting can pull it off better than CCFL backlighting screens because the former can turn on color for just the portion around the door, allowing all the rest of the screen to remain truly black.

Unlike CRT monitors and TVs, LCD screens don"t have a refresh rate. You might need to change the monitor"s refresh rate setting on your CRT screen if eye strain is a problem, but it"s not needed on the newer LCD screens.

Most LCD computer monitors have a connection for HDMI and DVI cables. Some still support VGA cables, but that"s much less common. If your computer"s video card only supports the older VGA connection, double-check that the LCD monitor has a connection for it. You might need to purchase a VGA to HDMI or VGA to DVI adapter so that both ends can be used on each device.

If there isn"t anything showing up on your computer monitor, you can run through the steps in our How to Test a Computer Monitor That Isn"t Working troubleshooting guide to find out why.

CRT hardware, LCD"s predecessor, was famously susceptible to screen burn-in, a faint image imprinted on the electronic display that could not be removed.

LCD conditioning solves minor problems that occur on LCD monitors, including persistent images or ghost images. The process involves flooding the screen or monitor with various colors (or with all white). Dell includes an image conditioning feature in its LCD monitors.

how lcd monitors work for sale

Your computer is running perfectly, but your monitor could use a makeover. There’s no reason to buy an entire machine if you simply want to upgrade your screen. Computer monitors are simple to purchase an install, and can change the way you use your Windows or Apple machine. On eBay, you have multiple buying options when it comes to selecting screens. You can shop by size and find just the right monitor for your desk, or you can shop the latest and greatest inventory to find an updated monitor with fresher features. On a budget? Shop refurbished monitors at unbeatable prices, and score a screen for less. Check out monitors from well known brands like Dell and HP, and put together the perfect machine for your needs.

Choosing the size of your new monitor can be difficult. If you’re working in a small space and you don’t have much room, you can go down to as little as 16 inches. However, since many users today are combining their computer use with their TV viewing, there are monitors that go all the way up to 40 inches and above. It’s best to measure the area you wish to place the monitor first, and if you’re mounting it, make sure you have enough space for your new monitor. Some models stand horizontally or vertically, to give you even more flexibility when it comes to using your computer monitor.

how lcd monitors work for sale

Whether you"re looking for a deal on an old computer monitor for your old computer or you"re a vintage computer monitor collector, buying the right old monitor on eBay for your needs and desires requires knowing how to identify and evaluate old PC monitors.

One obvious way to peruse old monitors for sale is by brand. This is especially important if you plan to use the monitor with an existing computer. In that case, you either want to buy the same brand or a compatible brand of old computer monitor for sale to make sure it will actually work. If, on the other hand, you"re collecting vintage computer monitors, then you may have a specific brand, or even model, you"re looking for. There are far more brands of old monitors than there are of computers to go with them. Brands of old monitor include:

Whether you"re seeking a vintage computer monitor to use or collect, there"s a chance you may need to buy it used if you can"t find a new model of the particular old PC monitor you"re seeking. Unless listed in brand-new condition or as "new in box," make sure any given monitor you"re considering is at least in acceptable working condition before you buy it. Make sure it comes with its original power cord. The same goes for manuals, especially if you plan to use the monitor.

Monochrome or color - Even if a monitor supports color, not all color monitors support the same number of colors. An old PC monitor may support 16 colors or 256 colors, among other possibilities.

Resolution - How vivid a picture a given monitor can produce is indicated by the number of pixels it contains per square inch, often seen like 720p or 1080p, meaning those monitors have 720 and 1,080 pixels per square inch, respectively. The more pixels per square inch, the higher the resolution and the richer the image.

Screen size - Monitors will also differ in their screen size, normally listed in dimensions of length and width, but sometimes given as a single measurement of the diagonal length between two opposite corners.

how lcd monitors work for sale

A crucial part of every system build, a well-made computer monitor ensures that you will realize the performance output by your computer hardware. Perhaps you spent days, weeks, and months choosing the right CPU and the best graphics card to play the games at the resolutions you want. However, suppose you blew your budget on all the horsepower and left none for the display. In that case, you’re not going to appreciate the intensity of all those pixels that your computer renders at incredible speeds. With PC games getting more graphically intense, you must ensure your display can keep up.

You’ve probably seen terms like HD and Full HD on the boxes of monitors and TVs, but what does that mean? As you may have guessed, HD refers to “High Definition,” a quick way to refer to a high-quality video output. So if you see the term “Full HD” on a monitor box, that’s just a shorthand to denote its resolution, which would be 1920 by 1080, also called 1080p. The reason why it’s specified as “Full HD” is that there are also some TVs and monitors that output at 720p (high definition but not relatively as high as 1080p), which is 1280 by 720 pixels. 1080p is considered the current standard for monitors, and popular manufacturers, including Dell, Acer, Samsung, LG, BenQ and Viewsonic, offer a variety of 1080p monitors in their product lineups.

When it comes to resolution, 4K is all the buzz right now. Game developers and graphics card manufacturers focus on making and running games at 4k resolutions, twice the horizontal and vertical resolution of 1080p. Officially labeled as 4K UHD, the full pixel resolution is 3840 by 2160. That’s why there had to be a new term to define the resolution scale because 4k is much clearer and more vibrant than 1080p. Many people would call it hyper-realistic because of how many pixels populate the display area. To make it easier to distinguish between the two resolution types, 1080p is often referred to as 2k resolution.

As you can imagine, the more pixels there are to display, the more critical it is that your monitor has a high refresh rate, especially when it comes to gaming. Typically, the standard has been a 120-hertz refresh rate in gaming monitors, but many features a 144-hertz refresh rate. The quicker a monitor can refresh the display, and the smoother the visual experience will be. This is because the refresh rate in the monitor works in tandem with a low response time (which specifies how quickly the monitor can send and receive new information) to make a seamless visual transition. Sometimes, if the response rate is not quick enough, some residual pixels can remain on the screen as the monitor is trying to refresh new ones. This is called ‘ghosting.’ Although it’s standard to have a four-millisecond response time on many gaming monitors, Samsung, LG, BenQ, Viewsonic, and more all offer 2k and 4k monitors with one-millisecond response times. It is also important to ensure refresh rates are identical if you plan to sync two monitors for your display.

Regarding the internal specs, response time and refresh rate are the main factors contributing to a smooth, immersive viewing experience. Still, the physical panel type of the monitor can also play into this. First, there’s the matter of how the monitor lights up: either with LCD or LED. The main difference lies in the material that is used to light the liquid crystals in the display. In LCD, it’s cold cathode fluorescent lamps (CCFLs), and in LEDs, it’s tiny light emitting and low-energy consuming diodes. This is the preferred type in most monitors because it consumes less power and produces less harsh light, so darker colors appear more vivid. Additionally, LED monitors can be much thinner than LCD ones.

Newer LCD monitors have improved with the implementation of IPS (In-Plane Switching) panels. For some, it’s a matter of preference, but where the IPS panels have shown their strength with accurate color reproduction, which is great for content creators who want to do photo editing or graphic design. The panel type you choose depends more on preference than anything else. Samsung is well known for championing the IPS panel in their monitors, and many people also enjoy using them for gaming.

For some people, it’s essential, not just the monitor specs. Having a monitor that is fast, intuitive, and also looks nice on their desk is a crucial part of a computer build designed to make a statement. Asus’ Predator X34 shows off with its 34-inch curved IPS panel that also features Nvidia’s Gsync technology, which matches the gaming framerates with the monitor’s native refresh rate to prevent screen tearing. For those who want the style without the price tag, Samsung offers a 29-inch curved monitor with a 4-millisecond response time.

Finally, another consideration is whether there are enough HDMI (High-Definition Multimedia Interface) ports. HDMI allows simultaneous digital video and audio transmission from one source to another. While HDMI ports are often standard, especially on gaming monitors, verifying that a monitor has enough HDMI compatibility for your setup before purchasing is essential.

They are a shorthand to describe how many pixels in total are displayed on the monitor. For 2k, that’s 1920 x 1080 in a 16:9 widescreen aspect ratio. For 4k, it’s 3840 by 2160 in a 16:9 widescreen aspect ratio.

Since monitors have to be lit in order for the viewer to see anything, the difference between the two types is in what is used to light up the crystals within the display. For LCD, that’s cold cathode fluorescent lamps (CCFL’s) and in LEDs, it’s tiny light emitting and low-energy consuming diodes. LED monitors tend to be thinner and more power-efficient, but improvements in the panel types have made LCDs more competitive.

how lcd monitors work for sale

Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is switched ON. Vertical ridges etched on the surface are smooth.

A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directlybacklight or reflector to produce images in color or monochrome.seven-segment displays, as in a digital clock, are all good examples of devices with these displays. They use the same basic technology, except that arbitrary images are made from a matrix of small pixels, while other displays have larger elements. LCDs can either be normally on (positive) or off (negative), depending on the polarizer arrangement. For example, a character positive LCD with a backlight will have black lettering on a background that is the color of the backlight, and a character negative LCD will have a black background with the letters being of the same color as the backlight. Optical filters are added to white on blue LCDs to give them their characteristic appearance.

LCDs are used in a wide range of applications, including LCD televisions, computer monitors, instrument panels, aircraft cockpit displays, and indoor and outdoor signage. Small LCD screens are common in LCD projectors and portable consumer devices such as digital cameras, watches, calculators, and mobile telephones, including smartphones. LCD screens have replaced heavy, bulky and less energy-efficient cathode-ray tube (CRT) displays in nearly all applications. The phosphors used in CRTs make them vulnerable to image burn-in when a static image is displayed on a screen for a long time, e.g., the table frame for an airline flight schedule on an indoor sign. LCDs do not have this weakness, but are still susceptible to image persistence.

Each pixel of an LCD typically consists of a layer of molecules aligned between two transparent electrodes, often made of Indium-Tin oxide (ITO) and two polarizing filters (parallel and perpendicular polarizers), the axes of transmission of which are (in most of the cases) perpendicular to each other. Without the liquid crystal between the polarizing filters, light passing through the first filter would be blocked by the second (crossed) polarizer. Before an electric field is applied, the orientation of the liquid-crystal molecules is determined by the alignment at the surfaces of electrodes. In a twisted nematic (TN) device, the surface alignment directions at the two electrodes are perpendicular to each other, and so the molecules arrange themselves in a helical structure, or twist. This induces the rotation of the polarization of the incident light, and the device appears gray. If the applied voltage is large enough, the liquid crystal molecules in the center of the layer are almost completely untwisted and the polarization of the incident light is not rotated as it passes through the liquid crystal layer. This light will then be mainly polarized perpendicular to the second filter, and thus be blocked and the pixel will appear black. By controlling the voltage applied across the liquid crystal layer in each pixel, light can be allowed to pass through in varying amounts thus constituting different levels of gray.

The chemical formula of the liquid crystals used in LCDs may vary. Formulas may be patented.Sharp Corporation. The patent that covered that specific mixture expired.

Most color LCD systems use the same technique, with color filters used to generate red, green, and blue subpixels. The LCD color filters are made with a photolithography process on large glass sheets that are later glued with other glass sheets containing a TFT array, spacers and liquid crystal, creating several color LCDs that are then cut from one another and laminated with polarizer sheets. Red, green, blue and black photoresists (resists) are used. All resists contain a finely ground powdered pigment, with particles being just 40 nanometers across. The black resist is the first to be applied; this will create a black grid (known in the industry as a black matrix) that will separate red, green and blue subpixels from one another, increasing contrast ratios and preventing light from leaking from one subpixel onto other surrounding subpixels.Super-twisted nematic LCD, where the variable twist between tighter-spaced plates causes a varying double refraction birefringence, thus changing the hue.

LCD in a Texas Instruments calculator with top polarizer removed from device and placed on top, such that the top and bottom polarizers are perpendicular. As a result, the colors are inverted.

The optical effect of a TN device in the voltage-on state is far less dependent on variations in the device thickness than that in the voltage-off state. Because of this, TN displays with low information content and no backlighting are usually operated between crossed polarizers such that they appear bright with no voltage (the eye is much more sensitive to variations in the dark state than the bright state). As most of 2010-era LCDs are used in television sets, monitors and smartphones, they have high-resolution matrix arrays of pixels to display arbitrary images using backlighting with a dark background. When no image is displayed, different arrangements are used. For this purpose, TN LCDs are operated between parallel polarizers, whereas IPS LCDs feature crossed polarizers. In many applications IPS LCDs have replaced TN LCDs, particularly in smartphones. Both the liquid crystal material and the alignment layer material contain ionic compounds. If an electric field of one particular polarity is applied for a long period of time, this ionic material is attracted to the surfaces and degrades the device performance. This is avoided either by applying an alternating current or by reversing the polarity of the electric field as the device is addressed (the response of the liquid crystal layer is identical, regardless of the polarity of the applied field).

Displays for a small number of individual digits or fixed symbols (as in digital watches and pocket calculators) can be implemented with independent electrodes for each segment.alphanumeric or variable graphics displays are usually implemented with pixels arranged as a matrix consisting of electrically connected rows on one side of the LC layer and columns on the other side, which makes it possible to address each pixel at the intersections. The general method of matrix addressing consists of sequentially addressing one side of the matrix, for example by selecting the rows one-by-one and applying the picture information on the other side at the columns row-by-row. For details on the various matrix addressing schemes see passive-matrix and active-matrix addressed LCDs.

LCDs are manufactured in cleanrooms borrowing techniques from semiconductor manufacturing and using large sheets of glass whose size has increased over time. Several displays are manufactured at the same time, and then cut from the sheet of glass, also known as the mother glass or LCD glass substrate. The increase in size allows more displays or larger displays to be made, just like with increasing wafer sizes in semiconductor manufacturing. The glass sizes are as follows:

Until Gen 8, manufacturers would not agree on a single mother glass size and as a result, different manufacturers would use slightly different glass sizes for the same generation. Some manufacturers have adopted Gen 8.6 mother glass sheets which are only slightly larger than Gen 8.5, allowing for more 50 and 58 inch LCDs to be made per mother glass, specially 58 inch LCDs, in which case 6 can be produced on a Gen 8.6 mother glass vs only 3 on a Gen 8.5 mother glass, significantly reducing waste.AGC Inc., Corning Inc., and Nippon Electric Glass.

In 1888,Friedrich Reinitzer (1858–1927) discovered the liquid crystalline nature of cholesterol extracted from carrots (that is, two melting points and generation of colors) and published his findings at a meeting of the Vienna Chemical Society on May 3, 1888 (F. Reinitzer: Beiträge zur Kenntniss des Cholesterins, Monatshefte für Chemie (Wien) 9, 421–441 (1888)).Otto Lehmann published his work "Flüssige Kristalle" (Liquid Crystals). In 1911, Charles Mauguin first experimented with liquid crystals confined between plates in thin layers.

In 1922, Georges Friedel described the structure and properties of liquid crystals and classified them in three types (nematics, smectics and cholesterics). In 1927, Vsevolod Frederiks devised the electrically switched light valve, called the Fréedericksz transition, the essential effect of all LCD technology. In 1936, the Marconi Wireless Telegraph company patented the first practical application of the technology, "The Liquid Crystal Light Valve". In 1962, the first major English language publication Molecular Structure and Properties of Liquid Crystals was published by Dr. George W. Gray.RCA found that liquid crystals had some interesting electro-optic characteristics and he realized an electro-optical effect by generating stripe-patterns in a thin layer of liquid crystal material by the application of a voltage. This effect is based on an electro-hydrodynamic instability forming what are now called "Williams domains" inside the liquid crystal.

In 1964, George H. Heilmeier, then working at the RCA laboratories on the effect discovered by Williams achieved the switching of colors by field-induced realignment of dichroic dyes in a homeotropically oriented liquid crystal. Practical problems with this new electro-optical effect made Heilmeier continue to work on scattering effects in liquid crystals and finally the achievement of the first operational liquid-crystal display based on what he called the George H. Heilmeier was inducted in the National Inventors Hall of FameIEEE Milestone.

In the late 1960s, pioneering work on liquid crystals was undertaken by the UK"s Royal Radar Establishment at Malvern, England. The team at RRE supported ongoing work by George William Gray and his team at the University of Hull who ultimately discovered the cyanobiphenyl liquid crystals, which had correct stability and temperature properties for application in LCDs.

The idea of a TFT-based liquid-crystal display (LCD) was conceived by Bernard Lechner of RCA Laboratories in 1968.dynamic scattering mode (DSM) LCD that used standard discrete MOSFETs.

On December 4, 1970, the twisted nematic field effect (TN) in liquid crystals was filed for patent by Hoffmann-LaRoche in Switzerland, (Swiss patent No. 532 261) with Wolfgang Helfrich and Martin Schadt (then working for the Central Research Laboratories) listed as inventors.Brown, Boveri & Cie, its joint venture partner at that time, which produced TN displays for wristwatches and other applications during the 1970s for the international markets including the Japanese electronics industry, which soon produced the first digital quartz wristwatches with TN-LCDs and numerous other products. James Fergason, while working with Sardari Arora and Alfred Saupe at Kent State University Liquid Crystal Institute, filed an identical patent in the United States on April 22, 1971.ILIXCO (now LXD Incorporated), produced LCDs based on the TN-effect, which soon superseded the poor-quality DSM types due to improvements of lower operating voltages and lower power consumption. Tetsuro Hama and Izuhiko Nishimura of Seiko received a US patent dated February 1971, for an electronic wristwatch incorporating a TN-LCD.

In 1972, the concept of the active-matrix thin-film transistor (TFT) liquid-crystal display panel was prototyped in the United States by T. Peter Brody"s team at Westinghouse, in Pittsburgh, Pennsylvania.Westinghouse Research Laboratories demonstrated the first thin-film-transistor liquid-crystal display (TFT LCD).high-resolution and high-quality electronic visual display devices use TFT-based active matrix displays.active-matrix liquid-crystal display (AM LCD) in 1974, and then Brody coined the term "active matrix" in 1975.

In 1972 North American Rockwell Microelectronics Corp introduced the use of DSM LCDs for calculators for marketing by Lloyds Electronics Inc, though these required an internal light source for illumination.Sharp Corporation followed with DSM LCDs for pocket-sized calculators in 1973Seiko and its first 6-digit TN-LCD quartz wristwatch, and Casio"s "Casiotron". Color LCDs based on Guest-Host interaction were invented by a team at RCA in 1968.TFT LCDs similar to the prototypes developed by a Westinghouse team in 1972 were patented in 1976 by a team at Sharp consisting of Fumiaki Funada, Masataka Matsuura, and Tomio Wada,

In 1983, researchers at Brown, Boveri & Cie (BBC) Research Center, Switzerland, invented the passive matrix-addressed LCDs. H. Amstutz et al. were listed as inventors in the corresponding patent applications filed in Switzerland on July 7, 1983, and October 28, 1983. Patents were granted in Switzerland CH 665491, Europe EP 0131216,

The first color LCD televisions were developed as handheld televisions in Japan. In 1980, Hattori Seiko"s R&D group began development on color LCD pocket televisions.Seiko Epson released the first LCD television, the Epson TV Watch, a wristwatch equipped with a small active-matrix LCD television.dot matrix TN-LCD in 1983.Citizen Watch,TFT LCD.computer monitors and LCD televisions.3LCD projection technology in the 1980s, and licensed it for use in projectors in 1988.compact, full-color LCD projector.

In 1990, under different titles, inventors conceived electro optical effects as alternatives to twisted nematic field effect LCDs (TN- and STN- LCDs). One approach was to use interdigital electrodes on one glass substrate only to produce an electric field essentially parallel to the glass substrates.Germany by Guenter Baur et al. and patented in various countries.Hitachi work out various practical details of the IPS technology to interconnect the thin-film transistor array as a matrix and to avoid undesirable stray fields in between pixels.

Hitachi also improved the viewing angle dependence further by optimizing the shape of the electrodes (Super IPS). NEC and Hitachi become early manufacturers of active-matrix addressed LCDs based on the IPS technology. This is a milestone for implementing large-screen LCDs having acceptable visual performance for flat-panel computer monitors and television screens. In 1996, Samsung developed the optical patterning technique that enables multi-domain LCD. Multi-domain and In Plane Switching subsequently remain the dominant LCD designs through 2006.South Korea and Taiwan,

In 2007 the image quality of LCD televisions surpassed the image quality of cathode-ray-tube-based (CRT) TVs.LCD TVs were projected to account 50% of the 200 million TVs to be shipped globally in 2006, according to Displaybank.Toshiba announced 2560 × 1600 pixels on a 6.1-inch (155 mm) LCD panel, suitable for use in a tablet computer,

In 2016, Panasonic developed IPS LCDs with a contrast ratio of 1,000,000:1, rivaling OLEDs. This technology was later put into mass production as dual layer, dual panel or LMCL (Light Modulating Cell Layer) LCDs. The technology uses 2 liquid crystal layers instead of one, and may be used along with a mini-LED backlight and quantum dot sheets.

Since LCDs produce no light of their own, they require external light to produce a visible image.backlight. Active-matrix LCDs are almost always backlit.Transflective LCDs combine the features of a backlit transmissive display and a reflective display.

CCFL: The LCD panel is lit either by two cold cathode fluorescent lamps placed at opposite edges of the display or an array of parallel CCFLs behind larger displays. A diffuser (made of PMMA acrylic plastic, also known as a wave or light guide/guiding plateinverter to convert whatever DC voltage the device uses (usually 5 or 12 V) to ≈1000 V needed to light a CCFL.

EL-WLED: The LCD panel is lit by a row of white LEDs placed at one or more edges of the screen. A light diffuser (light guide plate, LGP) is then used to spread the light evenly across the whole display, similarly to edge-lit CCFL LCD backlights. The diffuser is made out of either PMMA plastic or special glass, PMMA is used in most cases because it is rugged, while special glass is used when the thickness of the LCD is of primary concern, because it doesn"t expand as much when heated or exposed to moisture, which allows LCDs to be just 5mm thick. Quantum dots may be placed on top of the diffuser as a quantum dot enhancement film (QDEF, in which case they need a layer to be protected from heat and humidity) or on the color filter of the LCD, replacing the resists that are normally used.

WLED array: The LCD panel is lit by a full array of white LEDs placed behind a diffuser behind the panel. LCDs that use this implementation will usually have the ability to dim or completely turn off the LEDs in the dark areas of the image being displayed, effectively increasing the contrast ratio of the display. The precision with which this can be done will depend on the number of dimming zones of the display. The more dimming zones, the more precise the dimming, with less obvious blooming artifacts which are visible as dark grey patches surrounded by the unlit areas of the LCD. As of 2012, this design gets most of its use from upscale, larger-screen LCD televisions.

RGB-LED array: Similar to the WLED array, except the panel is lit by a full array of RGB LEDs. While displays lit with white LEDs usually have a poorer color gamut than CCFL lit displays, panels lit with RGB LEDs have very wide color gamuts. This implementation is most popular on professional graphics editing LCDs. As of 2012, LCDs in this category usually cost more than $1000. As of 2016 the cost of this category has drastically reduced and such LCD televisions obtained same price levels as the former 28" (71 cm) CRT based categories.

Monochrome LEDs: such as red, green, yellow or blue LEDs are used in the small passive monochrome LCDs typically used in clocks, watches and small appliances.

Today, most LCD screens are being designed with an LED backlight instead of the traditional CCFL backlight, while that backlight is dynamically controlled with the video information (dynamic backlight control). The combination with the dynamic backlight control, invented by Philips researchers Douglas Stanton, Martinus Stroomer and Adrianus de Vaan, simultaneously increases the dynamic range of the display system (also marketed as HDR, high dynamic range television or FLAD, full-area local area dimming).

The LCD backlight systems are made highly efficient by applying optical films such as prismatic structure (prism sheet) to gain the light into the desired viewer directions and reflective polarizing films that recycle the polarized light that was formerly absorbed by the first polarizer of the LCD (invented by Philips researchers Adrianus de Vaan and Paulus Schaareman),

A pink elastomeric connector mating an LCD panel to circuit board traces, shown next to a centimeter-scale ruler. The conductive and insulating layers in the black stripe are very small.

A standard television receiver screen, a modern LCD panel, has over six million pixels, and they are all individually powered by a wire network embedded in the screen. The fine wires, or pathways, form a grid with vertical wires across the whole screen on one side of the screen and horizontal wires across the whole screen on the other side of the screen. To this grid each pixel has a positive connection on one side and a negative connection on the other side. So the total amount of wires needed for a 1080p display is 3 x 1920 going vertically and 1080 going horizontally for a total of 6840 wires horizontally and vertically. That"s three for red, green and blue and 1920 columns of pixels for each color for a total of 5760 wires going vertically and 1080 rows of wires going horizontally. For a panel that is 28.8 inches (73 centimeters) wide, that means a wire density of 200 wires per inch along the horizontal edge.

The LCD panel is powered by LCD drivers that are carefully matched up with the edge of the LCD panel at the factory level. The drivers may be installed using several methods, the most common of which are COG (Chip-On-Glass) and TAB (Tape-automated bonding) These same principles apply also for smartphone screens that are much smaller than TV screens.anisotropic conductive film or, for lower densities, elastomeric connectors.

Monochrome and later color passive-matrix LCDs were standard in most early laptops (although a few used plasma displaysGame Boyactive-matrix became standard on all laptops. The commercially unsuccessful Macintosh Portable (released in 1989) was one of the first to use an active-matrix display (though still monochrome). Passive-matrix LCDs are still used in the 2010s for applications less demanding than laptop computers and TVs, such as inexpensive calculators. In particular, these are used on portable devices where less information content needs to be displayed, lowest power consumption (no backlight) and low cost are desired or readability in direct sunlight is needed.

STN LCDs have to be continuously refreshed by alternating pulsed voltages of one polarity during one frame and pulses of opposite polarity during the next frame. Individual pixels are addressed by the corresponding row and column circuits. This type of display is called response times and poor contrast are typical of passive-matrix addressed LCDs with too many pixels and driven according to the "Alt & Pleshko" drive scheme. Welzen and de Vaan also invented a non RMS drive scheme enabling to drive STN displays with video rates and enabling to show smooth moving video images on an STN display.

Bistable LCDs do not require continuous refreshing. Rewriting is only required for picture information changes. In 1984 HA van Sprang and AJSM de Vaan invented an STN type display that could be operated in a bistable mode, enabling extremely high resolution images up to 4000 lines or more using only low voltages.

High-resolution color displays, such as modern LCD computer monitors and televisions, use an active-matrix structure. A matrix of thin-film transistors (TFTs) is added to the electrodes in contact with the LC layer. Each pixel has its own dedicated transistor, allowing each column line to access one pixel. When a row line is selected, all of the column lines are connected to a row of pixels and voltages corresponding to the picture information are driven onto all of the column lines. The row line is then deactivated and the next row line is selected. All of the row lines are selected in sequence during a refresh operation. Active-matrix addressed displays look brighter and sharper than passive-matrix addressed displays of the same size, and generally have quicker response times, producing much better images. Sharp produces bistable reflective LCDs with a 1-bit SRAM cell per pixel that only requires small amounts of power to maintain an image.

Segment LCDs can also have color by using Field Sequential Color (FSC LCD). This kind of displays have a high speed passive segment LCD panel with an RGB backlight. The backlight quickly changes color, making it appear white to the naked eye. The LCD panel is synchronized with the backlight. For example, to make a segment appear red, the segment is only turned ON when the backlight is red, and to make a segment appear magenta, the segment is turned ON when the backlight is blue, and it continues to be ON while the backlight becomes red, and it turns OFF when the backlight becomes green. To make a segment appear black, the segment is always turned ON. An FSC LCD divides a color image into 3 images (one Red, one Green and one Blue) and it displays them in order. Due to persistence of vision, the 3 monochromatic images appear as one color image. An FSC LCD needs an LCD panel with a refresh rate of 180 Hz, and the response time is reduced to just 5 milliseconds when compared with normal STN LCD panels which have a response time of 16 milliseconds.

Samsung introduced UFB (Ultra Fine & Bright) displays back in 2002, utilized the super-birefringent effect. It has the luminance, color gamut, and most of the contrast of a TFT-LCD, but only consumes as much power as an STN display, according to Samsung. It was being used in a variety of Samsung cellular-telephone models produced until late 2006, when Samsung stopped producing UFB displays. UFB displays were also used in certain models of LG mobile phones.

In-plane switching is an LCD technology that aligns the liquid crystals in a plane parallel to the glass substrates. In this method, the electrical field is applied through opposite electrodes on the same glass substrate, so that the liquid crystals can be reoriented (switched) essentially in the same plane, although fringe fields inhibit a homogeneous reorientation. This requires two transistors for each pixel instead of the single transistor needed for a standard thin-film transistor (TFT) display. The IPS technology is used in everything from televisions, computer monitors, and even wearable devices, especially almost all LCD smartphone panels are IPS/FFS mode. IPS displays belong to the LCD panel family screen types. The other two types are VA and TN. Before LG Enhanced IPS was introduced in 2001 by Hitachi as 17" monitor in Market, the additional transistors resulted in blocking more transmission area, thus requiring a brighter backlight and consuming more power, making this type of display less desirable for notebook computers. Panasonic Himeji G8.5 was using an enhanced version of IPS, also LGD in Korea, then currently the world biggest LCD panel manufacture BOE in China is also IPS/FFS mode TV panel.

Most of the new M+ technology was employed on 4K TV sets which led to a controversy after tests showed that the addition of a white sub pixel replacing the traditional RGB structure would reduce the resolution by around 25%. This means that a 4K TV cannot display the full UHD TV standard. The media and internet users later called this "RGBW" TVs because of the white sub pixel. Although LG Display has developed this technology for use in notebook display, outdoor and smartphones, it became more popular in the TV market because the announced 4K UHD resolution but still being incapable of achieving true UHD resolution defined by the CTA as 3840x2160 active pixels with 8-bit color. This negatively impacts the rendering of text, making it a bit fuzzier, which is especially noticeable when a TV is used as a PC monitor.

In 2011, LG claimed the smartphone LG Optimus Black (IPS LCD (LCD NOVA)) has the brightness up to 700 nits, while the competitor has only IPS LCD with 518 nits and double an active-matrix OLED (AMOLED) display with 305 nits. LG also claimed the NOVA display to be 50 percent more efficient than regular LCDs and to consume only 50 percent of the power of AMOLED displays when producing white on screen.

This pixel-layout is found in S-IPS LCDs. A chevron shape is used to widen the viewing cone (range of viewing directions with good contrast and low color shift).

Vertical-alignment displays are a form of LCDs in which the liquid crystals naturally align vertically to the glass substrates. When no voltage is applied, the liquid crystals remain perpendicular to the substrate, creating a black display between crossed polarizers. When voltage is applied, the liquid crystals shift to a tilted position, allowing light to pass through and create a gray-scale display depending on the amount of tilt generated by the electric field. It has a deeper-black background, a higher contrast ratio, a wider viewing angle, and better image quality at extreme temperatures than traditional twisted-nematic displays.

Blue phase mode LCDs have been shown as engineering samples early in 2008, but they are not in mass-production. The physics of blue phase mode LCDs suggest that very short switching times (≈1 ms) can be achieved, so time sequential color control can possibly be realized and expensive color filters would be obsolete.

Some LCD panels have defective transistors, causing permanently lit or unlit pixels which are commonly referred to as stuck pixels or dead pixels respectively. Unlike integrated circuits (ICs), LCD panels with a few defective transistors are usually still usable. Manufacturers" policies for the acceptable number of defective pixels vary greatly. At one point, Samsung held a zero-tolerance policy for LCD monitors sold in Korea.ISO 13406-2 standard.

Dead pixel policies are often hotly debated between manufacturers and customers. To regulate the acceptability of defects and to protect the end user, ISO released the ISO 13406-2 standard,ISO 9241, specifically ISO-9241-302, 303, 305, 307:2008 pixel defects. However, not every LCD manufacturer conforms to the ISO standard and the ISO standard is quite often interpreted in different ways. LCD panels are more likely to have defects than most ICs due to their larger size. For example, a 300 mm SVGA LCD has 8 defects and a 150 mm wafer has only 3 defects. However, 134 of the 137 dies on the wafer will be acceptable, whereas rejection of the whole LCD panel would be a 0% yield. In recent years, quality control has been improved. An SVGA LCD panel with 4 defective pixels is usually considered defective and customers can request an exchange for a new one.

Some manufacturers, notably in South Korea where some of the largest LCD panel manufacturers, such as LG, are located, now have a zero-defective-pixel guarantee, which is an extra screening process which can then determine "A"- and "B"-grade panels.clouding (or less commonly mura), which describes the uneven patches of changes in luminance. It is most visible in dark or black areas of displayed scenes.

The zenithal bistable device (ZBD), developed by Qinetiq (formerly DERA), can retain an image without power. The crystals may exist in one of two stable orientations ("black" and "white") and power is only required to change the image. ZBD Displays is a spin-off company from QinetiQ who manufactured both grayscale and color ZBD devices. Kent Displays has also developed a "no-power" display that uses polymer stabilized cholesteric liquid crystal (ChLCD). In 2009 Kent demonstrated the use of a ChLCD to cover the entire surface of a mobile phone, allowing it to change colors, and keep that color even when power is removed.

In 2004, researchers at the University of Oxford demonstrated two new types of zero-power bistable LCDs based on Zenithal bistable techniques.e.g., BiNem technology, are based mainly on the surface properties and need specific weak anchoring materials.

Resolution The resolution of an LCD is expressed by the number of columns and rows of pixels (e.g., 1024×768). Each pixel is usually composed 3 sub-pixels, a red, a green, and a blue one. This had been one of the few features of LCD performance that remained uniform among different designs. However, there are newer designs that share sub-pixels among pixels and add Quattron which attempt to efficiently increase the perceived resolution of a display without increasing the actual resolution, to mixed results.

Spatial performance: For a computer monitor or some other display that is being viewed from a very close distance, resolution is often expressed in terms of dot pitch or pixels per inch, which is consistent with the printing industry. Display density varies per application, with televisions generally having a low density for long-distance viewing and portable devices having a high density for close-range detail. The Viewing Angle of an LCD may be important depending on the display and its usage, the limitations of certain display technologies mean the display only displays accurately at certain angles.

Temporal performance: the temporal resolution of an LCD is how well it can display changing images, or the accuracy and the number of times per second the display draws the data it is being given. LCD pixels do not flash on/off between frames, so LCD monitors exhibit no refresh-induced flicker no matter how low the refresh rate.

Color performance: There are multiple terms to describe different aspects of color performance of a display. Color gamut is the range of colors that can be displayed, and color depth, which is the fineness with which the color range is divided. Color gamut is a relatively straight forward feature, but it is rarely discussed in marketing materials except at the professional level. Having a color range that exceeds the content being shown on the screen has no benefits, so displays are only made to perform within or below the range of a certain specification.white point and gamma correction, which describe what color white is and how the other colors are displayed relative to white.

Brightness and contrast ratio: Contrast ratio is the ratio of the brightness of a full-on pixel to a full-off pixel. The LCD itself is only a light valve and does not generate light; the light comes from a backlight that is either fluorescent or a set of LEDs. Brightness is usually stated as the maximum light output of the LCD, which can vary greatly based on the transparency of the LCD and the brightness of the backlight. Brighter backlight allows stronger contrast and higher dynamic range (HDR displays are graded in peak luminance), but there is always a trade-off between brightness and power consumption.

Usually no refresh-rate flicker, because the LCD pixels hold their state between refreshes (which are usually done at 200 Hz or faster, regardless of the input refresh rate).

No theoretical resolution limit. When multiple LCD panels are used together to create a single canvas, each additional panel increases the total resolution of the display, which is commonly called stacked resolution.

LCDs can be made transparent and flexible, but they cannot emit light without a backlight like OLED and microLED, which are other technologies that can also be made flexible and transparent.

As an inherently digital device, the LCD can natively display digital data from a DVI or HDMI connection without requiring conversion to analog. Some LCD panels have native fiber optic inputs in addition to DVI and HDMI.

Limited viewing angle in some older or cheaper monitors, causing color, saturation, contrast and brightness to vary with user position, even within the intended viewing angle. Special films can be used to increase the viewing angles of LCDs.

Uneven backlighting in some monitors (more common in IPS-types and older TNs), causing brightness distortion, especially toward the edges ("backlight bleed").

Display motion blur on moving objects caused by slow response times (>8 ms) and eye-tracking on a sample-and-hold display, unless a strobing backlight is used. However, this strobing can cause eye strain, as is noted next:

As of 2012, most implementations of LCD backlighting use pulse-width modulation (PWM) to dim the display,CRT monitor at 85 Hz refresh rate would (this is because the entire screen is strobing on and off rather than a CRT"s phosphor sustained dot which continually scans across the display, leaving some part of the display always lit), causing severe eye-strain for some people.LED-backlit monitors, because the LEDs switch on and off faster than a CCFL lamp.

Fixed bit depth (also called color depth). Many cheaper LCDs are only able to display 262144 (218) colors. 8-bit S-IPS panels can display 16 million (224) colors and have significantly better black level, but are expensive and have slower response time.

Input lag, because the LCD"s A/D converter waits for each frame to be completely been output before drawing it to the LCD panel. Many LCD monitors do post-processing before displaying the image in an attempt to compensate for poor color fidelity, which adds an additional lag. Further, a video scaler must be used when displaying non-native resolutions, which adds yet more time lag. Scaling and post processing are usually done in a single chip on modern monitors, but each function that chip performs adds some delay. Some displays have a video gaming mode which disables all or most processing to reduce perceivable input lag.

Loss of brightness and much slower response times in low temperature environments. In sub-zero environments, LCD screens may cease to function without the use of supplemental heating.

The production of LCD screens uses nitrogen trifluoride (NF3) as an etching fluid during the production of the thin-film components. NF3 is a potent greenhouse gas, and its relatively long half-life may make it a potentially harmful contributor to global warming. A report in Geophysical Research Letters suggested that its effects were theoretically much greater than better-known sources of greenhouse gasses like carbon dioxide. As NF3 was not in widespread use at the time, it was not made part of the Kyoto Protocols and has been deemed "the missing greenhouse gas".

Kawamoto, H. (2012). "The Inventors of TFT Active-Matrix LCD Receive the 2011 IEEE Nishizawa Medal". Journal of Display Technology. 8 (1): 3–4. Bibcode:2012JDisT...8....3K. doi:10.1109/JDT.2011.2177740. ISSN 1551-319X.

Explanation of CCFL backlighting details, "Design News — Features — How to Backlight an LCD" Archived January 2, 2014, at the Wayback Machine, Randy Frank, Retrieved January 2013.

LCD Television Power Draw Trends from 2003 to 2015; B. Urban and K. Roth; Fraunhofer USA Center for Sustainable Energy Systems; Final Report to the Consumer Technology Association; May 2017; http://www.cta.tech/cta/media/policyImages/policyPDFs/Fraunhofer-LCD-TV-Power-Draw-Trends-FINAL.pdf Archived August 1, 2017, at the Wayback Machine

K. H. Lee; H. Y. Kim; K. H. Park; S. J. Jang; I. C. Park & J. Y. Lee (June 2006). "A Novel Outdoor Readability of Portable TFT-LCD with AFFS Technology". SID Symposium Digest of Technical Papers. 37 (1): 1079–1082. doi:10.1889/1.2433159. S2CID 129569963.

Jack H. Park (January 15, 2015). "Cut and Run: Taiwan-controlled LCD Panel Maker in Danger of Shutdown without Further Investment". www.businesskorea.co.kr. Archived from the original on May 12, 2015. Retrieved April 23, 2015.

NXP Semiconductors (October 21, 2011). "UM10764 Vertical Alignment (VA) displays and NXP LCD drivers" (PDF). Archived from the original (PDF) on March 14, 2014. Retrieved September 4, 2014.

"Samsung to Offer "Zero-PIXEL-DEFECT" Warranty for LCD Monitors". Forbes. December 30, 2004. Archived from the original on August 20, 2007. Retrieved September 3, 2007.

"Display (LCD) replacement for defective pixels – ThinkPad". Lenovo. June 25, 2007. Archived from the original on December 31, 2006. Retrieved July 13, 2007.

Explanation of why pulse width modulated backlighting is used, and its side-effects, "Pulse Width Modulation on LCD monitors", TFT Central. Retrieved June 2012.

An enlightened user requests Dell to improve their LCD backlights, "Request to Dell for higher backlight PWM frequency" Archived December 13, 2012, at the Wayback Machine, Dell Support Community. Retrieved June 2012.

Oleg Artamonov (January 23, 2007). "Contemporary LCD Monitor Parameters: Objective and Subjective Analysis". X-bit labs. Archived from the original on May 16, 2008. Retrieved May 17, 2008.

how lcd monitors work for sale

The Asus ProArt Display PA278CV has a great-looking screen with good enough color accuracy for most people and all the ports you need to hook up desktop or laptop PCs. The PA278CV’s stand can tilt, swivel, and pivot the screen and raise and lower its height, its USB-C port can provide enough power to charge most 13-inch laptops, and it comes with a three-year warranty and a good dead-pixel policy. Its QHD resolution (2560×1440) means it isn’t as sharp as a 4K screen, but it’s also hundreds of dollars cheaper than comparable 4K monitors.

The MD271QP has a USB-C connection, making it easy to connect a modern laptop without the need for an HDMI cable or extra dongle. However, you’ll still need to plug in your laptop’s charging cable.

The MSI Modern MD271QP is a simple, streamlined 1440p monitor that’s perfect for laptop users. If you have a laptop with a USB-C port, a single cable will send the image to the monitor and slowly charge your laptop with 15 watts of power. However, you’ll still need to plug in a power cable as well to keep your laptop fully charged. The MD271QP lacks features we liked in the Asus ProArt PA278CV,including a built-in USB hub, granular color calibration controls, and blue-light filtering modes for reading. But if you don’t need to tinker with color settings or those extra USB connections, the MSI Modern MD271QP is a great monitor for $100 less than our top pick.

The Dell S2722QC is a 3840×2160 display that’s great for anyone who watches 4K content or casually edits photos or video. However, if most of your time is spent on general office work or browsing the internet, you don’t really need to spend the extra cash. The S2722QC has a USB-C port with 65